Learning objectives How to interpret evolution by Natural selection What is evolution and where can it happen What are the conclusions of natural selection What are the conclusions of biological evolution What is artificial selection Where is the REAL debate about evolution

Evolution: a cumulative change over time 1928 1947 1990 Ex: Mickey mouse’s evolution

1980s 1990s 2000s

Geological Evolution, Astronomical Evolution, Chemical Evolution

Geological Evolution, Astronomical Evolution, Chemical Evolution

Geological Evolution, Astronomical Evolution, Chemical Evolution Textbook:

“Descent with Modification” or inherited changes Natural Selection: “Descent with Modification” or inherited changes Solutions that work (function) will get passed on more often than “solutions” that don’t work - These solution or adaptation often will continue to be selected for. Often the “solutions” will become more complex over time. We call these “solution” adaptations Ex: Eye organs (will see on next slide) Adaptations are NOT PERFECT but will perform their function to the point that it helps the creature to either survive or reproduce

What Biological Evolution means…. -If you go back far enough into the past, all life shares common ancestry: Hence scientists concluded that life has arisen once on earth. After “forming” evolution by Natural selection eventually it produced the variety of life we see today and in the fossil record Many refer to this as a “tree of life” and it also has changed as scientists learn more

BIG ideas from Evolution by Natural Selection: 1) The Environment picks the ‘best’ adaptation for any life to survive or reproduce ON THE TREE OF LIFE: 2) Tree of life has 1 ‘trunk’ = ALL life shares 1 origin and life only started 1 time 3a) Less time apart = more similarities = more recent common ancestor 3b)More time apart = more difference = common ancestor in distant past 4)Evolution is not perfect: 99% of all species that have lived have already gone extinct. What is alive today is > 1% of all variation that has ever lived again evolution is not perfect = those not able to adapt to their environment die and go extinct 5) Earth is far older than people thought in Darwin’s Day

BIG ideas from Evolution by Natural Selection: 1) The Environment picks the ‘best’ adaptations for any life to survive or reproduce ON THE TREE OF LIFE: 2) Tree of life has 1 ‘trunk’ = ALL life shares 1 origin and life only started 1 time ‘origin’ = start point

3a) Less time apart = 3b) more time apart = ON THE TREE OF LIFE: more similarities = more recent common ancestor 3b) more time apart = more difference = common ancestor in distant past

ON THE TREE OF LIFE: 4)Evolution is not perfect: 99% of all species that have lived have already gone extinct. What is alive today is > 1% of all variation that has ever lived = those not able to adapt to their environment die and go extinct 5) Earth is Old: (4.5 billon years) But in Darwin’s time was thought only a 400,000 -1million years old

Darwin’s own notes

What Biological Evolution means…. - ALL living things share some form of common ancestry - the more recent the shared ancestor : the more similar species should be (physically, behaviorally) Ex: Present Past Deer Tiger Lion Mammalian Ancestor

Try: Ostrich, Toucan, Cassowary Present Ex: Deer Tiger Lion Past Mammalian Ancestor Lions & Tigers shared a common ancestor more recently than either of them do with Deer, hence we expect them to seem more similar since they have had less time to evolve apart from each other Try: Ostrich, Toucan, Cassowary

Ostrich Present Past Ostrich Cassowary Toucan Toucan Cassowary

Natural Selection: The process by which favorable heritable traits become more common, and unfavorable heritable traits become less common in the natural world Artificial Selection: The intentional breeding for certain traits over others (ex: Dogs, Pigs, horses, cows, corn, grapes...basically all modern livestock, crops or pets have been selected for in someway) Przewalski's horse

(Felis silvestris lybica) African Wild Cat (Felis silvestris lybica) Red Jungle Fowl (Gallus gallus) (Solanum chilense)

Speciation: Evolution of 2 species from 1 ancestral species - Can happen because of geographic isolation (island populations) Galapagos Islands South America Cormorant - Can happen because of specialization in behavior Owl (night hunters) Falcon (day and night hunters)

Reproductive Isolation Geographic Isolation Behavioral Isolation Temporal Isolation SPECIATION SPECIATION: Species ‘A’ Species ‘B’ Common Ancestor

Evidence For Evolution by Natural Selection Evidence Darwin did NOT Know: Evidence Darwin Knew: Fossil Record: shows extinctions and that species have changed over long time, he also knew about the Law of Superposition Fossil Record: he knew nothing about half-life (λ) or how to tell how old the earth really is or exact age of fossils Embryology: he knew that certain features in embryos were not in the adults (ex: legs on snakes embryos) Comparative Biochemistry: knew nothing about DNA or genes or proteins or ATP (only knew parents looked similar to kids) Comparative Anatomy: knew of vestigial organs in creatures and of homologous and analogous structures How speciation worked: did not know of need for reproductive isolation to make new species, only that the environment pushed the ‘better’ adaptations to help survival and reproduction Artificial Selection: he knew how people selected for different dogs, horses, pigs, and farm plants

THE REAL DEBATE in Evolution by Natural Selection How fast does evolution occur? Gradualism vs. Punctuated Equilibrium Gradualism: The slow gradual change with many transitional forms in the speciation process Punctuated Equilibrium: slow gradual changes with small rapid periods of evolutionary change. Would expect fewer transitional forms than with gradualism