Lab 5 Flashcards
Natural selection
Darwin’s the theory that the fittest organisms survive and this is how species evolve
Micro evolution
Change in frequency of alleles in gene pool from one generation to the next
Macro evolution
Beyond the species level where a new group of organisms arise from a common ancestor through a series of speciation events
Hardy and Weinberg proposed that
Frequencies in alleles will stay constant is there is no sexual reproduction & mutations
Hardy-Weinberg principle
If several conditions are met,proportions in genotypes will remain constant over generations
Hardy-Weinberg principle
P^2 + 2pq + q^2 = 1. Where p^2 is dominant, q^2 is frequency of recessive genotype, p^2 is the frequency of the phenotype, and 2pq is the frequency of the heterozygote
What are the 5 principles that must be met in order to be at hardy Weinberg equilibrium?
No mutations, no gene flow, no natural selection, random mating must occur, population must be large
Four mechanisms of evolutionary change
Mutations, genetic flow, genetic drift, and natural selection
Stabilizing selection
Intermediate phenotype is favored
Disruptive selection
Favors both extreme phenotypes
Directional selection
Favors one phenotype over the other
If populations diverge then..
A speciation event has occurred
Molecular clock hypothesis
Determine approximate point where two species diverge
Phylogenetic trees
Graphical representation of evolutionary relationship between different taxonomic groups
Monophyletic group
Includes a common ancestor and all descendants
