Maddie Fetsko & Austin Futrell
What is Evolution?
Homologous vs. Analogous Stuctures
Analogous structures share a common appearance, but do not share a common origin.
Evidence of Evolution
Embryology- We can look at the physiological comparisons between the fertilized embryos to determine if they are related.
Molecular Evidence- We can compare the DNA of two organisms to determine how closely related they are.
Anatomy- We can compare the anatomical structures of organisms to determine whether or not they are related.
Convergent and Divergent Evolution.
Convergent evolution is evolution in which distantly related organisms evolve similar traits.
Divergent evolution is evolution in which species that once were similar to an ancestral species diverge.
Geographic and Reproductive Isolation.
Geographic isolation is when species are isolated geographically (ex. tree frog population with a river separating them).
Reproductive isolation can be either genetic or behavioral. Genetically, genetic material becomes so different that fertilization can't occur (ex. geographically separated populations of California salamanders). Behaviorally, populations don't mate at the same time of year (ex. one population of tree frogs mate in the fall and the other in the spring).