Happy Atheist Forum

General => Science => Topic started by: Recusant on November 08, 2021, 06:01:54 AM

Title: Asexual Reproduciton in Condors
Post by: Recusant on November 08, 2021, 06:01:54 AM
Female California condors have been found to occasionally produce fertile eggs without mating. It appears that the condors from those eggs aren't particularly fit, so maybe it's a holdover characteristic, or a rare throwback partially resulting from being in captivity.

"Surprise, California condors can reproduce without having sex, San Diego Zoo reports" | San Diego Union-Tribune (https://nordot.app/827093567735971840?c=592622757532812385)

QuoteHe's got his mother's eyes, and his father's ... nothing.

A scientific team led by the San Diego Zoo Wildlife Alliance announced Thursday that California condors can reproduce without having sex. Researchers made the finding after genetic tests showed that two condors born in captivity didn't have fathers.

Yes, fathers. And that's not a misspelling of "feathers."

This phenomenon, known as parthenogenesis, has been seen in certain insects, fish and reptiles. There have been a few cases among birds, too. But no one knew until now that female California condors could have offspring without males, a head-scratching finding that raises questions around how often this occurs and whether it matters in the wild.

Another unanswered question: Why did this happen? The mothers of both condors had each mated successfully before and were housed with a male at the time they reproduced asexually.

"I thought it was pretty remarkable," said Kevin Burns, an ornithologist at San Diego State University, who was not involved in the study. "That raises the issue that we should be looking for this more, I think."

[Continues . . . (https://nordot.app/827093567735971840?c=592622757532812385)]

The paper is open access:

"Facultative Parthenogenesis in California Condors" | Journal of Heredity

(https://academic.oup.com/jhered/advance-article/doi/10.1093/jhered/esab052/6412509)
QuoteAbstract:

Parthenogenesis is a relatively rare event in birds, documented in unfertilized eggs from columbid, galliform, and passerine females with no access to males. In the critically endangered California condor, parentage analysis conducted utilizing polymorphic microsatellite loci has identified two instances of parthenogenetic development from the eggs of two females in the captive breeding program, each continuously housed with a reproductively capable male with whom they had produced offspring.

Paternal genetic contribution to the two chicks was excluded. Both parthenotes possessed the expected male ZZ sex chromosomes and were homozygous for all evaluated markers inherited from their dams. These findings represent the first molecular marker-based identification of facultative parthenogenesis in an avian species, notably of females in regular contact with fertile males, and add to the phylogenetic breadth of vertebrate taxa documented to have reproduced via asexual reproduction.

[ΒΆ added. - R]

Title: Re: Asexual Reproduciton in Condors
Post by: Tank on November 08, 2021, 07:54:57 AM
Very interesting.