Navigation Links
Chewing their way to success
Date:10/28/2013

The subfamily of rodents known as Murinae (mice, rats, etc.), which first appeared in Asia 12 million years ago, spread across the entire Old World (Eurasia, Africa, Australia) in less than 2 million years, a remarkably fast rate. Researchers have long suspected that one of the reasons for their evolutionary success is related to their unique masticatory apparatus. Now, researchers have used the brilliant X-ray beams produced at the European Synchrotron (ESRF) to study several hundred specimens, both extant and extinct, to describe the evolutionary processes that caused rats and mice to acquire this characteristic feature. The study was published in the journal Evolution on 28 November 2013.

The research team, from the Institut de Paloprimatologie, Palontologie Humaine: volution et Paloenvironnements (CNRS / Universit de Poitiers), was able to determine the diet of extinct species and to trace the evolutionary history of these rodents. Today, the Murinae comprise 584 species, which represents over 10% of the diversity of present day mammals.

In their study the researchers were able to identify two key evolutionary moments in the acquisition of this masticatory apparatus.

The first one occurred around 16 million years ago when the ancestors of the Murinae changed from a herbivorous diet to an insectivorous diet. This new diet was encouraged by the acquisition of chewing movements that are unusual in mammals, forwardly directed but continuing to interlock opposing teeth. This aquisition helped them reduce tooth erosion and better preserve pointed cusps, which are used to puncture the exoskeletons of insects.

Then, twelve million years ago, the very earliest Murinae returned to a herbivorous diet, while at the same time retaining their chewing motion. This also enabled them to use both their mandibles simultaneously during mastication. The change in diet gave way to the formation of three longitudinal rows of cusps on their teeth. Their ancestors, like other related rodents such as hamsters and gerbils, only have two rows, as do humans.

To reconstruct this series of evolutionary events, the scientists studied several hundred teeth belonging to extant or extinct rodents at the European Synchrotron (ESRF) in Grenoble. The team applied methods originally used in map-making to analyze 3D digital models of the dental morphology of these species. Comparison of the dental structures of present day and fossil rodents enabled them to determine the diet of the extinct species. In addition, studying the wear on their teeth allowed them to reconstruct the chewing motion, either directed forwardly or obliquely, of these animals.

The study traces the way in which evolution progresses by trial and error, ending up with a morphological combination that lies behind the astonishing evolutionary success of an animal family.

The innovative methods used by the researchers to analyze and compare masticatory systems could be used to study dietary changes in other extinct mammals. This might prove to be especially interesting with regard to primates, since, before the appearance of hominids, primates underwent several dietary changes that affected their subsequent evolutionary history.


'/>"/>

Contact: Claus Habfast
claus.habfast@esrf.fr
33-666-662-384
European Synchrotron Radiation Facility
Source:Eurekalert  

Related biology news :

1. How chewing gum or a shed hair can let strangers read your Book of Life
2. Older siblings cells can be passed from female dogs to their puppies in the womb, MU researchers find
3. Long-term memory helps chimpanzees in their search for food
4. Rats! Humans and rodents process their mistakes
5. Cells molecular muscles help them sense and respond to their environments
6. When cells eat their own power plants; Pitt scientists solve mystery of cellular process
7. Coastal animals have their own tidal timer -- separate from the 24-hour body clock
8. How bacteria integrate autotransporters into their outer membrane
9. UdeMs IRIC and IRICoR achieve important milestone in their collaboration with Bristol-Myers Squibb
10. Hypertension researcher encourages colleagues to expand their focus
11. Surprising underwater-sounds: Humpback whales also spend their winter in Antarctica
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Chewing their way to success
(Date:5/20/2016)... 20, 2016  VoiceIt is excited to announce ... By working together, VoiceIt and VoicePass ... and VoicePass take slightly different approaches to voice ... security and usability. ... new partnership. "This marketing and technology ...
(Date:5/3/2016)... May 3, 2016  Neurotechnology, a provider of ... MegaMatcher Automated Biometric Identification System (ABIS) , a ... projects. MegaMatcher ABIS can process multiple complex biometric ... combination of fingerprint, face or iris biometrics. It ... and MegaMatcher Accelerator , which have ...
(Date:4/26/2016)... , April 27, 2016 ... the  "Global Multi-modal Biometrics Market 2016-2020"  report to ... ) , The analysts forecast the ... CAGR of 15.49% during the period 2016-2020.  ... number of sectors such as the healthcare, BFSI, ...
Breaking Biology News(10 mins):
(Date:5/18/2016)... ... May 18, 2016 , ... Shimadzu Scientific ... The University of Toledo. This two-day camp will take place annually starting June ... field of pharmaceutical sciences in preparation for a university academic program. , ...
(Date:5/18/2016)... ... 18, 2016 , ... Every day, more than 5,400 ER ... Costing more than $56 billion in direct costs annually, asthma remains a critical ... the suffering associated with uncontrolled asthma can be overwhelmingly disproportionate and better managed,” ...
(Date:5/17/2016)... May 18, 2016 Haselmeier announces ... pen following approval by EMA, the European Medicines Agency. ... and technology company, the new pen version includes enhancements ... level of confidence to patients during use. ... pen easier to handle with a larger display window ...
(Date:5/17/2016)... ... 2016 , ... PATH and Laerdal Global Health announced today ... feeding cup to market based on a reference design co-developed by PATH, the ... Hospital, thereby ensuring an innovative feeding option for the 7.6 million preterm infants ...
Breaking Biology Technology: