Sunday, April 22, 2018
Contact us    |    Advertise    |   Help   RSS icon Twitter icon Facebook icon
    Home  ·  News  ·  Forum  ·  Stories  ·  Image Gallery  ·  Columns  ·  Encyclopedia  ·  Videos
Find: in

DNA offers clues to woolly mammoth's demise


Posted on Saturday, 4 March, 2017 | Comment icon 13 comments

The mammoth held on until around 4,000 years ago. Image Credit: Charles Robert Knight
An analysis of mammoth DNA has revealed that the species had become wracked with genetic disease.
Study leader Dr Rebekah Rogers from the University of California, Berkeley maintains that just before it went extinct, the woolly mammoth had gone into "genomic meltdown".

The DNA sample in question had come from a mammoth which lived around 4,000 years ago - a time when the species had been all but wiped out save for a few isolated island populations.

To confirm the findings, the researchers also analyzed the DNA of a mammoth from 45,000 years ago which did not show the same signs of genetic disease as its more recent counterpart.

"You had this last refuge of mammoths after everything has gone extinct on the mainland," said Dr Rogers. "The mathematical theories that have been developed said that they should accumulate bad mutations because natural selection should become very inefficient."

The discovery is worrying as similar issues could also plague some of today's endangered species.

"When you have these small populations for an extended period of time they can go into genomic meltdown, just like what we saw in the mammoth," said Dr Rogers.

"So if you can prevent these organisms ever being threatened or endangered then that will do a lot more to help prevent this type of genomic meltdown compared to if you have a small population and then bring it back up to larger numbers."

Source: BBC News | Comments (13)

Tags: Mammoth, DNA

Recent comments on this story
Comment icon #4 Posted by godnodog on 5 March, 2017, 12:40
Ice ages are cyclic.  http://earthguide.ucsd.edu/virtualmuseum/climatechange2/01_1.shtml
Comment icon #5 Posted by EBE Hybrid on 5 March, 2017, 21:40
It sounds as if the last herd of mammoth had a lack of genetic variety, genetic defects becoming more common as they were past from one generation to the next. Norfolf!!!!
Comment icon #6 Posted by Carnoferox on 5 March, 2017, 21:44
The Wrangel Island population of mammoths had such a high number of genetic defects because they were inbreeding. Genetic bottlenecks happen when animals become stranded on small islands with limited resources. However, these genetic defects did not cause the extinction of the species as a whole.
Comment icon #7 Posted by Farmer77 on 5 March, 2017, 21:55
 Could geographic isolation due to human predation create conditions for sustained interbreeding and genetic degradation? 
Comment icon #8 Posted by oldrover on 5 March, 2017, 22:38
This is one of the key aspects to a major theory about the megafauna extinction in general. 
Comment icon #9 Posted by Carnoferox on 5 March, 2017, 22:51
Definitely. That is what happened to the Wrangel Island woolly mammoths. However, it is not known for sure if the geographic isolation was caused by human hunting. A more likely explanation is the gradual disappearance of the mammoth steppe (the natural habitat of the woolly mammoth and numerous other species) and its replacement with boreal forests.
Comment icon #10 Posted by oldrover on 5 March, 2017, 23:48
It's also one of the factors which played a part in the extinction of the thylacine, and the decline in devil numbers de to DFTD. Not necessarily in the case of the thylacine initially through human agency, and not in the case of the devil. Both instances are the result of geographic isolation. However with the tiger human hunting and land alteration probably exacerbated  the effect.  The same has I believe been postulated for hunting patterns in N America during the late Pliestocene early Holocene. Extinction has lots of little helpers. 
Comment icon #11 Posted by AnchorSteam on 6 March, 2017, 18:59
Wrangle wasn't always an island, the  Mammoths didn't swim there. Jean Auel said that it was habitat lose that did them in; their environment was the edge of the Glaciers, almost literally. Wrangle may have been the last place in the world they felt comfortable.   
Comment icon #12 Posted by Carnoferox on 6 March, 2017, 19:24
Woolly mammoths reached Wrangel Island while it was still part of the Bering Land Bridge, then became trapped as sea levels rose again. Habitat loss was a major contributing factor to the extinction of the woolly mammoth. Woolly mammoth habitat wasn't right at the edge of glaciers though, but rather on the wide open steppe. Auel is just an author (not a paleontologist), so I wouldn't use her as a reliable source.
Comment icon #13 Posted by AnchorSteam on 6 March, 2017, 21:01
Yeah, but I liked her books. 


Please Login or Register to post a comment.


  On the forums
Forum posts:
Forum topics:
Members:

6166410
262549
174756

 
Work on lunar space station to begin in 2019
4-21-2018
NASA has revealed that its ambitious Lunar Orbital Platform-Gateway will launch as early as 2022.
Cows could end up as world's largest mammals
4-21-2018
Scientists have warned that cows could eventually become the largest remaining mammals on Earth.
New species of 'exploding ant' discovered
4-20-2018
Capable of taking drastic action to protect their colonies, these ants have a rather unusual defense mechanism.
Missing Nazi submarine mystery finally solved
4-20-2018
The wreckage of one of Germany's most advanced U-boats has been discovered off the coast of Denmark.
Featured Videos
Gallery icon 
Revealing the secrets of the deep ocean
Posted 4-19-2018 | 0 comments
Scientist Mandy Joye has dedicated her life to exploring the depths of the world's oceans.
 
Giant 3D-printed man
Posted 4-15-2018 | 2 comments
British YouTuber James Bruton has created a giant 3D-printed sculpture of himself.
 
The world's roundest object
Posted 4-12-2018 | 2 comments
A look at how the roundest object can help us to define the humble kilogram.
 
Do fish talk to each other ?
Posted 4-10-2018 | 11 comments
Fish might seem silent, but in actual fact they make a wide range of different sounds.
 
The great Jaffa Cake debate
Posted 4-8-2018 | 4 comments
Revisiting the age-old question - is the humble Jaffa Cake a cake or a biscuit ?
 
 View: More videos
Stories & Experiences
Dreams and clues to the future
3-31-2018 | Philippines and Germany
 
Black cloaked figure
3-31-2018 | Carlisle, Cumbria, England
 
Three knocks
3-8-2018 | Canada
 
Two shadows of me
3-8-2018 | Bellflower, LA
 
I think I know what I saw
3-5-2018 | Near Sultan, Washington
 
Ghost, or something else ?
3-5-2018 | Ohio, USA
 
 
Black hole in Bismarck
2-14-2018 | Mandan
 
 
Trapped and chased
2-9-2018 | Saskatchewan canada
 

         More stories | Send us your story
 
Top   |  Home   |   Forum   |   News   |   Image Gallery   |  Columns   |   Encyclopedia   |   Videos   |   Polls
UM-X 10.7 Unexplained-Mysteries.com © 2001-2018
Terms   |   Privacy Policy   |   Cookies   |   Advertise   |   Contact   |   Help/FAQ