Ray of Hope: Researchers Identify Two Asexual Births Among Critically Endangered California Condors | The Weather Channel – Articles from The Weather…

A California condor.

It was just an ordinary day of analysing biological samples from California condors in the San Diego Zoo Wildlife Alliance for Leona Chemnick, a researcher in the alliance's conservation genetics labthat was until she came across something that was not quite ordinary. Leona found that two California condor chicks were genetically related to their mother but didn't seem to be related to any male.

Puzzled and likely bewildered, Leona discussed the situation with Oliver Ryder, the Director of Conservation Genetics at San Diego Zoo Wildlife Alliance. It dawned on them, or as Oliver put it, "hit them in the face," that the discovery that neither bird was genetically related to a male implied that both chicks were biologically fatherless. Which meant parthenogenesis, or asexual reproduction, had been at play.

Parthenogenesis is a natural form of asexual reproduction in which an embryo that hasn't been fertilised by sperm continues to develop with only the mother's genetic materials. This is the first time parthenogenesis that researchers have documented in condors. It is also the first time it has been discovered using molecular genetic testing and in any avian species where the female bird has access to a mate.

This phenomenon, although rare, has been observed in fishes and lizards before. So you might wonder why this is such a huge deal. Well, not long ago, California condors had teetered over the edge of extinction, and it was only through extensive and dedicated conservative methods that conservationists were able to save the species from total extinction. Even then, California condors continue to remain critically endangered. It's thus a big deal that condors can reproduce asexually, potentially increasing the species' chances of producing offspring.

Scientists have previously documented parthenogenesis in isolated domesticated birds such as turkeys and chickens, but this is the first time a "virgin birth" has produced viable chicks in a wild condor population.

The California condor parthenotes were produced by two different dams, each of which was housed with a fertile male continuously. Both of these females had a large number of offspring with their partnersone had 11 chicks, while the other had 23 chicks after being paired with a male for over 20 years. Following parthenogenesis, the latter pair reproduced twice more.

"We only confirmed it because of the normal genetic studies we do to prove parentage. Our results showed that both eggs possessed the expected male ZZ sex chromosomes, but all markers were only inherited from their dams, verifying our findings," said Oliver.

Unfortunately, one parthenogenic offspring died in 2003 at the age of 3, and another died in 2017 at 8.

Luckily, the San Diego Zoo Wildlife Alliance researchers could confirm this groundbreaking discovery by analysing data gathered during the successful and collaborative California Condor Recovery Program.

Using blood, eggshell membranes, tissues, and feathers to gather genetic data from 911 individual condors, conservationists have been conducting extensive genetics and genomics research for over 30 years. Before confirming the outcome of this unique case of parthenogenesis, they were able to cross-reference historical genetic records.

The study is expected to have a profound effect on wildlife genetics and conservation science.

The study was published in the Journal of Heredity last week and can be accessed here.

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Ray of Hope: Researchers Identify Two Asexual Births Among Critically Endangered California Condors | The Weather Channel - Articles from The Weather...