Micro evolutionary Biology Notes
Microevolutionary Process Notes
1) Natural selection works on individuals
2) Individuals do not evolve, populations do
Insecticide application didn’t result in insecticide resistance: some insects carry trait of resistance in their genes
Processes in Microevolution
-Mutation -Non-random mating
-Genetic Drift -Natural Selection
-Gene Flow
Hardy-Weinburg Theorem: Frequencies of alleles and genotypes are preserved from generation to generation in populations that are not evolving
-p2 + 2pq + q2 = 1
Hardy-Weinburg tells us that we will never get rid of bad genes and it’s used to figure how gene populations change over time
The Hardy-Weinberg theorem describes a pop’n that is not evolving. It has 5 assumptions:
1. Genetic Drift: This represents random changes in small gene pools due to sampling errors in propagation of alleles. The bottleneck effect and founder effect are prime examples of genetic drift. In either case the number of individuals in a population is drastically reduced distorting the original allelic frequencies. (H-W assumes large population)
2. Gene Flow: The movement of alleles into and out of a gene pool. Migration of an organism into different areas can cause the allelic frequencies of that population to increase. Most populations are not isolated, which is contrary to the Hardy-Weinberg Theorem. (H-W assumes the population isolated from others)
3. Mutations: These changes in the genome of an organism are an important source of natural selection.(H-W assumes no net mutation)
4. Nonrandom mating: Inbreeding is a popular form of nonrandom mating. Individuals will mate more frequently with close individuals than more distant ones. Assortive mating, is another form of non-random mating. Here the individuals will mate with partners that closely resemble themselves in certain characteristics.
*assortive mating decreases heterozygotes
*dissortive mating increases heterozygotes
*allele frequency does not change
(H-W assumes
1) Natural selection works on individuals
2) Individuals do not evolve, populations do
Insecticide application didn’t result in insecticide resistance: some insects carry trait of resistance in their genes
Processes in Microevolution
-Mutation -Non-random mating
-Genetic Drift -Natural Selection
-Gene Flow
Hardy-Weinburg Theorem: Frequencies of alleles and genotypes are preserved from generation to generation in populations that are not evolving
-p2 + 2pq + q2 = 1
Hardy-Weinburg tells us that we will never get rid of bad genes and it’s used to figure how gene populations change over time
The Hardy-Weinberg theorem describes a pop’n that is not evolving. It has 5 assumptions:
1. Genetic Drift: This represents random changes in small gene pools due to sampling errors in propagation of alleles. The bottleneck effect and founder effect are prime examples of genetic drift. In either case the number of individuals in a population is drastically reduced distorting the original allelic frequencies. (H-W assumes large population)
2. Gene Flow: The movement of alleles into and out of a gene pool. Migration of an organism into different areas can cause the allelic frequencies of that population to increase. Most populations are not isolated, which is contrary to the Hardy-Weinberg Theorem. (H-W assumes the population isolated from others)
3. Mutations: These changes in the genome of an organism are an important source of natural selection.(H-W assumes no net mutation)
4. Nonrandom mating: Inbreeding is a popular form of nonrandom mating. Individuals will mate more frequently with close individuals than more distant ones. Assortive mating, is another form of non-random mating. Here the individuals will mate with partners that closely resemble themselves in certain characteristics.
*assortive mating decreases heterozygotes
*dissortive mating increases heterozygotes
*allele frequency does not change
(H-W assumes