Contrary to widespread assumptions among biologists:
The animal they studied is the beetle mite Oppiella nova. Until now, the survival of an animal species over a geologically long period of time without sexual reproduction was considered very unlikely, if not impossible. However, the team of zoologists and evolutionary biologists from the Universities of Cologne and Göttingen as well as the University in Lausanne (Switzerland) and the University of Montpellier (France), demonstrated for the first time the so-called Meselson effect in animals in the ancient asexual beetle mite species O. nova. The Meselson effect describes a characteristic trace in the genome of an organism that suggests purely asexual reproduction. The results have been published in PNAS.University of Cologne, “Some animal species can survive successfully without sexual reproduction” at ScienceDaily (September 22, 2021)
It’s apparent that no one really knows how they do it:
The existence of ancient asexual animal species like O. nova are difficult for evolutionary biologists to explain because asexual reproduction seems to be very disadvantageous in the long run. Why else do almost all animal species reproduce purely sexually? Animal species such as O. nova, which consist exclusively of females, are therefore also called ‘ancient asexual scandals.’ Proving that the ancient asexual scandals really do reproduce exclusively asexually, as hypothesized (and that they have been doing so for a very long time), is a very complex undertaking: According to first author of the study Dr Alexander Brandt of the University of Lausanne, ‘There could be, for example, some kind of “cryptic” sexual exchange that is not known. Or not yet known. For example, very rarely a reproductive male could be produced after all — possibly even “by accident.” ” Purely asexual reproduction, however, at least theoretically leaves behind a particularly characteristic trace in the genome: the Meselson effect…
Their efforts were ultimately rewarded: they succeeded in proving the Meselson effect. ‘Our results clearly show that O. nova reproduces exclusively asexually. When it comes to understanding how evolution works without sex, these beetle mites could still provide a surprise or two,’ Bast concluded. The results show: the survival of a species without sexual reproduction is quite rare, but not impossible. The research team will now try to find out what makes these beetle mites so special.University of Cologne, “Some animal species can survive successfully without sexual reproduction” at ScienceDaily (September 22, 2021)
Hmmm. Another dogma for the museum.
The paper is open access.