Found a similar question with the following choices:
a. living things and flowing water
b. climate and soil properties
c. physical setting and biological community
d. climate and landscape features
In a watershed system, the two main parts are the A. LIVING THINGS AND FLOWING WATER
Answer:
Genetic drift is a mechanism of evolution in which allele frequencies of a population change over generations due to chance (sampling error).
Genetic drift occurs in all populations of non-infinite size, but its effects are strongest in small populations.
Genetic drift may result in the loss of some alleles (including beneficial ones) and the fixation.
Genetic drift can have major effects when a population is sharply reduced in size by a natural disaster (bottleneck effect) or when a small group splits off from the main population to found a colony (founder effect).
C. Would be the right answer!!!!!!
plutoids hope this helps :)
It is an example of directional selection.
The different kinds of natural selection can influence the distribution of phenotypes within a population. In stabilizing selection, an average phenotype is preferred.
In directional selection, a modification in the surrounding changes the spectrum of the observed phenotypes, and in diversifying selection the extreme values for a trait are preferred over the transitional values. This kind of selection usually pushes speciation.
The directional selection, in the field of population genetics, refers to a mode of natural selection in which an extreme phenotype is preferred over other phenotypes, making the allele frequency to change with time in the orientation of that phenotype.