3: evolution in front of our eyes

Hardy-Weinberg equilibrium

frequency of proportion of alleles in a gene pool of a generation wont change from generation to generation

factors that can affect HWE

1. mutations 

2. gene flow 

3. genetic pressure: inbreeding in isolated populations 

4. non - random mating 

5. natural selection

inclusive fitness

allele frequencies are not affected solely through own offspring, but the effect also works through an individual’s relatives who share (part of) the same genetic material

mutations 

The prevalence of a gene and its alleles B and b will not remain in equilibrium if B mutates more (or less) often than b

→ Changes allele frequency from generation to generation

gene flow

• Many species = small, local populations, individuals mate within the population

• every local gene pool will eventually develop a distinct gene pool which differs from that of other local populations.

• But! Within a population, can mate w sporadic immigrants → can alter the allele frequencies in population/ introduce completely new genes to local gene pool

non-random mating

allele happens to make an individual more attractive as a mating partner

frequency of this allele → increase in the population at the cost of other alleles

natural selection

frequency of alleles - associated with phenotypes - increase probability that an individual will successfully reproduce will increase in the population

Molecular genetics

Identification of polymorphisms (place on DNA strand that show variation in people) and genes

Polymorphisms

a place on the genome that displays variation between people

single nucleotide polymorphism

SNP

3 kinds of polymorphism

• Single nucleotide polymorphisms (SNPs)

• repeat polymorphisms (the more repeats, the more you have from that factor)

• Insertions/deletions

null hypothesis 

no difference in aggressive behaviour between the different genotype groups

alternative hypothesis 

mean differences between groups