Dolphin and bat DNA on the same wavelength

January 25, 2010

A new study has shown that echolocation evolved separately, but through the same genetic changes, in both dolphins and bats.

Scientists at Queen Mary, University of London have shown that the remarkable ability is shared by these very different animals at a much deeper level than anyone previously realised - all the way down to the molecular level.

Writing in the journal Current Biology, they describe how dolphins and bats have both evolved the same specialised form of inner-ear hair cells that allow them to use sophisticated echolocation: detecting unseen obstacles or tracking down prey by making a high frequency noise and listening for the echo that bounces back.

"The natural world is full of examples of species that have evolved similar characteristics independently, such as the tusks of elephants and walruses," said Stephen Rossiter of Queen Mary's School of Biological and Chemical Sciences. "However, it is generally assumed that most of these so-called 'convergent traits' have arisen by different changes in the animal's DNA. Our study shows that this very complex ability - echolocation - has in fact evolved by identical genetic changes in bats and dolphins."

According to Rossiter, the discovery represents an "unprecedented" example of convergence between two very different animals, and suggests that further studies might unearth more genetic similarities between species than scientists would have suspected.

"We were surprised by the strength of the evidence for convergence between these two groups of mammals, and, related to this, by the sheer number of convergent changes in the DNA that we found," he said.

Rossiter and colleague James Cotton teamed up with Shuyi Zhang from East China Normal University to sequence the Prestin gene, which describes a key protein found in the inner-ear hair cells of all mammals. The researchers discovered that this gene shows the very same changes in bats and dolphins, the results also clearly show how genetic changes have built up over time.

The prestin protein is known to drive the vibration of the hair cells in response to sound. It is possible that the genetic changes observed in bats and dolphins allow more rapid vibrations and, therefore, the higher frequency hearing that is needed for echolocation. Rossiter added; "the fact that it is the very same genetic changes that occurred twice in nature suggests that there might be a limited number of evolutionary routes to high frequency hearing in mammals".

Queen Mary University of London

Related DNA Articles from Brightsurf:

A new twist on DNA origami
A team* of scientists from ASU and Shanghai Jiao Tong University (SJTU) led by Hao Yan, ASU's Milton Glick Professor in the School of Molecular Sciences, and director of the ASU Biodesign Institute's Center for Molecular Design and Biomimetics, has just announced the creation of a new type of meta-DNA structures that will open up the fields of optoelectronics (including information storage and encryption) as well as synthetic biology.

Solving a DNA mystery
''A watched pot never boils,'' as the saying goes, but that was not the case for UC Santa Barbara researchers watching a ''pot'' of liquids formed from DNA.

Junk DNA might be really, really useful for biocomputing
When you don't understand how things work, it's not unusual to think of them as just plain old junk.

Designing DNA from scratch: Engineering the functions of micrometer-sized DNA droplets
Scientists at Tokyo Institute of Technology (Tokyo Tech) have constructed ''DNA droplets'' comprising designed DNA nanostructures.

Does DNA in the water tell us how many fish are there?
Researchers have developed a new non-invasive method to count individual fish by measuring the concentration of environmental DNA in the water, which could be applied for quantitative monitoring of aquatic ecosystems.

Zigzag DNA
How the cell organizes DNA into tightly packed chromosomes. Nature publication by Delft University of Technology and EMBL Heidelberg.

Scientists now know what DNA's chaperone looks like
Researchers have discovered the structure of the FACT protein -- a mysterious protein central to the functioning of DNA.

DNA is like everything else: it's not what you have, but how you use it
A new paradigm for reading out genetic information in DNA is described by Dr.

A new spin on DNA
For decades, researchers have chased ways to study biological machines.

From face to DNA: New method aims to improve match between DNA sample and face database
Predicting what someone's face looks like based on a DNA sample remains a hard nut to crack for science.

Read More: DNA News and DNA Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to