Land and oceans
White roofs could cool cities: study
Enzyme crystal helps crack HIV puzzle
Sugar sweetens decision making
Twilight zone secrets revealed
Astronomers spot asteroid collision
Algae master quantum mechanics
Protein 'ushers' key to beating malaria
Researchers spin artificial bee silk
New view of Pluto increases mystery
Cell's power packs came from within
Antarctic snow linked to WA dry
Termites inspire hydrophobic materials
Study shows why it's scary to lose money
Soil impact underestimated: climate study
Lack of oxygen forced fish's first breath
Harder Sudoku puzzles on the way?
Weed genes could help feed the world
Logging makes forests more flammable: study
Food crisis looms warn scientists
Tiny sensors track 'lost' objects
'Climategate' university orders review
'Plumbing' key to flowering success
New twist on solar cell design
Scientists set new temperature record
Moa eggshells yield ancient DNA
DNA has been extracted for the first time from the fossilised eggshells of birds such as emu and moa, providing a purer source of ancient DNA than bone, say scientists.

Dr Michael Bunce, head of the Ancient DNA Research Laboratory at Murdoch University in Perth and colleagues report their findings today in the Proceedings of the Royal Society B.

"Eggshell has got a number of good characteristics about it that make it interesting to study in both an archaeological and palaeontological context," says Bunce.

He says eggshell does not exchange air with its outside environment.

"It's a sealed environment. So it's very good for dating."

Bunce says eggshell also provides stable isotopes that give scientists information about the diet of the animal that lay the egg.

He believes this is the first published report of eggshell yielding ancient DNA, and the findings could be very useful in providing definitive species identification for birds such as the moa.

Bunce and team, which included graduate student, Charlotte Oskam, analysed fragments of eggshell from extinct moa and ducks from New Zealand, extinct elephant birds from Madagascar and emu and owl from Australia.

Elephant birds have the largest known eggs, 150 times bigger than a chicken egg.

The oldest DNA they extracted was 19,000 years old, from a fragment of Australian emu eggshell.
Advantage over bone

Bunce says the most common source of ancient DNA used for phylogenetic studies is bone.

But this is often contaminated by DNA from bacteria and fungi, making it difficult to use new generation genetic sequencing techniques.

Bunce and colleagues have found that eggshell has much less bacterial DNA than bone.

"When we compare moa eggshell to moa bone of similar age, we've got 125 times less bacterial contamination, which is significant if you're going to do genomic level studies," says Bunce.

"It's more pure, if you like."
Surviving heat

Bunce says the team was particularly excited to get ancient DNA from Australian emu eggshells.

"Australia is not a place conducive to long-term DNA preservation due to the heat," says Bunce.

He says the fact they found preserved DNA in Pleistocene eggshells from Australia and Holocene deposits from Madagascar suggests eggshell could be a good substrate for long-term preservation of DNA in warmer climates.

The researchers tried but failed to obtain DNA from a 50,000-year-old Genyornis eggshell.

"So there are limits to DNA survival in Australia," says Bunce.

Dr Jeremy Austin of the Australian Centre for Ancient DNA at University of Adelaide welcomes the study.

"It's another good new piece of ancient DNA research," he says.

"They've certainly covered a lot of different material from different species - important ones like the elephant bird from Madagascar."

He says the use of DNA from eggshell may be useful in phylogenetic studies where existing methods are inadequate.

Horny mother beetles fight for dung
Light-speed computing one step closer
Small asteroids 'just lumps of gravel'
Gene study reveals diverse gut zoo
Dinosaur extinction caused by asteroid: study
Study finds methane bubbling from Arctic
New view reveals Mars' icy history
Some nano-sunscreens 'come at a cost'
Dust bunnies could harbour toxic load
Aphid genome reveals its 'Achilles heel'
Tailored diet may slow down DNA damage
Scientist probe ballistic chameleon tongue
Moa eggshells yield ancient DNA
Toothbrush tech helps buses go green
Gene protects some Tassie devils from tumour
Smaller fish cope better with acidic water
Lunar mirror mystery solved
Parents give fewer bad genes than thought
Women on pill may live longer
Antarctic winds affect key ocean layer
Researchers uncover thalidomide mystery
Boost for evidence of early ocean
Ocean geoengineering may prove lethal
People leave unique 'germ print'
Rogue star on collision course
Butterflies 'fly early as planet warms'
Glaucoma may start in the brain
Tools push back dates for humans on Flores
Stem cell capsules to target broken bones
Ecstasy damages complex memory: study
Earliest animals flexed their muscles
Insomnia may shrink the brain: study
Experts call for 'resilience thinking'
Tutu's DNA could point to medical cures
Humble algae key to whale evolution
Happiness linked to healthy heart
Fewer cyclones, but more intense: study
Cosmic candles result of colliding stars
Flightless mosquitoes may curb dengue
Childhood poverty may leave its mark
Cautious response to technology strategy
Nanowire RAM to make ever-ready computers
Are non-smokers smarter than smokers?
There's iron in them thar Martian hills
'Shell Crusher' shark swam ancient oceans
Nanotechnology may tap into your mind
Small dogs originated in the Middle East
Brain 'hears' sound of silence
Swimmers 'may not understand' tsunami risk
Altruism surfaces on slow-sinking ship
Chile quake tops Haiti, but less deadly
Weedkiller 'makes boy frogs lay eggs'
Visit Statistics