Thursday, 29 July 2010
Aussie Marsupials share American ancestors
By Richard Black Environment correspondent, BBC News
The characteristic koalas, kangaroos, possums and wombats of Australia share a common American ancestor, according to genetic research from Germany.
A University of Muenster team drew up a marsupial family tree based on DNA.
Writing in the Public Library of Science (PLoS) Biology journal, they suggest a single marsupial species moved from the Americas to Australia.
Marsupials differ from other mammals in that mothers carry their young in a pouch after birth.
As well as the familiar Australian species, the family includes the opossums and shrew opossums of North and South America, and also has a presence in Asian countries including Indonesia and Papua New Guinea.
"I think this is pretty strong evidence now for the hypothesis of a single migration [to Australia] and a common ancestor," said Juergen Schmitz, one of the research team.Tracing relatives
The research was made possible by the recent sequencing of genomes from two marsupials - the gray short-tailed opossum (Monodelphis domestica) from South America, and the Australian tammar wallaby (Macropus eugenii).
The Muenster researchers looked for DNA elements called retroposons.
These are fragments that have been copied and inserted back into DNA in a random fashion at some point during the animal's evolutionary history.
They are among the "jumping genes" that can scatter genetic information along the genome.
If two species carry the same retroposon but a third does not, that indicates that the first two are more closely related to each other than they are to the third.
Sometimes one retroposon is inserted in the middle of another, again giving vital clues as to the sequence of events in a family's evolution.
Using this method, they showed that the American opossums separated from the main lineage first.
Then at some stage an ancestral species migrated to Australia and gave rise to the various families found there now.
When exactly this happened is still unknown, as this kind of analysis does not show when in evolutionary time the retroposons were inserted.
"Maybe it's around 30-40 million years ago, but we cannot say because jumping genes do not give this information," Dr Schmitz told BBC News.
"It's now up to other people, maybe from the palaeontology field, to find out when exactly it happened."
The overall marsupial history is virtually a circular migration.
The earliest identified species (Sinodelphys szalayi) is known from 125-million-year-old fossils found in China.
Subsequently the family - or perhaps a single species - moved across the super-continent of Gondwana into what is now South America.
The marsupial family began expanding about 70-80 million years ago.
After crossing into Australia, they penetrated north into the Indonesian archipelago - almost returning to their Chinese homeland.
Wednesday, 28 July 2010
"A plume from the extinct huia bird has sold for a record sum at auction in New Zealand. The feather was bought by a family from Wellington who declined to be identified. The brown and white feather traditionally used to adorn Maori chiefs sold for £3,800. No huia bird has been since 1907" -- Daily Sport, 23 June 2010.
During the compilation of the opus that is Australian Big Cats: An Unnatural History of Panthers,authors Michael Williams and Rebecca Lang were handed lots of intriguing video footage - and possibly one of the most puzzling was that of what appears to be a lioness roaming the Northern territory Outback.
'Shot' by NT resident Jan Donovan, this still from the footage (which featured this week on the front page of the Northern Territory News) could lend weight to the notion feral exotic cats are running around in Australia's wilderness.
You might recall the case of the recently shot pygmy hippo in the Top End, which appears to have been an escapee from a private zoo.
What do you think?
We'd love to hear your thoughts - and if you have a photograph or video footage, we'd be happy to have a look and venture an opinion.
Wednesday, 21 July 2010
by Frances Rand
South Coast Register
July 21, 2010
FOR over a hundred years big cats have stalked Kangaroo Valley.
Tuesday, 20 July 2010
CFZers and authors interviewed on NZ's The Cryptid Factor. Our part starts @ 10.20...Mike chimes in later in the show talking about other Australian cryptids including the yowie!
REGION - Eight years of research has gone into the production of the newly released book Australian Big Cats - An Unnatural History of Panthers, by Michael Williams and Rebecca Lang.
Saturday, 10 July 2010
Friday, 9 July 2010
AUSTRALIAN scientists have unearthed the remains of a small bizarre, prehistoric, sabre-toothed cat in an ancient former rainforest, where specimens stretch back 25 million years.
Lead paleontologist Henk Godthelp said it was the first time the carnivore - with fangs half the length of its skull, which fits into the palm of an adult human hand - had been seen in Australia, calling it an exciting and unique discovery.
"It's sort of like a native cat with a broad flattish head with large canines," Dr Godthelp said. "It's an animal we don't think we've seen before up at Riversleigh, so it was quite a nice find for us."
Thursday, 8 July 2010
The debate over whether big cats, such as panthers or pumas, are roaming the Australian bush has gone on for decades but as far as Michael Williams is concerned, there's no room for argument.
He spoke to Matt Dowling about researching the book and what inspired his fascination for big cats.