You've likely heard of polar bears (Ursus maritimus) and grizzly bears (Ursus arctos horribilis). Have you hear of a grolar bear or a pizzly bear? These might be unfamiliar because they are the offspring of matings between polar bears and grizzlies

Question

A handful of
these animals have been born in zoos; three have been documented in nature. Due to their
rarity, only a few grolars (grizzly dad and polar bear mom) or pizzlys (polar bear dad and
grizzly mom) have been studied in detail. Their fur color, head shape, and ear shape are
striking intermediates between the phenotypes of their parents.
It is thought that polar bears originated from a population of brown bears (Ursus arctos) that
became geographically isolated during a glaciation event that occurred about 150,000 years
ago (Lindqvist et al., 2010). Traditionally the territories of grizzly bears and polar bears did
not overlap, as grizzlies ranged from Alaska to Mexico, whereas polar bears stayed on the
annual sea ice over the Arctic continental shelf and within the Arctic archipelagos. Relatively
recently (last 50 years or so) grizzlies and polar bears have begun to come in contact in the
wild.
References:
Lindqvist, Charlotte; Schuster, Stephan C.; Sun, Yazhou; Talbot, Sandra L.; Qi, Ji; Ratan,
Aakrosh; Tomsho, Lynn P.; Kasson, Lindsay et al. (2010). Complete mitochondrial genome
of a Pleistocene jawbone unveils the origin of polar bear. PNAS 107 (11): 5053-5057.
doi:10.1073/pnas.0914266107. PMC 2814953. PMID 20194737.
The origin of polar bears was the result of
A. allopatric speciation.
B. sympatric speciation.
C. peripatric speciation.

Answer 1

A