BIO 012 Lecture Notes - Lecture 3: Endoderm, Heterotroph, Body Plan
19 Sep 2017
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Ancestral - a trait that is shared with your ancestors. Derived - a new trait that appears first with the species in question. Talk about the trait in terms of which species you are comparing. Synapomorphy: a shared derived trait usually used to identify a clade. Clade is all the ancestors that descended from a common ancestor. When a trait reappears that had previously been lost. Derived traits indicate something important about evolutionary process and can explain many unique observations. If the genetic underpinning is there for a trait, it can re-evolve, and reappear within phylogenies. The genetic material for a specific trait isn"t usually lost, just deactivated. Homology: when a trait evolved from a common ancestor. Convergent evolution: similar selection pressures lead to similar traits arising in. Independent evolution from different ancestors, begin to look the same/converge due to environmental conditions.
