Ecology and Behaviour Flashcards
the changes in allele frequency that occur over time within a population due to mutation, selection, gene flow, gene drift, and nonrandom mating
microevolution
the patterns of changes in groups of related species over broad periods of geologic time; patterns determine phylogeny
macroevolution
What was Lamarck’s theory?
Use and Disuse
-body parts can develop with increased usage and unused parts are weakened
-inheritance of acquired characteristics: body features acquired during lifetime can be passed to offspring
-natural transformation of species: organisms produce offspring with changes, transforming each later generation to be slightly more complex
What is Darwin’s theory?
Natural selection
- survival of the fittest, allele frequencies increase or decrease in order to adapt to the environment
- descent with modification: over time, traits with reproductive advantage will become more common
the development of an organism
ontogeny
the evolutionary development and diversification of a species
phylogeny
What is the evidence for evolution?
- Fossils
- Biogeography
- Embryology
body parts that resemble one another between different species that descended from a common ancestor (bat wings vs. bird wings)
homologous structures
body parts that resemble one another between different species that evolved independently (bat/bird wings vs. bee wings)
analogous structures
ability to survive and produce fertile offspring
fitness
What is stabilizing selection?
bell curve favours an intermediate, like how the average height in humans is in the middle
a group of individuals capable of interbreeding
species
What is industrial selection?
the selection of dark coloured, melanic, varieties in various species of moths as a result of industrial pollution (type of directional selection)
What is disruptive selection?
when the environment favours extreme or unusual traits while selecting against common traits
differential mating of males or females in a population
sexual selection
females choose superior males, which increases fitness of the offspring
INTERsexual selection
males compete and fight with other males for better mating opportunities
INTRAsexual selection
the differences in appearance of males and females
sexual dimorphism
this is a form of directional selection carried out by humans when they breed favourable traits, and is not natural selection
artificial selection
mating with unrelated partners resulting in mixing of different alleles and creating new allele combinations
outbreeding
the coexistence of two or more phenotypes
polymorphism
What is heterozygote advantage?
heterozygote condition has greater advantage than either homozygous conditions
Ex. sickle cell anemia is recessive, heterozygous trait is resistant against malaria
What is punctuated equilibrium?
the hypothesis that evolutionary development is marked by isolated episodes of rapid speciation between long periods of little or no change.
What is frequency-dependent selection (minority advantage)?
occurs when least common phenotype has selective advantage
Ex. predators use search images of common phenotypes to find prey, allowing prey with rare phenotypes to escape. The rare prey phenotype eventually becomes common and cycle repeats