Return to David's theory of evolution III (Evolution)

by David Turell , Thursday, January 30, 2025, 17:48 (1 day, 9 hours, 13 min. ago) @ David Turell

I think major evolution has run its course:

https://mail.google.com/mail/u/0/#inbox/FMfcgzQZSsKtxVwsKCJfFFSbLkqRhzlf

"Global study finds species are losing genetic diversity

"Genetic variation is what allows a species to adapt as climate changes, new diseases arise, and novel predators come on the scene. But just as the number of species is declining worldwide, there is a “silent extinction” underway because the genetic diversity within many species—a long overlooked aspect of biodiversity—is also being lost.

"Conservationists were already worried about declines in the genetic diversity of threatened species. But the new study indicates some animals and plants whose populations seem healthy are becoming less diverse . Conservation biologist Catherine Grueber and scores of colleagues assembled 882 papers written between 1985 and 2019 that traced diversity changes over time within individual species by analyzing the DNA of 628 species at two time points or more. They also tracked how conservation measures and ecological disturbances affected this diversity. Genetic diversity declined in two-thirds of the populations, which could make them less likely to bounce back from environmental stresses. The study also found that conservation efforts such as restoring habitat or eliminating pests failed to stem these losses, although transferring individuals into diminished populations or new habitats did help in some cases.

"The study reinforces a 2024 study that used population numbers as simpler, cheaper proxies for DNA, and found that 58% of the 919 species evaluated were losing diversity; a separate preprint concluded protecting existing habitat would not slow this loss. (my bold)

“'Finally, genetic diversity is getting the attention it deserves,” says Alicia Mastretta-Yanes, a co-author on the 2024 paper."

Comment: evolution can only advance if the available DNA is rich in diversity. I don't see humans taking over the designer's job. Major evolution producing totally new families is over.