BIOL 1004 Lecture Notes - Lecture 3: Vestigiality, Natural Selection, Genetic Variation
19 Jan 2016
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Document Summary
Variation exists within species (not all individuals look the same) The field of evolutionary biology is constantly expanding with new techniques and tools. Rocks of different age have different types of organisms. Paleontology: allows us to understand the sequence of events in history of life as well as the conditions prevailing in past environments. Radioactive isotopes are used to estimate the age of rocks. Radioactive isotopes have a known decay rate. The law of succession: general pattern of correspondence between fossil and living forms from the same local. The law of succession suggests the extinct species are the ancestors of living ones. Analogy: similarly in structure and function that is not due to common ancestry. (e. g. flying squirrels and sugar gliders are distantly relates and their common ancestor was not a gliding mammal. ) The independent evolution of similar structure is called convergent evolution. Vestigial structure: rudimentary traits that are homologous to fully functional traits in closely related species.
