BIO260H1 Lecture Notes - Lecture 14: Effective Population Size, Zygosity, Panmixia
Document Summary
Clade: consists of an ancestral node and all its descendants, de nes a monophyletic group. Phylogram: shows branch length, branch length proportional to evolutionary divergence. Root: provides orientation for the tree: out-group rooting. Inclusion of sequences that are known to be lie outside the diversity of the sequences of interest: mid-point rooting. Arbitrarily presenting the tree so that the lineages are balanced: changing the root of the tree change relationship. Siblings vs. ancestors: all sequences are extant (still alive), none can be ancestor. Homology: decent from a common ancestor, qualitative statement. Usually re ect species phylogenies (but there can be diversity of individual genes within a species) Coalescent theory: what past evolutionary forces have acted to give us the scope and distribution of genetic variation we see today, evolutionary and demographic forces leave genetic footprints. Evolutionary forces: mutation, genetic drift, migration, selection, recombination. Demographic forces: population expansion, breeding systems, neutrality.
