The California newt, Toricha toroso, lives in the coastal areas around Los Angeles. Which of the following is a valid null hypot
hesis relating fitness to survival of a bottleneck event in a coastal area where a small, isolated population of California newts resides? (A) Only those salamanders with the lowest evolutionary fitness will be eliminated by the bottleneck effect, lowering the allelic frequencies of their traits.
(B) Only those salamanders with the highest evolutionary fitness will survive the bottleneck event, raising the allelic frequencies of their traits.
(C) Surviving the bottleneck event will be random, so any change in the allelic frequencies of the salamander population is not attributed to fitness
(D) Surviving the bottleneck event will be random, so there will be no changes to the allelic frequencies due to the bottleneck event.
(B) Only those salamanders with the highest evolutionary fitness will survive the bottleneck event, raising the allelic frequencies of their traits.
Explanation:
Toricha toroso is a type of salamander which lives in the coastal areas of California after the bottleneck event. Bottleneck event is a kind of event in which population of organisms are reduced due to harsh climatic condition. In these harsh climatic condition of the environment, Toricha toroso survive because of the fitness of this salamander. Fitness plays a vital role in the survival of organisms.
The genetic drift caused by a population bottleneck can change the proportional random distribution of alleles and even lead to loss of alleles. The chances of inbreeding and genetic homogeneity can increase, possibly leading to inbreeding depression. Smaller population size can also cause deleterious mutations to accumulate.
