1. Unit 6 Lesson 2 https://youtu.be/O21VOcLIb3M
I. Evidence of Evolution

2. I. Evidence of Change Over Time A. Fossils
fossils= remains or imprints of once-living organisms
Usually form in sedimentary rock after years of mud and sediments layering on top of an organism or remains of the organism
cast fossil= minerals from the environment replace the parts of the organism that decomposed leaving a hard “cast”
fossil record= all of the fossils that have been found provides evidence about the order of species and how they change overtime
transitional fossils= fill in gaps between organisms

3. B. Common Structures related organisms share structural traits
common ancestor= the most recent species from which two different species have evolved from
homologous structures= organisms have similar structures to a common ancestor but the structures have a different function
ex: whale arm bones and human arm bones
analogous structures= organisms have structures that have similar function but the structure is different and they do not come from a common ancestor
ex: flippers of a penguin and a whale

4. vestigial organs: structures that are reduced in size or function that may have had complete function in an earlier ancestor
ex: appendix & coccyx (tail bone)

5. C. Similar DNA
Comparing similarities in an organisms DNA may show that they come from a common ancestor
amino acids join together to code for proteins
fewer differences may indicate an evolutionary common ancestor

6. D. Developmental similarities
embryology= the study of development
comparing the development of embryos of different species may show a common ancestor