1. Which climatic factor appears to be most responsible for a massive decline of brown bears across Europe, starting about 12,000 years ago?
a) Warmer winters
b) Drier summers
c) Excessive summer heat
d) Increased winter snowstorms
2. An ancestor of which of these bear species was recently found in Hungary (Europe):
a) Giant panda
b) Asiatic black bear
c) Sloth bear
d) Atlas bear
3. Which of these brown bear (Ursus arctos) subspecies seems to have “docile genes” and has never attacked a human (at least in the last century):
a) Syrian bear
b) Marsican bear
c) Ussuri bear
d) Isabelline bear
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1. ANSWER: (a) Warmer winters. A thorough investigation of climate change across Europe for 12,000 years corresponded with a decline of brown bears into smaller pockets. The authors attributed the principal change to warmer winters, which have 2 effects: (1) brown bears living in places with warm winters have lower reproductive rates; and (2) warmer winters encouraged more people to live there.
Albrecht et al. 2017. Humans and climate change drove the Holocene decline of the brown bear. Scientific Reports:
2. ANSWER: (a) Giant panda. Several species of giant panda have been found in the fossil record, as far west as Spain. The recent find of panda teeth in Hungary was quite old (10 million years), and indicated that this species likely ate bamboo. Note that it is not known whether this species predated or occurred together with pandas in Asia.
Summary and citation of reference:
3. ANSWER: (b) Marsican bear. If you never heard of the Marsican bear, you might have worked through this question by process of elimination, since the topic for the 3 questions was about “European bears”: the other brown bear subspecies listed in the multiple choice answers all live in Asia. The so-called Marsican bear (Ursus arctos marsicanus) lives in central Italy, and the reason it has its own subspecific name is that this population has been isolated for a very long time. The authors of this paper argue that through time, this population declined drastically, and had a massive loss of genetic variation: the bears with the more aggressive genes were killed, leaving a rather docile brown bear subspecies that has not attacked anyone in at least 100 years.
But that doesn’t mean it’s not involved in conflicts with people. See this video: http://www.telegraph.co.uk/news/2017/08/23/bear-goes-terrifying-rampage-italian-village/
Benazzo et al. 2017. Survival and divergence in a small group: The extraordinary genomic history of the endangered Apennine brown bear stragglers. Proc. National Acad. Sciences.