“Life goes on!”
© Harshal Ganpatrao Hayatnagarkar
version 2014.05.05
CC BY-SA 3.0
 Why do we feel hungry?
 What keeps our body temperature around 98.6 ℉ or 37 ℃ ?
 Why our wounds are healed, by themsel...
Although not apparently so,
these questions are connected and so are their answers.
The thread connecting them is –
Theory...
What is
Evolution?
How to study
evolution?
History of Life
as Evolution
What next?Summary
Credit: M. F. Bonnan
 “History of changes”
 Passive process.
 NOT limited to biology.
 NOT synonymous to progress.
 NOT same as Origin of ...
Origin of
Life
time
Evolution of Life
This presentation is about
Evolution of Life,
which starts
AFTER
Origin of Life.
Because
it is the study of history of Life,
the only known phenomenon in the Universe.
Medicines Food Climate Education
Technology Economics and
finance
Sociology Exobiology
“Nothing in biology makes sense except
in the light of evolution”
– Theodosius Dobzhansky
(Evolution) is a general postula...
This is a long story, so behold !
Evolution
Diversity
Time
Implications
+ one needs tools and techniques to
study each of these aspects.
Evolution
Diversity
Time
Implications
To understand
so much diversity,
that once existed,
exists today, including the Humans
and
probably would emerge,
and to w...
 Literally means ‘Classification’ in Latin.
◦ Grouping organisms in different classes (lets
call them ‘buckets’ for simpl...
 Linnaean Nomenclature
◦ Binomial nomenclature
 Naming organisms by dichotomous key
 Meaning ‘two words’.
◦ [Genus spec...
abstract class Phylum extends Kingdom
abstract class Family extends Order
abstract class Genus extends Family
…
abstract c...
 Taxonomy has raised more questions than it
answered.
 Organisms are similar to one another…
◦ How much similar?
◦ Why t...
 In wrong buckets - Whales were fishes once.
◦ Classification based on appearances.
◦ And whale is NOT a fish, only if on...
 In addition, there
are hints from the
development of
embryos of various
species.
 Tail at origin tells
tale of origin.
 Correction of such mistakes did not leave
taxonomy untouched of evolution, too.
 Taxonomy has itself been evolving sinc...
Linnaeus
1735
Haeckel
1866
Chatton
1937
Copeland
1956
Whittaker
1969
Woese et al.
1977
Woese et al.
1990
2
kingdoms
3 king...
Evolution
Diversity
Time
Implications
If two objects are separating at rate of 1 inch per year
Then
After 1 million year, they would be 25.4 kilometers apart.
12 %
of
Geological
time
All major phyla.
First fishes.
 To give glimpse of events occurred in the
history of the Universe to fit into the scale a
common person can understand
◦...
Courtesy-ArifBabul
But from such a remote past, what could survive to tell us the story?
 Literally means ‘Obtained by digging’ in Latin and
studied under ‘Paleontology’.
 A Fossil can be past impressions abou...
 Challenges
◦ Identifying if a specimen is a
fossil.
◦ Recovering a fossil as complete as
possible.
◦ Identifying parts a...
 Informally, an organism still alive
representing a lone species whose other
relatives are extinct.
◦ Coined by Charles D...
Lamarck’s
Theory
Darwin-
Wallace’s
Theory
Mendel's
Theory
Neo-
Darwinism
Modern
Evolutionary
Synthesis
 Theories have bee...
 ‘Inheritance of acquired
characteristics’
◦ For example, giraffes stretched
neck and passed it to progeny
generations af...
 Explains origin of diversity over time i.e. Evolution
 Charles Darwin and Alfred Russell Wallace
◦ Independently and th...
Origin of species
Multiplication
Competition
Variation
Competition
Adaptation
SurvivalGrowth
Multiplication
Theory of
Natural
Selection
Speciation
To understand
Theory of Natural Selection,
we should understand
role of diversity and ecological niche.
 Kind of approximation of term
‘habitat’.
 Subset of Ecosystem.
 Hyperspace of multiple dimensions.
 Dimensions can be...
 On Galapagos Islands Darwin observed variety
of finches, adapted for respective habitats.
◦ High altitude vegetation
◦ H...
 Species adapt to suit to their
habitat. Alternatively, only suitable
species survive in a habitat.
◦ Adaptation for food...
 Life forms are food for
others.
◦ Visually chains and
webs/networks.
◦ Mostly undiscovered.
◦ Delicate balance in
ecolog...
 Population/individual becomes better suited to
its habitat.
 Caused by variation through
◦ Mutation (random variation i...
 Evolution of ecological and phenotypic
diversity within a rapidly multiplying
lineage.
◦ Starting with a recent ancestor...
 Emergence of new species.
◦ Species : A group of organisms capable of interbreeding
and producing fertile offspring.
 C...
 An increase in taxonomic diversity or morphological disparity, due to
adaptive change or the opening of ecospace.
◦ Esse...
 Darwin postulated that species
change gradually and
continuously.
 However, Stephen Jay Gould
and others observed stasi...
All these variations do not survive over time.
In fact,
99.9% of species
that have ever existed,
are now extinct,
includin...
Predation Mating
Climate change
Externalities (such asteroid impact)
Job interviews
Marriages
Markets
Genetically Modified
Food/Organisms
&
Selective breeding
Conflicts and Wars
 Individuals survive because of useful variations
and perish because of harmful ones.
 Units of selection
◦ Self-reprodu...
 Ecological contrasts
◦ Snow
◦ Black soot deposited on roof tops.
 Altered predator-prey pattern
◦ Black soot was gettin...
“Slow though the process of selection may be, if feeble man can do
much by his powers of artificial selection, I can see n...
Source: http://en.wikipedia.org/wiki/File:Life_cycle_of_a_sexually_reproducing_organism.svg
 Fitness is NOT about being strong or healthy.
 “Ability to survive and to reproduce, both”
◦ Collective quality of a po...
But what makes a baby elephant as strong as its parents?
OR
How traits are transferred from parents to children,
in genera...
 Mendel’s Laws
◦ Law of Segregation
◦ Law of Independent Assortment.
 Discovery-rejection-rediscovery
◦ Work published i...
 Law of Segregation
◦ When any individual produces gametes, the copies
of a gene separate so that each gamete receives
on...
 Discovery of nucleic
acids DNA and RNA.
◦ Structure and role of
nucleic acids in
inheritance.
◦ Analogous to Mendel’s
wo...
 What Mendel called ‘factors’ then, are called
as Allele today.
 Allele
◦ Either of a pair (or series) of alternative fo...
 Darwinism + Chromosomal
inheritance
 ‘Gene-centered view’ or
‘Selfish gene theory’
◦ Holds that evolution occurs
throug...
Phenotype
•Observable trait
•For example morphology, anatomy,
behavior and so on.
•Expression of genes
•Extended Phenotype...
Amino acids Proteins
Nucleic acids
(RNA & DNA)
Chromosomes
and organelles
CellsTissuesOrgansIndividuals
Groups, herds,
soc...
 Brings together fields that are separated
◦ From geology to paleontology.
◦ From molecular biology to ecology.
◦ From li...
 Evolution = Study of
variation over time and
space
◦ Space  Variation across
individuals at any given time.
◦ Time  Va...
 “The history of organismal evolution” 1
◦ Evolution is regarded as a branching process, [whereby
populations are altered...
Tree of Life
from
Phylogeny
point of view
1. Single entry for all the animals
No surprise that microbes account for more
than half biomass on Earth.
2. Common ances...
Tree of Life (by David Hillis, based on genome sequences)
Explore more at
http://onezoom.org
Human Evolution Linux Evolution
 Variation - An individual is
different from others
◦ Of same kind – Attributes shared,
values differ.
◦ Of different kin...
Error in copying
information
Recombination
+
+
+
+
CreativityBorrowing/snatching
information
Mutation Horizontal transfer ...
time
Macroevolution
•Meteorology
•Economics
•Sociology
•Game theory
•Ecology
•Population genetics
•Behavioral science
Microevol...
4. Growth
and
multiplication
•Mating
1. Variation
•Useful
•Harmful
2.
Competition
•In presence of
limited
resources
3. Sel...
Proteins
RNA
DNA
Structure and
behavior
Physiology
Cellular
Metabolism
Ecosystem
Species
Individual
 Study of changes that occur at or above the level of species, in contrast
with microevolution.
 For example, a new spec...
 Extinction = Death of a species
◦ Extinction of species is continuous process.
◦ Sometimes, widespread and more destruct...
(A) Ordovician-
Silurian
•450-440 Mya
(million years
ago)
•60-70% of all
species - 2nd
largest of all.
(B) Devonian-
Carbo...
It’s not all that bad…as in creative destruction, creation follows destruction.
Sometimes, more creatively…
 Rise in speciation in relatively smaller time window.
 Accelerated increase in diversity in geologically shorter
time.
...
 Approximately 540 million ago.
 All major animal phyla emerged from this period.
 Blueprints for all vertebrates inclu...
Cambrian explosion
•540 Mya.
•All major animal
phyla emerged from
this period
•Blueprints for
vertebrates
including humans...
 When different organisms develop similar features to
survive in a common niche.
 For example, streamlined body for swim...
Okay, Evolution is a great story.
But, what if the tape is played again?
 For example (popular in sci-fi movies)
◦ Imagine you go on a jungle safari, albeit of Jurassic
age (150 Million years be...
 Small perturbation (at one place) may lead to large effects (at other
places).
 Observed by Edward Lorenz while modelin...
 Chaos is NOT same as randomness.
 Randomness necessitates denial of any pattern or order.
 Whereas chaos is often term...
 Emergence = property or behavior of a
system demonstrated by none of its
individual parts but collectively by them.
◦ Fo...
 A special kind of emergent phenomenon –
Spontaneous order arises out of local interactions of
components.
◦ For example,...
Self-
organization
Chaos
Helps achieve similar results from different initial conditions.
Thus acts as opposite of chaos.
EvolutionVariations
Combinations
Populations
Competitions
Generations
Overview of Factors
Evolution
Diversity
Time
Implications
Highlights some important
patterns in evolution
Functional integration
Functional differentiation
Complexity trend
Informa...
From To Notes
Replicating molecules
"Populations" of molecules in
compartments
Can't observe
Independent replicators
(prob...
 Increasing biocomplexity through Integration
 Smaller entities often have come about together to
form larger entities.
...
 Often smaller entities
◦ Have become differentiated as part of a larger entity.
 For example DNA & protein, organelles,...
 Complexity has been
rising since origin of
life.
 Cambrian Explosion
◦ A tipping point.
◦ Accelerated pace of
increase ...
 Quasi-closed system/habitat,
populations of species affect
each other.
 In predator-prey model, changes
in demand and s...
Bacteria Herb
Rabbit
Wolf
Single mutation in a bacterium
can significantly affect an herb,
which forms significant diet of...
 Life forms are food for
others.
◦ Visually chains and
webs/networks.
◦ Mostly undiscovered.
◦ Delicate balance in
ecolog...
 Biosphere is a self-regulating
entity.
 “Abiota affects biota and vice
versa”.
 Cycles in a Daisy World.
 Model for c...
 Now a fact instead of fiction.
 Major contribution by humans.
◦ By Gaia hypothesis, climate change in turn will affect ...
 “A condition or event by which a population
returns to subsistence level conditions once
population growth outpaces agri...
 Increasing population
has its impact on itself
too.
 An experiment to
understand impact of
overpopulation.
◦ From 1947 ...
 Many rats placed in a relatively small
area.
◦ Area divided into four rooms, with
decreasing amenities such as food, wat...
 Economy crisis
◦ Faltering growth.
◦ Booming and busting bubbles.
◦ Unemployment.
◦ Inequality.
 Energy crisis
◦ Deplet...
Evolution has brought us here.
It will guide us from here.
 Evolution is interplay of scale and diversity
over time.
 Change is the only constant thing.
◦ Hence evolution is omnip...
 Prof. N Swaminathan and other colleagues.
AND
To be continued with
Evolution: Understanding facts
Being evolutionary is not a bad idea,
perhaps because
being survived a...
Understanding Evolution - Life goes on
Understanding Evolution - Life goes on
Understanding Evolution - Life goes on
Understanding Evolution - Life goes on
Understanding Evolution - Life goes on
Understanding Evolution - Life goes on
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Understanding Evolution - Life goes on

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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.

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  • Evolution biological evolution has been one of those greatest disciplines which touches every other discipline. It is still happening and to such an extent that “Nothing in biology makes sense…”To go further, I would dare to say that nothing makes sense except in the light of evolution.
  • Evolution biological evolution has been one of those greatest disciplines which touches every other discipline. It is still happening and to such an extent that “Nothing in biology makes sense…”To go further, I would dare to say that nothing makes sense except in the light of evolution.
  • Evolution biological evolution has been one of those greatest disciplines which touches every other discipline. It is still happening and to such an extent that “Nothing in biology makes sense…”To go further, I would dare to say that nothing makes sense except in the light of evolution.
  • What is called as Taxonomy in Biology is called as Ontology in information systems.
  • Especially with respect to establishment of evidence to support argument for some evolutionary fact.
  • * There could many reasons to
  • * There could many reasons to
  • * There could many reasons to
  • The Jurassic Safari Across several such movies, more or less ‘the Tape is played again and again’  A team of commandos/tourists visits a jungle of Jurassic Age Three rules Commits one more mistakes And returns back in ‘current’ age, just to discover that things are not the same as they ‘were’ before the team left
  • The Jurassic Safari Across several such movies, more or less ‘the Tape is played again and again’  A team of commandos/tourists visits a jungle of Jurassic Age Three rules Commits one more mistakes And returns back in ‘current’ age, just to discover that things are not the same as they ‘were’ before the team left
  • Anthropic principle: Entire system is meant for humans Strong anthropic principle: Entire system is designed for humans to arise, survive and conquer Weak anthropic principle: Entire system is helping an intelligent being to emerge such as humansAnthropic principles are more emotional than scientific. Dr. Kauffman shows that determinism has more role to play by itself than that of anthropic principles.
  • Which is true for any kind of evolution, not just biological evolution…
  • John B. Calhoun
  • Understanding Evolution - Life goes on

    1. 1. “Life goes on!” © Harshal Ganpatrao Hayatnagarkar version 2014.05.05 CC BY-SA 3.0
    2. 2.  Why do we feel hungry?  What keeps our body temperature around 98.6 ℉ or 37 ℃ ?  Why our wounds are healed, by themselves?  How does our body fight diseases?  Why certain variety of wheat is more productive?  Why certain computer software perform better than others, in impossible situations?  Are we alone in the Universe? Can there be Life elsewhere?  …
    3. 3. Although not apparently so, these questions are connected and so are their answers. The thread connecting them is – Theory of Evolution
    4. 4. What is Evolution? How to study evolution? History of Life as Evolution What next?Summary
    5. 5. Credit: M. F. Bonnan
    6. 6.  “History of changes”  Passive process.  NOT limited to biology.  NOT synonymous to progress.  NOT same as Origin of Life.  Essentially interplay of variations over time.  Explained by various theories (to be discussed later).
    7. 7. Origin of Life time Evolution of Life This presentation is about Evolution of Life, which starts AFTER Origin of Life.
    8. 8. Because it is the study of history of Life, the only known phenomenon in the Universe.
    9. 9. Medicines Food Climate Education Technology Economics and finance Sociology Exobiology
    10. 10. “Nothing in biology makes sense except in the light of evolution” – Theodosius Dobzhansky (Evolution) is a general postulate to which all theories, all hypotheses, all systems must hence forward bow and which they must satisfy in order to be thinkable and true. Evolution is a light which illuminates all facts, a trajectory which all lines of thought must follow — this is what evolution is. Why study evolution?
    11. 11. This is a long story, so behold !
    12. 12. Evolution Diversity Time Implications + one needs tools and techniques to study each of these aspects.
    13. 13. Evolution Diversity Time Implications
    14. 14. To understand so much diversity, that once existed, exists today, including the Humans and probably would emerge, and to which we are the witness.
    15. 15.  Literally means ‘Classification’ in Latin. ◦ Grouping organisms in different classes (lets call them ‘buckets’ for simplicity). ◦ Well, putting buckets into bigger buckets. ◦ Deriving common properties for each bucket.  Linnaean Taxonomy ◦ Originally defined by Carolos Linnaeus in 1735. ◦ Based on morphology. ◦ Grouped organisms into groups and subgroups. ◦ Organisms were created by God and Carolos only classified and named them.
    16. 16.  Linnaean Nomenclature ◦ Binomial nomenclature  Naming organisms by dichotomous key  Meaning ‘two words’. ◦ [Genus species]. ◦ For example  Humans  Homo sapiens  Elephant  Elephas maximu  Potato  Solanum tuberosum  Groups (we called them buckets earlier) ◦ Common features abstracted. ◦ Resulted in initial hierarchy.  Final hierarchical definition ◦ With criteria ◦ E.g. Kingdoms  Plantae, Animalia, Fungi.
    17. 17. abstract class Phylum extends Kingdom abstract class Family extends Order abstract class Genus extends Family … abstract class Homo extends Genus class Homo_Sapiens extends Homo harshal = new Homo_Sapiens(“Harshal”); Only ‘Species’ can be instantiated *Java programming language
    18. 18.  Taxonomy has raised more questions than it answered.  Organisms are similar to one another… ◦ How much similar? ◦ Why those similarities? ◦ For example, fox is similar to wolf.  As well as different… ◦ How much different? ◦ Why those differences? ◦ Fox is not wolf.
    19. 19.  In wrong buckets - Whales were fishes once. ◦ Classification based on appearances. ◦ And whale is NOT a fish, only if one looks INSIDE.
    20. 20.  In addition, there are hints from the development of embryos of various species.  Tail at origin tells tale of origin.
    21. 21.  Correction of such mistakes did not leave taxonomy untouched of evolution, too.  Taxonomy has itself been evolving since then. Morphology Anatomy Physiology Microbiology BiochemistryGenomicsProteomics 300 years of journey
    22. 22. Linnaeus 1735 Haeckel 1866 Chatton 1937 Copeland 1956 Whittaker 1969 Woese et al. 1977 Woese et al. 1990 2 kingdoms 3 kingdoms 2 empires 4 kingdoms 5 kingdoms 6 kingdoms 3 domains (not treated)) Protista Prokaryota Monera Monera Eubacteria Bacteria Archaebacteria Archaea Eukaryota Protista Protista Protista EukaryaVegetabilia Plantae Fungi Fungi Plantae Plantae Plantae Animalia Animalia Animalia Animalia Animalia Wikipedia:Taxonomy
    23. 23. Evolution Diversity Time Implications
    24. 24. If two objects are separating at rate of 1 inch per year Then After 1 million year, they would be 25.4 kilometers apart.
    25. 25. 12 % of Geological time All major phyla. First fishes.
    26. 26.  To give glimpse of events occurred in the history of the Universe to fit into the scale a common person can understand ◦ From Big Bang till today ◦ Thirteen billion years of the Universe’s history scaled into 365 days of a year  January 1st, 00:00:00 AM Big Bang Each month is roughly equivalent to a billion years Prof. Carl Sagan
    27. 27. Courtesy-ArifBabul
    28. 28. But from such a remote past, what could survive to tell us the story?
    29. 29.  Literally means ‘Obtained by digging’ in Latin and studied under ‘Paleontology’.  A Fossil can be past impressions about the living being (like a thumb impression). ◦ Impression of a leaf on a then-wet mud. ◦ An insect caught in a tree amber. ◦ Petrified skeletons of animals.  All one gets from such an antiquity is a fossil. A paleontologist must make sense out of them, such as to ‘extract’, preserve, connect and date the specimen.  Fossils can still tell the story of the organism when it was dying. ◦ Morphology ◦ Anatomy ◦ Physiology (possibly)
    30. 30.  Challenges ◦ Identifying if a specimen is a fossil. ◦ Recovering a fossil as complete as possible. ◦ Identifying parts and whole of a fossil. ◦ Identifying organism of that fossil. ◦ Determining age of a fossil. ◦ Preserving for future study.
    31. 31.  Informally, an organism still alive representing a lone species whose other relatives are extinct. ◦ Coined by Charles Darwin himself. ◦ To understand certain anomalous species that have survived evolutionary pressure for very long time.  For example, platypus or duck-bill.
    32. 32. Lamarck’s Theory Darwin- Wallace’s Theory Mendel's Theory Neo- Darwinism Modern Evolutionary Synthesis  Theories have been evolving since last 200 years to answer these questions
    33. 33.  ‘Inheritance of acquired characteristics’ ◦ For example, giraffes stretched neck and passed it to progeny generations after generations.  It does not hold good today. ◦ There is no known reverse path from phenotype to genotype. Jean-Baptiste Lamarck
    34. 34.  Explains origin of diversity over time i.e. Evolution  Charles Darwin and Alfred Russell Wallace ◦ Independently and then together ◦ Popular as ‘Darwinism’ or ‘Survival of Fittest’  Darwin influenced by Malthusian Catastrophe ◦ Human population tends to increase a lot faster than food supply, which may lead to catastrophic implications for entire planet. Charles Darwin Alfred Russell Wallace
    35. 35. Origin of species Multiplication Competition Variation
    36. 36. Competition Adaptation SurvivalGrowth Multiplication Theory of Natural Selection Speciation
    37. 37. To understand Theory of Natural Selection, we should understand role of diversity and ecological niche.
    38. 38.  Kind of approximation of term ‘habitat’.  Subset of Ecosystem.  Hyperspace of multiple dimensions.  Dimensions can be temperature, Humidity, salinity, language and so on.  For example ◦ Salt water/fresh water. ◦ Arctic deep ocean water. ◦ Amazon rain forests. ◦ Highland forests. ◦ Top and bottom of Maple trees. ◦ Roof-tops in Manchester city. ◦ Marathi-speaking regions in India. ◦ Traffic signals in India . ◦ and almost anyplace where life-forms exist. Source: http://www.geol.umd.edu/~jmerck/GEOL388/lectures/06.html Source: http://hhh.gavilan.edu/rmorales/EcologySpring200 8.htm
    39. 39.  On Galapagos Islands Darwin observed variety of finches, adapted for respective habitats. ◦ High altitude vegetation ◦ Highland forests ◦ Lowland forests ◦ Bushes ◦ Shoreline vegetation  Even various levels of the same habitat, for example, from top to bottom of tree trunk. Source - http://hhh.gavilan.edu/rmorales/EcologySpring2008.htm Source - http://14yunhyu.wordpress.com/2013/08/31/d-2d-macroevolution/ Source: http://www.geol.umd.edu/~jmerck/GEOL388/lectures/06.html
    40. 40.  Species adapt to suit to their habitat. Alternatively, only suitable species survive in a habitat. ◦ Adaptation for food, safety, nursing and so on.  Competitive Exclusion Principle OR Gause’s Law ◦ No two species can occupy the same niche in the same environment for a long time. ◦ “Complete competitors cannot coexist”. ◦ Thus if two organisms occupy exactly same niche, then they are the same species. Source - http://hhh.gavilan.edu/rmorales/EcologySpring2008.htm Source - http://14yunhyu.wordpress.com/2013/08/31 /d-2d-macroevolution/
    41. 41.  Life forms are food for others. ◦ Visually chains and webs/networks. ◦ Mostly undiscovered. ◦ Delicate balance in ecologies.  Human interference. ◦ Try removing few species here and there, the ecological collapse may happen (See Gaia Hypothesis). ◦ For example, cell towers and insecticides are killing bees, reducing crop output. Source: http://en.wikipedia.org/wiki/File:Chesapeake_Waterbird_Food_Web.jpg
    42. 42.  Population/individual becomes better suited to its habitat.  Caused by variation through ◦ Mutation (random variation in genes) ◦ Breeding (sexual reproduction) ◦ Horizontal gene transfer (Asexual borrowing. Typically occurs in bacteria).  For example, in highland forests, those finches will survive better which can crack nuts with hard shells.
    43. 43.  Evolution of ecological and phenotypic diversity within a rapidly multiplying lineage. ◦ Starting with a recent ancestor, this process results in an array of species with different traits with which they can exploit a range of divergent environments. ◦ For example, over generations few finches moved up the tree and few moved down.  Likely to trigger Evolutionary Radiation in local ecosystem. Source - http://14yunhyu.wordpress.com/2013/08/31/d-2d- macroevolution/ Source - http://hhh.gavilan.edu/rmorales/EcologySpring2008.htm
    44. 44.  Emergence of new species. ◦ Species : A group of organisms capable of interbreeding and producing fertile offspring.  Consistent variation passed to offspring.
    45. 45.  An increase in taxonomic diversity or morphological disparity, due to adaptive change or the opening of ecospace. ◦ Essentially adaptive radiation spread across species. ◦ Essentially many branches in a phylogenic tree.  Evolutionary Explosion ◦ A rapid radiation in a relatively short span of time. ◦ For example, Cambrian Explosion, The Internet.  Cambrian Explosion ◦ Span of 10 million years happened 425 million years before. ◦ Blueprints of all known phyla emerged in this short span.
    46. 46.  Darwin postulated that species change gradually and continuously.  However, Stephen Jay Gould and others observed stasis and sudden speciation, called as ‘Punctuated Equilibria’.  Species ‘accumulate’ changes and then ‘suddenly’ radiate into new species.  Introduced and reinforced idea that species are Darwinian individuals and not just classes.  Reasons are unknown. Source - http://en.wikipedia.org/wiki/File:Punctuated-equilibrium.svg
    47. 47. All these variations do not survive over time. In fact, 99.9% of species that have ever existed, are now extinct, including dinosaurs.
    48. 48. Predation Mating Climate change Externalities (such asteroid impact)
    49. 49. Job interviews Marriages Markets Genetically Modified Food/Organisms & Selective breeding Conflicts and Wars
    50. 50.  Individuals survive because of useful variations and perish because of harmful ones.  Units of selection ◦ Self-reproducing molecules ◦ Genes ◦ Cells ◦ Individuals ◦ Groups ◦ Species ◦ Societies ◦ Nations
    51. 51.  Ecological contrasts ◦ Snow ◦ Black soot deposited on roof tops.  Altered predator-prey pattern ◦ Black soot was getting accumulated on roof-tops, in all seasons. ◦ White moths were becoming visible even during winter, on accumulated black soot on roof-tops and predators could find and eat them. ◦ Thus increasing black moths population over white ones. Black moth Black mothWhite moth White moth Black soot deposited by textile factories Snow deposited in winter Black soot from textile factories of Manchester
    52. 52. “Slow though the process of selection may be, if feeble man can do much by his powers of artificial selection, I can see no limit to the amount of change, to the beauty and infinite complexity of the co-adaptations between all organic beings, one with another and with their physical conditions of life, which may be effected in the long course of time by nature's power of selection.” Charles Darwin Probably origin of term ‘Natural Selection’.
    53. 53. Source: http://en.wikipedia.org/wiki/File:Life_cycle_of_a_sexually_reproducing_organism.svg
    54. 54.  Fitness is NOT about being strong or healthy.  “Ability to survive and to reproduce, both” ◦ Collective quality of a population of species. ◦ Also thought in terms of average contribution to ‘Gene pool’. ◦ Simply, determines if a species would continue to survive.
    55. 55. But what makes a baby elephant as strong as its parents? OR How traits are transferred from parents to children, in general?
    56. 56.  Mendel’s Laws ◦ Law of Segregation ◦ Law of Independent Assortment.  Discovery-rejection-rediscovery ◦ Work published in 1865-66. ◦ Initially rejected by scientific community of his time. ◦ Later rediscovered in 1900 independently by Hugo de Vries and Carl Correns and was acknowledged.  A set of primary tenets relating to the transmission of hereditary characteristics from parent organisms to their offspring; ◦ Units of heredity called as Factors  Today known as Genes  Basis of chromosomal inheritance and genetics. Gregor Mendel
    57. 57.  Law of Segregation ◦ When any individual produces gametes, the copies of a gene separate so that each gamete receives only one copy.  Law of Independent Assortment ◦ Alleles of different genes assort independently of one another during gamete formation. ◦ Also known as "Inheritance Law" ◦ True only for ‘unrelated genes’
    58. 58.  Discovery of nucleic acids DNA and RNA. ◦ Structure and role of nucleic acids in inheritance. ◦ Analogous to Mendel’s work.  Genes - Segments of DNA and RNA. ◦ Functional units of inheritance. ◦ For example, color of eye/hairs. James Watson Francis Creek
    59. 59.  What Mendel called ‘factors’ then, are called as Allele today.  Allele ◦ Either of a pair (or series) of alternative forms of a gene that can occupy the same locus on a particular chromosome and that control the same character; ◦ “Some alleles are dominant over others”
    60. 60.  Darwinism + Chromosomal inheritance  ‘Gene-centered view’ or ‘Selfish gene theory’ ◦ Holds that evolution occurs through the differential survival of competing genes as if such genes are selfish. ◦ Even further, altruistic behavior of organisms are in fact manifestations of selfish genes.  Replicators ◦ Introduces concept of ‘replicator’ and two instances of them – Genes and memes. ◦ What genes are for organisms, memes are for cultures.
    61. 61. Phenotype •Observable trait •For example morphology, anatomy, behavior and so on. •Expression of genes •Extended Phenotype •For example bird’s nest. •Extended expression of genes. Genotype •Genetic make-up •For example, chromosomes, nucleotide sequences in some cell organelles. •Translates into phenotypes. •Replication through extra-dimension of time.
    62. 62. Amino acids Proteins Nucleic acids (RNA & DNA) Chromosomes and organelles CellsTissuesOrgansIndividuals Groups, herds, societies and nations Ecosystem Planet
    63. 63.  Brings together fields that are separated ◦ From geology to paleontology. ◦ From molecular biology to ecology. ◦ From linguistics to political science.  Neo-Darwinism becomes subset.  It becomes possible to explain many phenomena due to borrowed learning.
    64. 64.  Evolution = Study of variation over time and space ◦ Space  Variation across individuals at any given time. ◦ Time  Variation across individuals in past and present.  Systematics ◦ Study of the diversification of life on the planet Earth, both past and present, and the relationships among living things through time. Evolution – A primer
    65. 65.  “The history of organismal evolution” 1 ◦ Evolution is regarded as a branching process, [whereby populations are altered over time and may speciate into separate branches, hybridize together, or terminate by extinction]. This may be visualized as a multidimensional character-space that a population moves through over time.  Basically family tree of species  Further reading
    66. 66. Tree of Life from Phylogeny point of view
    67. 67. 1. Single entry for all the animals No surprise that microbes account for more than half biomass on Earth. 2. Common ancestor of animals and fungi
    68. 68. Tree of Life (by David Hillis, based on genome sequences) Explore more at http://onezoom.org
    69. 69. Human Evolution Linux Evolution
    70. 70.  Variation - An individual is different from others ◦ Of same kind – Attributes shared, values differ. ◦ Of different kind – Attributes differ, values differ.  Classification ◦ One combines similar individuals into a group, and then such groups into larger groups and so on, forming a hierarchy of groups called Taxonomy. ◦ Shared attributes of groups in a taxonomy ◦ In biology, species are loose groups of similar, compatible individuals, different from one another.
    71. 71. Error in copying information Recombination + + + + CreativityBorrowing/snatching information Mutation Horizontal transfer Sexual reproduction Creativity
    72. 72. time
    73. 73. Macroevolution •Meteorology •Economics •Sociology •Game theory •Ecology •Population genetics •Behavioral science Microevolution •Anatomy •Physiology •Genetics •Microbiology •Chemistry •Quantum mechanics Individual
    74. 74. 4. Growth and multiplication •Mating 1. Variation •Useful •Harmful 2. Competition •In presence of limited resources 3. Selection •Survival 1. Adaptation 2. Radiation 3. Speciation Microevolution
    75. 75. Proteins RNA DNA Structure and behavior Physiology Cellular Metabolism
    76. 76. Ecosystem Species Individual
    77. 77.  Study of changes that occur at or above the level of species, in contrast with microevolution.  For example, a new species emerges or a group of species goes extinct.  Explosions and extinctions - Two recurring patterns in macroevolution . Source: http://evolution.berkeley.edu/evolibrary/article/evoscales_01
    78. 78.  Extinction = Death of a species ◦ Extinction of species is continuous process. ◦ Sometimes, widespread and more destructive. ◦ Either due to evolutionary pressure or external events. ◦ Great evolutionary significance. A B C D E D i v e r s i t y Time (million years ago) Major causes Asteroid impact Volcano Fall in sea levels
    79. 79. (A) Ordovician- Silurian •450-440 Mya (million years ago) •60-70% of all species - 2nd largest of all. (B) Devonian- Carboniferous •375-360 Mya •70% of all species. •Extinction pulses within this period. (C) Permian- Triassic •250 Mya •Deadliest of all, Known as ‘Great Dying’. •Killed upto 95% of all species. •End of Trilobites, arguably longest surviving organisms. (D) Triassic- Jurassic •200 Mya •Killed 70-75% of all species. (E) Cretecious- Paleogene •65 Mya •Killed 75% species. •Known for end of dinosaurs. A B C D E D i v e r s i t y Time (million years ago)
    80. 80. It’s not all that bad…as in creative destruction, creation follows destruction. Sometimes, more creatively…
    81. 81.  Rise in speciation in relatively smaller time window.  Accelerated increase in diversity in geologically shorter time.  Usually, driven by rush to fill empty niches.  It could be triggered by an innovative trait and sustained by competition. For example development of – ◦ Photosynthesis. ◦ Oxygen-based metabolism. ◦ Aging. ◦ Sex. ◦ Eye. ◦ Endoskeleton and jaw. ◦ Endothermic mechanism.
    82. 82.  Approximately 540 million ago.  All major animal phyla emerged from this period.  Blueprints for all vertebrates including fishes, dinosaurs and humans.  Triggered by – ◦ Invention of ‘eye’. ◦ Increase in oxygen levels. ◦ Snowball earth. ◦ Sustained by arms race thereafter.  Rise of trilobites ◦ Arguably longest lived organisms till date – 300 million years. ◦ Highest inter-species diversity.
    83. 83. Cambrian explosion •540 Mya. •All major animal phyla emerged from this period •Blueprints for vertebrates including humans. •Triggered by – •Innovation of ‘eye’. •Increase in oxygen levels. •Snowball earth. •Sustained by arms race thereafter. Devonian explosion •440 Mya. •First major adaptive radiation of land- based life such as rise and spread of free-spore vascular plants. •Rise of fishes, and known as ‘age of fishes’. Triassic explosion •240 Mya. •After the largest extinction event ‘P- T’. •Rise of dinosaurs. •Rise of first true mammals. Paleogene explosion •60 Mya. •Adaptive radiation of mammals, birds and reptiles.
    84. 84.  When different organisms develop similar features to survive in a common niche.  For example, streamlined body for swimming swiftly in the water. Shark (Fish) Whale (Mammal) Penguin (Bird) Dolphin (Mammal) Kronosaurus (Reptile/dinosaur)
    85. 85. Okay, Evolution is a great story. But, what if the tape is played again?
    86. 86.  For example (popular in sci-fi movies) ◦ Imagine you go on a jungle safari, albeit of Jurassic age (150 Million years before present). ◦ You make a simply change, say killing a butterfly and come back to present time. ◦ Should there be any impact of that killing on future? ◦ Alternative History.
    87. 87.  Small perturbation (at one place) may lead to large effects (at other places).  Observed by Edward Lorenz while modeling weather patterns that very small changes in values (such as a flap of butterfly’s wings) lead to dramatic changes in patterns (such as hurricane formation) over time. Hence the name.  For example , using wind speed of ‘10.0000001 Km/h’ instead of ‘10 Km/h’ may lead to vastly different predictions. Edward Lorenz time
    88. 88.  Chaos is NOT same as randomness.  Randomness necessitates denial of any pattern or order.  Whereas chaos is often termed as Hidden Order.  “Extreme sensitivity to initial conditions”. ◦ Vastly different outcomes over time due to slightly different initial conditions. ◦ Chaotic is property of all non-linear dynamical systems. ◦ Highlights significant path dependence. ◦ For example – Weather, Stock market crashes, Epidemics, etc.  Always prevalent situation – any point in space-time is an initial condition. ◦ Analogous to sliding rule, the window of study moves thus making any point on rule as start of the window. ◦ Interesting part is about emergence of the other end of this window.
    89. 89.  Emergence = property or behavior of a system demonstrated by none of its individual parts but collectively by them. ◦ For example, intelligence is emergent property of brain, made from zillions of neurons, though none of them individually has this property. ◦ For example, locomotion is property of automobile, but none of its parts.  Natural selection makes it possible to achieve similar goals with different routes. ◦ For example, due to convergent evolution, vision, flight and streamlined body have been emerged in different species in the past.  Actually it may not matter in many cases whether we play the tape once or many times, due to phenomenon namely Self- organization. Changes in Environment Changes in Population Changes in Individual
    90. 90.  A special kind of emergent phenomenon – Spontaneous order arises out of local interactions of components. ◦ For example, crystallization, galaxy formation, flocks of birds, multicellular organisms, human societies and so on. ◦ Islands of predictability in the ocean of unpredictability.  Perhaps, it’s an answer to every question regarding Life, or at least participatory. ◦ Life is because of, is a and has self-organization. ◦ Natural selection itself is a kind of self-organization phenomenon.
    91. 91. Self- organization Chaos Helps achieve similar results from different initial conditions. Thus acts as opposite of chaos.
    92. 92. EvolutionVariations Combinations Populations Competitions Generations Overview of Factors
    93. 93. Evolution Diversity Time Implications
    94. 94. Highlights some important patterns in evolution Functional integration Functional differentiation Complexity trend Information aspect of evolution
    95. 95. From To Notes Replicating molecules "Populations" of molecules in compartments Can't observe Independent replicators (probably RNA) Chromosomes RNA world hypothesis RNA as both genes and enzymes DNA as genes; proteins as enzymes Prokaryotes Eukaryotes Can observe Asexual clones Sexual populations Evolution of sex Protists Multicellular organisms — animals, plants, fungi Evolution of multicellularity Solitary individuals Colonies with non-reproductive castes Primate societies Human societies with language, enabling memes Sociocultural evolution
    96. 96.  Increasing biocomplexity through Integration  Smaller entities often have come about together to form larger entities.  For example Chromosomes, eukaryotes, sex multicellular colonies.
    97. 97.  Often smaller entities ◦ Have become differentiated as part of a larger entity.  For example DNA & protein, organelles, anisogamy, tissues, castes and so on. ◦ Are unable to replicate in the absence of the larger entity. ◦ For example, organelles, tissues, castes and so on. ◦ Can sometimes disrupt the development of the larger entity. ◦ For example, meiotic drive (selfish non-Mendelian genes), parthenogenesis, cancers, coup d’état and so on.  New ways of transmitting information have arisen. ◦ For example, DNA-protein, cell heredity, epigenesis, universal grammar and so on.
    98. 98.  Complexity has been rising since origin of life.  Cambrian Explosion ◦ A tipping point. ◦ Accelerated pace of increase in complexity. ◦ A pattern in evolution, typically preceded by an extinction event/span.
    99. 99.  Quasi-closed system/habitat, populations of species affect each other.  In predator-prey model, changes in demand and supply.  Complex relationship in presence of multiple predator and prey species.  Such patterns affect environment. ◦ For example, if a grass consumed by rabbits will affect population of not only rabbits, but also wolfs.
    100. 100. Bacteria Herb Rabbit Wolf Single mutation in a bacterium can significantly affect an herb, which forms significant diet of a species like rabbit and thus affecting population of wolves too, that feed upon rabbits.
    101. 101.  Life forms are food for others. ◦ Visually chains and webs/networks. ◦ Mostly undiscovered. ◦ Delicate balance in ecologies.  Human interference. ◦ Try removing few species here and there, the ecological collapse may happen (See Gaia Hypothesis). ◦ For example, cellphone towers and insecticides are killing bees, reducing crop output. Source: http://en.wikipedia.org/wiki/File:Chesapeake_Waterbird_Food_Web.jpg
    102. 102.  Biosphere is a self-regulating entity.  “Abiota affects biota and vice versa”.  Cycles in a Daisy World.  Model for climate change. Prof. James Lovelock
    103. 103.  Now a fact instead of fiction.  Major contribution by humans. ◦ By Gaia hypothesis, climate change in turn will affect humans. ◦ Rise in ocean levels, resulting into submerging of coastal cities. ◦ Frequent hurricanes and cyclones.  Changes in seasons to affect ◦ Harvest - ‘Malthusian catastrophe’. ◦ Ecology – Book ‘Collapse – How societies choose to succeed or fail’.  However, humans will affect humans too. ◦ ‘Behavioral sink’
    104. 104.  “A condition or event by which a population returns to subsistence level conditions once population growth outpaces agricultural growth” – Wikipedia ◦ An Essay on the Principle of Population published in 1798. ◦ Inspired Charles Darwin, to late discover Theory of Origin of Species.  Criticism ◦ New knowledge and technology can avert such crisis. For example, Green Revolution. ◦ Socio-economic aspects such as birth control and urbanization play their role too. Thomas Malthus
    105. 105.  Increasing population has its impact on itself too.  An experiment to understand impact of overpopulation. ◦ From 1947 to 1972. ◦ Published initial result in Scientific American in 1968. ◦ Though experiment involved rats, results are indicative to humans too. John B. Calhoun
    106. 106.  Many rats placed in a relatively small area. ◦ Area divided into four rooms, with decreasing amenities such as food, water and protection. ◦ Rats in each room showed different behavior.  Least resourceful room was termed as Behavioral Sink. ◦ Rats showed destructive behavior, especially towards weaker rats such as females and babies. ◦ It resulted into inability of females to carry through pregnancy and mortality rates as high as 96 percent.  Similar indicative behavior can be seen in patches of human societies too.
    107. 107.  Economy crisis ◦ Faltering growth. ◦ Booming and busting bubbles. ◦ Unemployment. ◦ Inequality.  Energy crisis ◦ Depleting fossil fuel sources. ◦ No viable alternative in sight.  Ecology crisis ◦ Mining, petroleum and heavy industries. ◦ Automobiles and livestock. ◦ Shrinking fisheries, forests, glaciers and icecaps. Humanity Crisis Ecology crisis Economy crisis Energy crisis
    108. 108. Evolution has brought us here. It will guide us from here.
    109. 109.  Evolution is interplay of scale and diversity over time.  Change is the only constant thing. ◦ Hence evolution is omnipresent and almighty.  Never underestimate power of small change. ◦ Butterfly effect ◦ An action sets the Universe on a new course, every time and all the time. (“Everything else is an illusion” – Bhagvadgeeta)
    110. 110.  Prof. N Swaminathan and other colleagues. AND
    111. 111. To be continued with Evolution: Understanding facts Being evolutionary is not a bad idea, perhaps because being survived as fittest is not a bad idea too.
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