Evidence for Evolution A slide extravaganza…

Types of evidence… z1. Evidence from the fossil record (dead things)

Fossil formation zBones and shells undergo mineral replacement and are turned into rock zSoft material either disappears, or leaves an impression in the earth (that turns to rock)

A selection of fossils…

Fossils show transitions The Archaeopterix -- between reptile and bird

Scallops

From early to modern horse

(Living things show transitions too)

Coelacanths - “the living fossil”

Types of evidence… z1. Evidence from the fossil record

Types of evidence… z1. Evidence from the fossil record z2. Comparative Anatomy

A. Homologous Structures Homo - logy Homologous structures have the same underlying forms

Wing anatomy comparison And compared to our arm…

Arm anatomy comparison

B. Analogous Structures Ana - logy Analogous structures have a similar outward appearance (but different underlying forms)

Types of evolution Convergent evolution Distantly related organisms evolve similar external features Divergent evolution A common ancestor gives rise to organisms that evolve for different environments

Which goes with which? …. Homologous structures Analogous structures Convergent evolution Distantly related organisms evolve similar external features Divergent evolution A common ancestor gives rise to organisms that become more different with time.

Which goes with which? Homologous structures Analogous structures Convergent evolution Distantly related organisms evolve similar external features Divergent evolution A common ancestor gives rise to organisms that become more different with time.

C. Vestigial Structures Vestige - a left-over/ remnant Vestigial structures are evolutionary “leftovers” from an earlier ancestor

The “dew” claw of a wild cat

The human appendix Rabbit Fetal Human Adult Human

Membranes in our eyes

Hip bones in whales (Look at that “hand” too!)

Types of evidence… z1. Evidence from the fossil record z2. Comparative Anatomy

Types of evidence… z1. Evidence from the fossil record z2. Comparative Anatomy z3. Comparative Embryology

Human embryo at 5 weeks

Embryos… …can you guess which one is human?

…how about now? Embryos…

And now… Were you right?

Types of evidence… z1. Evidence from the fossil record z2. Comparative Anatomy z3. Comparative Embryology

Types of evidence… z1. Evidence from the fossil record z2. Comparative Anatomy z3. Comparative Embryology z4. Molecular Evidence

Comparing DNA…

Determining relationships DNA similarity between species is used to determine how closely related they are. This is in turn used to construct possible evolutionary trees.

How closely related are these fellows? Giant Panda Brown Bear Mystery critter! (I’m not telling) …got your guess?

An Evolutionary Tree …so why is he called a red panda? This tree was constructed by looking at % similarity of DNA among “bears”

Types of evidence… z1. Evidence from the fossil record z2. Comparative Anatomy z3. Comparative Embryology z4. Molecular Evidence

Types of evidence… z1. Evidence from the fossil record z2. Comparative Anatomy z3. Comparative Embryology z4. Molecular Evidence z5. Behavior

Behavioral similarities zDuck and other bird mating dances zHow primates carry their young zFish swimming motions and salamander walks zAnd on and on and on….

Types of evidence… z1. Evidence from the fossil record z2. Comparative Anatomy z3. Comparative Embryology z4. Molecular Evidence z5. Behavior

Types of evidence… z1. Evidence from the Fossil Record z2. Comparative Anatomy z3. Comparative Embryology z4. Molecular Evidence z5. Behavior z6. Direct observation  also known as microevolution

Artificial selection Remember us?

And look at us!

And Natural Selection Hawaiian Rock Wallabies!

The Beak of the Finch zBiologists Peter and Rosemary Grant documented natural selection occurring in populations of finches on the Galapagos islands over a period of only 20 years! This generation to generation changes in the frequency of certain traits is called microevolution.