Female Sharks Can Reproduce Alone 293
mikesd81 writes "The Washington Post has an article about a team of American and Irish researchers that have discovered that some female sharks can reproduce without having sex, the first time that scientists have found the unusual capacity in such an ancient vertebrate species. Their report concludes that sharks can reproduce asexually through the process known as parthenogenesis (the growth and development of an embryo or seed without fertilization by a male). Scientists started investigating after a female hammerhead shark was mysteriously born at Omaha's Henry Doorly Zoo in a tank that housed 3 female sharks. It was originally thought one had stored sperm from a male shark before fertilizing an egg. However, baby shark's genetic makeup perfectly matched one of the females in the tank, with no sign of a male parent."
Parthenogenesis does not create a clone (Score:5, Informative)
Re:Obligatory (Score:4, Informative)
--AC
Great Whites? (Score:5, Informative)
Re:Obligatory (Score:2, Informative)
@yg
Re:On Henry Doorly (Score:3, Informative)
Dan East
Re:Womyn rejoice! (Score:4, Informative)
Re:"And who can tell me" (Score:3, Informative)
Right actor, wrong movie?
Re:Parthenogenesis does not create a clone (Score:5, Informative)
You've misread the article (which in fairness was not precisely written) and you're misunderstanding how parthogenesis is working here. The article claims only that the offspring is a perfect genetic "match" for the mom, not that it is identical to the mom since it also says the offspring has half the variability. What this means is the genetic test they did not pick up any polymorphisms not found in the mother. That's what they mean by "identical match".
Also parthogenesis does not create homozygotic offspring (although given enough generations it will), the immediate offspring is a result of a fusion event between 2 products of meiosis - the egg and one of the polar bodies. Thus the offspring will have a different genetic makeup to the mother. In particular half (on average) of the mother's heterozygous loci will become homozygous in the offspring. Thus the offspring has half the genetic variability.
This has potentially bad consequences because of the # of recessive lethal alleles the average organisms carry. Think of parthogenesis as the worst form of incest possible.
Re:Obligatory (Score:3, Informative)
Hopefully, you will be more likely to believe that the people at catholic.com [catholic.com] were able to get it right.
Re:Bacterial Conjugation (Score:3, Informative)
Sure they do. Google for "Bacterial Conjugation". Of course, they don't have genitalia like we do, but they manage anyway. Pretty much all bacteria that have been studied in any depth have been found to use conjugation to exchange DNA. There's even "bacterial porn" online, videos of the conjugation process.
Actually, most of them only engage in sex occasionally, Mostly they reproduce by cloning (i.e., dividing). When they have several populations of clones intermingling, they produce lots of random mixtures of the different populations' genes in a big orgy of conjugation. Natural selection then decides which of these mixtures deserve to survive. The result is the same sort of pooling of beneficial genes that happens in us multi-cellular organisms during sex.
Something similar already found in Komodo Dragons (Score:2, Informative)