evolution

robinbeck1

A 55-million-year old fossil found in rural Queensland is forcing scientists to rewrite their theories about the origin of Australia’s iconic marsupials, revealing an ancient evolutionary link between Australia and South America.

The fossil, a tiny anklebone smaller than a grain of rice, is from a mouse-sized marsupial previously known only from South America.

“As soon as I saw the bone under the microscope, I knew it was a really significant find,” says Robin Beck, the University of New South Wales paleontologist who carried out the research.

“It has very distinctive features that show it is an ‘ameridelphian’ marsupial, a group that until now was thought to be restricted to South America. It’s a bit like finding a fossil kangaroo in Brazil,” he says.

The bone was collected from the Tingamarra fossil site, near the small town of Murgon in southeastern Queensland. The discovery of a ‘South American’ marsupial shows that 55 million years ago Australia and South America shared at least one group of marsupials in common. At this time, Australia, South America and Antarctica were connected, which may have allowed marsupials to move between the continents.

“This shows that we’re still a long way from fully understanding the history of marsupials in Australia,” Robin says. “I think we can expect plenty more surprises like this in future.”

NSW State Finalist: Robin Beck, University of New South Wales

http://freshscience.org.au/2013/tiny-fossils-link-old-bastard-marsupials-to-south-america-and-africa

Two thymus glands fast-track immune defences

Baby wallaby photos available

Until now, it was a mystery why many marsupials have two thymuses—key organs in the immune system—instead of the one typical of other mammals. Now postdoctoral researcher Dr Emily Wong from the University of Sydney and her colleagues have found that the two organs are identical, which suggests why they are there. [click to continue…]

A compound produced by a pregnant lizard may provide important information on the origins and treatment of cancer in humans, according to zoologist Bridget Murphy from the University of Sydney, who discovered the protein, which is pivotal to the development of the lizard placenta.

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p8070118‘Fool’s gold’ has tricked many amateur gold miners, but Queensland researchers have discovered it can reveal much about the early evolution of life on Earth.

Three billion years ago the Earth couldn’t support life as we know it – the atmosphere was deadly to oxygen-breathing plants and animals.
But two and half billion years ago life changed the Earth’s atmosphere creating the oxygen-rich air we rely on today. [click to continue…]

Bore hole through ice. Credit: Mike Craven Australian Antarctic Division (AAD)Researchers at Geoscience Australia have unravelled the development of a unique seafloor community thriving in complete darkness below the giant ice sheets of Antarctica.

The community beneath the Amery Ice Shelf in Antarctica is 100 km from open water and hidden from view by ice half a kilometre thick. This ecosystem has developed very slowly over the past 9000 years, since the end of the last glaciation.

Today it is home to animals such as sponges and bryozoans fed by plankton carried in on the current. [click to continue…]

tropical_rock_lobster2A team of Queensland researchers have discovered that lobsters, prawns and other crustaceans have evolved a unique way of making colours: making the complex patterns appreciated by biologists and connoisseurs of seafood.

Their work will help with conservation, aquaculture and may even lead to a new food colourant. And all the colours come from just one molecule.

The colour of seafood is directly linked to its acceptability as food. Highly coloured lobsters and prawns attract a premium price. And for the crustaceans themselves, it’s a matter of survival. [click to continue…]

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Why don’t elephants (and humans) have thousands of little babies instead of one big one?

Sydney researchers have discovered and modelled the key factors responsible for offspring and family size.

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Certain small reef fish use wing-like fins to ‘fly’ underwater, allowing them to cruise at speeds equivalent to tuna, a team of Australian and US researchers has found. The design of the fins has drawn the attention of underwater submersible designers and the US Office of Naval Research.   

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Australian orchids are engaged in an arms race, using sensory overload to seduce male insects.

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Billion year old bacteria in NT rocks and bugs from outer space

Researchers from the CSIRO, Sydney University and Colorado State University have developed a means of detecting signs of ancient microbes which may have lived on Earth or come from outer space.

The group already has picked up signs of bacteria more than a billion years old inside rocks from the Northern Territory.

The technique centres around analysing tiny oil droplets-sealed inside rocks as they formed-for traces of chemical compounds known only to be produced by particular types of organisms. The results provide unequivocal evidence of their presence.

“Oil forms from decayed organisms, and therefore contains fatty tracers or biomarkers for the organism from which they came-like the footprint of a dinosaur, but at a molecular level,” says Herbert Volk from CSIRO Petroleum, a member of the research team.

“It’s important that we understand these early organisms, as they were the building blocks for the evolution of the more complex life forms which play an important part in today’s ecosystems.”

The team has managed to extract such biomarkers from oil droplets sealed in Precambrian rocks from the Northern Territory for more than a billion years.

The chemical analysis of the oil indicates that it is derived from single-celled cyanobacteria, the aquatic and photosynthetic bacteria responsible for increasing oxygen levels in the atmosphere. There is also evidence of the presence of more complex strains of life.

“Microscopic evidence of fossilised microbes is very rare in rocks of this age, and if present are often fiercely debated,” Volk says. “Biomarkers have been extracted from rocks of similar age before, but these were not from oil droplets sealed in crystals, so they may have been contaminated by more recent life forms. The new results are free of such doubt.

“And should oil inclusions be found in extraterrestrial rocks such as meteorites or Martian rocks, the molecular signature would be perfectly protected from traces of terrestrial life that could otherwise compromise the information.”

Herbert is one of 13 Fresh Scientists presenting their research to the public for the first time thanks to Fresh Science, a national program hosted by the State Library of Victoria. One of the Fresh Scientists will win a trip to the UK courtesy of the British Council to present his or her work to the Royal Institution.

To view larger image, click on image:  
Remote arid landscape near the drill site in the Roper Superbasin in the Northern Territory, near the Gulf of Carpentaria.
Photo: Dr David Rawlings
The Roper Superbasin is one of the oldest basins known to contain petroleum which is where the researchers look for life.
 This is a thin slice of rock viewed through a microscope with UV light. The oil inclusions are seen fluorescing in bright blue. What the researchers look for are biomarkers of life. Some of the chemical structures they look for are hopanes, derived mainly from hopanols which are fatty alcohols in the cell walls of bacteria.
This is the chemical structure of a hopane molecule.
Herbert Volk (right) and colleague Simon George (left), analysing the oil droplets using a mass spectrometer.

 Many pet snakes are venomous!

Big trouble for the global pet trade in snakes.

 Dr. Bryan Grieg Fry of the Australian Venom Research Unit at the University of Melbourne has discovered that the number of venomous snakes in the world is not around 250 but actually closer to 2700. [click to continue…]

Forget meteorites. Bin volcanic eruptions. When it comes to mass extinction continental drift is the mega-killer, claims Australian palaeontologist Dr Malte Ebach. [click to continue…]

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Are we viruses?

26 August 2001

in 2001

A radical new theory that could dramatically alter the way scientists view the evolution of life has been recently accepted for publication in the leading “Journal of Molecular Evolution”.  Supported by an increasing body of evidence, the theory proposes that the nucleus of our cells evolved from a virus that infected ancient bacteria-like organisms. [click to continue…]

Scientists agree: some people are universally gorgeous. Studies in evolutionary biology show that few things are more advantageous to success than being attractive, since good looking individuals leave more offspring than their unattractive contemporaries. [click to continue…]

Australia’s Serengeti: Clash of the Marsupial Carnivores – a Tasmanian researcher’s study of marsupial carnivores and their teeth will help us conserve our remaining marsupial carnivores. [click to continue…]

How does the Earth’s surface evolve? A geologist is using 3D animated reconstructions to explore ancient landscapes. [click to continue…]