Question

which scenario describes an example of gene flow?
some individuals in a population of bears have very thick coats that help them conserve heat and energy during cold winters. after several generations, the proportion of bears with thick coats increases.
a mistake during dna replication causes the offspring of a yellow flowering plant to have blue flowers. the blue flower trait is passed on to successive generations.
a species of snake is spread across a wide area of the country living in separate populations within relatively close proxim to one another. migration between the populations prevents speciation from occurring.
overhunting of the american bison caused the population to decrease from millions to a few hundred by the late 1800s. conservation efforts brought the population back up, but there is lit ersity.

Explanation:

Gene flow is the transfer of genetic material from one population to another. In the case of the snake species, migration between populations (which is a form of gene flow) prevents speciation. Speciation is the process by which new species form, and gene flow can act against it by keeping the gene pools of the populations similar.

• The first option is an example of natural selection (thick - coated bears being favored in cold winters).
• The second option is an example of mutation (a change in DNA during replication leading to a new trait).
• The fourth option is an example of a bottleneck effect (a significant reduction in population size leading to low genetic diversity).

Answer:

A species of snake is spread across a wide area of the country living in separate populations within relatively close proximity to one another. Migration between the populations prevents speciation from occurring.