Did Lucy live in the woods? - Science - News - The Independent

Did Lucy live in the woods?

Humans may have walked first in the forest, not on the savannah, says Jerome Burne

There are plenty of mysteries about human evolution. Are we all really descended from one pre-human woman? How did we develop the power of speech? Until very recently, though, there was pretty wide agreement about our first step. This was standing upright and walking on two legs, or bipedalism as it's technically known. Look in any relevant textbook and you'll see the secular, triumphalist version of the Garden of Eden story.

Once, the old theory goes, we were like all the other apes, living in trees in the lush forest, picking fruit from the branches whenever we wanted it. Then came a change in the weather, the forests thinned out and we had to come down from the trees and survive in the harsher, more arid world of the savannah. But being thrown out of Eden was the making of us. We stood upright, we learnt to hunt, our brains grew and we went on to dominate the planet.

However, unlike religious myths that are impervious to facts, scientific stories constantly have to earn their keep - and the evidence that once underpinned the savannah story is looking increasingly shaky. "The savannah paradigm has been overthrown," says Phillip Tobias, senior palaeoanthropologist at the University of Witwatersrand, Johannesburg. "We have to look for some other explanation."

Only three years ago, palaeontologist Elizabeth Vrba of Yale University was able to confidently declare: "The lineage of upright primates was one of the founding groups of the great African savannah biota [the life of a region or period]." She had found that between about 2.5 and two million years ago - when hominids were starting to use tools - conditions got harsher and forest-living animals disappeared, to be replaced by ones suited to the savannah. Other researchers found similar evidence for global cooling around five million years ago - about the time humans were supposed to be going bipedal.

This fitted with the theory that walking upright happened before we started growing our big brains. Key evidence for this came from Lucy, the fossil found 20 years ago, and dated to 3.2 million years ago, who had a chimp- sized brain but already walked upright. It also fitted in with the famous footprints found frozen in volcanic ash at Laetoli, Tanzania - showing an early hominid family walking on two legs 3.5 million years ago.

But the theory that this change was climate-driven was looking increasingly shaky. Andrew Hill and John Kingston, also of Yale, looked at carbon isotopes in geological strata in an area of Kenya where many hominid fossils had been uncovered. Plants from arid periods leave different ratios of isotopes from those flourishing in wet soils. They found no evidence for a dramatic shift to grassland. Other new finds also undermined the savannah theory, such as early hominid remains along with pigs whose legs were adapted for life in heavy woods. Ocean-based research found evidence for a cooling in Africa only 2.8 million years ago - far too late to explain Lucy's new gait. Yet more evidence was suggesting that the ground Lucy was covering may not have been that dry after all.

The possibility that hominids were walking around upright in a forested area at least a million years before Lucy came dramatically alive last year when two new sets of fossils were found by Lake Turkana in Kenya. One, known as Australopithecus anamensis, was dated to 4.2 million years while the other, Ardipithecus ramidus, was estimated at 4.4 million years old.

Anamensis was walking upright, but according to a co-discoverer, Alan Walker of Penn State University, not exclusively on the savannah. The lake, he says, was much bigger than it is now and was fed by massive rivers that would have supported forests a mile or two wide on either bank.

The clincher should be ramidus. These hominids definitely lived in dense woods along with monkeys and antelope adapted for forests. But there is an academic cliff-hanger here. The team that found it are refusing to say whether it is bipedal until they have finished a full analysis and that won't be until 1998. If it is bipedal, the savannah story is certainly dead.

The great attraction of the savannah theory, apart from the way it seemed to fit the facts as far as they were known, was that it was a tale of plucky little hominids surviving against the odds. But if our distant ancestors weren't pushed into walking upright we are left with the considerable mystery of why they did do it. It's not as if it's a particularly good way of getting about, and osteopaths say our upright gait is the reason why humans generally are so prone to back problems.

There is no shortage of theories but they all have problems. One says that it was a development of what some chimps do when they are feeding on the ground - they reach up and pull down branches. Another suggestion is that it comes from chimps' aggression display, when they pull themselves up to full height to scare off an attacker. But that still doesn't answer the question of why we took these occasional behaviours to such an extreme.

If the drive wasn't feeding or fighting then perhaps it could be sex, or rather parenting. That's what Owen Lovejoy of Kent State University in Ohio suggests. He believes that what distinguished Lucy and her upright forebears was that dad helped out more with the kids, which would have improved their chances of survival. The parents stayed together and worked as a team and in return he got more sex.

Instead of just fending for himself the male would go foraging and bring back a selection of fruit and vegetables. But to do this he had to have his hands free - which walking upright gave him. What this scenario doesn't deal with is that the whole point of the savannah theory is that life was too easy in the forest.

The facts, then, are turning against the savannah scenario. But we also know that scientific theories have a cultural dimension. Perhaps in the face of the looming threat of global warming, we have suddenly become less keen on a theory which is so heavily based on the bracing effect of climatic change.

News
Paper trail: the wedding photograph found in the rubble after 9/11 – it took Elizabeth Keefe 13 years to find the people in it
newsWho are the people in this photo? It took Elizabeth Stringer Keefe 13 years to find out
Arts and Entertainment
Evil eye: Douglas Adams in 'mad genius' pose
booksNew biography sheds light on comic genius of Douglas Adams
Sport
FootballFull debuts don't come much more stylish than those on show here
News
i100
PROMOTED VIDEO
Life and Style
Kim Kardashian drawn backlash over her sexy swimsuit selfie, called 'disgusting' and 'nasty'
fashionCritics say magazine only pays attention to fashion trends among rich, white women
Arts and Entertainment
TVShows like Agents of S.H.I.E.L.D are little more than marketing tools
Arts and Entertainment
Hit the roof: hot-tub cinema east London
architectureFrom pools to football pitches, rooftop living is looking up
Travel
travel
News
The ecological reconstruction of Ikrandraco avatar is shown in this illustration courtesy of Chuang Zhao. Scientists on September 11, 2014 announced the discovery of fossils in China of a type of flying reptile called a pterosaur that lived 120 millions years ago and so closely resembled those creatures from the 2009 film, Avatar that they named it after them.
SCIENCE
Life and Style
tech
News
ebooksAn unforgettable anthology of contemporary reportage
Arts and Entertainment
Matisse: The Cut-Outs exhibition attracted 562,000 visitors to the Tate Modern from April to September
art
Life and Style
Models walk the runway at the Tom Ford show during London Fashion Week Spring Summer 2015
fashionLondon Fashion Week 2014
News
Kenny G
news
News
peopleThe black actress has claimed police mistook her for a prostitute when she kissed her white husband
Life and Style
techIndian model comes with cricket scores baked in
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Energy Markets Analyst

£400000 Per Annum: The Green Recruitment Company: Job Title: Energy Markets An...

Junior Web Analyst – West Sussex – Up to £35k DOE

£30000 - £35000 Per Annum Plus excellent benefits: Clearwater People Solutions...

Nursery Manager

£22000 - £23000 per annum: Randstad Education Bristol: We are currently recrui...

Web Analyst – Permanent – Up to £40k - London

£35000 - £40000 Per Annum: Clearwater People Solutions Ltd: We are currently r...

Day In a Page

Mystery of the Ground Zero wedding photo

A shot in the dark

Mystery of the wedding photo from Ground Zero
His life, the universe and everything

His life, the universe and everything

New biography sheds light on comic genius of Douglas Adams
Save us from small screen superheroes

Save us from small screen superheroes

Shows like Agents of S.H.I.E.L.D are little more than marketing tools
Reach for the skies

Reach for the skies

From pools to football pitches, rooftop living is looking up
These are the 12 best hotel spas in the UK

12 best hotel spas in the UK

Some hotels go all out on facilities; others stand out for the sheer quality of treatments
These Iranian-controlled Shia militias used to specialise in killing American soldiers. Now they are fighting Isis, backed up by US airstrikes

Widespread fear of Isis is producing strange bedfellows

Iranian-controlled Shia militias that used to kill American soldiers are now fighting Isis, helped by US airstrikes
Topshop goes part Athena poster, part last spring Prada

Topshop goes part Athena poster, part last spring Prada

Shoppers don't come to Topshop for the unique
How to make a Lego masterpiece

How to make a Lego masterpiece

Toy breaks out of the nursery and heads for the gallery
Meet the ‘Endies’ – city dwellers who are too poor to have fun

Meet the ‘Endies’ – city dwellers who are too poor to have fun

Urbanites are cursed with an acronym pointing to Employed but No Disposable Income or Savings
Paisley’s decision to make peace with IRA enemies might remind the Arabs of Sadat

Ian Paisley’s decision to make peace with his IRA enemies

His Save Ulster from Sodomy campaign would surely have been supported by many a Sunni imam
'She was a singer, a superstar, an addict, but to me, her mother, she is simply Amy'

'She was a singer, a superstar, an addict, but to me, her mother, she is simply Amy'

Exclusive extract from Janis Winehouse's poignant new memoir
Is this the role to win Cumberbatch an Oscar?

Is this the role to win Cumberbatch an Oscar?

The Imitation Game, film review
England and Roy Hodgson take a joint step towards redemption in Basel

England and Hodgson take a joint step towards redemption

Welbeck double puts England on the road to Euro 2016
Relatives fight over Vivian Maier’s rare photos

Relatives fight over Vivian Maier’s rare photos

Pictures removed from public view as courts decide ownership
‘Fashion has to be fun. It’s a big business, not a cure for cancer’

‘Fashion has to be fun. It’s a big business, not a cure for cancer’

Donatella Versace at New York Fashion Week