Evolution

adaptation

a trait that makes an individual successful in its environment.

relate the concepts of adaptation and fitness to the theory of natural selection

the better the species is adapted or has better fitness the longer and easier it will survive than those without those traits.

homologous structure

anatomical structures that occur in different species and that originated by hereditary from a structure in the most recent common ancestor of the species.

directional selection

extreme form of a trait=higher fitness

disruptive selection

extreme variation of a trait=highest fitness

describe how convergent evolution can result among different species

it leads to organisms that come from different ancestors but they evolve in similar ways to adapt to their surroundings.

describe 5 conditions under which a population will maintain genetic equilibrium

1. mutation 2. gene flow 3. genetic drift 4. nonrandom mating 5. natural selection

summarize the history of scientific ideas about evolution

Darwin realized that certain species varied from island to island. evolution: organisms change over time. Heritable change in characteristics.

sexual selection

a type of natural selection in which some individuals out reproduce others because they are better at securing mates.

genetic drift

allele frequencies in a population change in the result of a random event (hurricane kills people only by the ocean).

compare artificial selection and natural selection

artificial selection breeds for certain traits while natural selection is non-forced breeding of certain traits that make new characteristics.

stabilizing selection

average form of a trait=greatest fitness

contrast the model of punctuated equilibrium and gradualism

equilibrium-change of a species over a long period of time gradualism-change at a regular gradual change.

describe how fossils, transitional species, anatomy and embryology, and biological molecules are evidence for evolution

fossils-depending on where the fossils are found can determined how they looked and changed, can tell the age and see how organisms looked in the past with similar skeletal structure. transitional species-fossils that are similar to both past and present organisms. anatomy-can show that bones were similar to other species embryology-shows that organisms can develop similarly.

explain how genetic drift can affect populations of different sizes

genetic drift can wipe away a whole population if it is small or a majority of a population if it is larger causing it to lose alleles needed for reproduction.

explain how geographic and reproductive isolation can lead to new species

geographic-individuals are separated from same species and are forced to breed with other populations. reproductive-not possible for the individual to reproduce with the same specie in the population.

analogous structure

have closely related function but do not derive from the same ancestral structure.

vestigial structure

have no function but resemble structures with functional roles in related organisms.

explain how migration can affect the genetics of populations

if individuals move, genes move with them.

explain how divergent evolution can lead to species diversity

organisms come from a similar ancestor but they all adapt to their certain environments in which they live in.

explain how organisms undergo coevolution

organisms undergo coevolution when one adapts to the needs of another. EX: humans take penicillin to kill bacteria but over time, bacteria adapted to the use of penicillin.

describe Charles Darwin's contributions to scientific thinking about evolution

scientists did not think animals changed over time but after visiting islands, Darwin proved a theory of evolution.

contrast the effects of stabilizing selection, directional selection, and disruptive selection on populations over time.

stabilizing selection-most common, average form of a trait=highest fitness directional selection- more extreme form of a trait=higher disruptive selection-more extreme variation of a trait=higher fitness.

analyze the reasoning in Darwin's theory of evolution by natural selection

survival of the fittest. The species with the best traits will survive the longest.

evolution

the developments of new types of organisms from pre-existing types of organisms over time.

fitness

the measure of and individuals hereditary contribution to the next generation.

natural selection

the mechanism for descent with modification.

immigration

the movement of individuals into a population.

emigration

the movement of individuals out of a population.

gene flow

the process of genes moving from one population to another.