Featured Research

from universities, journals, and other organizations

A hop from South America: Tracking Australian marsupials

Date:
August 5, 2010
Source:
Public Library of Science
Summary:
Debates have raged for decades about how to arrange the Australian and South American branches of the marsupial family tree. While marsupials like the Australian tammar wallaby and the South American opossum seem to be quite different, new research shows otherwise.

Tammar wallaby of Australia.
Credit: iStockphoto/Susan Flashman

Debates have raged for decades about how to arrange the Australian and South American branches of the marsupial family tree. While marsupials like the Australian tammar wallaby and the South American opossum seem to be quite different, research by Maria Nilsson and colleagues at the University of Mόnster, soon to be published in the online open access journal PLoS Biology, shows otherwise.

Using sequences of a kind of "jumping gene," the team has reconstructed the marsupial family to reveal that all living Australian marsupials have one ancient origin in South America. This required a simple migration scenario whereby theoretically only one group of ancestral South American marsupials migrated across Antarctica to Australia.

Previous studies theorize that marsupials originated in Australia and that some lineages might have been split when the landmasses separated 80 million years ago. There are few ancient marsupial fossils found in South America or Australia, and previous genetic studies based on nuclear and mitochondrial genes have revealed contradictory results about which lineages are most closely related and which split off first.

Nilsson, Jόrgen Schmitz, and colleagues screened the genomes of the South American opossum and the Australian tammar wallaby, as well as the DNA of 20 other marsupial species, including the wallaroo, the common wombat, and the marsupial mole for retroposons. Retroposons are unlikely to independently arise in both these species in exactly the same part of the genome by chance and can be used as unambiguous phylogenetic markers. Thus, the overwhelming likelihood is that retroposons shared between species are derived from a long-lost ancestor.

Today's Australian marsupials appear to have branched off from a South American ancestor to form all currently known marsupials -- kangaroos, the rodent-like bandicoots, and the Tasmanian devil. It is still a mystery how the two distinct Australian and South American branches of marsupials separated so cleanly, but perhaps future studies can shed light on how this occurred.

This work was supported by a Swedish Research Council post doc grant to MN (2007-1053), the Deutsche Forschungsgemeinschaft (DFG, SCHM 1469/3 and NI 1284/1), and the Conservation, Research and Education Opportunities (CREO), Seattle, USA. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.


Story Source:

The above story is based on materials provided by Public Library of Science. Note: Materials may be edited for content and length.


Journal Reference:

  1. Nilsson MA, Churakov G, Sommer M, Tran NV, Zemann A, et al. Tracking Marsupial Evolution Using Archaic Genomic Retroposon Insertions. PLoS Biology, 2010; 8 (7): e1000436 DOI: 10.1371/journal.pbio.1000436

Cite This Page:

Public Library of Science. "A hop from South America: Tracking Australian marsupials." ScienceDaily. ScienceDaily, 5 August 2010. <www.sciencedaily.com/releases/2010/07/100727174911.htm>.
Public Library of Science. (2010, August 5). A hop from South America: Tracking Australian marsupials. ScienceDaily. Retrieved July 31, 2014 from www.sciencedaily.com/releases/2010/07/100727174911.htm
Public Library of Science. "A hop from South America: Tracking Australian marsupials." ScienceDaily. www.sciencedaily.com/releases/2010/07/100727174911.htm (accessed July 31, 2014).

Share This




More Plants & Animals News

Thursday, July 31, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Thousands Flocking to German Crop Circle

Raw: Thousands Flocking to German Crop Circle

AP (July 30, 2014) — Thousands of people are trekking to a Bavarian farmer's field to check out a mysterious set of crop circles. (July 30) Video provided by AP
Powered by NewsLook.com
Concern Grows Over Worsening Ebola Crisis

Concern Grows Over Worsening Ebola Crisis

AFP (July 30, 2014) — Pan-African airline ASKY has suspended all flights to and from the capitals of Liberia and Sierra Leone amid the worsening Ebola health crisis, which has so far caused 672 deaths in Guinea, Liberia and Sierra Leone. Duration: 00:43 Video provided by AFP
Powered by NewsLook.com
At Least 20 Chikungunya Cases in New Jersey

At Least 20 Chikungunya Cases in New Jersey

AP (July 30, 2014) — At least 20 New Jersey residents have tested positive for chikungunya, a mosquito-borne virus that has spread through the Caribbean. (July 30) Video provided by AP
Powered by NewsLook.com
Xtreme Eating: Your Daily Caloric Intake All On One Plate

Xtreme Eating: Your Daily Caloric Intake All On One Plate

Newsy (July 30, 2014) — The Center for Science in the Public Interest released its 2014 list of single meals with whopping calorie counts. 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