Evolution 2

-heritable trait taht increases the fitness of an individual in a particular environment relative to those lacking the trait

• -ends with adaptation
• -NOT physiological (ex. warm weather, different genes turned on)

• Precondition:
• 1. must be a heritable variation in a population

• -1930-1940
• -argued that population processes (mutation, recombination, natural selection) account for the orgin of species

• -change in genetic makeup of a poptulation over time
• -driven by natural selection

• -Incorrect replication: spontaneous
• -Chemical/radiation mutations: induced

• -mismatching DNA pairs.
• -proof reading andr repair enzymes help
• -not mutation until its stuck forever

• ex. substitution (transition-similar, transverson)
• -frameshift (deletion, insertion)
• -inversion (flipping 180)
• -reciprocal translocatoin (break DNA and reinsert somewhere else)

• nonsynonymous: change
• synonymous: no change

• -mutation in repair enzymes cause 100-1000x higer mutation rate
• -high mutation rate under changed conditions can be an advantage

• -most lead to death
• -deleterious- incorrect protein, no protein, homeotic mutations
• -reduce by 2%
• -neurtral mutations- no effect on fitness, silent
• -positive
• -rare (ex. mutate to grow better at different conditions)

• -unequal crossing over: prophase, meiosis 1- lose gene
• -transposable elements: jumping genes
• -gene duplications: only need 1 to do function, other can mutate
• -chromosome mutations: inversion (ABCDE to ABEDC)
• -good evidence for natrual selection
• -genome duplication: may create new species, masive gene duplication

• selective advantage
• -yes, mutations do NOT occur due to need
• postion
• -no, mutational hot spots (due to unusual character)

• -total of all the alleles of a gene that occur in a population
• -same species = same genes
• -the alleles of these genes may vary

• environment causes change in phenotype
• -ex coloring

-conditions on which a population will NOT evolve

-within popluations (group of interbreeding individuals and thier offspring)

• -large populations with random mating, allele frequences remain constant
• -allele: p +q = 1
• -genotype: p2 +2pq + q2 = 1

• Population NOT to evolve:
• -no mutation
• -no migration
• -no natural selection
• -large population size
• -random mating

• -mutation
• -migration
• -natural selection: certain genotypes produce more offspring, causes divergence, leads to adaptation
• -genetic drift: due to chance alone
• -non random mating: interbreeding cause heterozygous to disapper and homo to appear

• -isolated colonies are founded by a small number of individuals
• -allele frequences may be different than large group

• sympatric: populations overlap in distribution
• parapatric: adjacent populations
• allopatric: populations w/ isolated distributions

change in character or allele frequencies over geographic distance

on population having an allele and not the other popluation