darwinism

Darwins work was heavily influenced by the work of ?

Malthus and Wallace

natural selection

differential survival and reproduction of individuals due to differences in phenotype - mechanism of evolution

Dawin’s theory of…

natural selection and adaptive radiation

adaptive radiation

process in which organisms diversify rapidly from an ancestral species into a multitude of new forms

Malthus published a book called…

essay on the principles of population

Charles Darwin published what book outlining his ideas on evolution ?

the origin of species

what are the 2 types of selection that drive evolution ?

positive directional and negative purifying

panmictic population

all individuals are potential partners - random mating

what is meant by a positive selective sweep ?

whole population has a beneficial mutation - fixed

why have some deleterious traits eg. Huntingtons not been purged from species ?

effects of mutation occur after reproductive age

why do allelic frequencies change ?

genetic drift, neutral evolution, chance

changes in allelic frequencies has a greater effect in…

small isolated populations

how do increased ploidy levels avoid inbreeding depression ?

more variation in genome - acts as buffer to avoid homozygous recessive traits

positive directional selection

alleles that benefit organism become more frequent

result of positive directional selection

unidirectional evolution, decreased genetic diversity

negative purifying selection

removes deleterious or harmful alleles

result of negative purifying selection

reduces genetic variation but maintains stability

genetic drift

change in allele frequency due to chance