Mechanisms of Evolution Study Guide Review

What effect should traits have on the fitness of an organism if the organism is to succeed? It must increase fitness     

What factors determine how natural selection affects a population? Favorable adaptations increase fitness, leading to increased allele frequencies through successful mating

Differences in the shape of tortoise shells, or the length of their necks on different Galapagos Islands would most likely be attributed to?   adaptations to different environments such as feeding or habitat

  What attributes would help organisms survive under limitations, such as resources? Adaptations that are suited to the environment in which the organism lives

Half of a large population being geographically isolated can lead to what change over time? Reproductive isolation

An isolated population can be subject to what types of genetic issues? a small gene pool, no change in the allele frequency over time, low genetic diversity Ex> Polydactyly -- extra fingers or toes -- is one symptom of Ellis-van Creveld syndrome, commonly found among the Amish of Pennsylvania

What is an adaptation?   A trait that allows an organism to survive and reproduce

What happens when a population is subjected to speciation? New species arise

What is the struggle for existence? more members of population are born than can survive and must compete for food, living space, and other necessities

What is artificial selection? How does it differ from natural selection? Breeding of organisms possessing desirable characteristics; controlled by man  

What are the conditions necessary for natural selection to occur? more offspring are born than can survive, fitness varies among individuals, and there is heritable variation among members of the population.

What is the principle behind common descent? organisms who share common ancestors will share common inherited characteristics

What is fitness? the ability of an organism to survive and reproduce in its specific environment

Which organisms thrive in a particular environment? Those that are best adapted to that environment

A population decreases and a significant decrease in variation is observed in this population. This may be caused by_______________.   a genetic bottleneck

In natural selection, individuals best adapted to their environment survive due to   possession of inherited characteristics that increase fitness.

Charles Darwin’s theory of evolution by natural selection explains Through evolution, species descend from common ancestors, and those with low fitness become extinct.

What effect on frequency of genes will those associated with traits beneficial to the survival of a species in a particular environment have? they become more frequent

Organisms well suited to their environment not only survive, but also________. reproduce

The evolution of weeds that are resistant to pesticides illustrates_________. natural selection

According to the theory of evolution by natural selection, populations that thrive have what relationship with the environment? They are best adapted to their environment.

Courtship dancing, mating calls, attractive plumage (feathers) in birds are all examples of what type of isolating mechanism? Behavioral

A species of squirrel mating at a different time than another squirrel species would be an example of what type of isolating mechanism?   temporal