There are pairs of species living in the same general area in which the members look identical but cannot interbreed, usually due to their chromosomes being incompatible and unable to form correct gametes. as time goes on we would expect those species

begin to show physical differences  

Explanation:

The answer is

"begin to show physical differences".

Any organisms or species in order to breed, their chromosomes should be compatible and should be able to form a gamete.

In an area,the pair of species, though they look identical are unable to breed because their chromosomes are incompatible and they do not form the correct gametes.

But these species are expected to show different physical characteristics and behaviors as time goes on because their chromosomes are different.

Thus the answer is

"begin to show physical differences".

ne pare rău, dar când mi-am căutat întrebarea, doar avioanele au apărut .. deci, ar putea fi răspunsul, sau ar putea fi baloane cu aer cald, deoarece acestea pot conta și ca ambarcațiunile de aer, dar nu sunt complet sigur de asta. a fost doar o presupunere, sper că am ajutat, îmi pare rău dacă nu am făcut-o. de asemenea, folosesc traducerea google, pentru a traduce ceea ce spun în engleză, așa că îmi pare rău dacă gramatica sau chiar limba nu este corectă

well its is frequent rain

have a good day