What are the three major areas of evidence for evolution?

Answer 1

The 3 major areas of evolution: homologies, fossil evidence and geographical distribution of species

A. Homology or similarities between and across species is a key evidence for evolution. The theory goes that species that are related to each other share similarities that were derived from a common ancestor. For example, the forelimb of tetrapods: i.e. the arm of a human, flipper of a dolphin, wing of a bat, and the wing of a bird--reveal similar structures. When compared to a common ancestor such as the Eusthenopteron -- one can see that each aforementioned descendants retains some of the same ancestral characteristics.

B. Fossil are remnants of organisms fro past geological times that have been encased in rocks. Through radioactive dating, scientist can determine the approximate age of the fossils. In addition, by examining each stratigraphic levels (rock layers)--scientists can make assessments that for example if an when an organism originated and died out. Comparative studies of fossil records with now-living organisms can be used to show how that organism or related ones evolved over time.

C. Different species can be found in geographic regions. Some species can also be found in one region. For example, the flightless cormorant can only be found on the Galapagos Island. Other cormorants found in other regions still retain the ability to fly.

Answer 2

Vestigial organs and homologous structures are often listed as evidence for common descent.