All Members of the Golden Hamster Species Known Today Are

Multiple Choice

All members of the golden hamster species known today are descendants of a single litter collected in Syria in 1939. Its diploid chromosome number is 44. Two other species of hamster, each with a diploid number of 22, overlap in Syria. The golden hamster is thought to be a new species from the mating of a male and female of the two other hamster species. What mechanism might explain this recent event of speciation?

A) adaptive radiation
B) formation of a fertile hybrid and halving of the chromosome number of this hybrid
C) polyploidy
D) temporal isolation
E) disruptive selection