{"id":288101,"date":"2023-11-19T16:28:45","date_gmt":"2023-11-19T15:28:45","guid":{"rendered":"https:\/\/climatescience.press\/?p=288101"},"modified":"2023-11-19T16:28:48","modified_gmt":"2023-11-19T15:28:48","slug":"walrus-and-polar-bear-population-size-changes-in-the-n-atlantic-over-the-last-20k-years","status":"publish","type":"post","link":"https:\/\/climatescience.press\/?p=288101","title":{"rendered":"Walrus and polar bear population size changes in the N. Atlantic over the last 20k years"},"content":{"rendered":"\n
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From polarbearscience<\/a><\/p>\n\n\n\n

This is a lesson in how to assess the potential worth of scientific papers. One of two similar Arctic evolution studies got media attention, at least in Canada<\/a> \u2014 about the polar bears<\/a>, of course \u2014 but in my opinion the walrus research conclusions<\/a> are much better supported, less biased by climate change rhetoric, and lack the hubris present in the polar bear paper<\/a>.<\/p>\n\n\n\n

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Both studies use similar sample sizes for the regions they had in common (North Atlantic) and used computer models to determine genetic diversity and population size changes since the LGM. However, the tone of the walrus paper was less emotionally-charged and the caveats of the work were appropriately stated. In my opinion, papers like the polar bear example contribute to eroding the public\u2019s trust in science<\/a>.<\/p>\n\n\n\n

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The last Ice Age peaked between about 27,000 and 19,000 years ago. At this time the Arctic was buried under kilometers of glacial ice sheets, and so marine mammals were pushed southwards to areas of ice floes and more open water. Walrus survived in some areas of the Atlantic\u00a0located further to the south, and as soon as climates warmed again, the ice edge retreated and walrus populations pushed quickly northwards again. This combination of warming and climate-driven dispersal led to local walrus populations becoming more genetically differentiated<\/em>. Walrus study, Lund University\u00a0press release<\/a>\u00a027 September 2023<\/p>\n\n\n\n

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The walrus paper<\/strong><\/p>\n\n\n\n

By Emily Ruiz-Puerta and 17 other authors, called \u201cHolocence deglaciation drove rapid genetic diversification of Atlantic walrus.\u201d<\/a><\/p>\n\n\n\n