Full Story in the link below!A female boa constrictor snake has given birth to two litters of extraordinary offspring.
Evidence suggests the mother snake has had multiple virgin births, producing 22 baby snakes that have no father.
More than that, the genetic make-up of the baby snakes is unlike any previously recorded among vertebrates, the group which includes almost all animals with a backbone.
Exclusively this way, some. Right? Or was I wrong about there being a species of exclusively lesbian lizards? I hope not. A world without lesbian lizards would be a sad place.GenesForLife wrote:Parthenogenesis innit? There are lizard species that reproduce this way, too.
http://en.wikipedia.org/wiki/ParthenogenesisParthenogenesis has been studied extensively in the New Mexico whiptail (genus Cnemidophorus), of which 15 species reproduce exclusively by parthenogenesis. These lizards live in the dry and sometimes harsh climate of the southwestern United States and northern Mexico. All these asexual species appear to have arisen through the hybridization of two or three of the sexual species in the genus leading to polyploid individuals. The mechanism by which the mixing of chromosomes from two or three species can lead to parthenogenetic reproduction is unknown. Because multiple hybridization events can occur, individual parthenogenetic whiptail species can consist of multiple independent asexual lineages. Within lineages, there is very little genetic diversity, but different lineages may have quite different genotypes.
An interesting aspect to reproduction in these asexual lizards is that mating behaviors are still seen, although the populations are all female. One female plays the role played by the male in closely related species, and mounts the female that is about to lay eggs. This behaviour is due to the hormonal cycles of the females, which cause them to behave like males shortly after laying eggs, when levels of progesterone are high, and to take the female role in mating before laying eggs, when estrogen dominates. Lizards who act out the courtship ritual have greater fecundity than those kept in isolation, due to the increase in hormones that accompanies the mounting. So, although the populations lack males, they still require sexual behavioral stimuli for maximum reproductive success.[15]
Yes, but, in the article it says that they were all female, but WW which is pretty much unique. And they were all identical, and only had half the mother's genes.GenesForLife wrote:Or Meiosis I didn't result in reduction division. (when producing haploid gametes the chromosomal complement of a gamete is halved during Meiosis I, Meiosis II is equational)
The thing we will have to take into account is the presence of 22 offspring, too. Reptiles have a different sex determination system, where males have two sex chromosomes of the same time, while females have two different sex chromosomes.
http://rsbl.royalsocietypublishing.org/ ... hort?rss=1Parthenogenesis in vertebrates is considered an evolutionary novelty. In snakes, all of which exhibit genetic sex determination with ZZ : ZW sex chromosomes, this rare form of asexual reproduction has failed to yield viable female WW offspring. Only through complex experimental manipulations have WW females been produced, and only in fish and amphibians. Through microsatellite DNA fingerprinting, we provide the first evidence of facultative parthenogenesis in a Boa constrictor, identifying multiple, viable, non-experimentally induced females for the first time in any vertebrate lineage. Although the elevated homozygosity of the offspring in relation to the mother suggests that the mechanism responsible may be terminal fusion automixis, no males were produced, potentially indicating maternal sex chromosome hemizygosity (WO). These findings provide the first evidence of parthenogenesis in the family Boidae (Boas), and suggest that WW females may be more common within basal reptilian lineages than previously assumed.
Behavioral (sensory?) stimuli might still be needed to cause the necessary physiological responses.ScienceRob wrote:Cnemidophorus uniparens is the species that I was recently reading about that did this. I always did find it interesting that they still perform mating rituals, performing the male role during the trough of their ovulation cycle.
My Lepidodactylus lugubris (parthenogenetic) behave in a similar way, showing mating behaviours and even psuedo-copulating. They're all female.ScienceRob wrote:Cnemidophorus uniparens is the species that I was recently reading about that did this. I always did find it interesting that they still perform mating rituals, performing the male role during the trough of their ovulation cycle.
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