EVIDENCE OF EVOLUTION

Evidence of Evolution Scientist who study fossils focus on more than the fossil itself. They also think about: Its age It’s location and what the environment was like when the organism it came from was alive

Evidence of Evolution Darwin hypothesized that at some point in time the species from the South American mainland had migrated to the Galapagos Islands. Biogeography: The study of the distribution of organisms around the world. One clear example : Darwin’s finches

Evidence of Evolution Developmental similarities: Notochord, Dorsal nerve cord,Pharyngeal arches

Evidence of Evolution Homologous Structures: Features that are similar in structure but appear in different organisms and have different functions. Strong evidence for common descent.

Evidence of Evolution Analogous Structures: Structures that perform a similar function but are not similar in origin. Ex: Bird wings and Insect wings. Not common descent.

Evidence of Evolution Vestigial Structure: remnants of organs or structures found in an early ancestor that no longer serve a useful function or may now serve a different function. Ex: The wings of an ostrich or the appendix in humans. Considered the most important way to demonstrate how evolution works.

Evolutionary Biology Today Paleontology: the study of fossils or extinct organisms, continues to provide new information and support current hypothesis about how evolution occurs. Fossil record is not complete because most living organisms do not create fossils. No fossil evidence that contradicts evolution.

Evolutionary Biology Today Molecular and genetic evidence: 1.) DNA Sequence Analysis- The more related two organisms are, the more similar their DNA will be. 2.)Pseudogenes- Genes that no longer have a function but are carried along with DNA still. 3.) Protein Comparisons: Cells from different species that have the same proteins most likely come from a common ancestor. 4.) Homeobox Genes: Genes that control the development of specific structures.