Featured Research

from universities, journals, and other organizations

Hanging in there: Koalas have low genetic diversity

Date:
October 23, 2012
Source:
BioMed Central Limited
Summary:
A species relies on genetic diversity to survive and low diversity usually indicates that there has been inbreeding due to a decrease in population size.  By looking at historic mitochondrial DNA (mtDNA) from museum samples, new research has found that koalas (Phascolarctos cinereus) have had low genetic diversity for over 120 years.

Koala. Koalas (Phascolarctos cinereus) have had low genetic diversity for over 120 years.
Credit: Dr Eveline Dungl of the Tierpark Schönbrunn, Vienna, Austria

A species relies on genetic diversity to survive and low diversity usually indicates that there has been inbreeding due to a decrease in population size.  By looking at historic mitochondrial DNA (mtDNA) from museum samples, new research published in BioMed Central’s open access journal BMC Genetics has found that koalas (Phascolarctos cinereus) have had low genetic diversity for over 120 years.

The genetic diversity of koalas is known to be low in modern populations but historical reports suggest that koala populations have had a chequered past. When Europeans first noticed koalas in the late18th century they noted that numbers of this newly described species (originally called Lipurus cinereus) were very low due to Aboriginal hunting and they believed that the species would soon become extinct. Instead hunting declined allowing the koala to become a common animal by the mid 1800s.

At this point in time koala fur became fashionable and the international fur trade decimated the population once more. The koala population was also hit by loss of their habitat to European settlement, and by devastating epidemic diseases such as Chlamydia. 

Researchers from Germany, Denmark and the USA compared the mitochondrial DNA of modern koalas and 14 museum specimens from across the world (where the date of the specimen was known) to see how these changes in population sizes had affected koala genetic diversity.  Despite the 14 historic koalas being from different places and time points, they each had only one of four different haplotypes (variations in the mtDNA hypervariable region) and all of these can be found in modern koalas.

Prof Alex Greenwood, from the Leibniz-Institute for Zoo and Wildlife Research, who led this study, commented, “We thought that, like other species such as the grey wolf where the population has recently declined, there should be greater diversity in museum samples than modern specimens. We found this not to be true. The event which reduced the genetic diversity of koalas must have happened a long time ago, perhaps during the late Pleistocene  when the larger species of koala, P. stirtoni, became extinct.”

Low genetic diversity may mean that the species is less able to survive changes to its environment such as global warming, or competing for habitat with humans. The low diversity may also be responsible for the widespread inability of the koala to resist diseases such as Chlamydia and the newly discovered koala retrovirus (KoRV).


Story Source:

The above story is based on materials provided by BioMed Central Limited. Note: Materials may be edited for content and length.


Journal Reference:

  1. Kyriakos Tsangaras, Maria C Avila-Arcos, Yasuko Ishida, Kristofer M Helgen, Alfred L Roca and Alex D Greenwood. Historically low mitochondrial DNA diversity in koalas (Phascolarctos cinereus). BMC Genetics, 2012 (in press)

Cite This Page:

BioMed Central Limited. "Hanging in there: Koalas have low genetic diversity." ScienceDaily. ScienceDaily, 23 October 2012. <www.sciencedaily.com/releases/2012/10/121023204636.htm>.
BioMed Central Limited. (2012, October 23). Hanging in there: Koalas have low genetic diversity. ScienceDaily. Retrieved April 24, 2014 from www.sciencedaily.com/releases/2012/10/121023204636.htm
BioMed Central Limited. "Hanging in there: Koalas have low genetic diversity." ScienceDaily. www.sciencedaily.com/releases/2012/10/121023204636.htm (accessed April 24, 2014).

Share This



More Plants & Animals News

Thursday, April 24, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deadly Fungus Killing Bats, Spreading in US

Deadly Fungus Killing Bats, Spreading in US

AP (Apr. 24, 2014) — A disease that has killed more than six million cave-dwelling bats in the United States is on the move and wildlife biologists are worried. White Nose Syndrome, discovered in New York in 2006, has now spread to 25 states. (April 24) Video provided by AP
Powered by NewsLook.com
Blood From World's Oldest Woman Suggests Life Limit

Blood From World's Oldest Woman Suggests Life Limit

Newsy (Apr. 24, 2014) — Scientists say for the extremely elderly, their stem cells might reach a state of exhaustion. This could limit one's life span. Video provided by Newsy
Powered by NewsLook.com
Raw: Kangaroo Rescued from Swimming Pool

Raw: Kangaroo Rescued from Swimming Pool

AP (Apr. 24, 2014) — A kangaroo was saved from drowning in a backyard suburban swimming pool in Australia's Victoria state on Thursday. Australian broadcaster Channel 7 showed footage of the kangaroo struggling to get out of the pool. (April 24) Video provided by AP
Powered by NewsLook.com
Could Marijuana Use Lead To Serious Heart Problems?

Could Marijuana Use Lead To Serious Heart Problems?

Newsy (Apr. 24, 2014) — A new study says marijuana use could lead to serious heart-related complications. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins