"Living Dinosaur" Is Fastest-Evolving Animal

Dave Hansford in Wellington, New Zealand
for National Geographic News
March 31, 2008

New Zealand's "living dinosaur," the tuatara, hasn't changed its look in millions of years. But the reptile is actually evolving faster than any other animal studied so far, new DNA analysis reveals.

Scientists recovered DNA from 8,000-year-old tuatara bones and compared it with DNA in blood samples from living tuatara. The modern species is the only surviving member of the order Sphenodontia, which flourished around 200 million years ago.

The results showed that tuatara evolve faster than bears, horses, and many other warm-blooded vertebrates.

(Related: "'Instant' Evolution Seen in Darwin's Finches, Study Says" [July 14, 2006].)

Slowpokes

"Tuatara do most things slowly," said study lead author David Lambert of New Zealand's Massey University. He and colleagues published the findings in the March issue of the journal Trends in Genetics.

Tuatara "have a very low metabolic rate. So you would be forgiven for thinking that they haven't been doing very much over 200 million years of evolution."

But Lambert said the reptile's ancient anatomy hides the rapid evolution of DNA within the animals' cells.

"What [the research] is telling us is that the processes that govern anatomical evolution are quite different from those governing molecular evolution."

Axel Meyer, of the University of Konstanz in Germany, agreed.

"There can be a real disconnect" between an animal's physical and genetic evolution rates, said Meyer, who was not involved in the research.

"Fast [evolution] does not necessarily imply 'good' or 'adaptive,'" he added.

Continued on Next Page >>


SOURCES AND RELATED WEB SITES

ADVERTISEMENT

NATIONAL GEOGRAPHIC'S PHOTO OF THE DAY

NEWS FEEDS     After installing a news reader, click on this icon to download National Geographic News's XML/RSS feed.   After installing a news reader, click on this icon to download National Geographic News's XML/RSS feed.

Get our news delivered directly to your desktop—free.
How to Use XML or RSS

National Geographic Daily News To-Go

Listen to your favorite National Geographic news daily, anytime, anywhere from your mobile phone. No wires or syncing. Download Stitcher free today.
Click here to get 12 months of National Geographic Magazine for $15.