4 Fields of Study Leading Tothe Evidence That Supports Evolution

Evidence of Evolution

Homologies

Evolutionary theory predicts that related organisms will share similarities that are derived from common ancestors. Similar characteristics due to relatedness are known as homologies. Homologies can be revealed by comparing the anatomies of different living things, looking at cellular similarities and differences, studying embryological development, and studying vestigial structures within individual organisms.

4 fields of study leading tothe evidence that supports Evolution:

1. Embryology (developmental): -Study of Embryos

-The embryos (which are the earliest stages of growth in plants and animals) of fish, reptiles, birds, and mammals cannot be told apart.

-they all have gill slits, tails, and notochord

-Fish/Chicken/Pig/Human

2. Comparative Anatomy (anatomical): -The study of living and extinct species anatomy (body structures)

-Wooly Mammoth vs. an Elephant

A) Vestigial Structures – Use to have a function but no longer does.

Ex: Appendix/ Snakes have structures that resemble hipbones

Ex: eyes on cave fish that are blind

B) Homologous structures – Same in structure and possibly the same in function

Ex: Human arm and fore leg of dog.

C) Analogous structures – Same in function but different in structure.

Ex: Insect wing and bird wing

3. Biogeography: The study of Geographical distribution of living things

4. Molecular biology:

-Genetics: All organisms have DNA/RNA

-Purines: A G (Aggies are pure)Primidines:TCU

Types of Dating Fossils:

-Relative Dating: layers of rock with the youngest fossils on top and the oldest in the bottom layers. One can conclude that the land could’ve been a completely different environment at different points in time.

-Absolute Dating/ Radiometric dating: Potassium 40 is used to date over a million years old, carbon 14 is used for less than 50,000 years old. (Isotopes/ Half-life)

Fossil Records

-Physical evidence of an organism that lived long ago

-Not all fossils have been found

-Bases of the geological time scale (marks mass extinctions)

Natural Selection:

Survival of the Fittest: Those best “fit” for their environment will survive the best and reproduce the most

Camouflage - concealment by some means that alters or obscures the appearance.

Mimicry – The close external resemblance of an organism, the mimic, to some different organism, the model, such that the mimic benefits from the mistakes the identity, as seeming to be unpalatable or harmful.