BIOL1105 Lecture Notes - Lecture 20: Autotroph, Mixotroph, Convergent Evolution
Document Summary
Taxonomy is the ordered division and naming of organisms. Phylogeny is the evolutionary history of a species or group of related species. Organisms share many characteristics because of common ancestry. Each branch point = divergence of two taxa from a common ancestor. A clade is a group of species that include an ancestral species and all its descendants. What we can and cannot learn from phylogenetic trees. Phylogenetic trees show patterns of descent, not necessarily phenotypic similarity. When constructing a phylogeny, need to distinguish whether a similarity is the results of homology or analogy. Convergent evolution occurs when similar environmental pressures and natural selection produce similar (analogous) adaptations in organisms from different evolutionary lineages. Bat and bird wings are homologous as forelimbs, but analogous as functional wings. Yams and sweet potatoes (may look closely similar, but not closely related) A shared ancestral character is a character that originated in an ancestor of the taxon.
