Mr Caveman stayed close to home

2011-06-02 10:12
Paris - Scientists on Wednesday unveiled evidence that two species of early cavemen lived and died near their places of birth while most females of the same species settled down after coming from afar.

The study, published in Nature, offers an unprecedented glimpse into the social fabric of australopithecines, an extinct line related to humans that dwelt in southern Africa some two million years ago.

It also challenges the axiomatic idea that our distant forebears began to walk on two legs rather than four in order to cover great distances in search of food or shelter.

If males limited their wanderings to hunt-and-gather forays, then the shift to walking upright might have been driven by other needs, the findings suggest.

Up to now, very little was known of the lifestyle and kinship patterns of our two-legged ancestors.

Behavioural clues


"Disembodied skulls and teeth are notoriously poor communicators," quipped Matt Sponheimer, an anthropology professor at the University of Colorado at Boulder and a co-author of the study.

For the new study, scientists devised a method worthy of Sherlock Holmes to "make these old bones speak", Sponheimer said.

The behavioural clues were locked inside a handful of two-million-year-old teeth.

Tiny variations in the atoms of a heavy metal element called strontium correspond to various types of soil and rock, thus acting as a telltale of identifiable geographic locations.

Because strontium works its way into tooth enamel only during the first years of life, the element thus shows whether a primate grew up in the same place where she or he dwelt and died.

The scientists examined teeth from 19 individuals who lived 2.4 to 1.7 million years ago, eight Australopithecus africanus and 11 Paranthropus robustus.

Both species lived in woodland savannahs, probably subsisting on a mix of tree fruits, grass, seeds and nuts.

Lifestyle

Males and females in the sampling were differentiated on the basis of size.

Laser analysis of the strontium isotopes showed that only 10% of the males originated from outside a range of 30km2, compared to more than half of the females.

The males, in other words, probably strayed only rarely more than a few kilometres from their caves.

Their female partners, however, had often migrated from afar, even if they adopted the same close-to-home lifestyle once settled.

"Here we have the first direct glimpse of the geographic movements of early hominids, and it appears the females preferentially moved from their residential groups," said Sandi Copeland, also of the University of Colorado and lead author of the study.

The practice of females leaving the nest to join the family of their mates has been common in most human cultures across history. Chimpanzees and bonobos also follow the same pattern.

But most other primates, including gorillas, do the opposite: females stay with the group they are born to while males move elsewhere.

Problems

The discovery came as a surprise, and calls into question long-held views about how primates came to prefer moving on two feet rather than four, the researchers said.

"We assumed more of the hominids would be from non-local areas since it is generally thought the evolution of bipedalism was due in part to allow individuals to range longer distances," said Copeland.

"Such small home ranges could imply that bipedalism evolved for other reasons."

The study sheds new light on the "diet, group size, predator avoidance and home-range size" of what may be our direct ancestors, Margaret Schoeninger, a professor at the University of California at San Diego, wrote in a commentary, also in Nature.

But it also raises many vexing problems, she added: "How the australopithecines balanced predator avoidance and the need to compete for food remains an open question."
Read more on:    paleontology
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
27 comments
Add your comment
Comment 0 characters remaining
 

Inside News24

 
/Sport
Traffic & Train Alerts
Traffic
Kuils River 10:01 AM
Road name: Polkadraai Road Eastbound

ROADWORKS between the R102 Van Riebeeck Road and the R310 Baden Powell Drive exit - HEAVY DELAYS

Cape Town 09:59 AM
Road name: N2 Inbound

STATIONARY VEHICLE in the left lane at the Mowbray Main Road exit - DELAYS from Bhunga Avenue

Jobs in Cape Town [change area]

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

Up to 60% off - clearance sale!

Save up to 60% on appliances, books, electronics, toys, movies and more. Offer valid while stocks last. Shop now!

Deal of the Week!

Get bestselling John Green novels now just R99 each! Hurry and get yours while stocks last. Shop here.

Mind blowing deals on beauty & fragrances

Save up to 30% off beauty and fragrances. Offer valid while stocks last. Shop now!

Up to 50% off hair care products!

Save up to 50% on professional hair care products at kalahari.com. Offer valid while stocks last. Shop now!

30% off academic books

Score a mind blowing 30% off academic books! 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

Social media is pulling you in and you have the desire to find out everything you know about your friends and you have the urge to...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.