Recombination, Mutation, Genetic Drift, Gene Flow Also evolution Also evolution.
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Transcript of Recombination, Mutation, Genetic Drift, Gene Flow Also evolution Also evolution.
Recombination, Recombination, Mutation, Genetic Drift, Mutation, Genetic Drift,
Gene FlowGene FlowAlso evolution Also evolution
RecombinationRecombination
Remember Meiosis?Remember Meiosis? This is when recombination occursThis is when recombination occurs Shuffling of chromosomes/genes/allelesShuffling of chromosomes/genes/alleles Also crossing overAlso crossing over
Remember fertilization?Remember fertilization? Coming together of shuffled genesComing together of shuffled genes
New alleles not created, just New alleles not created, just
rearranged for more genetic variabilityrearranged for more genetic variability
MutationsMutations
Creates new allelesCreates new alleles Beneficial, neutral, or lethalBeneficial, neutral, or lethal Passed on to new generations if they arise Passed on to new generations if they arise
in gametesin gametes Can reduce chances of survival and Can reduce chances of survival and
reproductionreproduction
If it causes severe reductions, usually ends with If it causes severe reductions, usually ends with deathdeath
Neutral mutation changes base sequence but Neutral mutation changes base sequence but has no effect on survival or reproductionhas no effect on survival or reproduction
Beneficial mutation ex. – corn plant has a Beneficial mutation ex. – corn plant has a mutation that makes it grow faster or larger mutation that makes it grow faster or larger giving it best access to sunlight and nutrientsgiving it best access to sunlight and nutrients
Neutral mutation might prove helpful if the Neutral mutation might prove helpful if the environment changesenvironment changes
Genetic DriftGenetic Drift
Random changes in allele frequencies over Random changes in allele frequencies over timetime
Effect is greatest in small populations – Effect is greatest in small populations – leads to loss of genetic diversityleads to loss of genetic diversity Allele will become more or less prevalent in Allele will become more or less prevalent in
small popssmall pops
Bottleneck Bottleneck and Founder Effectand Founder Effect
BottleneckBottleneck
Drastic reduction in population size Drastic reduction in population size because of severe pressurebecause of severe pressure
Founder EffectFounder Effect A few individuals establish a new A few individuals establish a new
populationpopulation Unpredictable genetic shifts occurUnpredictable genetic shifts occur
Gene FlowGene Flow
Physical movement of alleles into and out of a Physical movement of alleles into and out of a populationpopulation
Opposes the effects of mutation, natural Opposes the effects of mutation, natural selection, and genetic driftselection, and genetic drift
Keeps populations similar to one anotherKeeps populations similar to one another
Increases genetic variability in that new Increases genetic variability in that new populationpopulation
CladogramsCladograms
Aka. Phylogenetic tree, branching tree, Aka. Phylogenetic tree, branching tree, evolutionary treeevolutionary tree
Lines not still apparent at present are Lines not still apparent at present are extinctextinct
Do not have to all face the same wayDo not have to all face the same way