Tag Archives: thyroid hormone

The story of polar bear evolution could not be told without discussing climate change

Polar bears arose as a new species because the climate changed and forced some brown bears to colonize the sea ice. Polar bears epitomize the story of how evolution works but perhaps not quite how you imagined it.

Moving from extremes in warmth to extremes in cold characterized the last million years of geological history, as the graph above shows, where odd-numbered Marine Isotope Stages (MIS) are warm interglacials and even-numbered stages along the bottom are cold glacials. MIS 2 was the Last Glacial Maximum.

But where and when during this period of change did polar bears come to be–and how, exactly, did it happen? My new book tells the whole story, which has never been done before. Not long to wait now, the release date is only about a week away (1st week June).

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Podcast with WildFed about polar bears and domestication as speciation

A couple weeks ago I had a fabulous chat with Daniel Vitalis from Wildfed about a wide range of topics, including my work on polar bears and domestication as a process of speciation. The podcast went live this morning – have a listen here (also copied below), I think you’ll enjoy it. One hour, 36 minutes.