7. Evolution - Selection Flashcards
What is natural selection?
The non-random increase in frequency of DNA sequences that increase survival
What is sexual selection?
The non-random increase in frequency of DNA sequences that increase reproduction
What is stabilising selection?
When individuals either side of the mean phenotype are selected against, keeping the mean phenotype unchanged over generations (e.g. mean-sized individuals in population are fittest)
What is directional selection?
When individuals on one side of the mean phenotype are selected against, causing the phenotype to move progressively every generation towards the other extreme (e.g largest individuals in population are fittest)
What is disruptive selection?
When individuals close to the mean phenotype are selected against, causing the population to have two distinct phenotypes and few with the mean (e.g. largest and smallest individuals are fitter than others in population)
