Evidence for Evolution Direct Instruction then synthesis on 24R

EVOLUTION = Change over Time =Descent With Modification =Adaptation of a species Takes Place Over Long Periods of Time -usually millions of years

Descent With Modification Species Today Look Different From Their Ancestors Each Living Species Has -Descended -With Changes -From Other Species -Over Time

Descent With Modification Implies All Living Organisms Are Related Single Tree of Life DNA, Body Structures, Energy Sources Common Descent All Species, Living (Extanct) & Extinct, Were Derived From Common Ancestors

Descent With Modification: An Example

Evidence of Evolution Fossil Record Comparative Anatomy Comparative Embryology Comparative Biochemistry Comparative Biogeography

Evidence of Evolution— 1. The Fossil Record Evidence of orderly change can be seen when fossils are arranged according to their age. Derived Traits vs. Ancestral Traits

Evidence for Evolution – The Fossil Record

Evidence of Evolution— 2. Comparative Anatomy Anatomy has different functions but constructed of similar bones in similar way. Evo predicts that modifications of ancestral body parts are more likely than formation of entirely new parts 2 Kinds: Homologous Structures: same structures/different functions Analogous Structures: different structures/same functions an analogy= a comparison using like or as (this snake tastes like chicken, but is it?)

Homologous Structures Structures in different organism that indicate a shared ancestry Check out these vertebrate forelimbs.

Homologous Structures

Check out these flying machines. Analogous Structures Different Structures in different organisms that have a common function. Check out these flying machines.

Ape and Hominid Skeletons

Type of Homologous Structure Vestigial Structures Reduced or nonfunctional structures provide evidence of an organism’s evolutionary history.

Ex of vestigial structures Whale Evolution Video Ex of vestigial structures http://www.pbs.org/wgbh/evolution/l ibrary/03/4/l_034_05.html 5 min, 9 sec

Evidence of Evolution— 3. Comparative Embryology Similarities In Embryonic Development

Human Fetus – 5 weeks

Comparative Embryology Shows common ancestry Video: http://www.pbs.org/wgbh/evolution/l ibrary/04/2/l_042_02.html

Evidence of Evolution— 4. Comparative Biochemistry Proteins (Amino Acid) MORE differences in AA sequences of distant related species LESS differences = species that are more closely related. Nucleic Acids MORE differences in DNA sequences of distant related species

Similar DNA = Similar AA = Similar Organisms Which is more related to the human, the snake or the tuna? Similar DNA = Similar AA = Similar Organisms

Evidence of Evolution— 5. Comparative Biogeography Different Species On Different Continents Have Similar Adaptations due to similarities of the Environments

Organisms from different land masses look similar The most recent common ancestor is those of the same geographical region. But, the similar comparative anatomy demonstrates a distant common ancestor before the land masses separated.

Elephants Asian African Ex of a species with a common ancestor that became geographically isolated over 5.5 MYA from others in their species and then continued to evolve. And the evolution was convergent –Becoming the African and Asian Elephants we know today.

Evidence of Evolution Fossil Record Comparative Anatomy Comparative Embryology Comparative Biochemistry Comparative Biogeography