BIO101 Final Exam

Scientists that contributed the theory of evolution

  • Aristotle

  • Buffon

  • Hutton

  • Cuvier

  • Lamarck his remained a hypothesis

  • Lyell (hypothesis of acquired characteristics)supported hutton

  • Darwin and wallace: darwin became father of evolution wallace is the father of biogeography

Darwin

  • Father of evolution

  • He went on a voyage where he found evidence for evolution

  • He proposed the ideas of descent modification

  • He studied finches in the galapagos island

  • He thought the different finch species all descended from the same finch ancestor the

  • Darwin saw environment of each island influenced the survival and reproduction of the finches living there

Artificial selection

  • It changes allele frequencies

  • Wild mustard plant population shows a variety of different traits

  • Plant breeders bred mustard plants with the traits th

  • Artificial selection or selective breeding also helped darwin form his theory

Natural selection

  • It molds/ a tool of evolution

  • Does not create alleles

  • It just selects alleles that arise by chance

  • Alleles conferring camouflage become more frequent in each generation

Bacteria undergo natural selection

  • Bacteria that are resistant to antibiotics have an adaptive trait that non resistant bacteria lack

  • When antibiotics are administered, resistant bacteria survive and reproduce and non resistant bacteria does not

Adaptations enhance reproductive success

Survival of the fittest

  • Fitness describes an organism genetic contribution to the next generation

  • Orchis that are best suited to wasp pollination are the most ‘’fit’’ because they are most likely to reproduce

Equilibrium allele frequencies do not change (can be short answer)

  • Hardy-weinberg equilibrium occurs only if a population meets all of the following

  • Natural selection does not occur

  • No mutations

  • The population is large enough to eliminate random changes in allele frequencies

  • Individuals mate at random

  • No migration

  • 2 equation allow us to calculate allele frequencies

  • If all the hardy weinberg equilibrium are met 2 equations represent relationship b/w allele frequencies and genotype frequencies

  • p+q = 1

  • p^2 + 2pq + q^2 =1

  • P= the frequency of the dominant allele

  • q = frequency of recessive allele

Natural selection can shape populations in many ways (go back to slides 20 &21)

  • 3 modes of natural selection

  • They are distinguished by their effects on the phenotypes in population

  • Directional

  • Disruptive

  • Stabilizing

Why are harmful alleles sometimes maintained in a population? Slide 23

  • One explanation on why some

Sexual selection

  • A type of natural selection

  • Results from variation in the ability to obtain mates

  • Results either from competition for access to the other sex (rams) or drom one sex choosing attractive mates of the other sex

  • In some populations there is competition for mating

  • Intrasexual selection occurs when the stronger individuals in a population battle to win access to mate

  • Weaker individual is denied access

Mutation cause evolution to occur

  • Mutations create genetic diversity

  • Mutations are random changes in sequence of DNA

  • Can be harmful but many are harmless and some are beneficial

  • Beneficial mutations are passed on to the next generation

  • Their frequency increases over generations

Genetic drift causes evolution to occur

  • Genetic drift is random sampling error

  • Allele frequencies can start dramatically and often become eliminated when only part of a population survives to reproduce

  • Decrease of genes in a population

Founder effect causes genetic drift

  • When only a few individuals establish a new population the allele frequency might change

  • This process illustrates founder effect

Population bottlenecks cause genetic drift

  • A population bottleneck occurs if a disaster drastically reduces the size of population

SHE MIGHT GIVE AN EXAMPLE AND YOU HAVE TO GUESS WHICH EFFECT IT IS

Gene flow causes evolution to occur

  • Gene flow moves alleles b/w populations