Book of Days: asher553

... found to give birth without a mate - in the wild.

http://www.bbc.co.uk/nature/19555550

'A form of virgin birth has been found in wild vertebrates for the first time.

Researchers in the US caught pregnant females from two snake species and genetically analysed the litters.

That proved the North American pit vipers reproduced without a male, a phenomenon called facultative parthenogenesis that has previously been found only in captive species.

Scientists say the findings could change our understanding of animal reproduction and vertebrate evolution. ...'

http://www.washingtonpost.com/wp-dyn/content/article/2007/05/22/AR2007052201405.html

A team of American and Irish researchers 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 that sharks can reproduce asexually through the process known as parthenogenesis is being published online today in the British journal Biology Letters. Researchers have observed parthenogenesis in certain species of birds, reptiles, amphibians and bony fishes, but the new finding suggests that vertebrates' ability to reproduce without sex evolved much earlier than scientists had thought.

Scientists began their investigation after a female hammerhead shark was mysteriously born at Omaha's Henry Doorly Zoo in December 2001, in a tank that held three adult, female hammerheads but no males. The seven-inch-long baby was killed within a day of its birth, apparently because another fish in the tank, probably a stingray, attacked it.

Those damn stingrays.

Though the three females had been caught before they reached sexual maturity and held in captivity for more than three years, researchers initially thought one had stored sperm from a male shark before fertilizing an egg. But the team -- which included scientists at Nova Southeastern University in Florida, Queen's University Belfast and the zoo -- determined that the baby shark's genetic makeup perfectly matched one of the females in the tank, with no sign of a male parent.

Read the rest at the link. Hat tip: Tammy.
http://tammybruce.com/

... and other wonders of science.

Thanks to heyfoureyes for this one:

Virgin births by Komodo dragons.  'A clutch of four Komodo dragons that hatched at London Zoo this year were all the result of virgin births, according to research that could help scientific efforts to protect the world’s largest lizards.  Genetic tests conducted at the University of Liverpool have proved that all four born to a female called Sungai were conceived by parthenogenesis, a form of asexual reproduction that is known to take place in lizards but never documented in this species before.'

PhysOrg has more:  'In an evolutionary twist, Flora the Komodo dragon has managed to become pregnant all on her own without any male help. She is carrying seven baby Komodo dragons.  Other reptile species reproduce asexually in a process known as parthenogenesis. But Flora's virginal conception, and that of another Komodo dragon earlier this year at the London Zoo, are the first time it has been documented in a Komodo dragon. The reptiles, renowned for their intelligence, are native to Indonesia. They are the world's largest lizards and have no natural predators - making them on par with sharks and lions at the pinnacle of the animal kingdom. The cases of Flora and the London lizard, Sungai, are described in a paper published Thursday in Nature.'

Big bacteria.  'The oldest-known animal eggs and embryos, whose first pictures made the cover of Nature in 1998, were so small they looked like bugs – which, it now appears, they may have been.  This week, a study in the same prestigious journal presents evidence for reinterpreting the 600 million-year-old fossils from the Precambrian era as giant bacteria.'

New light on black holes.  'Nature has again thrown astronomers for a loop. Just when they thought they understood how gamma-ray bursts formed, they have uncovered what appears to be evidence for a new kind of cosmic explosion. These seem to arise when a newly born black hole swallows most of the matter from its doomed parent star.  Gamma-ray bursts (GRBs), the most powerful explosions in the Universe, signal the formation of a new black hole and come in two flavours, long and short ones. In recent years, international efforts have shown that long gamma-ray bursts are linked with the explosive deaths of massive stars (hypernovae; see e.g. ESO PR 16/03). ... The newly found gamma-ray bursts, however, do not fit the picture. They instead seem to share the properties of both the long and short classes.  "Some unknown process must be at play, about which we have presently no clue," said Massimo Della Valle of the Osservatorio Astrofisico di Arcetri in Firenze, Italy, lead author of one of the reports published in this week's issue of the journal Nature. "Either it is a new kind of merger which is able to produce long bursts, or a new kind of stellar explosion in which matter can't escape the black hole."'