Principle of differential fitness different variants

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Unformatted text preview: ees ● Assessing overall similarity ● Cladistics (phylogenetic systematics) Willi Hennig (1956, 1966) ● incorporates actual evolutionary relationships Derived versus primitive character ● Derived Trait ○ a trait that is present in an organism, but was absent in the last common ancestor of the group being considered ● Primitive Trait ○ a character that is present in the common ancestor We build phylogenies based on comparisons of: ● Gross anatomy ● Molecules ● Fossils 2 Types of Shared Characters: Primitive Derived ● Homology ○ Similarity due to descent from a common ancestor (indicates evolutionary relationship) ● Analogy ○ Similarity due to independent evolution for a common function in separate groups ○ (This is also called convergent evolution.) ○ (Can also be called parallel evolution if the organisms are pretty closely related. The Controversy of Evolution ● Before Darwin ○ variation is just “noise” ○ Teleology (order is inherent) ○ A static world ● Jean Baptiste de Lamarck ○ Transmutation ○ Teleological Evolution by Natural Selection ● Transmutation/evolution was not new ● Theory of evolution BY NATURAL SELECTION was new ● Selection by the environment brings order out of randomness (accumulation of...
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