1. Evidences for Evolution
Lab 12
Evidences for Evolution

2. 3 types of evidence Fossil record Comparative anatomy
Biochemical evidence

3. Fossil record
How are fossils dated? First fossils were found in which era? What type of organisms were the first fossils? What are the 3 eras in the geologic time scale? Lab manual exercises will look at which type of fossils appeared in which era.

4. For table 12-2 use these organisms for examples of specimens from each era.
Cenozoic-angiosperms
Mesozoic-euypterids
Paleozoic –giant club mosses
Note which types of organisms are extinct.

5. Comparative Anatomy
Comparison of homologous structures (synapomorphies)
Analogous structures (homoplastic features) do not indicate evolutionary relatedness
Compare forelimbs of several mammals to the ancestral condition. Discuss the possible reasons for some of the differences seen.
Compare chimp and human skeletons and skulls.

6. Comparison of embryos Vertebrate embryos share 3 characteristics
post-______ tail
___________pouches
Mesodermal segments called ______
Look at chick embryo slides with a dissecting microscope. Try to locate the features that are found in the drawings. At what embryonic stage can these features be seen?

7. Biochemical comparisons
Comparisons of protein sequences, DNA, ribosomal RNA.
More similarities in sequence- more evolutionary relatedness.
Compare similarities of molecule cytochrome c among species
Work on handout which requires you to count the difference in amino acid sequences.

8. Lab Report due next week
Page 160 of lab manual “Lab Review 12”
Questions from cytochrome c handout