"the aging ovary is a potential third hit for ovarian cancer, with the first hit being genetic and the second hit being environmental..." This is important work crossing generations. Further, it shows that medical research (once centered on younger patients) is reaching older cohorts.
I had a conversation about a month ago with a friend who had gone through menopause and I realized I had no idea what the ovaries did when they stopped producing eggs. She didn’t either! I can see why it isn’t the most obvious target for research when the primary focus is fertility, but I do find it fascinating that women’s bodies stop the reproductive cycle and keep on kicking for decades. So much complexity, it’s quite the evolutionary trait.
I’m not sure about that. Evolution has two mechanisms: mutation to roll the dice for new traits, and natural selection against any traits that hinder survival up to the point of successful reproduction.
Because this ovarian trait only manifests well after reproductive function it cannot be explained by selection pressure; the remaining culprit would be happy mutation.
Yet while every post-reproductive trait is free to vary without selection, but this one appears to be unvaried across the entire class Mammalia. What force would preserve a non reproductively-advantageous trait so broadly?
True, but this has become much less important for humans than for their ancestors, because a large part of what humans eat is nutrient-dense and easy to digest, so that does not rely on the help from gut bacteria.
Thus many humans may live most of their lives without their appendix, without any serious consequences.
Understanding of the role of the gut microbiome is continually being expanded. It is resposible for a lot of important hormones, for example. It goes way beyond digestion.
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[ 0.23 ms ] story [ 23.5 ms ] threadGreat job.
I’m not sure about that. Evolution has two mechanisms: mutation to roll the dice for new traits, and natural selection against any traits that hinder survival up to the point of successful reproduction.
Because this ovarian trait only manifests well after reproductive function it cannot be explained by selection pressure; the remaining culprit would be happy mutation.
Yet while every post-reproductive trait is free to vary without selection, but this one appears to be unvaried across the entire class Mammalia. What force would preserve a non reproductively-advantageous trait so broadly?
In reality the appendix vermiformis serves as a reservoir for gut bacteria (useful), and possibly supports the immune system
Thus many humans may live most of their lives without their appendix, without any serious consequences.
[example source: https://gut.bmj.com/content/71/5/1020]
[note: human use of em-dash; no LLMs here]