Darwins Five Points Observations regarding natural selection: populations have variations some variations are beneficial / favorable more offspring are produced than survive those that survive will have favorable traits because of this, a population will change over time
Genetic Equilibrium Recall – natural selection affects POPULATIONS not individuals Gene Pool – the collection of genes within a population allelic frequency – the frequency of certain alleles within a population
Genetic Equilibrium – contd Genetic Equilibrium – a steady-state of genetic material/information within a population no new traits added, none removed doesnt really happen in nature [will discuss why soon]
Genetic Equilibrium – contd Hardy-Weinburg Law can find out how many alleles are in population if you assume that there is genetic equilibrium at any single point in time
Discuss List and explain Darwins Five Points. Name and explain reasons why genetic equilibrium does NOT exist in nature.
Genetic Equilibrium – contd Genetic Equilibrium could be achieved if: there is a large breeding population no selection all traits must be as favorable than others to maintain the same amounts of each allele random mating exists if there is sexual selection, certain traits would be favorable…which would change the amounts of each allele in the population
Genetic Equilibrium – contd Genetic Equilibrium could be achieved if: no change due to mutations any loss or gain of alleles would change the genetic ratios no immigration or emigration when organisms leave, they take with them their traits when organisms arrive, they bring in new traits
Genetic Equilibrium – contd Genetic Equilibrium does not exist because of… selection natural or otherwise – changes amount of certain genes mutation loss or gain of info – changes amount of certain genes gene flow emigration / immigration
Genetic Equilibrium – contd Genetic Equilibrium does not exist because of… genetic drift small populations exist in which certain genes are more prevalent than in the general populus American Indians do not have blood group B Amish – marry within their own community, so more likely to have certain recessive conditions like polydactyly [extra fingers]
Genetic Equilibrium – contd Genetic Equilibrium does not exist because of… natural disasters / mass illness cause the bottleneck effect
Discuss Again, summarize the reasons why genetic equilibrium does NOT exist in nature.