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 Schφnbrunn, 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).

Related Articles



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) [link]

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 21, 2015 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 21, 2015).

Share This


More From ScienceDaily



More Plants & Animals News

Tuesday, April 21, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Deepwater And Dolphins: The Oil Spill's Impact 5 Years On

Deepwater And Dolphins: The Oil Spill's Impact 5 Years On

Newsy (Apr. 20, 2015) — Five years on, the possible environmental impact of the Deepwater Horizon spill includes a sustained die-off of bottlenose dolphins, among others. Video provided by Newsy
Powered by NewsLook.com
Five Years Later, the BP Oil Spill Is Still Taking Its Toll

Five Years Later, the BP Oil Spill Is Still Taking Its Toll

AFP (Apr. 20, 2015) — On April 20, 2010, an explosion and fire on the Deepwater Horizon rig in the Gulf of Mexico started the biggest oil spill in US history. BP recently reported the Gulf is recovering well, but scientists paint a different picture. Duration: 02:36 Video provided by AFP
Powered by NewsLook.com
Thai Customs Seize African Elephant Tusks Worth $6 Mn

Thai Customs Seize African Elephant Tusks Worth $6 Mn

AFP (Apr. 20, 2015) — Thai customs seize four tonnes of African elephant ivory worth $6 million at a Bangkok port in a container labelled as beans. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com
Un-Bee-Lievable: Bees on the Loose After Washington Truck Crash

Un-Bee-Lievable: Bees on the Loose After Washington Truck Crash

Reuters - US Online Video (Apr. 17, 2015) — A truck carrying honey bees overturns near Lynnwood, Washington, spreading boxes of live bees across the highway. Rough Cut (no reporter narration). Video provided by Reuters
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:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

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