Evolution is the scientific theory that organisms gradually change over generations through natural selection acting on genetic variation. The evidence for evolution includes fossil records showing gradual changes in organisms over time, anatomical similarities between different species, and molecular biological evidence from DNA and protein comparisons. Charles Darwin's theory of natural selection proposed that variations arise in populations, and individuals with traits more suited to their environment will survive and pass on those traits, gradually changing the species over many generations.
human evolution, origin of life, big bang theory, theories on origin of life, evolution of life forms, experimental evidence on theory of chemical evolution, evidences of evolution, homology and analogy, biochemical and biogeographical evidences, adaptive radiation, lamarck's theory of evolution, darwins theory of evolution, mechanism of evolution, hardy weinberg principle, mutations
I tried to integrate basic and important concepts of evolution from different ppt that can be downloaded here in slideshare to have a consolidated theme about evolution.
human evolution, origin of life, big bang theory, theories on origin of life, evolution of life forms, experimental evidence on theory of chemical evolution, evidences of evolution, homology and analogy, biochemical and biogeographical evidences, adaptive radiation, lamarck's theory of evolution, darwins theory of evolution, mechanism of evolution, hardy weinberg principle, mutations
I tried to integrate basic and important concepts of evolution from different ppt that can be downloaded here in slideshare to have a consolidated theme about evolution.
Delivered this as talk series on Evolution to some of my colleagues interested in systems thinking. It was a great learning for me and will incorporate it into a sequel later.
Updates:
1. Version 2013.11.23 - Reorganized some slides, added images and credits
2. Version 2013.11.25 - Reorganized presentation around three aspects. Added better intro.
3. Version 2013.11.26 - Updated implications aspect for global warming and behavioral sink.
4. Version 2013.11.27 - Updated taxonomy discussion.
5. V 2013.12.05 - Updated natural selection, convergent evolution and punctuated equilibrium. Reorg of slides.
6. V 2013.12.16 - Added chaos and self-organization slides.
7. V 2013.12.21 - Added extinctions and explosions.
8. V2013.12.23 - Added more chaos explanation and Wikipedia logo.
9. V2014.05.05 - Corrected spelling mistakes and cleaned up slides.
This document will help you and will clear your concepts about the terms of Orthogenesis, Allometry & Adaptive Radiations, which are usually studied in evolution.
Delivered this as talk series on Evolution to some of my colleagues interested in systems thinking. It was a great learning for me and will incorporate it into a sequel later.
Updates:
1. Version 2013.11.23 - Reorganized some slides, added images and credits
2. Version 2013.11.25 - Reorganized presentation around three aspects. Added better intro.
3. Version 2013.11.26 - Updated implications aspect for global warming and behavioral sink.
4. Version 2013.11.27 - Updated taxonomy discussion.
5. V 2013.12.05 - Updated natural selection, convergent evolution and punctuated equilibrium. Reorg of slides.
6. V 2013.12.16 - Added chaos and self-organization slides.
7. V 2013.12.21 - Added extinctions and explosions.
8. V2013.12.23 - Added more chaos explanation and Wikipedia logo.
9. V2014.05.05 - Corrected spelling mistakes and cleaned up slides.
This document will help you and will clear your concepts about the terms of Orthogenesis, Allometry & Adaptive Radiations, which are usually studied in evolution.
2. What is Evolution?
A well-supported scientific theory stating that
organisms change over time
3. Evidence in stone
Preserved remains of a
once living organism is
called a FOSSIL
Fossil evidence supported
that organisms changed
gradually
4. Anatomical Evidence
Comparative Anatomy: study of
similarities and differences between
organisms
Homologous Structures
Analogous Structures
Vestigial Organs
5. Homologous Structures
As similar organisms adapt to different
environments, the function of their appendages
changed
A bird’s arms became
wings to flap
A human’s arm is used
to pick-up, carry, grasp,
etc…
A horse’s arm became
a fore-leg to run on
6. Analogous Structures
Different organisms began living in similar
environments, their appendages evolved to
perform the same function
A butterfly has wings to fly that
are made from an exoskeleton
A sparrow has wings to fly that
have an endoskeleton
Butterfly Bird
7. Vestigial Structures
Structures which remain in organisms but have
no obvious function
Leg bones in snakes and whales
Appendix in humans **
Ear muscles in humans
10. Genetic Evidence
DNA passes on traits
When mutations occur the genes and
chromosomes can change
Humans have imposed change through
selective breeding
The higher the percentage of similarities
the closer the relationship between two
organisms
11. Jean Baptiste de Lamark
First to recognize that
organisms change
Published his hypotheses
in 1809
Theory was disproved!
12. Jean Baptiste de Lamark
3 Key Assumptions:
Desire to Change: organisms have an
inborn urge to better themselves
Law of Use and Disuse: body parts that are
used will develop; those not used will
become smaller/disappear
Inheritance of Acquired Characteristics:
organisms pass on traits acquired during
their lifetime
13. Charles Darwin
Credited for the theory of evolution
HMS Beagle sailed in 1831 – Galapagos Islands
Published Origin of Species in 1858
14. Darwin’s Observations
Observed tortoises,
iguanas, and finches
The islands had different
climates and vegetation
The animals were
similar… but had
noticeable differences
WHY?
15. Darwin’s Assumptions
Variations
Differences among members of the same species
Struggle for Existence
Predation and competition
Overproduction
More offspring are produced than will survive
Survival of the Fittest (Natural Selection)
Individuals best suited for the environment will survive,
reproduce, and pass on traits to their offspring
Descent with Modification
Principle that species change but descend from common
ancestors
17. Darwin’s Theory of Natural Selection
Variations help
members of a species to
survive in a given
environment
The environment selects
the beneficial adaptation
and over time this trait
will become more
prevelant
19. Fossil Formation
Water carries small Dead organisms are buried The preserved remains
rock particles to lakes by layers of sediment, may later be discovered
and seas which forms new rock and studied.
20. Fossil Record
Preserved remains of a once living
organism is called a FOSSIL
IE: amber, sedimentary rock, tar, and ice
Fossil record is incomplete
21. Relative Dating
Used to ESTIMATE
the age of fossils
Older fossils are in
deeper layers of rock
22. Genes and Evolution
In terms of genetics, evolution is the change in
frequency of alleles in a population’s gene
pool
Natural selection leads to change in gene frequency
Molecular clocks use mutation rates to estimate
how recent a common ancestor was
23. Hox Genes
Genes which control an organism’s basic body plan
Anterior/posterior ends
Limbs, wings
24. Genetic Drift
Changes in the gene
pool of a small
population due to
random chance
ex: small group
colonizes a new habitat
– founder effect
25. Speciation
Gradualism – change in species
is slow and steady
Punctuated Equilibrium – long
periods of stability followed by
short periods of rapid change
27. Speciation – Isolating Mechanisms
For new species to form, reproductive
isolation needs to occur
Organisms don’t interbreed
- gene pools become separate
- Behavioral, Geographic, Temporal
29. Convergent
Evolution
Organisms come to
resemble one another
but evolved
differently
Analogous structures!
Examples:
Dolphins and sharks
Marsupials and mammals
38. Hominine Evolution
Ardipithecus ramedus “Ardi”, 4.4 mya
Australopithecus afarensis “Lucy”, 3.2 mya
Homo habilis “handy man”, ≈ 2 mya
Used tools, first of the genus Homo
Homo erectus, “Java Man”, ≈ 1.6 mya
1st to use fire
Homo neanderthalensis ≈ 200,000 years ago
Homo sapien
Modern Human ≈ 100,000 years ago
Why are really old Fossils are hard to come by? -The remains decay. -Special circumstance embed bones into rocks or images of animals like the Trilobites I recommend visiting the Museum of Science and Industry. How would you date fossils from rocks?
What is an example of a homologous Structure? Birds wing to mans arm, or horse leg
Analagous- similar to the word analogy: A comparison between two different situations that have something in common
Does anyone have any examples of selective breeding? Tell the class about Cats I am waiting until they breed cats they have less of a chemical that causes allergic reactions because I love cats, but allergic to them