AP Biology 3.5 Evolution

AP Biology 3.5 Evolution. What is the reproductive barrier in the video best described as?

APAP Biology
AP BiologyEvolution
Evolve in changing environmentReproductive isolation
LanguageEnglish Language
Test PrepAP Biology

Transcript

00:18

And here are the potential answers: Many species are seasonal breeders based on

00:28

favorable conditions, such as abundant food and water supplies.

00:31

Many species’ wives wish they were romantic breeders who would bring home flowers and [Rhino wife wishing for more romantic Rhino husband]

00:35

chocolates once in a while.

00:37

Species like ring-tailed lemurs, horses, hamsters, and groundhogs prefer breeding in spring, [two groundhogs together in a forest]

00:42

while sheep, goats, elk, and mice prefer the fall.

00:46

Rabbits, however, pay no attention to the calendar. [lots of rabbits together]

00:49

Though is this seasonal reproductive barrier best described as “mechanical”?

00:53

Well, “mechanical” refers to the fact that some species are unable to mate with [A snake and a turtle side by side]

00:58

other species because…well, physically they just can’t.

01:02

The mechanics of the process are incompatible, which means A is incorrect.

01:07

How about B?

01:08

Is seasonal mating a geographical reproductive barrier?

01:11

Let’s say a body of water separates one herd of hippos from another. [Two hippo's either side of a body of water]

01:16

While that would be a darn shame, it wouldn’t have anything to do with the seasons.

01:20

So B isn’t our answer, either. [Hippo entering the ocean]

01:22

Let’s look at answer “D”.

01:24

A hybrid zygote is formed when no barriers exist to interspecies mating. [A zebra and a horse together and a hybrid of the two appears]

01:30

Since this is a pretty big no-no in nature, a post-zygotic reproductive barrier kicks

01:36

in to insure that the hybrid is infertile and won’t reproduce. [Hybrid of zebra and horse disappears]

01:40

Since “D” is all about isolation mechanisms, we can eliminate it as our correct answer.

01:46

That leaves us just with “C,” temporal.

01:48

Temporal separation is defined as a mating barrier achieved by differences in the timing

01:54

of species’ mating seasons.

01:58

Looks like C is our right answer.

01:59

Now will someone please get that poor rhino a box of chocolates…? [Two rhinos sniffing for chocolates]