ANTH 1 Lecture Notes - Lecture 5: Genetic Distance, Evolutionary Taxonomy, Nucleic Acid Hybridization
6 Aug 2020
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Q: how do we determine relatedness of species: physical morphology. Ancestral traits (appear earlier in a lineage)/derived traits (appear later in a lineage) Fish and dolphins look more similar; but humans and dolphins are more similar. Occams razor given a particular phenomenon the most simplest explanation is the correct one: genetic distance data. You can create a relative scale based on the degree of separation from heat and prepare a phylogeny. Based on morphology and genetic distance (dna) More emphasis is placed on physical morphology if there is a inconsistency. Because evolution acts on the physical traits, not the dna code between the two pieces of evidence. Cladistic systematics: (used more today less mistakes) Genetic data best reflects relatedness: dna inherited. Rate of change: variable in many lineages. Short periods of much change, long periods of little change. But, slow gradual change in some lineages. Phyletic gradualists: fossil record is imperfect/incomplete: illusion of variable change.
