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Topic Six: Evolution
Variation in Stickleback
5.1 Evidence for Evolution
Essential idea: There is overwhelming evidence for the
evolution of life on Earth.
Understandings
Statement Guidance
5.1 U.1 Evolution occurs when heritable characteristics of a species
change.
5.1 U.2 The...
Applications and Skills
Statement Guidance
5.2 A.1 Development of melanistic insects in polluted areas.
5.2 A.2 Comparison...
Evolution is the accumulated inherited changes in a
population over time
Evolution is one of the most powerful unifying co...
But the Fossil recordBut the Fossil record ……
OBSERVATIONOBSERVATION
Evidence supporting evolution
I. Fossil record
• transition species
I. Anatomical record
• homologous & vestigial structur...
5.1 U.1 Evolution occurs when heritable characteristics of a species
change.
The raw genetic material
(variation) is hidde...
5.1 U.1 Evolution occurs when heritable characteristics of a species
change.
5.1 U.1 Evolution occurs when heritable characteristics of a species change.
http://4.bp.blogspot.com/-
6EXGifOabDY/T75wOI...
5.1 U.2 The fossil record provides evidence for evolution.
Mount Everest
29,002 ft above sea level29,002 ft above sea level
Hillary’s Step
Fossilized
sea shells located
just a few feet
away from the
top of the world
5.1 U.2 The fossil record provides evidence for evolution.
Fossil Record
• Sedimentary rock is laid down
over time… new on...
5.1 U.2 The fossil record provides evidence for evolution.
• Layers of sedimentary rock contain fossils
– new layers cover...
The fossil record provides the dimension of time to the study of
evolution – the layer of rock in which a fossil is found ...
http://sciencelearn.org.nz/Contexts/Dating-the-Past/Sci-Media/Images/Fossils-in-sedimentary-rock
5.1 U.2 The fossil record...
Fossil Preservation
• Petrified
• Prints and molds
• Resins which turn to Amber
• Tar
• Peat which is acidic preventing de...
5.1 U.2 The fossil record provides evidence for evolution.
5.1 U.2 The fossil record provides evidence for evolution.
Radioactive Dating
• Unstable atomic isotopes that decay
over t...
5.1 U.2 The fossil record provides evidence for evolution.
• For instance, organisms take
up C, both as 14
C and 12
C but ...
5.1 U.2 The fossil record provides evidence for evolution.
Potassium-Argon dating
• Proportions of parent 40
K atoms and d...
5.1 U.3 Selective breeding of domesticated animals shows that artificial
selection can cause evolution.
Artificial selecti...
5.1 U.3 Selective breeding of domesticated animals shows that artificial
selection can cause evolution.
https://phaven-pro...
Selective breeding
5.1 U.3 Selective breeding of domesticated animals shows that artificial
selection can cause evolution.
Comparative Anatomy
• Homologous structures
• Analogous structures
Convergent evolution
Parallel Evolution
• Vestigial O...
Homologous structures Pentadactly limb)
similarities in characteristics resulting from common ancestry
Divergent Evolutio...
Homologous structures
• Similar structure
• Similar development
• Different functions
• Evidence of close evolutionary
rel...
Vestigial Structures
• describes a characteristic of organisms that
have seemingly lost all or most of its original
functi...
Embryology
• Similar features seen in developmental stages of related organisms
• Gill pouches and tails seen in developin...
The climate of the
Galapagos Islands
varies seasonally and
yearly. Coastal areas
and higher
elevations also show
a large t...
Darwin found… birds
Finch?
Sparrow?
Woodpecker? Warbler?
Collected manyCollected many
different birds on thedifferent bird...
Darwin was amazed to
find out:
All 14 species of birds
were finches…
Finch? Sparrow?
Woodpecker? Warbler?
But Darwin found...
Correlation of species to food source
SeedSeed
eaterseaters
FlowerFlower
eaterseaters
InsectInsect
eaterseaters
Hawaiian violets (Viola)
– Nine taxa, seven species distributed over most islands
– Species occupy several different habit...
Ages of the Hawaiian Islands
Kauai = 5.1 my
Hawaii =
400,000-180,000 my
Maui Nui complex =
1.9 my-800,000 y
Oahu = 3.7-2.6...
Topography of Kauai
Waimea Canyon
(extremely arid)
Alakai Swamp/Mt Waialeale
(wettest place on earth)
Sandy or rocky
Coast...
Some Viola species on Kauai
Viola tracheliifolia
(treelet, dry forest)
Viola wailenalenae
(shrub, swamp)
Viola kauaiensis
...
5.1 A.1 Development of melanistic insects in
polluted areas.
http://upload.wikimedia.org/wikipedia/commons
http://en.wikip...
5.1 A.1 Development of melanistic insects in
polluted areas.
http://upload.wikimedia.org/wikipedia/commons/b/b7/Lichte_en_...
5.1 U.6 Continuous variation across the geographical range of related
populations matches the concept of gradual divergenc...
Essential idea: The diversity of life has evolved and
continues to evolve by natural selection.
5.1 Natural Selection
http...
Understandings
Statement Guidance
5.1.U.1 Natural selection can only occur if there is variation among members
of the same...
Applications and Skills
Statement Guidance
5.2 A.1 Changes in beaks of finches on Daphne Major.
5.2 A.2 Evolution of antib...
Mechanism for Evolution
Natural Selection The ultimate goal of any population is that it must
produce the next generation....
5.2 U.1 Natural selection can only occur if there is
variation among members of the same species.
Variation among individu...
1. Frequency of Genes (Genetic Variation)
• Inheritable differences among
individuals
• Raw material of evolution
• Happen...
A. Mutations
• Permanent change in genetic variation
• Only source of new alleles
• Do not arise out of need
• Causes of m...
Results of Mutations
• Harmful
Non-adaptive
Eliminated by selection
• Beneficial
Adaptive
Selected and persist
• Neutr...
Example of a gene mutation: phenylketonuria (PKU)
• C to T base-substitution mutation results in wrong amino acid
(similar...
Example of a point mutation
Example of a chromosomal mutation:
Klinefelter’s syndrome:
• receipt of an extra ‘X’ chromosome by males-> result is
femin...
B. Recombination
• Major source of genetic variation
• Two processes
Segregation
Independent assortment
5.2 U.2 Mutation...
C. Fertilization
5.2 U.2 Mutation, meiosis and sexual reproduction
cause variation between individuals in a species.
5.2 U.3 Adaptations are characteristics that make an
individual suited to its environment and way of life.
http://www.gerl...
5.2 U.4 Species tend to produce more offspring
than the environment can support.
http://evolutionbyfl.weebly.com/uploads/3...
5.2 U.5 Individuals that are better adapted tend to survive
and produce more offspring while the less well adapted tend
to...
LaMarck
• Organisms adapted to their
environments by acquiring traits
– change in their life time
• Disuse
organisms lost ...
5.2 U.6 Individuals that reproduce pass on characteristics to their offspring.
[Students should be clear that characterist...
5.2 U.7 Natural selection increases the frequency of characteristics
that make individuals better adapted and decreases th...
Populations evolve
• Natural selection acts on individuals
– differential survival
• “survival of the fittest”
– different...
Distribution of genes (population genetics)
•is the study of genetic variability in a population
*Extension of Mendelian g...
Genes and Populations
• Gene pool: The collection of genes in a population
Because diploids have only two versions of eac...
Alleles and Population Genetics
• Although individuals are affected by the process of natural
selection, it is the makeup ...
Warbler finch
Woodpecker finch
Small insectivorous
tree finch
Large
insectivorous
tree finch
Vegetarian
tree finch
Cactus ...
Darwin’s finches
• Darwin’s conclusions
– small populations of original South American finches landed
on islands
• variati...
Darwin’s finches
• Differences in beaks
allowed some finches to…
– successfully compete
– successfully feed
– successfully...
5.2 A.1 Changes in beaks of finches on Daphne Major.
Changes on the island story *
https://whyevolutionistrue.files.wordpr...
Antibiotic resistance story*
http://www.blueplanetgreenliving.com/wp-content/uploads/2009/08/Pill-bottles.jpg
• Antibiotic...
5.3 Classification of biodiversity
• Essential idea: Species are named and classified using an
internationally agreed syst...
Understandings
Statement Guidance
5.3 U.1 The binomial system of names for species is universal
among biologists and has b...
Applications and Skills
Statement Guidance
5.3 A.1 Classification of one plant and one animal
species from domain to speci...
• Formal two naming system of classifying species.
• Originally developed by Swedish naturalist
Carolus Linnaeus.
• Curren...
5.3 U.2 When species are discovered they are given scientific names using the
binomial system.
5.3 U.2 When species are discovered they are given scientific names
using the binomial system.
https://d2m2lkhawsaq1u.clou...
5.3 U.2 When species are discovered they are given scientific names
using the binomial system.
5.3 U.2 When species are discovered they are given scientific names
using the binomial system.
5.3 U.2 When species are discovered they are given scientific names
using the binomial system.
5.3.U3 Taxonomists classify species using a hierarchy of taxa.
5.3.U5 The principal taxa for classifying eukaryotes are ki...
5.3 U.5 The principal taxa for classifying eukaryotes are kingdom,
phylum, class, order, family, genus and species.
5.3 U.5 The principal taxa for classifying eukaryotes are kingdom,
phylum, class, order, family, genus and species.
Dear
K...
• Revision of the classification system
lead to a new level of taxon called
domains.
• The Prokaryotae are now divided int...
5.3 U.4 All organisms are classified into three domains.
Archaea Bacteria (Eubacteria) Eukaryota
Examples are often, but a...
5.3 A.1 Classification of one plant and one animal species from domain to species level.
Learn a mnemonic, one animal exam...
Plant Kingdom Diversity
The plant kingdom has within it 4 major groups:
• Bryophytes (mosses & liverworts)
• Filicinophyte...
5.3 A.2 Recognition features of bryophyta, filicinophyta, coniferophyta
and angiospermophyta.
1. Bryophytes 3. Coniferophy...
5.3 A.2 Recognition features of bryophyta, filicinophyta, coniferophyta
and angiospermophyta.
Leaves, roots and stems Vasc...
5.3 A.4 Recognition of features of birds, mammals, amphibians, reptiles
and fish.
The most familiar
animal from the
chorda...
5.3 A.4 Recognition of features of birds, mammals, amphibians, reptiles and fish.
Limbs Gas Exchange Reproduction Other fe...
5.3.A3 Recognition features of porifera, cnidaria, platylhelmintha,
annelida, mollusca, arthropoda and chordata.
chordata
...
Phylum: Porifera (sponges)
https://bioelevenncuevas.wordpress.com/phylum-porifera/
Phylum: Cnidaria
Phylum: Platyhelminthes (flatworms)
 Phylum: Annelida (segment worms)
Phylum: Mollusca
(Snails, slugs and octopus)
Phylum: Arthropoda (Insects, Crustaceans,
Spiders, Scorpions, Millipedes)
http://animals-pics.com/bird-eating-tarantula-si...
Phylum: Chordata
https://animalterritory.wordpress.com/tag/wildlife/
5.3 A.3 Recognition features of porifera, cnidaria, platylhelmintha,
annelida, mollusca, arthropoda and chordata.
Chordata...
5.3.A3 Recognition features of porifera, cnidaria, platylhelmintha,
annelida, mollusca, arthropoda and chordata.
Can you m...
5.3 A.3 Recognition features of porifera, cnidaria, platylhelmintha,
annelida, mollusca, arthropoda and chordata.
Symmetry...
5.3 S.1 Construction of dichotomous keys for use in identifying
specimens.
5.3.S1 Construction of dichotomous keys for use in identifying specimens.
5.3.U.6 In a natural classification, the genus and accompanying higher taxa consist of
all the species that have evolved f...
5.3 U.7 Taxonomists sometimes reclassify groups of species when new evidence shows that a
previous taxon contains species ...
5.3.U.8 Natural classifications help in identification of species and allow
the prediction of characteristics shared by sp...
10.3 Gene Pools and Speciation
Essential idea: Gene pools change over time.
Understandings
Statement Guidance
10.3 U.1 A gene pool consists of all the genes
and their different alleles, present in
a...
Applications and Skills
Statement Utilization
10.3 A.1 Identifying examples of directional,
stabilizing and disruptive sel...
10.3 U1 A gene pool consists of all the genes and their different alleles,
present in an interbreeding population
Speciati...
10.3 U.2 Evolution requires that allele frequencies change with time in
populations.
If the allele frequencies of a popula...
10.3 U.2 Evolution requires that allele frequencies change with time in
populations.
Frequencies add up to 1.0
e.g. — a population has two alleles, A and a with A is dominant over a
The allele frequencies mu...
10.3 U.2 Evolution requires that allele frequencies change with time in
populations.
•Evolution is the cumulative change i...
10.3 S.1 Comparison of allele frequencies of geographically isolated
populations
• Cod fish have a gene that codes for an
...
10.3 U3 Reproductive isolation of populations can be temporal,
behavioral or geographic.
• Reproductive isolation of popul...
How and why do new species originate?
• Species are created by a series of
evolutionary processes
– populations become iso...
10.3 U3 Reproductive isolation of populations can be temporal,
behavioral or geographic.
Temporal isolation
•Species that ...
10.3 U3 Reproductive isolation of populations can be temporal,
behavioral or geographic.
Behavioral Isolation
•In most ani...
So…what is a species?
Western MeadowlarkWestern Meadowlark
Eastern Meadowlark
Distinct species:
songs & behaviors are diff...
10.3 U3 Reproductive isolation of populations can be temporal,
behavioral or geographic.
Geographic Isolation
Species occu...
10.3 A.1 Identifying examples of directional, stabilizing and disruptive
selection.
• If no selection occurs to a populati...
10.3 A.1 Identifying examples of directional, stabilizing and disruptive
selection.
Directional Selection:
•Selection that...
10.3 A.1 Identifying examples of directional, stabilizing and disruptive
selection.
Stabilizing Selection:
A type of selec...
10.3 A.1 Identifying examples of directional, stabilizing and disruptive
selection.
Disruptive Selection:
•Removes individ...
10.4 U.4 Speciation due to divergence of isolated populations can be
gradual.
• Speciation can occur gradually over long p...
Gradualism
•Gradual divergence over long spans of
time
– assume that big changes occur as
the accumulation of many small
o...
10.3 U.5 Speciation can occur abruptly.
Punctuated Equilibrium
Species remain stable for long
periods of time (several mil...
10.3 U.5 Speciation can occur abruptly.
http://static.skynetblogs.be/media/130852/12.11.jpg
Over 75% of all life on Earth ...
10.3 U.5 Speciation can occur abruptly.
https://evolutionliteracy.files.wordpress.com/2014/09/t
rilobites-evolution-litera...
10.3 U.5 Speciation can occur abruptly.
http://www.gohobby.com/wp-
content/uploads/2012/11/Velociraptor-
Jurassic-Park.jpe...
10.3 U.5 Speciation can occur abruptly.
https://evolutionliteracy.files.wordpress.com/2014/09/t
rilobites-evolution-litera...
Gradualism
Punctuated Equilibrium
10.3 U.5 Speciation can occur abruptly.
10.3 A.2 Speciation in the genus Alliumby polyploidy.
• Polyploidy organisms contain more
than two pairs of the same
chrom...
10.3 A.2 Speciation in the genus Alliumby polyploidy.
10.3 A.2 Speciation in the genus Alliumby polyploidy.
• The genus Allium comprises monocot
flowering plants and includes t...
10.3 A.2 Speciation in the genus Alliumby polyploidy.
Allium grayi tetraploid (2n=32)
tetraploid (2n=32)
10.3 A.2 Speciation in the genus Alliumby polyploidy.
pentaploid (2n=40)
10.3 A.2 Speciation in the genus Alliumby polyploidy.
http://upload.wikimedia.org/wikipedia/commons/7/79/Allium_tulipifoli...
5.4 Cladistics
Essential idea: The ancestry of groups of species can be deduced by comparing their base or amino acid
sequ...
Understandings
Statement Guidance
5.4.U.1 A clade is a group of organisms that have evolved from a common
ancestor.
5.4.U....
Applications and Skills
Statement Guidance
5.4.A.1 Cladograms including humans and other primates.
5.4.A.2 Reclassificatio...
5.4 U.1 A Clade is a group of organisms that have
evolved from a common ancestor
• Cladistics (From the
ancient Greek for
...
5.4 U.1 A Clade is a group of organisms that have
evolved from a common ancestor
http://upload.wikimedia.org/wikipedia/com...
http://upload.wikimedia.org/wikipedia/commons/2/2b/Tiktaalik_roseae_life_restor.jpg
5.4 U.1 A Clade is a group of organism...
5.4 U.1 A Clade is a group of organisms that have
evolved from a common ancestor
http://upload.wikimedia.org/wikipedia/com...
5.4 U.1 A Clade is a group of organisms that have
evolved from a common ancestor
http://upload.wikimedia.org/wikipedia/com...
Archaeopteryx is a famous example transitional fossils – it gives evidence for the evolution of
birds from reptiles like d...
5.4 U.1 A Clade is a group of organisms that have
evolved from a common ancestor
http://upload.wikimedia.org/wikipedia/com...
Mammals have the unique homologousMammals have the unique homologous
characteristic of producing milkcharacteristic of pro...
For example, Fish,
Amphibians, Reptiles,
Birds, Mammals, and
all descendants from
a common ancestor to
form a clade
5.4 U....
http://bridgeurl.com/xrmmmk/all
Vertebrate
Hair Shelled
eggs
Amniotic Egg
Four Limbs
Bony Skeleton
Each clade
is determine...
Morphology (or there outward appearance) is only
one part of the story in cladistics. DNA and the
amino acids they code fo...
All known organisms use
DNA as genetic material
The genetic code is
universal. Gene
sequences inserted in
different organi...
The same 20 amino
acids are used to
make all proteins
http://commons.wikimedia.org/wiki/File:Protein_primary_structure.svg
Taking the example of the protein cytochrome c.
It is not identical in all species because single
point mutations in the D...
Molecular biology
Protein and DNA Structures Reveal Associations Between
Organisms
• Nuclear DNA code is highly conserved ...
Base Sequence Comparisons
• Divergence (difference) in
nucleotide base sequence
allows us to draw
relationships between
di...
Molecular Clocks
• DNA undergoes relatively
steady rates of mutation over
time
• More divergence in structure
is assumed t...
The assumption is that these changes occur at a regular rate. (which
may not always be the case)
Therefore if species A ha...
spines
tendrils
succulent leaves
colored leaves
Homologous structures
leaves
needles
5.4 U.4 Traits can be analogous or ho...
Analogous structures
• Separate evolution of structures
similar functions
similar external form
different internal stru...
Convergent evolution
• Fish: aquatic vertebratesvertebrates
• Humpback Whale: aquatic mammalsmammals
similar adaptations ...
5.4 U.4 Traits can be analogous or homologous.
Convergent evolution
• Flight evolved in 3 separate
animal groups
– evolved similar “solution” to
similar “problems”
– ana...
5.4.5 Cladograms are tree diagrams that show the most
probable sequence of divergence in clades.
• These two cladograms ar...
Human HumanChimp ChimpGorilla Gorilla
Root
Terminal nodes Sister clades: have a
common ancestor
Out group: Defines
the anc...
http://www.studentsoftheworld.info/infopays/photos/PER/orig/lamas.jpg
5.4 U.6 Evidence from cladistics has shown that clas...
http://www.scratchwireless.com/pad/wp-content/uploads/2015/02/SheepFlock.jpg
5.4 U.6 Evidence from cladistics has shown th...
http://ianadamsphotography.com/news/wp-content/uploads/2014/12/Bactrian-Camels-the-Wilds.jpg
5.4U.6 Evidence from cladisti...
Evolutionary Links
Classification allows us to see evolutionary relationships. Organisms
that are grouped together share a...
This is part of a molecular phylogeny of all of the
living primates. It clearly shows chimpanzees (Pan)
as more closely re...
5.4 S.1 Analyze cladograms to deduce evolutionary relationships.
1
2
3
DCBA
Which two species
are most closely-
related by...
Characters Shark Frog Kangaroo Human
Vertebrae X X X X
Two pairs of limbs X X X
Mammary glands X X
Placenta X
1) Compile a...
2) Use the data to construct
a Venn diagram,
Start with the
characteristic
shared by all
taxa in the
biggest circle
and wo...
Shark Frog Kangaroo Human
Mammary Glands
Lungs
Vertebrae
Placenta
3) Convert the Venn diagram into a cladogram
Characters Sponge Jellyfish Flatworm Earth-
worm
Snail Fruit fly Starfish Human
Cells with flagella X X X X X X X X
Symmet...
Cells with flagella: Sponge
Symmetry: Jellyfish
Bilateral symmetry: Flatworm
Mesoderm
Head develops first Anus develops fi...
Flagella
Mesoderm
Bilateral symmetry
Symmetry
Vertebrae
Anus develops first
Chitinous
shell
Head develops
first
Sponge Sta...
• Morphology was used to classify
the Figworts. Until recently,
Figworts were the 8th
largest
family of angiosperms (flowe...
5.4 A.1 Discuss reclassification of the figwort family using
evidence from cladistics.
http://upload.wikimedia.org/wikiped...
5.4 A.1 Discuss reclassification of the figwort family using
evidence from cladistics.
http://upload.wikimedia.org/wikiped...
5.4 A.1 Discuss reclassification of the figwort family using
evidence from cladistics.
Snapdragon (out)
• Botanists in the 18th and 19th
centuries used plant taxonomy to
separate out groups.
• Now with the use of modern
techni...
IB Biology Evolution 2015
IB Biology Evolution 2015
IB Biology Evolution 2015
IB Biology Evolution 2015
IB Biology Evolution 2015
IB Biology Evolution 2015
IB Biology Evolution 2015
IB Biology Evolution 2015
IB Biology Evolution 2015
IB Biology Evolution 2015
IB Biology Evolution 2015
IB Biology Evolution 2015
IB Biology Evolution 2015
IB Biology Evolution 2015
IB Biology Evolution 2015
IB Biology Evolution 2015
IB Biology Evolution 2015
IB Biology Evolution 2015
IB Biology Evolution 2015
IB Biology Evolution 2015
IB Biology Evolution 2015
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IB Biology Evolution 2015

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IB Biology 2015

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IB Biology Evolution 2015

  1. 1. Topic Six: Evolution Variation in Stickleback
  2. 2. 5.1 Evidence for Evolution Essential idea: There is overwhelming evidence for the evolution of life on Earth.
  3. 3. Understandings Statement Guidance 5.1 U.1 Evolution occurs when heritable characteristics of a species change. 5.1 U.2 The fossil record provides evidence for evolution. 5.1 U.3 Selective breeding of domesticated animals shows that artificial selection can cause evolution. 5.1 U.4 Evolution of homologous structures by adaptive radiation explains similarities in structure when there are differences in function. 5.1 U.5 Populations of a species can gradually diverge into separate species by evolution. 5.1 U.6 Continuous variation across the geographical range of related populations matches the concept of gradual divergence.
  4. 4. Applications and Skills Statement Guidance 5.2 A.1 Development of melanistic insects in polluted areas. 5.2 A.2 Comparison of the pentadactyl limb of mammals, birds, amphibians and reptiles with different methods of locomotion.
  5. 5. Evolution is the accumulated inherited changes in a population over time Evolution is one of the most powerful unifying concepts in science and is a critical underpinning to modern biology. It has been stated that without evolution biology, biology makes no sense. Dobzhansky, 1973 5.1 U.1 Evolution occurs when heritable characteristics of a species change.
  6. 6. But the Fossil recordBut the Fossil record …… OBSERVATIONOBSERVATION
  7. 7. Evidence supporting evolution I. Fossil record • transition species I. Anatomical record • homologous & vestigial structures • embryology & development I. Biogeography (Contential Drift) II. Molecular record (Neo-Darwinsim) • protein & DNA sequence 5.1 U.1 Evolution occurs when heritable characteristics of a species change.
  8. 8. 5.1 U.1 Evolution occurs when heritable characteristics of a species change. The raw genetic material (variation) is hidden there http://upload.wikimedia.org/wikipedia/commons/9/90/Rock_Dove_ (Feral_Pigeon)_(Columba_livia)_-_geograph.org.uk_-_1309587.jpg
  9. 9. 5.1 U.1 Evolution occurs when heritable characteristics of a species change.
  10. 10. 5.1 U.1 Evolution occurs when heritable characteristics of a species change. http://4.bp.blogspot.com/- 6EXGifOabDY/T75wOIZARKI/AAAAAAAAEkk/OSmkn 25kUhE/s1600/darwin-finches.jpg
  11. 11. 5.1 U.2 The fossil record provides evidence for evolution. Mount Everest 29,002 ft above sea level29,002 ft above sea level
  12. 12. Hillary’s Step Fossilized sea shells located just a few feet away from the top of the world
  13. 13. 5.1 U.2 The fossil record provides evidence for evolution. Fossil Record • Sedimentary rock is laid down over time… new on top, older rocks below • As one digs down, find related fossils, which are progressively older as one digs deeper • Consistent and steady increases in size/complexity of structures or the whole organism, or just the opposite, are seen in successive stratigraphic layers Oldest Youngest
  14. 14. 5.1 U.2 The fossil record provides evidence for evolution. • Layers of sedimentary rock contain fossils – new layers cover older ones, creating a record over time – fossils within layers show that a succession of organisms have populated Earth throughout a long period of time
  15. 15. The fossil record provides the dimension of time to the study of evolution – the layer of rock in which a fossil is found can be dated and therefore used to deduce the age of the fossil. http://sciencelearn.org.nz/Contexts/Dating-the-Past/Sci-Media/Images/Fossils-in-sedimentary-rock 5.1 U.2 The fossil record provides evidence for evolution.
  16. 16. http://sciencelearn.org.nz/Contexts/Dating-the-Past/Sci-Media/Images/Fossils-in-sedimentary-rock 5.1 U.2 The fossil record provides evidence for evolution. There are gaps in the fossil record due to: •Special circumstances are required for fossilization to occur •Only hard parts of an organism are preserved •Fossils can be damaged so that only fragments remain to be discovered The fossil record is the sum of all discovered and undiscovered fossils and their relative placement in rock.
  17. 17. Fossil Preservation • Petrified • Prints and molds • Resins which turn to Amber • Tar • Peat which is acidic preventing decay • Frozen in Ice or Snow • Sediments which turn to rock 5.1 U.2 The fossil record provides evidence for evolution. http://upload.wikimedia.org/wikipedia/commons/d/de/Ambre_Dominique_Moustique.jpg
  18. 18. 5.1 U.2 The fossil record provides evidence for evolution.
  19. 19. 5.1 U.2 The fossil record provides evidence for evolution. Radioactive Dating • Unstable atomic isotopes that decay over time. Organisms incorporate these isotopes in their bodies. This can be detected and used to radioactive dating a fossil, because radioactive decay follows a predictable exponential decay with time. Half-life is the period of time it takes for a substance undergoing decay to decrease by half. Example below
  20. 20. 5.1 U.2 The fossil record provides evidence for evolution. • For instance, organisms take up C, both as 14 C and 12 C but the 14 C decays away, so that one can determine how old the fossil is by the ratio of 14 C to 12 C in the fossil. The older it is, the greater the relative quantity of 12 C vs. 14 C. Then, as with 14 C dating, the age in half lives can be deduced from the decay curve Half life of 14 C is 5730 years, so it is useful for dating samples that are between 1000 & 100,000 years old
  21. 21. 5.1 U.2 The fossil record provides evidence for evolution. Potassium-Argon dating • Proportions of parent 40 K atoms and daughter 40 Ar atoms are measured • Half-life of 40 K is 1250 million years so it is very useful for dating samples older than 100,000 years old.
  22. 22. 5.1 U.3 Selective breeding of domesticated animals shows that artificial selection can cause evolution. Artificial selection Wild Mustard Plant http://www.evolutionevidenc e.org/wp- content/uploads/2013/08/mu stardselection1.jpg http://upload.wikimedia.org/wikipedia/commons/2/2f/Wi ld_Mustard.jpg
  23. 23. 5.1 U.3 Selective breeding of domesticated animals shows that artificial selection can cause evolution. https://phaven-prod.s3.amazonaws.com/files/image_part/asset/954254/z9zJXMj-QvJF- DjAAnbdUsdnL2I/large_Brassica_oleracea_cauliflower_broccoli_etc_DP347.jpg
  24. 24. Selective breeding 5.1 U.3 Selective breeding of domesticated animals shows that artificial selection can cause evolution.
  25. 25. Comparative Anatomy • Homologous structures • Analogous structures Convergent evolution Parallel Evolution • Vestigial Organs • Embryology 5.2 A.2 Comparison of the pentadactyl limb of mammals, birds, amphibians and reptiles with different methods of locomotion.
  26. 26. Homologous structures Pentadactly limb) similarities in characteristics resulting from common ancestry Divergent Evolution 5.2 A.2 Comparison of the pentadactyl limb of mammals, birds, amphibians and reptiles with different methods of locomotion.
  27. 27. Homologous structures • Similar structure • Similar development • Different functions • Evidence of close evolutionary relationship – recent common ancestor 5.2 A.2 Comparison of the pentadactyl limb of mammals, birds, amphibians and reptiles with different methods of locomotion.
  28. 28. Vestigial Structures • describes a characteristic of organisms that have seemingly lost all or most of its original function through evolution. • Fossil record supports the hypothesis that whales are derived from ancient vertebrates • Vestigial hind limbs are present in modern whales internal bones. Vestigial limbs are found in many animals, including the python. 5.2 A.2 Comparison of the pentadactyl limb of mammals, birds, amphibians and reptiles with different methods of locomotion.
  29. 29. Embryology • Similar features seen in developmental stages of related organisms • Gill pouches and tails seen in developing vertebrates • They have a common ancestor 5.2 A.2 Comparison of the pentadactyl limb of mammals, birds, amphibians and reptiles with different methods of locomotion.
  30. 30. The climate of the Galapagos Islands varies seasonally and yearly. Coastal areas and higher elevations also show a large temperature difference. Ages of the Galapagos Island 5.1 U.4 Evolution of homologous structures by adaptive radiation explains similarities in structure when there are differences in function.
  31. 31. Darwin found… birds Finch? Sparrow? Woodpecker? Warbler? Collected manyCollected many different birds on thedifferent birds on the Galapagos Islands.Galapagos Islands. Thought he foundThought he found very different kinds…very different kinds…
  32. 32. Darwin was amazed to find out: All 14 species of birds were finches… Finch? Sparrow? Woodpecker? Warbler? But Darwin found… a lot of finches Large Ground Finch Small Ground Finch Warbler Finch But there is only one species of finch on the mainland! Veg. Tree Finch
  33. 33. Correlation of species to food source SeedSeed eaterseaters FlowerFlower eaterseaters InsectInsect eaterseaters
  34. 34. Hawaiian violets (Viola) – Nine taxa, seven species distributed over most islands – Species occupy several different habitats across five islands • Dry forest • Dry cliff • Stream bank • Swamp (cloud) forest • Open bog – Species growing in same habitat on different islands are almost identical morphologically, anatomically 5.1 U.5 Populations of a species can gradually diverge into separate species by evolution.
  35. 35. Ages of the Hawaiian Islands Kauai = 5.1 my Hawaii = 400,000-180,000 my Maui Nui complex = 1.9 my-800,000 y Oahu = 3.7-2.6 my
  36. 36. Topography of Kauai Waimea Canyon (extremely arid) Alakai Swamp/Mt Waialeale (wettest place on earth) Sandy or rocky Coastal sites Low-elevation Moist forest High-elevation wet forest, cliffs
  37. 37. Some Viola species on Kauai Viola tracheliifolia (treelet, dry forest) Viola wailenalenae (shrub, swamp) Viola kauaiensis (herb, open bog)
  38. 38. 5.1 A.1 Development of melanistic insects in polluted areas. http://upload.wikimedia.org/wikipedia/commons http://en.wikipedia.org/wiki/Peppered_moth_evolution #mediaviewer/File:Biston.betularia.f.carbonaria.7209.jp g Example of evolution taking place •The peppered moth…. Two forms (morphs) the gray mottled form and the dark form. Changes in relative numbers was hypothesized to be the result of selective predation by birds. High industrial pollution make the darker moth less likely to be seen. •Melanin gives color to moths Black is a mutation of the white form (morphs), it is dominant. With industrial pollution the black allele became favorable. Increase in population of the dominant allele. Clean air, return of lichen , increase in recessive allele.
  39. 39. 5.1 A.1 Development of melanistic insects in polluted areas. http://upload.wikimedia.org/wikipedia/commons/b/b7/Lichte_en_zwarte_versie_berkenspanner.jpg
  40. 40. 5.1 U.6 Continuous variation across the geographical range of related populations matches the concept of gradual divergence. • Geographic variation is the term used to refer to differences between populations. Differences in phenotype associated with local environment • For instance, yarrow plants vary with geographical location across the Sierra Nevada
  41. 41. Essential idea: The diversity of life has evolved and continues to evolve by natural selection. 5.1 Natural Selection https://s-media-cache-ak0.pinimg.com/736x/51/3d/86/513d86a093998ac870e98e052dde0ed3.jpg
  42. 42. Understandings Statement Guidance 5.1.U.1 Natural selection can only occur if there is variation among members of the same species. 5.1.U.2 Mutation, meiosis and sexual reproduction cause variation between individuals in a species 5.1.U.3 Adaptations are characteristics that make an individual suited to its environment and way of life. 5.1.U.4 Species tend to produce more offspring than the environment can support. 5.1.U.5 Individuals that are better adapted tend to survive and produce more offspring while the less well adapted tend to die or produce fewer offspring 5.1. U.6 Individuals that reproduce pass on characteristics to their offspring. [Students should be clear that characteristics acquired during the lifetime of an individual are not heritable. The term Lamarckism is not required.] 5.1 U.7 Natural selection increases the frequency of characteristics that make individuals better adapted and decreases the frequency of other characteristics leading to changes within the species.
  43. 43. Applications and Skills Statement Guidance 5.2 A.1 Changes in beaks of finches on Daphne Major. 5.2 A.2 Evolution of antibiotic resistance in bacteria.
  44. 44. Mechanism for Evolution Natural Selection The ultimate goal of any population is that it must produce the next generation. This is complicated by four basic characteristics of life: 1. Variation among individuals means they individually have different ability to obtain resources. Sexual reproduction promotes variation in a species. 2. Reproduction Individuals that survive and then reproduce transmit these variations to their offspring. *The environment is the agent of natural selection determining which species will survive. 3. Overpopulation Each generation produces more offspring then the environment can support. 4. Competition with finite resources along with an increase in the population there is a competition of those resources leading, a survival of the fittest.
  45. 45. 5.2 U.1 Natural selection can only occur if there is variation among members of the same species. Variation among individuals means they individually have different ability to obtain resources. Sexual reproduction promotes variation in a species. http://upload.wikimedia.org/wikipedia/commons/thumb/5/53/Theba_geminata_variability.jpg/1280px-Theba_geminata_variability.jpg
  46. 46. 1. Frequency of Genes (Genetic Variation) • Inheritable differences among individuals • Raw material of evolution • Happens in 3 ways A. Mutations B. Recombination (meiosis) C. Fertilization 5.2 U.2 Mutation, meiosis and sexual reproduction cause variation between individuals in a species. http://media-2.web.britannica.com/eb-media/70/81270-004-3B7A77F2.jpg
  47. 47. A. Mutations • Permanent change in genetic variation • Only source of new alleles • Do not arise out of need • Causes of mutation – Spontaneous occurrence – Radiation – Chemicals – Transposons 5.2 U.2 Mutation, meiosis and sexual reproduction cause variation between individuals in a species. http://www.britannica.com/EBchecked/topic/376514/Merychippus
  48. 48. Results of Mutations • Harmful Non-adaptive Eliminated by selection • Beneficial Adaptive Selected and persist • Neutral Neither adaptive nor non- adaptive May or may not persist in gene pool 5.2 U.2 Mutation, meiosis and sexual reproduction cause variation between individuals in a species. http://4.bp.blogspot.com/-- zKT77cA4Rc/URACaqRE7kI/AAAAAAAAAFI/ZktOQD8BRkY/s1 600/horse_evolution.gif
  49. 49. Example of a gene mutation: phenylketonuria (PKU) • C to T base-substitution mutation results in wrong amino acid (similar to sickle-cell mutation) • Individuals can not metabolize amino acid phenylalanine an enzyme needed to degrade phenylalanine is not made so it accumulates in the brain and causes developmental disabilities. 5.2 U.2 Mutation, meiosis and sexual reproduction cause variation between individuals in a species.
  50. 50. Example of a point mutation
  51. 51. Example of a chromosomal mutation: Klinefelter’s syndrome: • receipt of an extra ‘X’ chromosome by males-> result is feminization of secondary sex characteristics, sterility and learning impairment may be present. • Chromosomal mutations tend to have less evolutionary significance because they typically cause death or sterility and will not be passed on.
  52. 52. B. Recombination • Major source of genetic variation • Two processes Segregation Independent assortment 5.2 U.2 Mutation, meiosis and sexual reproduction cause variation between individuals in a species.
  53. 53. C. Fertilization 5.2 U.2 Mutation, meiosis and sexual reproduction cause variation between individuals in a species.
  54. 54. 5.2 U.3 Adaptations are characteristics that make an individual suited to its environment and way of life. http://www.gerlachnaturephoto.com/Yellowstone/Bison3791_MASTER_For_Web.jpg • Where and how an organism lives is largely due to its specific adaptations that allow it to survive and reproduce in a particular area or habitat • In other words their structure allows them to function in that environment • Polar bears are well adapted to life in the Arctic. They have a large layer of blubber to keep them warm. They are strong swimmers, aided by their strong forearms and layer of blubber for buoyancy. They have hollow fur to aid in insulation as well. For plants, cacti have water storage tissue and spines (prevent water loss) because of the infrequent rainfall in the desert. • Adaptations develop over time through natural selection
  55. 55. 5.2 U.4 Species tend to produce more offspring than the environment can support. http://evolutionbyfl.weebly.com/uploads/3/9/7/9/39791607/5832564_orig.jpg • Populations tend to produce more offspring than the environment. • For example, fish produce thousands of eggs but only few make it to adulthood. • When parents don’t spend a lot or even any time caring for their young, they produce many offspring. This is a reproductive method used to make sure some offspring make it to the next generation. • Overpopulation and a limited amount of resources creates competition within a population.
  56. 56. 5.2 U.5 Individuals that are better adapted tend to survive and produce more offspring while the less well adapted tend to die or produce fewer offspring. • Within a population, there is genetic variation between the individuals in the population. • The organisms with the beneficial characteristics will be able to out-compete the other individuals with the less beneficial or harmful genetic traits for limited resources and mates. • These individuals will survive and reproduce and pass these genetic traits onto the next generation of offspring. • Organisms with less desirable traits will die or produce less offspring
  57. 57. LaMarck • Organisms adapted to their environments by acquiring traits – change in their life time • Disuse organisms lost parts because they did not use them — like the missing eyes & digestive system of the tapeworm • Perfection with Use & Need the constant use of an organ leads that organ to increase in size — like the muscles of a blacksmith or the large ears of a night-flying bat – transmit acquired characteristics to next generation Modern Theory: Mechanism for Evolution 5.2 U.6 Individuals that reproduce pass on characteristics to their offspring. [Students should be clear that characteristics acquired during the lifetime of an individual are not heritable. The term Lamarckism is not required.]
  58. 58. 5.2 U.6 Individuals that reproduce pass on characteristics to their offspring. [Students should be clear that characteristics acquired during the lifetime of an individual are not heritable. The term Lamarckism is not required.]
  59. 59. 5.2 U.7 Natural selection increases the frequency of characteristics that make individuals better adapted and decreases the frequency of other characteristics leading to changes within the species.
  60. 60. Populations evolve • Natural selection acts on individuals – differential survival • “survival of the fittest” – differential reproductive success • who bears more offspring • Populations evolve – genetic makeup of population changes over time – favorable traits (greater fitness) become more common Presence of lactate dehydrogenase Mummichog 5.2 U.7 Natural selection increases the frequency of characteristics that make individuals better adapted and decreases the frequency of other characteristics leading to changes within the species.
  61. 61. Distribution of genes (population genetics) •is the study of genetic variability in a population *Extension of Mendelian genetics •Populations are individuals of the same species that live in the same locations Exhibit variation in traits •Examination of the assemblage of traits reveals genetic information and shows the kind and proportion of alleles in a population 5.2 U.7 Natural selection increases the frequency of characteristics that make individuals better adapted and decreases the frequency of other characteristics leading to changes within the species.
  62. 62. Genes and Populations • Gene pool: The collection of genes in a population Because diploids have only two versions of each gene, each has only a small fraction of possible alleles in a population • Genotype: The genetic makeup of an individual at a given locus, taking into account the two possible alleles Genotype frequencyGenotype frequency is the proportion of a given genotype in the population Allele frequencyAllele frequency refers to the proportion of a particular allele, such as A or a • Phenotype: the traits of an individual Phenotype frequencyPhenotype frequency is the proportion of a given phenotype in the population Phenotype frequency is influenced by the dominance characteristic of an allele 5.2 U.7 Natural selection increases the frequency of characteristics that make individuals better adapted and decreases the frequency of other characteristics leading to changes within the species.
  63. 63. Alleles and Population Genetics • Although individuals are affected by the process of natural selection, it is the makeup of the population that is critical for determining the subsequent generations • Changes in the gene pool refer to changes in the frequency of the alleles • If the allele frequencies in a population do not undergo change over time, we say that the population is in genetic equilibrium 5.2 U.7 Natural selection increases the frequency of characteristics that make individuals better adapted and decreases the frequency of other characteristics leading to changes within the species.
  64. 64. Warbler finch Woodpecker finch Small insectivorous tree finch Large insectivorous tree finch Vegetarian tree finch Cactus finch Sharp-beaked finch Small ground finch Medium ground finch Large ground finch Insect eaters Bud eater Seed eaters Cactus eater Warbler finch Treefinches Ground finches Darwin’s finches • Differences in beaks – associated with eating different foods – survival & reproduction of beneficial adaptations to foods available on islands 5.2 A.1 Changes in beaks of finches on Daphne Major.
  65. 65. Darwin’s finches • Darwin’s conclusions – small populations of original South American finches landed on islands • variation in beaks enabled individuals to gather food successfully in the different environments – over many generations, the populations of finches changed anatomically & behaviorally • accumulation of advantageous traits in population • emergence of different species 5.2 A.1 Changes in beaks of finches on Daphne Major.
  66. 66. Darwin’s finches • Differences in beaks allowed some finches to… – successfully compete – successfully feed – successfully reproduce • pass successful traits onto their offspring 5.2 A.1 Changes in beaks of finches on Daphne Major.
  67. 67. 5.2 A.1 Changes in beaks of finches on Daphne Major. Changes on the island story * https://whyevolutionistrue.files.wordpress.com/2014/08/05jpessa1-master675.jpg
  68. 68. Antibiotic resistance story* http://www.blueplanetgreenliving.com/wp-content/uploads/2009/08/Pill-bottles.jpg • Antibiotics kill bacteria directly or weaken the bacteria so your immune system can fight and destroy the invading pathogen. • Some bacteria might not die because of changes within their DNA. These changes could be caused by mutations within their genome or the transfer of an antibiotic resistant gene from another bacterium. • Resistance is more likely to occur if the proper amounts of antibiotics aren’t taken or if a patient doesn’t finish the prescription. • These resistant bacteria will survive and reproduce, creating more identical resistant bacteria. • These resistant bacteria will make the person sick again in the future. • However if given the same antibiotic, these bacteria will no longer be destroyed. • Another antibiotic can be prescribed to kill these new resistant bacteria. • Resistance can be passed onto other pathogenic bacteria, creating more species of resistant bacteria. 5.2 A.2 Evolution of antibiotic resistance in bacteria.
  69. 69. 5.3 Classification of biodiversity • Essential idea: Species are named and classified using an internationally agreed system.
  70. 70. Understandings Statement Guidance 5.3 U.1 The binomial system of names for species is universal among biologists and has been agreed and developed at a series of congresses. 5.3 U.2 When species are discovered they are given scientific names using the binomial system. 5.3 U.3 Taxonomists classify species using a hierarchy of taxa. 5.3 U.4 All organisms are classified into three domains. Archaea, eubacteria and eukaryote should be used for the three domains. Members of these domains should be referred to as archaeans, bacteria and eukaryotes. Viruses are not classified as living organisms. 5.3 U.5 The principal taxa for classifying eukaryotes are kingdom, phylum, class, order, family, genus and species. 5.3 U.6 In a natural classification, the genus and accompanying higher taxa consist of all the species that have evolved from one common ancestral species. 5.3 U.7 Taxonomists sometimes reclassify groups of species when new evidence shows that a previous taxon contains species that have evolved from different ancestral species. 5.3 U.8 Natural classifications help in identification of species and allow the prediction of characteristics shared by species within a group.
  71. 71. Applications and Skills Statement Guidance 5.3 A.1 Classification of one plant and one animal species from domain to species level. 5.3 A.2 Recognition features of bryophyta, filicinophyta, coniferophyta and angiospermophyta. Students should know which plant phyla have vascular tissue, but other internal details are not required. 5.3 A.3 Recognition features of porifera, cnidaria, platylhelmintha, annelida, mollusca, arthropoda and chordata. Recognition features expected for the selected animal phyla are those that are most useful in distinguishing the groups from each other and full descriptions of the characteristics of each phylum are not needed. 5.3 A.4 Recognition of features of birds, mammals, amphibians, reptiles and fish. 5.3 S.1 Construction of dichotomous keys for use in identifying specimens.
  72. 72. • Formal two naming system of classifying species. • Originally developed by Swedish naturalist Carolus Linnaeus. • Currently, many scientists and specialists meet in a series of International Congresses of Zoology which meet in different cities every 4 years • They meet to discuss their findings regarding genetics, animal behavior and classification • A main topic is the binomial nomenclature system and decisions regarding the classification of new organisms or the reclassification of old ones because of new evidence regarding ancestry. • The main objectives with regards to using the binomial nomenclature system developed are to • Make sure each organism has a unique name that cannot be confused with another organism • The name can be universally understood regardless of the nationality or culture that is using the name • Stability exists within the system by not allowing people to change the name without 5.3 U.1 The binomial system of names for species is universal among biologists and has been agreed and developed at a series of congresses. http://iszscon2012.haifa.ac.il/ http://www.ibc2017.cn/index.html
  73. 73. 5.3 U.2 When species are discovered they are given scientific names using the binomial system.
  74. 74. 5.3 U.2 When species are discovered they are given scientific names using the binomial system. https://d2m2lkhawsaq1u.cloudfront.net/uploads/trial /1128697-charles-darwin.jpg_1396593169.png
  75. 75. 5.3 U.2 When species are discovered they are given scientific names using the binomial system.
  76. 76. 5.3 U.2 When species are discovered they are given scientific names using the binomial system.
  77. 77. 5.3 U.2 When species are discovered they are given scientific names using the binomial system.
  78. 78. 5.3.U3 Taxonomists classify species using a hierarchy of taxa. 5.3.U5 The principal taxa for classifying eukaryotes are kingdom, phylum, class, order, family, genus and species. Not all domains use the same taxa – the example above is for Eukaryotes
  79. 79. 5.3 U.5 The principal taxa for classifying eukaryotes are kingdom, phylum, class, order, family, genus and species.
  80. 80. 5.3 U.5 The principal taxa for classifying eukaryotes are kingdom, phylum, class, order, family, genus and species. Dear King Philip Come Over For Good Spaghetti
  81. 81. • Revision of the classification system lead to a new level of taxon called domains. • The Prokaryotae are now divided into two domains, the Bacteria and the Archaea • These are organisms that do not have a membrane bound nucleus and their DNA is not associated with proteins. • The Bacteria domain consists of Eubacteria and archaebacteria are classified as Archaeans. • The Eukarya domain includes eukaryotes, or organisms that have a membrane bound nucleus. This domain is further subdivided into the kingdoms Protista, Fungi, Plantae, and Animalia • Groups organisms primarily based on differences in ribosomal RNA structure. Ribosomal RNA is a molecular building block for ribosomes. 5.3 U.4 All organisms are classified into three domains.
  82. 82. 5.3 U.4 All organisms are classified into three domains. Archaea Bacteria (Eubacteria) Eukaryota Examples are often, but always, extremophiles: •Sulfolobus sp. grow in volcanic springs with optimal growth occurring at pH 2-3 and temperatures of 75-80 °C •Halobacterium sp. (lives in water with high salt concentrations) • Staphylococcus aureus (above) can cause skin infections and respiratory disease • Cyanobacteria sp. Are photosynthetic • Rhizobium sp. live symbiotically with plants and fix nitrogen Includes several kingdoms including fungi, animals and plants. Examples range from algae to Humans. • No nuclear membrane • RNA and biochemistry distinct from bacteria • No nuclear membrane • Nuclear membrane Features and examples of each domain: http://en.wikipedia.org/wiki/Three-domain_system
  83. 83. 5.3 A.1 Classification of one plant and one animal species from domain to species level. Learn a mnemonic, one animal example and one plant example: Domain Does Eukaryota Eukaryota Kingdom Kennard Animalia Plantae Phylum Play Chordata Spermatophyta Class Classical Mammalia Eudicotyledons Order Or Primates Magnoliidae Family Folk Hominidae Ranunculales Genus Guitar Homo Ranunculus Species Songs? Sapiens Acris Human Meadow Buttercup http://commons.wikimedia.org/wiki/File:Masai_Woman.jpg http://commons.wikimedia.org/wiki/File:Ranunculus_macro.jpg Dear King Philip Come Over For Good Spaghetti
  84. 84. Plant Kingdom Diversity The plant kingdom has within it 4 major groups: • Bryophytes (mosses & liverworts) • Filicinophytes (Ferns) • Coniferophytes (Conifers & Pines) • Angiospermophytes ( Flowering Plants) 5.3 A.2 Recognition features of bryophyta, filicinophyta, coniferophyta and angiospermophyta.
  85. 85. 5.3 A.2 Recognition features of bryophyta, filicinophyta, coniferophyta and angiospermophyta. 1. Bryophytes 3. Coniferophytes 4. Angiosperms 2. Filicinophytes
  86. 86. 5.3 A.2 Recognition features of bryophyta, filicinophyta, coniferophyta and angiospermophyta. Leaves, roots and stems Vascular tissue Reproductive structures Bryophytes (mosses, hornworts and liverworts) • No roots, but structures similar to root hairs called rhizoids • Mosses have simple leaves and stems • Liverworts have a flattened thallus None Spores produced in capsules, which develop at the end of a stalk Filicinophytes (ferns) • Roots present • Short non-woody stems. • Leaves usually divided into pairs of leaflets Yes Spores produced in sporangia on the underside of the leaves Coniferophytes (conifer shrubs and trees) • Roots, present • Woody stems • Leaves usually narrow with a thick waxy cuticle Yes Seeds develop from ovules in female cones. Male cones produce pollen. Angiospermophytes (flowering plants) • Leaves and roots variable in structure • Stems maybe woody (shrubs and trees) Yes Seeds develop from ovules in ovaries, inside flowers. Seeds are dispersed by fruits which develop from the ovaries.
  87. 87. 5.3 A.4 Recognition of features of birds, mammals, amphibians, reptiles and fish. The most familiar animal from the chordata phyla belong the to subphylum vertebrata. Can you match the different classes with the images? http://commons.wikimedia.org/ Fish (Agnatha, Chondrichthyes, Osteichthyes) Birds (aves) Mammals (mammalia) Amphibians (amphibia) Reptiles (reptilia)
  88. 88. 5.3 A.4 Recognition of features of birds, mammals, amphibians, reptiles and fish. Limbs Gas Exchange Reproduction Other features Mammals 4 Pentadactyl limbs Lungs with alveoli • Internal fertilization • Give birth to live young • Mammary glands secrete milk • Hairs growing from the skin • Teeth including living tissue birds 4 Pentadactyl limbs, 2 limbs modified as wings Lungs with parabronchial tubes • Internal fertilization • Hard shells around the eggs • Feathers growing from skin • Beak but no teeth reptiles 4 Pentadactyl limbs Lungs with extensive folding • Internal fertilization • Soft shells around eggs • Dry scaly impermeable skin • Simple teeth – no living tissue amphibians 4 Pentadactyl limbs Simple lungs with small internal folds and moist surfaces • External fertilization in water • Protective jelly around eggs • Larval stage lives in water • Soft moist permeable skin fish Fins Gills • External fertilization in most species • Scales grow from the skin • with a single gill slit • Swim bladder for buoyancy A summary of key features that can be used to distinguish between the vertebrate classes
  89. 89. 5.3.A3 Recognition features of porifera, cnidaria, platylhelmintha, annelida, mollusca, arthropoda and chordata. chordata porifera cnidaria platylhelmintha annelida mollusca arthropoda What about other phyla? Can you match the names with the images?
  90. 90. Phylum: Porifera (sponges) https://bioelevenncuevas.wordpress.com/phylum-porifera/
  91. 91. Phylum: Cnidaria
  92. 92. Phylum: Platyhelminthes (flatworms)
  93. 93.  Phylum: Annelida (segment worms)
  94. 94. Phylum: Mollusca (Snails, slugs and octopus)
  95. 95. Phylum: Arthropoda (Insects, Crustaceans, Spiders, Scorpions, Millipedes) http://animals-pics.com/bird-eating-tarantula-size/33/go-back-gallery-for-goliath-bird-eating-spider-size-comparison/
  96. 96. Phylum: Chordata https://animalterritory.wordpress.com/tag/wildlife/
  97. 97. 5.3 A.3 Recognition features of porifera, cnidaria, platylhelmintha, annelida, mollusca, arthropoda and chordata. Chordata (animals with a backbone) should be easy. Try using the key to help identify the rest of the phyla.
  98. 98. 5.3.A3 Recognition features of porifera, cnidaria, platylhelmintha, annelida, mollusca, arthropoda and chordata. Can you match the phyla with the images? chordata porifera cnidaria platylhelmintha annelida mollusca arthropoda
  99. 99. 5.3 A.3 Recognition features of porifera, cnidaria, platylhelmintha, annelida, mollusca, arthropoda and chordata. Symmetry Segmentation Digestive tract Other features porifera (sponges) None None No mouth or anus • Porous • attached to rocks • Filter feeder cnidaria (corals, jellyfish) Radial None Mouth but no anus • Stinging cells • Tentacles platylhelmintha (flatworms) Bilateral None Mouth but no anus • Flattened body annelida (earthworms, leeches) Bilateral Very segmented Mouth and anus • bristles often present Mollusca (oyster, snails, octopus) Bilateral Non-visible segmentation Mouth and anus • Most have shell made of CaCO3 Arthropoda (ant, scorpion, crab) Bilateral Segmented Mouth and anus • Exoskeleton • jointed appendages Chordata (fish, birds, mammals) Bilateral Segmented Mouth and anus • notochord • hollow dorsal nerve cord • (some have ) pharyngeal slits A summary of key features that can be used to distinguish between animal phyla
  100. 100. 5.3 S.1 Construction of dichotomous keys for use in identifying specimens.
  101. 101. 5.3.S1 Construction of dichotomous keys for use in identifying specimens.
  102. 102. 5.3.U.6 In a natural classification, the genus and accompanying higher taxa consist of all the species that have evolved from one common ancestral species. Natural classification groups together species that share a common ancestor from which they evolved. This is called the Darwinian principle of common descent . • Members of a group share important attributes or 'homologous’ traits that are inherited from common ancestors. For example Lions share more traits with Jaguars than with Leopards. • Grouping together birds, bats and bees because they fly would be an artificial classification as they do not share a common ancestor and evolved the ability to fly independently. • Natural classification is not straightforward as convergent evolution can make distantly related organisms appear similar and adaptive radiation can make similar organisms appear very different from each other.
  103. 103. 5.3 U.7 Taxonomists sometimes reclassify groups of species when new evidence shows that a previous taxon contains species that have evolved from different ancestral species. • Historically classification systems have been revised repeatedly based on emerging evidence. • Recent evidence from genetic studies of ribosomal RNA has shown that "prokaryotes" are far more diverse than anyone had suspected. • Ribosomal RNA is found in all organisms and evolves slowly so is a good way to track evolution over long time periods. Previously in the second half of the 20th century all living organisms were classified into five kingdoms. This included prokaryotes being placed in one kingdom and eukaryotes were split-up into the remaining four kingdoms. http://academic.pgcc.edu/~kroberts/Lecture/Chapter%204/04-23_WhittakerTax_L.jpg
  104. 104. 5.3.U.8 Natural classifications help in identification of species and allow the prediction of characteristics shared by species within a group. If a new species of Ant is discovered then scientists would predict that the species should possess amongst other characteristics six jointed legs, a head, thorax, abdomen, elbowed antennae, ‘antibiotic’ secretory glands. If the species does not match the expected set of characteristics this brings into question either the classification of the species or of Ants as a family. Natural classification is very helpful when dealing with new species: “New species of legless amphibian discovered in remote Cambodian rainforest” http://www.abc.net.au/news/2015-01-17/new-species-of-legless- amphibian-found-in-cambodia/6022048 Dichotomous keys can be used to help identify the species. The keys can place a specimen with the most closely related species, genus, family or phyla using natural classification. To what level of classification a specimen can be placed depends on how unique it is.
  105. 105. 10.3 Gene Pools and Speciation Essential idea: Gene pools change over time.
  106. 106. Understandings Statement Guidance 10.3 U.1 A gene pool consists of all the genes and their different alleles, present in an interbreeding population. 10.3 U.2 Evolution requires that allele frequencies change with time in populations. Punctuated equilibrium implies long periods without appreciable change and short periods of rapid evolution. 10.3 U.3 Reproductive isolation of populations can be temporal, behavioral or geographic. 10.3 U.4 Speciation due to divergence of isolated populations can be gradual. 10.3 U.5 Speciation can occur abruptly.
  107. 107. Applications and Skills Statement Utilization 10.3 A.1 Identifying examples of directional, stabilizing and disruptive selection. 10.3 A.2 Speciation in the genus Alliumby polyploidy. Many crop species have been created to be polyploid. Polyploidy increases allelic diversity and permits novel phenotypes to be generated. It also leads to hybrid vigor. 10.3 S.1 Comparison of allele frequencies of geographically isolated populations.
  108. 108. 10.3 U1 A gene pool consists of all the genes and their different alleles, present in an interbreeding population Speciation •A species a group of individuals who produce offspring after mating. This make individual of that species reproductively isolated from other species. •A gene pool is the set of all genes, in an interbreeding population. http://data1.whicdn.com/images/63849/large.jpghttp://arkansasagnews.uark.edu/monarchs95.jpg
  109. 109. 10.3 U.2 Evolution requires that allele frequencies change with time in populations. If the allele frequencies of a population are not in equilibrium then the frequencies are changing or evolving. The following processes facilitate evolution by either adding or removing genetic variation from a population: •Mutation •Migration (Gene Flow) •Genetic Drift •Unequal Mating and/or Fertilization Success (Sexual Selection) •Unequal Viability (Natural Selection) Gene pool: The collection of genes in a population Because diploids have only two versions of each gene, each has only a small fraction of possible alleles in a population Genotype: The genetic makeup of an individual at a given locus, taking into account the two possible alleles Genotype frequency is the proportion of a given genotype in the population Allele frequency refers to the proportion of a particular allele, such as A or a Phenotype: the traits of an individual Phenotype frequency is the proportion of a given phenotype in the population Phenotype frequency is influenced by the dominance characteristic of an allele
  110. 110. 10.3 U.2 Evolution requires that allele frequencies change with time in populations.
  111. 111. Frequencies add up to 1.0 e.g. — a population has two alleles, A and a with A is dominant over a The allele frequencies must sum to 1.0 (frequency of A) + (frequency of a) = 1.0 The genotype frequencies must sum to 1.0 (frequency of AA) + (frequency of Aa) + (frequency of aa) = 1.0 The phenotype frequencies must sum to 1.0 (frequency of AA and Aa phenotype) + (frequency of aa phenotype) = 1.0 Imagine 2 alleles, A and a p is the frequency of A q the frequency of a So, p + q = 1 The mathematical equivalent of a random mating can be given by multiplying this relationship by itself Therefore, (p + q)2 = 1 = p2 + 2pq + q2 p2 = frequency of AA 2pq = frequency of Aa q2 = frequency of aa Given this condition, we can always work out the frequencies of each allele in a sexual population. 10.3 U.2 Evolution requires that allele frequencies change with time in populations.
  112. 112. 10.3 U.2 Evolution requires that allele frequencies change with time in populations. •Evolution is the cumulative change in allele frequency or heritable characteristics in a population over time •The cumulative change can occur as a result of genetic changes and/or selective pressures which favor certain heritable characteristics over other less favorable characteristics •These populations have to be reproductively isolated, thus preventing gene flow between populations P equals the dominant gene Q equals the recessive gene
  113. 113. 10.3 S.1 Comparison of allele frequencies of geographically isolated populations • Cod fish have a gene that codes for an integral membrane protein called pantophysin. • Two alleles of the gene, PanIA and PanIB , code for versions of pantophysin, that differ by four amino acids in one region of the protein. • Samples were collected from 23 locations in the North Atlantic (numbered 1–23 in each pie chart), on the map to the right. • The frequency of an allele can vary from 0.0 to 1.0. PanIA light grey sectors of the pie charts show the allele frequency for the PanIA gene PanIB black sectors show the allele frequency for the PanIB gene. • The biggest difference in allele frequency occurs in the Cod fish isolated at the two extremes of the map.
  114. 114. 10.3 U3 Reproductive isolation of populations can be temporal, behavioral or geographic. • Reproductive isolation of populations occurs when barriers or mechanisms prevent two populations from interbreeding, keeping their gene pools isolated from each other. • There are different types of reproductive isolation including temporal, behavioral, and geographic
  115. 115. How and why do new species originate? • Species are created by a series of evolutionary processes – populations become isolated • geographically isolated • reproductively isolated – isolated populations evolve independently • Isolation – allopatric • geographic separation – sympatric • still live in same area 10.3 U3 Reproductive isolation of populations can be temporal, behavioral or geographic.
  116. 116. 10.3 U3 Reproductive isolation of populations can be temporal, behavioral or geographic. Temporal isolation •Species that breed during different times of day, different seasons, or different years cannot mix gametes – reproductive isolation – sympatric speciation • “same country” Eastern Spotted Skunk (Top Right) & Western Spotted Skunk (Bottom Right) overlap in range but Eastern mates in late winter & Western mates in late summer Eastern Spotted Skunk (Top Right) & Western Spotted Skunk (Bottom Right) overlap in range but Eastern mates in late winter & Western mates in late summer http://upload.wikimedia.org/wikipedia/ commons/f/f2/Spilogale_putorius_(2).jp g http://upload.wikimedia.org/wikipe dia/commons/9/98/Spilogale_gracili s_amphiala.jpg
  117. 117. 10.3 U3 Reproductive isolation of populations can be temporal, behavioral or geographic. Behavioral Isolation •In most animal species, members of the two sexes must first search for each other and come together. •Unique behavioral patterns & rituals isolate species  identifies members of species attract mates of same species  courtship rituals, mating calls  reproductive isolation Blue footed boobies mate only after a courtship display unique to their species Blue footed boobies mate only after a courtship display unique to their specieshttp://upload.wikimedia.org/wikipedia/commo ns/a/aa/Bluefooted_Booby_Comparison.jpg
  118. 118. So…what is a species? Western MeadowlarkWestern Meadowlark Eastern Meadowlark Distinct species: songs & behaviors are different enough to prevent interbreeding Distinct species: songs & behaviors are different enough to prevent interbreeding 10.3 U3 Reproductive isolation of populations can be temporal, behavioral or geographic.
  119. 119. 10.3 U3 Reproductive isolation of populations can be temporal, behavioral or geographic. Geographic Isolation Species occur in different areas – physical barrier – allopatric speciationallopatric speciation • “other country” Harris’s Antelope Squirrel inhabits the canyon’s south rim (L). Just a few miles away on the north rim (R) lives the closely related White-tailed Antelope Squirrel Harris’s Antelope Squirrel inhabits the canyon’s south rim (L). Just a few miles away on the north rim (R) lives the closely related White-tailed Antelope Squirrel
  120. 120. 10.3 A.1 Identifying examples of directional, stabilizing and disruptive selection. • If no selection occurs to a population (for whatever means), population doesn’t change with succeeding generations. • If selection pressure is applied then those not receiving selection pressure tend to predominate…  Stabilizing: the extremes are selected against; center stays same and grows in numbers  Directional: one tail of the distribution is selected against and the opposite tail grows in numbers  Disruptive: a mid-group is selected against; the tails are allowed to predominate and grow compared to middle As an example: in Humans we have selected for a babies birth weight. This protects the mother and the babies health.
  121. 121. 10.3 A.1 Identifying examples of directional, stabilizing and disruptive selection. Directional Selection: •Selection that removes individuals from one end of a phenotypic distribution and thus causes a shift in the distribution towards the other end. •Over time, the favored extreme will become more common and the other extreme will be less common or lost.
  122. 122. 10.3 A.1 Identifying examples of directional, stabilizing and disruptive selection. Stabilizing Selection: A type of selection that removes individuals from both ends of a phenotypic distribution, thus maintaining the same distribution mean. This occurs when natural selection favors the intermediate phenotypes. Over time, the intermediate states become more common and each extreme variation will become less common or lost. Same mouse example where medium colored fur is favored over dark or light fur color.
  123. 123. 10.3 A.1 Identifying examples of directional, stabilizing and disruptive selection. Disruptive Selection: •Removes individuals from the center of a phenotype. This occurs when natural selection favors both ends of the phenotypic variation. •Over time, the two extreme variations will become more common and the intermediate states will be less common or lost. •This can lead to two new species.
  124. 124. 10.4 U.4 Speciation due to divergence of isolated populations can be gradual. • Speciation can occur gradually over long periods of time, with several intermediate forms in between species leading to today’s current species. This can be seen in some of the more complete fossil records, like the whale or the horse. • In some species, large gaps were evident for certain species in the fossil record. This imperfections in the fossil record, maybe the result of transitional species have not been discovered yet or abrupt speciation. http://www.sivatherium.narod.ru/library/Dixon/pics_01/p0010_e.gif
  125. 125. Gradualism •Gradual divergence over long spans of time – assume that big changes occur as the accumulation of many small ones 10.4 U.4 Speciation due to divergence of isolated populations can be gradual. http://cnx.org/resources/22b17901c8ce6510b03e2f89df0bc072/graphics1.png
  126. 126. 10.3 U.5 Speciation can occur abruptly. Punctuated Equilibrium Species remain stable for long periods of time (several million years) interrupted by periods of significant change, during which time a new species may evolve.  rapid bursts of change  long periods of little or no change  species undergo rapid change when they 1st bud from parent population
  127. 127. 10.3 U.5 Speciation can occur abruptly. http://static.skynetblogs.be/media/130852/12.11.jpg Over 75% of all life on Earth was lost during the late Devonian mass extinction which took place about 375-359 million years ago
  128. 128. 10.3 U.5 Speciation can occur abruptly. https://evolutionliteracy.files.wordpress.com/2014/09/t rilobites-evolution-literacy-g-paz-y-mino-c-photo.jpg Over 97% of all life on Earth was lost during theOver 97% of all life on Earth was lost during the End-Permian mass extinction which took place 252End-Permian mass extinction which took place 252 million years agomillion years ago
  129. 129. 10.3 U.5 Speciation can occur abruptly. http://www.gohobby.com/wp- content/uploads/2012/11/Velociraptor- Jurassic-Park.jpeg Over 50% of all life on Earth was lost during the TriassicOver 50% of all life on Earth was lost during the Triassic mass extinction which took place 201 million years agomass extinction which took place 201 million years ago
  130. 130. 10.3 U.5 Speciation can occur abruptly. https://evolutionliteracy.files.wordpress.com/2014/09/t rilobites-evolution-literacy-g-paz-y-mino-c-photo.jpg Over 80% of all life on Earth was lost during the endOver 80% of all life on Earth was lost during the end Cretaceous. The mass extinction took place 252 millionCretaceous. The mass extinction took place 252 million years agoyears ago
  131. 131. Gradualism Punctuated Equilibrium 10.3 U.5 Speciation can occur abruptly.
  132. 132. 10.3 A.2 Speciation in the genus Alliumby polyploidy. • Polyploidy organisms contain more than two pairs of the same chromosomes. • A likely advantage is it allows for additional raw materials (i.e. DNA, genes) for evolution. Every gene is theoretically free to evolve without substantial negative effect. • Polyploidy plants tend to be larger. The reproductive organs and fruit, in particular, are usually enlarged in polyploidy. The likely mechanism for this is simple: more DNA results in a larger nucleus, which results in larger cells, especially in the reproductive organs. http://www.vims.edu/newsandevents/topst ories/_images/diploid_triploid_250.jpg Oysters
  133. 133. 10.3 A.2 Speciation in the genus Alliumby polyploidy.
  134. 134. 10.3 A.2 Speciation in the genus Alliumby polyploidy. • The genus Allium comprises monocot flowering plants and includes the onion, garlic, chives, scallion, shallot, and the leek. • In many of these species of plants, chromosome doubling has created a large number of different phenotypes. • This results is a number of reproductively isolated but similar populations. Examples: of this are seen in 7 natural populations Allium grayi. They showed • tetraploid (2n=32) • pentaploid (2n=40) • hexaploid (2n=48) http://i.dailymail.co.uk/i/pix/2008/09/12/article-1054890- 029CF17900000578-854_233x364.jpg
  135. 135. 10.3 A.2 Speciation in the genus Alliumby polyploidy. Allium grayi tetraploid (2n=32) tetraploid (2n=32)
  136. 136. 10.3 A.2 Speciation in the genus Alliumby polyploidy. pentaploid (2n=40)
  137. 137. 10.3 A.2 Speciation in the genus Alliumby polyploidy. http://upload.wikimedia.org/wikipedia/commons/7/79/Allium_tulipifolium_(inflorescence).jpg hexaploid (2n=48)
  138. 138. 5.4 Cladistics Essential idea: The ancestry of groups of species can be deduced by comparing their base or amino acid sequences.
  139. 139. Understandings Statement Guidance 5.4.U.1 A clade is a group of organisms that have evolved from a common ancestor. 5.4.U.2 Evidence for which species are part of a clade can be obtained from the base sequences of a gene or the corresponding amino acid sequence of a protein. 5.4.U.3 Sequence differences accumulate gradually so there is a positive correlation between the number of differences between two species and the time since they diverged from a common ancestor. 5.4.U.4 Traits can be analogous or homologous. 5.4.U.5 Cladograms are tree diagrams that show the most probable sequence of divergence in clades. 5.4.U.6 Evidence from cladistics has shown that classifications of some groups based on structure did not correspond with the evolutionary origins of a group or species.
  140. 140. Applications and Skills Statement Guidance 5.4.A.1 Cladograms including humans and other primates. 5.4.A.2 Reclassification of the figwort family using evidence from cladistics. 5.4 S..1 Analysis of cladograms to deduce evolutionary relationships.
  141. 141. 5.4 U.1 A Clade is a group of organisms that have evolved from a common ancestor • Cladistics (From the ancient Greek for "branch") is a method of classifying species of organisms into groups called clades, which consist of an ancestor organism and all its descendants (and nothing else).
  142. 142. 5.4 U.1 A Clade is a group of organisms that have evolved from a common ancestor http://upload.wikimedia.org/wikipedia/commons/6/6b/Lutjanus_kasmira_school.jpg
  143. 143. http://upload.wikimedia.org/wikipedia/commons/2/2b/Tiktaalik_roseae_life_restor.jpg 5.4 U.1 A Clade is a group of organisms that have evolved from a common ancestor TiktaalikTiktaalik •Represents the evolutionary transitionRepresents the evolutionary transition from fish to amphibians. And as such thefrom fish to amphibians. And as such the common ancestor to every animal in thecommon ancestor to every animal in the Clade after the fish.Clade after the fish.
  144. 144. 5.4 U.1 A Clade is a group of organisms that have evolved from a common ancestor http://upload.wikimedia.org/wikipedia/commons/1/19/Caerulea3_crop.jpg
  145. 145. 5.4 U.1 A Clade is a group of organisms that have evolved from a common ancestor http://upload.wikimedia.org/wikipedia/commons/d/dc/Furcifer_pardalis_-Z%C3%BCrich_Zoo-8a.jpg
  146. 146. Archaeopteryx is a famous example transitional fossils – it gives evidence for the evolution of birds from reptiles like dinosaurs. http://commons.wikimedia.org/wiki/File:Archaeopteryx_lithographica_%28Berlin_specimen%29.jpg http://commons.wikimedia.org/wiki/File:Archaeopteryx_NT.jpg Bird features: •feathers Dinosaur features include: •jaws with sharp teeth •three fingers with claws •long bony tail 5.4 U.1 A Clade is a group of organisms that have evolved from a common ancestor
  147. 147. 5.4 U.1 A Clade is a group of organisms that have evolved from a common ancestor http://upload.wikimedia.org/wikipedia/commons/0/03/Mountain_Bluebird.jpg Likewise, birds share the common characteristics of feathers They too form a clade
  148. 148. Mammals have the unique homologousMammals have the unique homologous characteristic of producing milkcharacteristic of producing milk They form a cladeThey form a clade 5.4 U.1 A Clade is a group of organisms that have evolved from a common ancestor http://images.nationalgeographic.com/wpf/media- live/photos/000/334/cache/freshwater-mammals-hippo_33402_600x450.jpg
  149. 149. For example, Fish, Amphibians, Reptiles, Birds, Mammals, and all descendants from a common ancestor to form a clade 5.4 U.1 A Clade is a group of organisms that have evolved from a common ancestor
  150. 150. http://bridgeurl.com/xrmmmk/all Vertebrate Hair Shelled eggs Amniotic Egg Four Limbs Bony Skeleton Each clade is determined by common characteristics of its members that are different from that of the other species from which it has diverged
  151. 151. Morphology (or there outward appearance) is only one part of the story in cladistics. DNA and the amino acids they code for are the primary basis for grouping organisms into clades and determining likely paths of evolutionary descent Ex: Crocodiles are more closely related to birds than lizards… 5.4 U.2 Evidence for which species are part of a clade can be obtained from the base sequences of a gene or the corresponding amino acid sequence of a protein.
  152. 152. All known organisms use DNA as genetic material The genetic code is universal. Gene sequences inserted in different organisms express the same proteins 5.4 U.2 Evidence for which species are part of a clade can be obtained from the base sequences of a gene or the corresponding amino acid sequence of a protein.
  153. 153. The same 20 amino acids are used to make all proteins http://commons.wikimedia.org/wiki/File:Protein_primary_structure.svg
  154. 154. Taking the example of the protein cytochrome c. It is not identical in all species because single point mutations in the DNA that codes for it can lead to different amino acids making up the protein. Both humans and chimpanzees have identical cytochrome c molecules, while rhesus monkeys share all but one of the amino acids. This suggests that humans and chimpanzees are more closely related to each other than to rhesus monkeys. http://www.flickr.com/photos/stuffinhergoose/571672799 5.4 U.2 Evidence for which species are part of a clade can be obtained from the base sequences of a gene or the corresponding amino acid sequence of a protein. I didn’t want to beI didn’t want to be closely related toclosely related to stinking humansstinking humans anywayanyway!
  155. 155. Molecular biology Protein and DNA Structures Reveal Associations Between Organisms • Nuclear DNA code is highly conserved across phyla – although there are variations, there are no alternate codes • Nuclear DNA can be used to show associations between organisms when comparing very long suspected evolutionary times • Ribosomal RNA and mitochondrial DNA & RNA more useful when comparing shorter evolutionary times… they are inherently more variable over time because they are subjected to fewer selection pressures. • Small changes are seen in the DNA code between closely related species. • Monkeys, apes, and humans clearly have common ancestry 5.4 U.3 Sequence differences accumulate gradually so there is a positive correlation between the number of differences between two species and the time since they diverged from a common ancestor.
  156. 156. Base Sequence Comparisons • Divergence (difference) in nucleotide base sequence allows us to draw relationships between different organisms. • Here, differences in nucleotide base sequence of humans and other primates compared • Chimps closest, spider monkeys most dissimilar 5.4 U.3 Sequence differences accumulate gradually so there is a positive correlation between the number of differences between two species and the time since they diverged from a common ancestor.
  157. 157. Molecular Clocks • DNA undergoes relatively steady rates of mutation over time • More divergence in structure is assumed to mean more time has passed • Changes in homologous DNA from different species allows biologists to construct molecular clocks based on the rates of change in known and homologous DNA • This can aid in the dating of branching points in the evolutionary record 5.4 U.3 Sequence differences accumulate gradually so there is a positive correlation between the number of differences between two species and the time since they diverged from a common ancestor.
  158. 158. The assumption is that these changes occur at a regular rate. (which may not always be the case) Therefore if species A had 5 differences from species B and 10 differences from species C, then the lineages for A and C must have split twice as long ago as for A and B C B A Time
  159. 159. spines tendrils succulent leaves colored leaves Homologous structures leaves needles 5.4 U.4 Traits can be analogous or homologous.
  160. 160. Analogous structures • Separate evolution of structures similar functions similar external form different internal structure & development different origin no evolutionary relationship Solving a similar problem with a similar solutionSolving a similar problem with a similar solution http://upload.wikimedia.org/wikipedia/commons/5/5c/Male_- _black_phase_-_short_tail_hawk.JPG http://www.redorbit.com/media/uploads/2004/1 0/40_03aa91083d476b07bcc9228e134d6c56.jpg Convergent evolution 5.4 U.4 Traits can be analogous or homologous.
  161. 161. Convergent evolution • Fish: aquatic vertebratesvertebrates • Humpback Whale: aquatic mammalsmammals similar adaptations to life in the sea not closely related 5.4 U.4 Traits can be analogous or homologous.
  162. 162. 5.4 U.4 Traits can be analogous or homologous.
  163. 163. Convergent evolution • Flight evolved in 3 separate animal groups – evolved similar “solution” to similar “problems” – analogous structuresanalogous structures http://upload.wikimedia.org/wikipedia/commons /7/77/Big-eared-townsend-fledermaus.jpg http://upload.wikimedia.org/wikipedia/commons/e/e0/ 5.4 U.4 Traits can be analogous or homologous.
  164. 164. 5.4.5 Cladograms are tree diagrams that show the most probable sequence of divergence in clades. • These two cladograms are identical (although they don’t look it) • The shape and the order of the terminal nodes does not matter. • The only information to be gathered from the cladograms below is the order of nesting of sister clades and the relative relatedness of species http://commons.wikimedia.org/wiki/File:Identical_cladograms.svg
  165. 165. Human HumanChimp ChimpGorilla Gorilla Root Terminal nodes Sister clades: have a common ancestor Out group: Defines the ancestral characters Nodes: Common ancestors
  166. 166. http://www.studentsoftheworld.info/infopays/photos/PER/orig/lamas.jpg 5.4 U.6 Evidence from cladistics has shown that classification of some groups based on structure did not correspond with the evolutionary origins of a group or species.
  167. 167. http://www.scratchwireless.com/pad/wp-content/uploads/2015/02/SheepFlock.jpg 5.4 U.6 Evidence from cladistics has shown that classification of some groups based on structure did not correspond with the evolutionary origins of a group or species.
  168. 168. http://ianadamsphotography.com/news/wp-content/uploads/2014/12/Bactrian-Camels-the-Wilds.jpg 5.4U.6 Evidence from cladistics has shown that classification of some groups based on structure did not correspond with the evolutionary origins of a group or species.
  169. 169. Evolutionary Links Classification allows us to see evolutionary relationships. Organisms that are grouped together share a lot of similar features (homologous structures). These shared characteristics help us see how organisms have evolved from a common ancestor. HOWEVER, morphology (or there outward appearance) has its limitations in terms of evolutionary classification and DNA/ Amino Acid evidence is now far more accurate and trustworthy… http://www.flickr.com/photos/doug88888/3458057235/http://www.flickr.com/photos/mrapplegate/2423991076/ e.g. Llamas were originally compared to sheep but a study of their genetics later placed them in the camel family 5.4 U.6 Evidence from cladistics has shown that classification of some groups based on structure did not correspond with the evolutionary origins of a group or species.
  170. 170. This is part of a molecular phylogeny of all of the living primates. It clearly shows chimpanzees (Pan) as more closely related to humans than to gorillas. It was made by comparing 34,927 base pairs sequenced from 54 genes taken from each of a single species in each genus. 5.4 U.7 Analyze cladograms including humans and other primates.
  171. 171. 5.4 S.1 Analyze cladograms to deduce evolutionary relationships. 1 2 3 DCBA Which two species are most closely- related by evolution? Which node represents the earliest speciation / divergence? Which species is D more closely related to; A or B?
  172. 172. Characters Shark Frog Kangaroo Human Vertebrae X X X X Two pairs of limbs X X X Mammary glands X X Placenta X 1) Compile a table of the characters being compared Modified from: http://www.bu.edu/gk12/eric/cladogram.pdf
  173. 173. 2) Use the data to construct a Venn diagram, Start with the characteristic shared by all taxa in the biggest circle and work inwards
  174. 174. Shark Frog Kangaroo Human Mammary Glands Lungs Vertebrae Placenta 3) Convert the Venn diagram into a cladogram
  175. 175. Characters Sponge Jellyfish Flatworm Earth- worm Snail Fruit fly Starfish Human Cells with flagella X X X X X X X X Symmetry X X X X X X X Bilateral symmetry X X X X X X Mesoderm X X X X X Head develops first X X X Anus develops first X X Segmented body X X Calcified shell X Chitinous Exoskeleton X Water Vascular system X Vertebrae X Another Example:
  176. 176. Cells with flagella: Sponge Symmetry: Jellyfish Bilateral symmetry: Flatworm Mesoderm Head develops first Anus develops first Segmented Body: Earthworm Calcified Shell: SnailChitinous exoskeleton: Fruit fly Water Vascular system: Starfish Vertebrae: Human
  177. 177. Flagella Mesoderm Bilateral symmetry Symmetry Vertebrae Anus develops first Chitinous shell Head develops first Sponge StarfishFruit flySnail Flat- worm EarthwormJellyfish Human Water vascular system Calcified shell Segmented body
  178. 178. • Morphology was used to classify the Figworts. Until recently, Figworts were the 8th largest family of angiosperms (flowering plants). It grew from 16 genera in 1789 to 275 genera • Flowers of plants in Figworts tend to be pretty uniform in their appearance, typically having corollas with bilateral symmetry • Taxonomists recently examined chloroplast genes and found the 5000 figwort species should be split into 5 different clades rather than just one. 5.4 A.1 Discuss reclassification of the figwort family using evidence from cladistics. http://www.jardinexotiqueroscoff.com/site/uploads/pictures/plante /800x800/scrophulariaceae-diascia-rigescens-13.jpg
  179. 179. 5.4 A.1 Discuss reclassification of the figwort family using evidence from cladistics. http://upload.wikimedia.org/wikipedia/commons/2/2e/2007_Hippuris_vulgaris.jpg Hippuris vulgaris (out)
  180. 180. 5.4 A.1 Discuss reclassification of the figwort family using evidence from cladistics. http://upload.wikimedia.org/wikipedia/commons/4/40/Castilleja_angustifolia_1.jpg Applegate Indian paintbrush (out)
  181. 181. 5.4 A.1 Discuss reclassification of the figwort family using evidence from cladistics. Snapdragon (out)
  182. 182. • Botanists in the 18th and 19th centuries used plant taxonomy to separate out groups. • Now with the use of modern techniques, less than half of the original species remain in the Figwort family; now only the 36th largest among angiosperms • Reclassification was helpful since old Figwort family was too large and dissimilar to be a helpful grouping • We should consider ourselves fortunate to be a part of what is one of the eras of greatest advancement in the field it is a tremendous age of discovery No longer a Figwort. Sad

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