Help
Options
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't Know
Remaining cards (0)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
mechanisms of evolut
ap bio unit 6 chapter 17
| Term | Definition |
|---|---|
| 5 Hardy-Weinberg equilibrium conditions | 1. no mutation 2. no migration 3. large population 4. no sexual selection (must be random) 5. no natural selection (reproductive success must be random) |
| genetic drift | the change is allele frequencies due to a small population |
| geographic isolation | closely related species being separated by a physical barrier |
| niche | the functional role in an ecosystem that a species takes, but when they are unoccupied they must be filled by another species |
| character displacement | two closely related species overlap niches and evolve to not compete or waste gametes |
| punctuated equilibrium | a rapid rate of evolution that produces fast changes over time |
| gradualism | when evolution occurs at a slower pace |
| what does it mean if a population is in H-W equilibrium | allele frequencies do not change (evolution is stopped) |
| one word that best described evolution | change |
| who is the Father of Modern Biology | Charles Darwin |
| what are homologous structures | structures that are similar in different species ex: bones (hands) |
| what are vestigial structuers | a structure that is no longer useful but was in ancient species ex: wisdom teeth, hip bones in whales |
| artificial selection | breeding for certain traits that may or may not help an organism |
| natural selection | breeding by chance (those w/ good traits survive to reproduce) |
| 4 mechanisms for a population to evolve | O - overproduction (too many babies that can survive) V - variation (all babies are different because of DNA) A - adaptation (survival of the fittest) I - inheritances (survivors life to reproduce and pass on their genes) |
| populations, not individuals evolve according the Theory of Evolution | true |
| how is it possible for genetic variation to keep occurring generation after generation? | 1. sex (meiosis[independent assortment]) 2. crossing over 3. mutations |
| for evolution to occur in a population, reproduction must be totally ________________ | nonrandom |
| genetic drift has more evolutionary impact on small populations than large ones | true |
| somatic mutation does not provide raw material for evolution | true |
| many genes are simultaneously subject to both positive and negative selection pressures | true |
| polymorphism | the occurrence in a population of two or more distinct forms of a genetically determined character |
| bright colored insects are usually distasteful to predators | true |
| Müllerian mimicry | a natural phenomenon in which two or more well-defended species, often foul-tasting and sharing common predators, have come to mimic each other's honest warning signals, to their mutual benefit |
| in a large population with random mating, mutational equilibrium, and no migration, a disadvantageous allele will NOT gradually disappear | because allele frequencies will not change |
| selection in heterozygotes can result in an increase in the frequency of lethal recessive alleles | true |
| the diploid condition helps protect longer-lived species from the effects of deleterious mutations | true |
| mutations are ______ significant for evolutionary change than recombination of existing alleles | less |
| sexual selection may result in characteristics that natural selection selects against | true |
| adapted | more general refers to an organism's possession of any genetically controlled characteristic that increases its fitness to survive in the existing environment |
| preadapted | an organisms's possession of genes that increase its fitness to survive if the environment changes in certain respects; the organism is adapted to a new environment before it encounters that environment |
| horizontal transmission | a species acquires a gene from another species. can occur when a parasite picks up a host gene and releases it in its next victim |
| exon recombination | individual exons from different genes of a single species are brought together to form a new gene |
| directional selection | acts against individuals exhibiting one extreme of a character, causing the population to evolve along a particular line |
| disruptive selection | when two opposing selection pressures are present, favors individuals exhibiting both extremes of a character, thereby dividing the population into two distinct types |
| stabilizing selection | acts against individuals exhibiting characters that are too different from the mean conditions, thus maintaining stability in the population |
| Batesian mimicry | a palatable species mimics in appearance some unpalatable species' warning coloration |
| Müllerian mimicry | two or more unpalatable species mimic each other in appearance |
| cryptic appearance | blending into ones' surroundings |
| symbiosis | "living together" |
| mutualism | both species benefit |
| commensalism | one species benefits the other is neutral |
| parasitism | one species benefits at the expense of the other |
| enslavement | one species maintains members of another species an controls their reproduction |
| coevolution | when two or more species reciprocally affect each other's evolution through the process of natural selection; two traits in the same species affecting each other's evolution |
| natural selection can best be defined as | nonrandom reproduction |
| the theory of natural selection postulates that | to at least a small extent the survival and reproductive success of individuals depend on the extent to which they are genetically adapted to their environment |
| gene pool | the collection of genes for all the traits in a population; all of the alleles for all of the genes |
| allele frequency | the percentage of a specific allele of a gene in the gene pool (dominant+recessive=1) (total of 1 allele/total of ALL alleles) |
| what is evolution? | a slow, gradual change of a species (population) over time |
| Jean Baptist Lamarck | the first scientist to step forward and suggest that organisms changed slowly over time (theory of evolution by the inheritance of acquired characteristics) |
| evidence of changes (fossils) | - amber/ice - bones/teeth/shells - casts |
| relative dating | comparing ages of different fossils based on positions in sedimentary rock |
| absolute dating | using radioactive elements to determine actual age of organism |
| homologous structures | parts of organisms that have similar structures because each species inherited them from a common ancestor (bones in the hand) |
| vestigal structures | remnants of structures that were functional in ancestral forms but no longer have an apparent function (hind leg bones in whales) |
| embryological similarities | closely related species have embyros that share common patterns of development (humans/fish) |
| biochemical similarities | closely related species have similar DNA sequences |
| artificial selection (selective breeding) | humans have produced huge changes in species by allowing only plants or animals with desired traits to breed (dogs) |
| evolution can only act through variation that is _________ | inherited |
| sources of variation | - sexual recombination (meiosis) - crossing over in meiosis - mutations (in gonad cells) (most important type are gene duplications [transposons]) |
| genetic equilibrium | the allele frequency stays the same generation after generation |
| gene flow | when immigration occurs there are new alleles introduced or when emigration looses alleles (change in allele frequencies due to chance) |
| population | made up of all the members of the same species that live in a certain location at the same time |
| adaptations | characteristic that enhances an organism's chances of perpetuating its genes; increase an organisms fitness (ability to reproduce) |
| coevolution | a process of two or more species evolving together, each becoming more finely tuned to each other's needs |
| apesematic appearance | contrasting colors which serve as warning |
| Batesian mimicry | when a species evolves similar warning coloration as a harmful species, yet lacks real danger |
| mullerian mimicry | when two harmful species both evolve similar warning coloration |
| how does divergent speciation occur? | 1. separated geographically by extrinsic barriers 2. the two populations evolve independently and accumulate genetic differences (initial allele frequency, mutations, selection pressures) 3. develop intrinsic reproductive isolating mechanisms |
| intrinsic isolation (pre-fertilization) | - ecogeographic - habitat - seasonal - behavioral - mechanical - gamete |
| intrinsic isolation (after fertilization) | - developmental (embyros don't form correctly) - hybrid inviability - hybrid sterility - selective hybrid elimination |
| selection with favor individuals whose behavior morphology and physiology ______ the chance of gamete wastage | reduces |
Created by:
tpolinsky24
Popular Biology sets