Navigation Links
From minute to massive -- mammal size evolution explained
Date:6/25/2013

Scientists have added another piece to the evolutionary puzzle to explain why certain mammal families evolved to be very large, while others remained tiny.

In research published in Proceedings of the Royal Society B, an international group of scientists including Monash University's Dr Alistair Evans proposed a new theory explaining the diversity of mammal sizes - from the Etruscan shrew which weighs around two grams, to the blue whale which clocks in at almost 200 tonnes. Surprisingly, baby weight relative to adult body mass is key.

Dr Evans, of the Monash School of Biological Sciences, said size impacts on all aspects of an animal's physiology and anatomy, and the roles it can play in ecosystems.

"Size is fundamental to your life and your body how fast your heart beats, how much food you need to eat, and how you move," Dr Evans said.

Following the extinction of the dinosaurs, mammals flourished and their size increased dramatically. The study examined the maximum size of groups including whales, elephants, primates and rodents over this period to examine the constraints on size.

The researchers found that species that matured more quickly and produced a larger mass of young each year relative to body weight were able to evolve to a larger maximum size. Further, they are likely to reach that size in fewer generations.

This high rate of biological production is vital, regardless of whether many small young or just one large offspring are born in a year.

Dr Evans said whales were an excellent example of the theory.

"The blue whale is the largest animal to have evolved, even larger than dinosaurs, and it reached this size at the fastest rates we recorded. Key to this success is that they produce large young that mature quickly, reaching around 30 metres in eight to 10 years," Dr Evans said.

Lead author of the study, Dr Jordan Okie from Arizona State University, said primates were at the opposite end of the spectrum.

"Primates have a low production rate and have evolved very slowly. They have never got bigger than about 500 kilograms," Dr Okie said.

The study also linked maximum size to mortality rate. Because larger animals tend to breed less frequently than smaller animals, if the mortality rate doubles, the maximum size is predicted to be 16 times smaller.

"This is a really surprising finding," said Dr Evans.

"It points to why many of the large animals went extinct after the last Ice Age, as changing climates probably increase mortality rates. Large animals are also at high risk of extinction in modern environments because it takes a long time for their population to rebound from disasters."

In the future, this work will be extended to help explain how extinction risk may be reduced in the face of climate change.


'/>"/>

Contact: Emily Walker
emily.walker@monash.edu
61-399-034-844
Monash University
Source:Eurekalert

Related biology news :

1. Killer silk: Making silk fibers that kill anthrax and other microbes in minutes
2. A step toward minute factories that produce medicine inside the body
3. 30 minutes of daily exercise does the trick
4. A minute crustacean invades the red swamp crayfish
5. Schools should provide opportunities for 60 minutes of daily physical activity to all students
6. Gene mutations cause massive brain asymmetry
7. NCEAS DataONE streamlines search and analysis of massive amounts of ecological data
8. Mini-pig tale provides massive amount of genomic data for human health
9. Fungus responsible for 5 deaths in the wake of massive tornado
10. New system to restore wetlands could reduce massive floods, aid crops
11. University of Tennessee professor links massive prehistoric bird extinction to human colonization
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:3/22/2017)... Calif. , March 21, 2017 ... analytics company serving law enforcement agencies, announced today the ... as director of public safety business development. ... diversified law enforcement experience, including a focus on the ... In his most recent position, Mr. Sheridan served as ...
(Date:3/20/2017)... PMD Healthcare announces the release of its ... System (WMS), a remote, real-time lung health monitoring and ... is a Medical Device, Digital Health, and Chronic Care ... innovative solutions that empower people to improve their healthcare ... developed the first ever personal spirometer, Spiro PD, which ...
(Date:3/13/2017)... March 13, 2017 Future of security: Biometric Face Matching ... ... DERMALOGs Face Matching enables to match face pictures against each ... to identify individuals. (PRNewsFoto/Dermalog Identification Systems) ... DERMALOG,s "Face Matching" is the fastest software for biometric Face Matching on ...
Breaking Biology News(10 mins):
(Date:6/22/2017)... ... June 22, 2017 , ... The first human cell line HeLa, established in ... data on cross-contamination of human cell lines with HeLa cells were published. Until recently, ... culture labs and is associated with dramatic consequences for research. , In this ...
(Date:6/20/2017)... (PRWEB) , ... June 20, 2017 , ... ... announced that the CTNext board of directors has formed a Higher Education Entrepreneurship ... working group composed of institution presidents and other high-ranking representatives from 35 higher ...
(Date:6/20/2017)...  Kibow Biotech Inc., a pioneer in developing "Enteric ... a new patent covering a unique method for preventing ... and Trademark Office on May 23 rd 2017. ... Bio award in 2014 in San Diego, ... to chronic disease. Renadyl™, the first and only dietary ...
(Date:6/20/2017)... San Francisco, CA (PRWEB) , ... June 20, ... ... with patented technology for discovery of antibody therapeutics from millions-diverse immune repertoires, announces ... International Conference in San Diego, California. Dave Johnson, PhD, CEO of GigaGen, will ...
Breaking Biology Technology: