Exam 24: Species and Speciation

On the Bahamian island of Andros, mosquitofish populations live in various, now-isolated freshwater ponds that were once united. Currently, some predator-rich ponds have mosquitofish that can swim in short, fast bursts; other predator-poor ponds have mosquitofish that can swim continuously for a long time. When placed together in the same body of water, the two kinds of female mosquitofish prefer to breed only with males that have their same swimming ability. Which of the following phenomena have helped promote divergence between the mosquito populations?

Plant species X has a diploid number of 12. Plant species Y has a diploid number of 16. A new species, Z, arises as an allopolyploid from X and Y. The diploid number for species Z would probably be ________.

Some geographic areas contain two closely related species of birds (sympatry), while other areas contain only one of the species (allopatry). Males from allopatric populations look very similar to each other, but males in the sympatric populations look different from each other and from both allopatric types of males. Which of the following outcomes is most likely if a female in a sympatric area is courted by a male that migrated into the area from an allopatric area?

Which of the following statements most accurately applies to speciation?

Dog breeders maintain the purity of breeds by keeping dogs of different breeds apart when they are fertile. This kind of isolation is most similar to which of the following reproductive isolating mechanisms?