Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Mouse study suggests mammoth evolutionary change

22.05.2003


The white-footed mouse
Credit: Jim Schulz, Brookfield Zoo


A study of a common wild mouse by two University of Illinois at Chicago biologists has found evidence of dramatic evolutionary change in a span of just 150 years, suggesting genetic evolution can occur a lot faster than many had thought possible.
The findings are the first report of such quick evolution in a mammal and appear in the May 22 issue of the journal Nature.

Oliver Pergams, a conservation biology researcher with the Chicago Zoological Society in Brookfield, Ill. and visiting research assistant professor at UIC, conducted the research as his Ph.D. thesis project at UIC with Dennis Nyberg, associate professor of biology.


Pergams’ study began as a comparison of the genetics of two mice common to the Chicago region -- the white-footed mouse and the prairie deer mouse. But the search for historical samples quickly showed the white-footed mouse had squeezed out the prairie deer mouse from its dominant position, diminishing the samples needed to do a comparative study, so Pergams and Nyberg focused attention on the white-footed mouse.

"This intensified focus resulted in our discovery of rapid evolution," said Pergams. "It was a great surprise. We were simply trying to quantify the amount of genetic variation over time, not show evolution."

The researchers analyzed DNA samples taken from 56 museum specimens dating as far back as 1855, along with 52 recently captured mice from local forest preserves and state parks. Wayne Barnes, professor of biochemistry and molecular biophysics at the Washington University in St. Louis School of Medicine, assisted in analyzing the DNA.

The changes in gene sequence frequencies were dramatic, Pergams said, across the three 50-year intervals studied.

Only one of the mice from the latest period had the same DNA sequence as the most common sequence among the mice collected before 1950. The first mouse with the sequence currently common was captured back in 1906 at Volo Bog, some 45 miles northwest of Chicago. That discovery prompted Pergams to get all the museum specimens that were collected in Illinois’ Cook and Lake counties.

The researchers used DNA taken not from the nucleus, but from mitochondria, the power plants of the cell. Each cell contains many mitochondria, but only one nucleus.

"If you are working with very degraded, ancient DNA like that from museum skins, you are way ahead using this DNA with lots of copies," said Pergams. Mitochondrial DNA evolves much more rapidly than nuclear DNA, he said, though this evolution was previously thought only to occur over thousands of years.

"We did not expect to find the rapid, consistent and directional change that we did find," he said.

While evidence of such fast change has been cited in studies of fruit flies, this is the first reported study to document such quick evolution in a mammal.

What may account for this change?

"We think it likely that the new gene sequence was either unconditionally advantageous, or that it was advantageous relative to environmental changes caused by humans," Pergams said.

"Settlers may have brought in mice with the favorable gene that were able to out-compete mice with the native variant. A less likely possibility is that mice with these new gene sequences were already present, and that dramatic changes that humans caused in the environment allowed the new gene sequence to be selectively advantageous."

Since all the mice studied were caught in forest preserves and parks, Pergams and Nyberg consider the second alternative unlikely. Future studies should reveal if the favorable gene is in older mouse specimens held by museums in other parts of the country.

In any event, Pergams thinks this research may have broad implications.

"It suggests that humans are a likely cause of such rapid evolution," Pergams said, "and that much of current phylogenetic and phylogeographic methodology may be flawed because it does not take the possibility of rapid mitochondrial DNA evolution into account."

"It also suggests that the ’molecular clock’ may sometimes, and sporadically, tick blindingly fast."

Paul Francuch | EurekAlert!
Further information:
http://www.uic.edu/

More articles from Life Sciences:

nachricht Glycosylation: Mapping Uncharted Territory
21.09.2017 | IMBA - Institut für Molekulare Biotechnologie der Österreichischen Akademie der Wissenschaften GmbH

nachricht Molecular Force Sensors
20.09.2017 | Max-Planck-Institut für Biochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Highly precise wiring in the Cerebral Cortex

Our brains house extremely complex neuronal circuits, whose detailed structures are still largely unknown. This is especially true for the so-called cerebral cortex of mammals, where among other things vision, thoughts or spatial orientation are being computed. Here the rules by which nerve cells are connected to each other are only partly understood. A team of scientists around Moritz Helmstaedter at the Frankfiurt Max Planck Institute for Brain Research and Helene Schmidt (Humboldt University in Berlin) have now discovered a surprisingly precise nerve cell connectivity pattern in the part of the cerebral cortex that is responsible for orienting the individual animal or human in space.

The researchers report online in Nature (Schmidt et al., 2017. Axonal synapse sorting in medial entorhinal cortex, DOI: 10.1038/nature24005) that synapses in...

Im Focus: Tiny lasers from a gallery of whispers

New technique promises tunable laser devices

Whispering gallery mode (WGM) resonators are used to make tiny micro-lasers, sensors, switches, routers and other devices. These tiny structures rely on a...

Im Focus: Ultrafast snapshots of relaxing electrons in solids

Using ultrafast flashes of laser and x-ray radiation, scientists at the Max Planck Institute of Quantum Optics (Garching, Germany) took snapshots of the briefest electron motion inside a solid material to date. The electron motion lasted only 750 billionths of the billionth of a second before it fainted, setting a new record of human capability to capture ultrafast processes inside solids!

When x-rays shine onto solid materials or large molecules, an electron is pushed away from its original place near the nucleus of the atom, leaving a hole...

Im Focus: Quantum Sensors Decipher Magnetic Ordering in a New Semiconducting Material

For the first time, physicists have successfully imaged spiral magnetic ordering in a multiferroic material. These materials are considered highly promising candidates for future data storage media. The researchers were able to prove their findings using unique quantum sensors that were developed at Basel University and that can analyze electromagnetic fields on the nanometer scale. The results – obtained by scientists from the University of Basel’s Department of Physics, the Swiss Nanoscience Institute, the University of Montpellier and several laboratories from University Paris-Saclay – were recently published in the journal Nature.

Multiferroics are materials that simultaneously react to electric and magnetic fields. These two properties are rarely found together, and their combined...

Im Focus: Fast, convenient & standardized: New lab innovation for automated tissue engineering & drug

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems Holding GmbH about commercial use of a multi-well tissue plate for automated and reliable tissue engineering & drug testing.

MBM ScienceBridge GmbH successfully negotiated a license agreement between University Medical Center Göttingen (UMG) and the biotech company Tissue Systems...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

“Lasers in Composites Symposium” in Aachen – from Science to Application

19.09.2017 | Event News

I-ESA 2018 – Call for Papers

12.09.2017 | Event News

EMBO at Basel Life, a new conference on current and emerging life science research

06.09.2017 | Event News

 
Latest News

Glycosylation: Mapping Uncharted Territory

21.09.2017 | Life Sciences

Highly precise wiring in the Cerebral Cortex

21.09.2017 | Health and Medicine

Did marine sponges trigger the ‘Cambrian explosion’ through ‘ecosystem engineering’?

21.09.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>