CAS BI 107 Lecture Notes - Lecture 2: Bushmeat, Maximum Likelihood Estimation, Ribosomal Dna
Document Summary
Descent with modification results in a natural hierarchy of life. Over long periods of time, relationships give rise to lineages, which then split and form groups. Phylogenies are viewed as hypothesis of hierarchical, evolutionary relationships of organisms, genes or populations. Ribosomal dna sequencing lead to new division of archaea. Numbers on a phylogenetic chart represent how much confidence we have in the hypothesis. Species at one point in time becomes a lineage as we follow it through time. A split occurs when the ancestral lineage divides into two lineages. Each lineage continues to evolve independently as different traits represented by red dots (nodes) The closer lineages are to each other, the more related they are. Nodes can be rotated without changing the meaning of the tree. Tree states that humans and chimpanzees are equally similar to gorillas, and can be rotated without changing the meaning.
