Question

Which of the following factors influences the process of adaptive radiation resulting in rapid speciation the least?
A. Genetic drift.
B. Migration to a new area with appropriate resources and few competitors.
C. Ecological niche vacated by extinction.
D. The adaptive radiation in a group of organisms that another group of organisms use as a food source.

Answer 1

Adaptive radiation is a process in evolutionary biology in which organisms rapidly evolve from an original species into a plethora of new forms, especially when a change in the environment makes new resources accessible, changes biotic interactions, or creates new environmental niches. Darwin’s finches are examples of adaptive radiation.

Complete answer:
Option: A – Genetic drift is a random process and is completely based on chance events which leads to variation in a population. Thus, the probability of speciation becomes low due to genetic drift. Furthermore, genetic drift may result in adaptive radiation.
Thus, Option A is correct.
Option: B - Migration to new areas with appropriate resources and few competitors will only decrease the rates of speciation and adaptive radiation, as the optimum conditions of survival won’t promote the species to move towards other lands leading to adaptive radiation and speciation.
Thus, option B is not correct.
Option: C – Ecological niche vacated by extinction generally does not lead to adaptive radiation.
So, Option C is not correct.
Option: D - The adaptive radiation in a group of organisms that another group of organisms use as a food source is not too much observed phenomenon.
So, Option D is not correct.

Hence, Option A. Genetic drift is the correct answer.

Note:
Random variations in the number of gene variants in a population are referred to as genetic drift. When the prevalence of alternative versions of a gene, known as alleles, rises and decreases by chance over time, this is referred to as genetic drift. Changes in allele frequencies are used to quantify these differences in allele presence. Genetic drift is most common in small populations.