Determine the most likely reason why natural selection may cause prezygotic reproductive isolating mechanisms to evolve if postzygotic reproductive isolating mechanisms are already present

Determine the most likely reason why natural selection may cause prezygotic reproductive isolating mechanisms to evolve if postzygotic reproductive isolating mechanisms are already present, but natural selection can never cause the evolution of postzygotic reproductive isolating mechanisms.

Natural selection may lead to the evolution of prezygotic reproductive isolation in organisms that already have postzygotic isolation to prevent wasted reproductive effort.
Prezygotic isolation can evolve if postzygotic isolation has generated genetic variation during earlier periods of anagenesis.
If postzygotic isolation is present, then natural selection is already acting on the same suite of traits that may lead to evolution of prezygotic isolation.
Prezygotic reproductive isolating mechanisms are the necessary physiological and behavioral precursors for the evolution of postzygotic isolation via natural selection.

Solutions

Expert Solution

Reproductive isolation and geographical isolation are two major mechanisms that lead to evolution of new species. Reproductive isolation can further be divided into two parts on the basis of whether the barrier is acting before or after the formation of zygote. If barriers are present before zygote formation, it is called pre zygotic isolation, whereas if barriers act after the formation of zygote, it is called post zygotic isolating mechanism.

Pre zygotic isolation mechanisms include mechanisms which prohibit mating or don't allow formation of a zygote . It includes gamete incompatibility, different mating signals, different maturation timing , etc. On the other hand, post zygotic barriers include hybrid sterility , zygote mortality, etc. Post zygotic isolation leads to wastage of energy and resources, whereas pre zygotic barriers prevent wastage of reproductive effort.

Thus, most likely reason for evolution of pre-zygotic isolation mechanisms is :

Natural selection may lead to the evolution of prezygotic reproductive isolation in organisms that already have postzygotic isolation to prevent wasted reproductive effort.

gladiator answered 1 year ago

Next > < Previous

Related Solutions

Distinguish between postzygotic and prezygotic isolating mechanisms. Which might evolve first if speciation were sympatric? Which...

Distinguish between postzygotic and prezygotic isolating mechanisms. Which might evolve first if speciation were sympatric? Which might evolve first if speciation were allopatric?

Darwin argued that natural selection would never cause a trait to evolve in one species that...

Darwin argued that natural selection would never cause a trait to evolve in one species that benefitted another species at a fitness expense to the first species. A study of egrets in Florida found that parents eject some of their own chicks from the next. This behavior feeds alligators living in the swamps below the nests. The steady supply of food improves the health and condition of the alligators. In view of Darwin’s logic, what are two hypotheses that might...

Why would plants need to evolve vascular tissue, lignin, and the different reproductive mechanisms (cone versus...

Why would plants need to evolve vascular tissue, lignin, and the different reproductive mechanisms (cone versus flower).

INFLUENZA a. Name the virus most likely to cause the flu. b. Why was the H1N1...

INFLUENZA a. Name the virus most likely to cause the flu. b. Why was the H1N1 swine flu so dangerous? c. How do flu symptoms differ from the common cold? List at least 4 differences.

1.) Describe what type of alleles natural selection works most strongly on, and explain why. 2.)...

1.) Describe what type of alleles natural selection works most strongly on, and explain why. 2.) How does Dawson’s experiment demonstrate the concept referred to in question 1? 3.) Differentiate between overdominance and underdominance and give an example of when overdominance can occur. 4.) Explain how frequency-dependent selection works. 5.) Describe the potency of mutation as an evolutionary force, and explain why. 6.) What happens when mutation is combined with selection and how does cystic fibrosis exemplify this? I need...

1. Which of the lab values is the most likely cause of this patient’s swelling in his wrist and toe? Explain why this can cause pain.

A 54-year-old male presents to the clinic with severe pain in his left wrist and right great toe. The affected joints are swollen, erythematous and painful. The patient has limited range of motion of these joints. He denies injury to these areas. The patient is afebrile with a temperature of 98.8, all vital signs are within normal limits. The patient has a history of hypertension and hyperlipidemia. He has been steadily gaining weight over the past few years and is now about...

Subjects