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:12/15/2016)... Dec. 15, 2016 Advancements in ... health wellness and wellbeing (HWW), and security ... three new passenger vehicles begin to feature ... recognition, heart beat monitoring, brain wave monitoring, ... monitoring, and pulse detection. These will be ...
(Date:12/15/2016)... -- "Increase in mobile transactions is driving the growth ... is expected to grow from USD 4.03 billion in ... CAGR of 29.3% between 2016 and 2022. The market ... for smart devices, government initiatives, and increasing penetration of ... expected to grow at a high rate during the ...
(Date:12/8/2016)... Market Research Future published a half cooked research report on Mobile ... Service Market is expected to grow over the CAGR of ~35% ... ... Mobile Biometric Security and Service Market is increasing at ... and security from unwanted cyber threats. The increasing use of mobile ...
Breaking Biology News(10 mins):
(Date:1/20/2017)... , Jan. 20, 2017 Ginkgo ... of Gen9, a pioneer in the synthesis and ... unique expertise in assembling pathway-length synthetic DNA into ... and capacity in the construction of new organism ... industries. "Gen9 was founded to significantly ...
(Date:1/19/2017)... and HOUSTON , ... ("NX Prenatal") today announced the formation of its ... leading clinicians and industry veterans who enhance the ... as it accelerates development of its novel prenatal ... provide medical, clinical and strategic guidance for the ...
(Date:1/19/2017)... Md. and GAITHERSBURG, Md. ... (NYSE MKT: PIP) and Altimmune, Inc., a privately-held ... signing of a definitive agreement for the merger ... Altimmune,s current investors include Novartis Venture Fund, HealthCap, ... will be a fully-integrated and diversified immunotherapeutics company ...
(Date:1/19/2017)... (PRWEB) , ... January 19, 2017 , ... FireflySci Inc. ... exponential rate. The tremendous growth is accounted to two main factors. The ... and the expanding network of vendors supplying FireflySci products all around the world. , ...
Breaking Biology Technology: