Question

Explain with examples how each of the concepts below can impact medicine and human health. (Examples with evidence, may be real or well-articulated potential scenarios).

1. Genetic drift

2. Gene flow

3. Dispersal

4. Natural Selection

5. Cline

Answer 1

Answer=

1. Genetic drift = Is a mechanism of evolution in which allele frequencies of a population change over generations due to chance i.e.sampling error.

It occurs in all populations of non-infinite size,but its effects are strongest in small populations.

Examples=

In hypothetical population:A population of rabbits lives in the woods.The rabbits have many different coat colors:Black,brown,tan ,white,Grey,and even red.

In the population,the different alleles that create coat color are equally distributed.A disease comes in rabbit population and kills 90% of the rabbits.The only rabbits that are left are red and grey rabbits,simply by chance.The genes have thus "drifted" from 6 alleles to only 2.This is an example of bottleneck.

In real life -genetic drift happens all the time in populations,although it is not easily seen.

Often mutations arise that have little effect on the organism.these mutations get passed on if the organism reproduces ,and do not get passed on if the organism does not survive.Although genetic drift used to be thought of in only small populations,even large populations experiances drift of certain alleles.

2. Gene flow = Is the transfer of genetic variation from one population to another.

Example= A bee carrying pollen from one flower population to another ,or a caribou from one herd mating with members of another herd.

3. Dispersal -it refers to the both movements of inviduals i.e.animals ,plants fungi.bacteria from their birth siteto their breeding site called as dispersal.

4. Natural Selection - Is the process whereby organisms better adapted to their environment tend to survive and produce more offspring.The theory of its action was first fully expounded by Charles Darwin.

Examples- treefrogs are sometimes eaten by snakes and birds.Gray Treefrogs blend well in dark wooded areas on tree bark and green treefrog blend in well with green vegetation found in marshes and swamps.A green treefrog on the bark of a tree is easier for a predator to find,compared to a green treefrog on a green leaf.