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) [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 September 3, 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 September 3, 2014).

Share This



More Plants & Animals News

Wednesday, September 3, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Snack Attack: Study Says Action Movies Make You Snack More

Snack Attack: Study Says Action Movies Make You Snack More

Newsy (Sep. 2, 2014) — You're more likely to gain weight while watching action flicks than you are watching other types of programming, says a new study published in JAMA. Video provided by Newsy
Powered by NewsLook.com
Get A Mortgage, Receive A Cat — Only In Russia

Get A Mortgage, Receive A Cat — Only In Russia

Newsy (Sep. 2, 2014) — The incentive is in keeping with a Russian superstition that it's good luck for a cat to be the first to cross the threshold of a new home. Video provided by Newsy
Powered by NewsLook.com
U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

Newsy (Sep. 2, 2014) — The U.N. says the problem is two-fold — quarantine zones and travel restrictions are limiting the movement of both people and food. Video provided by Newsy
Powered by NewsLook.com
Sharks Off the Menu and on the Tourist Trail in Palau

Sharks Off the Menu and on the Tourist Trail in Palau

AFP (Sep. 2, 2014) — Tourists in Palau clamour to dive with sharks thanks to a pioneering conservation initiative -- as the island nation plans to completely ban commercial fishing in its vast ocean territory. 01:15 Video provided by AFP
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