Evolution, Mutation, Reproduction Flashcards
Natural selection
Certain heritable characteristics survive and reproduce
Can only increase or decrease traits
Doesn’t create new traits but select present ones
Analogous structure
Adapt to environment
Convergent evolution
Same features but not related = environment
Evidence for evolution
Fossil record
Homology: same features + related= ancestry
Convergent evolution: same features + not related= environment
Biogeography
Genetics
Study of hereditary
Blending hypothesis
Genes from both parents mixed
Particulate hypothesis
Pass on discrete genes
Characters
Distinct heritable features
Genotype
Genetic makeup
Phenotype
Appearance
Homozygous
2 identical alleles
Not true breeding
Heterozygous
2 different alleles
True breeding
Micro evolution
Change in allele frequencies in a population
Factors that alter alleles
Genetic drift
Gene flow
Natural selection
Genetic drift
Unpredictable
Founder effect: individuals become isolated from large population
Bottleneck effect: sudden reduction in population b/c of environment
Gene flow
Directional
Disruptive
Stabilization
Sexual selection
Mating success for natural selection
Sexual dimorphism
Difference between sexes
Intrasexual (males)
Compete for mates
Intersexual (females)
Choose mates
Prokaryotic
Single cell
Known as bacteria
Eukaryotic
Plant and animal cell
Multicellular
Endosymbiosis theory
Ancestor ‘eats’ smaller prokaryote
Both benefit from relationship
Speciation
Orgin of new species
Hybrids
Cross between different species
Prezygotic barriers
Block fertilization