Tusk buddy Antonio Zamora tipped me off to the paper below revealing that a global loss of genetic males coincides exactly with the comet impact at ~12,882. Tony does an indispensable job surfacing literature highly relevant to the Younger Dryas Impact. I had missed the stunning 2015 gene paper.
Following the depth of the greatest climate crisis in human history, earth’s female-to-male ratio began a dive to 17 females to one male.
To help explain the sudden collapse of breeding men, the authors unfortunately ignore the well published evidence for a cosmic impact, and make an awkward claim (for the mainstream) that a global diffusion of some unknown cultural/tech meme spread ’round the earth — and all the dads were gone.
The 100 authors speculate about a cause with a parenthetical reference to missing padres due to the “invention of the wheel,” and “open water sailing:”
Innovations in transportation technology (e.g., the invention of the wheel, horse and camel domestication, and open water sailing) might have contributed to this pattern. Likely, the effect we observe is due to a combination of culturally driven increased male variance in offspring number within demes and an increased male-specific variance among demes, perhaps enhanced by increased sex-biased migration patterns (Destro-Bisol et al. 2004; Skoglund et al. 2014) and male-specific cultural inheritance of fitness.
That’s a really odd paragraph in an important paper. For better or worse, there is no peer-reviewed evidence of the “wheel” or “open water sailing” prior to, at the start, during, or following the Younger Dryas — for more than 5000 years. Such claims are stuff for Atlanteans. Strangely, the authors reach for more speculative elements of the yet to be revealed YD story, such as precursor civilizations. But in this paper at the expense of the well supported Younger Dryas Impact.
When I first wrote this post, and tweeted it, I heard back from other YDI proponents who were reluctant to believe the YDI was responsible for the dad crash. First they pointed out that the total collapse followed the YDI by nearly two thousand years; and second, the missing males may have been born and alive after the comet impact, but sidelined from reproduction by a global shift towards “harem formation.”
This is worthy speculation, but the first objection seems to leave out, that while more modest than the ultimate downturn, RIGHT AT the initiation of the Younger Dryas (i.e. comet impact) the males begin to recede for the first time in genetic history. So perhaps the ultimate crash was a “tipping point” for an accentuation of the initial cause of the decline?
The second objection is certainly on the table, but does not preclude a comet cause. It also begs several questions. Why was the entire globe suddenly overcome with harem formation? And how on earth did the 1/17 of male parents dominate the rest so thoroughly — around the world?
It is also tough to understand why Karmin et al. failed to properly cite — even to dismiss — the much better published YDI. They could have listed dozens of papers providing a milestone event that may have catalyzed the unexplained demasculinization…but instead they make uncited speculation from the gray literature.
The authors are both timid — and wild — at the same time.