From Newsgroup: talk.origins

https://abcnews.go.com/US/survival-snow-leopard-populations-precarious-researchers/story?id=126327136

The PNAS article is paywalled. Their measure of genetic diversity is heterozygousity. Sumatran tigers and cheetahs have greater
heterozygousity, but may be more inbred. Heterozygousity isn't a good
measure for the amount of genetic diversity because it involves
individuals of distinct populations that are obviously genetically
separated and divergent from each other. While all cheetahs are as
closely related as cousins, my guess is that a lot of the snow leopards
are not that genetically related. The paper has 47 samples that
identify 3 distinct populations (India, Russia, China) that are inbred
within populations. They are inbred within populations, but the
populations are genetically distinct. They found 379,861 private SNPs
in the North and 364,010 private SNPs to the South, and 598,449 SNPs
shared between populations. This just means that heterozygousity could
more than double just by crossing a Snow Leopard from the South to the
North.

What they need to do is somehow restore the genetic connections between populations that have now been isolated from each other. If this isn't
done the populations will either survive (if they have a low enough
genetic load) or go to extinction if inbreeding depression becomes an issue.

The decrease in heterozygousity may be due to a more ancient population bottleneck because they have fewer runs of homozygousity (recent
inbreeding) than puma. The high number of private SNPs between north
and south indicates that these populations are derived from different bottlenecked populations. Where did these populations exist during the
last ice age when their current habitat was likely not habitable. My
guess is that during the ice age their territory was greatly expanded,
and that the bottle neck occurred during the last warm period when they
would have been restricted to territory similar to what they exist in
today. Their populations would have been isolated from each other, and
last warm period things may have been even warmer and their territory
may have been more restricted than it has become with the current human factor. Hunting has decimated the current populations, but last warm
period more ice melted than has yet melted, so we haven't yet seen the
extent that their habitat had been reduced last time. It just means
that things are going to get worse then they are now.

Ron Okimoto

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