Cavemen sex gave humans immune boost

2011-08-26 08:29
Washington - Sexual encounters with archaic humans like the Neanderthals produced children who inherited key genes that have helped modern humans fight illness and disease, said a study said.

"The cross-breeding wasn't just a random event that happened, it gave something useful to the gene pool of the modern human," said Stanford University's Peter Parham, senior author of the study in the journal Science.

Equipped with knowledge of the genome of the Neanderthals and the Denisovans, of whom a tooth and a finger bone were discovered in a Russian cave in 2010, researchers scoured the data for hints of what genes crossed over.

Scientists already knew that about 4% of Neanderthal DNA and up to 6% of Denisovan DNA are present in some modern humans.

This study took a close look at a group called HLA class I genes which help the immune system adapt to fight off new pathogens that could cause various infections, viruses and diseases.

Rare

Researchers traced the origin of one type, HLA-B*73, to the Denisovans, who likely mated with humans arriving in West Asia on their way out of Africa. The variant is rare in modern African populations but is common in people in west Asia.

"We think this had a lot to do with the pathogenic environment in different parts of the world," said Laurent Abi-Rached, a French researcher and lead author of the study.

"When modern humans came out of Africa, they were going into a new environment. This gave them an advantage. It was a rapid way of acquiring defence," he said.

These ancient HLA genes have multiplied among modern populations and are seen in more than half of Eurasians today, said the study.

"If canoodling was the whole story, that's an awful lot of genes," said Milford Wolpoff, a paleoanthropologist at the University of Michigan who was not involved with the study but said he supported its findings.

"This is called multiregional evolution. We have been talking about this for 30 years," he said.

"Many of the genes we find are doing something useful. The only answer for that is natural selection."

Latest findings

Neanderthals died off about 30 000 years ago. They and the Denisovans shared a common ancestor with modern humans about 400 000 years ago.

Modern humans eclipsed these ancient cousins when our contemporaries began expanding into Asia and Europe from Africa about 65 000 years ago.

Some mating must have occurred, given the evidence that lingers in our DNA, but even the latest findings have shed little light on the nature of those relationships - whether violent or consensual, short or long-term.

"Even though there was probably interbreeding, that was not necessarily very frequent," said Abi-Rached.

"But it has played a major role in shaping modern human immunity."

Abi-Rached said he hopes further research will reveal more about the role that the immune genes may have played in protecting those who survived but also their role in autoimmune diseases that humans face today.

The work of studying the legacies left by ancient ancestors in our bodies could lead to new pathways for treatment of modern diseases, which has researchers excited about the potential of the emerging field.

"Most of the money in genetics is related to diseases," said Wolpoff.

"Paleoanthropology is just like politics. You follow the money."
Read more on:    palaeontology
NEXT ON NEWS24X
SHARE:

Read News24’s Comments Policy

24.com publishes all comments posted on articles provided that they adhere to our Comments Policy. Should you wish to report a comment for editorial review, please do so by clicking the 'Report Comment' button to the right of each comment.

Comment on this story
78 comments
Add your comment
Comment 0 characters remaining
 

Inside News24

 
SPONSORED CONTENT
5 crucial questions to ask before you take that job 2014-10-30 08:00

You choose your employer just as much as they choose you. Here are 5 of the most important things you should find out about a company before you sign up.

/News
 

10 facts about swimming you didn't know

This will make you want to jump right into the pool.

 
 

Where were you when you last felt alive?

Snors with a cause - creating awareness of male health
Inspiring: Rock climbing with just one leg
Watch! Skateboarders racing cyclists
Exciting new zipline for Cape Town!

Jobs in Cape Town [change area]

Jobs in Western Cape region

Health and Safety Practitioner

Durbanville
Cozens Recruitment Group ( Western Cape)
R25 000 - R35 000 Per Month

Temp Creditors Clerk

Somerset West
Quantum Recruitment

Sales Representative

Cape Town Southern Suburbs
Mpumalanga Personnel & Training Consultants

Property [change area]

Travel - Look, Book, Go!

Magical Massinga

Spend 5 nights at the gorgeous Massinga Beach Lodge in Mozambique and only pay for 4 from R13 220 per person sharing. Includes return flights, accommodation, transfers and romantic turndown. Book now!

Kalahari.com - shop online today

Save up to R2100 on electronics! – As seen in the catalogue

Wishing for tech gadgets this festive? Save up to R2100 on hot tech products at kalahari.com. While stocks last. Shop now!

TV Series – 2 for R299

Loads of hot titles to choose from. Shop now!

Hot offer: Up to 50% off irons

Save up to 50% on all Philips irons. While stocks last. Shop now!

Seen something you like in our catalogue?

Find the perfect gift and save up to R5000 – As seen on the catalogue. Hurry and shop now!

Toys 4 for the price of 3

Buy 4 toys and get the cheapest FREE! Offer valid while stocks last. Shop now!

OLX Free Classifieds [change area]

Samsung Galaxy s4

Mobile, Cell Phones in South Africa, Western Cape, Cape Town. Date October 24

Best bargain in big bay

Real Estate, Houses - Apartments for Sale in South Africa, Western Cape, Cape Town. Date October 25

VW Golf 6, 1.6 Trendline (Excellent condition)

Vehicles, Cars in South Africa, Western Cape, Cape Town. Date October 25

Horoscopes
Aquarius
Aquarius

You may be doing the work and playing the game, but your innovative mind is on a far away planet planning the next big thing....read more

There are new stories on the homepage. Click here to see them.
 
English
Afrikaans
isiZulu

Hello 

Create Profile

Creating your profile will enable you to submit photos and stories to get published on News24.


Please provide a username for your profile page:

This username must be unique, cannot be edited and will be used in the URL to your profile page across the entire 24.com network.

Settings

Location Settings

News24 allows you to edit the display of certain components based on a location. If you wish to personalise the page based on your preferences, please select a location for each component and click "Submit" in order for the changes to take affect.








Facebook Sign-In

Hi News addict,

Join the News24 Community to be involved in breaking the news.

Log in with Facebook to comment and personalise news, weather and listings.