Sorry to be a pedant but the antlers-too-big thing is contentious& probably not true. I forget the details right now but I was persuaded that the idea was false by a chapter in Stephen Jay Gould’s book (which I highly recommend) ‘Ever Since Darwin.’
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Replying to @Una_May_Barker
Thanks Una. Yes, I am aware that there is a debate around this, and no scientific consensus either way. I originally wrote "the Irish elk *is said to have* died out because...", however, that made my tweet more than 280 characters. I had to simplify just to make the tweet fit!
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Replying to @G_S_Bhogal @Una_May_Barker
Okay, I just read Gould's chapter, and he seems to have gotten a couple things wrong. (1/7)
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Replying to @G_S_Bhogal @Una_May_Barker
Gould assumes the original theory postulated that the antlers caused extinction by making the elk an easy target for predators. He doesn’t consider that the elks suffered osteoporosis as a result of nutrients from bones being diverted to antlers: http://www.evolutionary-ecology.com/abstracts/v01/1026.html … (2/7)
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Replying to @G_S_Bhogal @Una_May_Barker
Gould claims on page 90 that the elk likely went extinct because of the cold epoch that followed the Allerod interstadial phase 11,000 years ago. However, he gets the extinction date wrong, by a couple thousand years. (3/7)
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Replying to @G_S_Bhogal @Una_May_Barker
The last elk fossils date from 7000 years ago – long after the Allerod interstadial phase. Analysis of the last specimens disproves Gould’s theory that the elk died out due to an ice snap: https://web.archive.org/web/20071001031248/http://serv-umr5023.univ-lyon1.fr/~cdouady/publications/Hughes.2006.MPE.pdf … (4/7)
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Replying to @G_S_Bhogal @Una_May_Barker
Of all theories suggested for the elk’s end, its antlers would only have exacerbated matters. Whether it was the aforementioned osteporosis, or its antlers making it an easy target for humans, or putting such a burden on it that it couldn’t consume the requisite calories. (5/7)
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Replying to @G_S_Bhogal @Una_May_Barker
We can't be sure exactly how much the antlers worsened matters. But what we do know is that evolutionary dead ends are commonplace – as you know, 99% of all historical species are now extinct, because evolution regularly leads to maladaptations as environments change. (6/7)
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Replying to @G_S_Bhogal @Una_May_Barker
So I don’t think it's a stretch for me to use the elk’s likely maladaptation as a metaphor to speculate about whether our overencephalised brains are also likely maladaptions. The key thing is to see extinctions of creatures like the elk as possible warnings for ourselves (7/7)
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Replying to @G_S_Bhogal @Una_May_Barker
Correction: a slight misreading by me. Replace all instances of "allerod interstadial phase" with "younger dryas cold phase". The points I made still stand.
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And here's the full paper regarding the reduced resorption of minerals into malnourished elks' bones due to their antlers. https://www.d.umn.edu/~rmoen/Dld/Moen_1999.pdf …
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