Q24.3-2CC Consider two species that diverg... [FREE SOLUTION]

Chapter 24: Q24.3-2CC (page 518)

Consider two species that diverged while geographically separated but resumed contact before reproductive isolation was complete. Predict the outcome over time if the two species mated indiscriminately.
(a) hybrid offspring survived and reproduced more poorly than offspring from intraspecific matings or
(b) hybrid offspring survived and reproduced as well as offspring from intraspecific matings.

Short Answer

Expert verified

The statement 鈥渉ybrid offspring survived and reproduced more poorly than offspring from intraspecific mating鈥� is true.
The statement 鈥渉ybrid offspring survived and reproduced as well as offspring from intraspecific mating鈥� is false.

Step by step solution

Reproductive isolation

The related species fails to reproduce successfully due to various barriers, and such inability is known as reproductive isolation.The obstacles might be physiological, genetic, or geographical differences.

The mating seasons and mating behavior also act as barriers to reproduction between two divergent species.

Explanation of option ‘(a)’

When the two divergent species which are reproductively isolated come in contact, they might breed, and such mating is called interspecific mating. However, due to reproductive isolation, the hybrid offspring produced perhaps shows lower survivorship and decreased fertility.

Hybrid often shows decreased fertility than the parental population.

Thus, the hybrid species reproduce poorly due to interspecific mating. The offspring produced from intraspecific mating is more fertile.

Therefore, the given statement is true.

Explanation of option ‘(b)’

The hybrid offspring produced from indiscriminate mating from diverge species cannot reproduce well as their parental population. However, reinforcement of factors such action of natural selection might strengthen the hybrid species to proceed speciation.

It is often proved that the relative fitness of the parental population is maximum than the hybrids鈥� relative fitness.

Thus, interspecific or indiscriminate mating between two species would not produce well-reproducing offspring.

Therefore, the given statement is false.