1 Laetoli Steps

They are the world's earliest human tracks, a set of footprints pressed into volcanic ash that have lain perfectly preserved for more than three and a half million years. Made by a group of ancient apemen, the prints represent one of the most important sites in human evolutionary studies, for they show that our ancestors had already stopped walking on four legs and had become upright members of the primate world.

The Laetoli steps were discovered in 1976 by a team of scientists led by the late Mary Leakey, mother of conservationist Richard Leakey. They found a couple of prints that had been exposed by the wind and then uncovered a trail that led across an expanse of volcanic ash, like footprints left behind by holidaymakers walking on the beach. The researchers could make out the arch of each foot, the big toe, even the heel. The prints had clearly been made by creatures who had long been adapted to walking on two legs. Yet tests showed the prints had been made about 3.6 mln years ago.

At that time, the area was populated by a short, small-brained species of apeman known as Australopithicus Afarensis, an ancestor of modern human beings. Most scientists believe these were the creators of the Laetoli footprints, individuals who may have been escaping an eruption of the nearby Sadiman volcano.

By studying the prints, scientists conclude that a smaller individual – presumed by Leakey to be a female – stopped in her tracks and glanced at some threat or sound to her left. “This motion, so intensely human, transcends time,” Leakey wrote in National Geographic. “Three million, six hundred thousand years ago, a remote ancestor – just as you or I – experienced a moment of doubt. It is this window on human behaviour that makes Laetoli so important, say scientists.

But now the Laetoli steps in northern Tanzania are in danger of destruction. The footprints, though reburied ten years ago and covered by a special protection coating, are suffering storm erosion. A study presented at an international conference last month warns that unless urgent action is taken, the site will suffer serious irreparable damage, and the Laetoli steps – 'the rarest, oldest and most inmportant evidence' documenting human's ability to walk on two legs, will be lost to civilization.

Upright – прямоходящий

eruption – извержение

irreparable damage – непоправимый ущерб

to be exposed by wind – быть открытым ветру

urgent action – срочные меры

Text 2. Battlefield Archaeology

Introduction

The British Isles are really one huge cemetery. Think how many generations have lived, died and been buried over the time that our islands have been permanently inhabited. Many of these people lie in places that we can recognise, in churchyards and cemeteries, or under prehistoric burial mounds, but many more lie unrecognised, in places that were special to those who buried them, but have now faded from memory. Many of these burials are rediscovered and excavated each year, either because sites need to be developed for roads, housing or quarries, or for research purposes, to help in our understanding of the past. In either case, the excavations are carried out by trained archaeologists, the remains treated with great respect, and the results of both excavation and scientific analysis made available through publications and museums.

The question of whether the person is male or female can usually be answered by examining the pelvis and skull.

Coming across human remains may often be the most exciting part of a dig, but in many ways the most important (and time-consuming) part of the whole process is what happens after the excavation is over. This is the 'detective story', where the bones and other finds from the site are analysed to provide the clues that we need to build a picture of a person and their surroundings. The skeleton itself will provide the first clues. The question of whether the person is male or female can usually be answered by examining the pelvis and skull. Height can be calculated from the length of the femur (thigh bone) and age from teeth and other aspects of the skeleton's growth and degeneration.

Detective work

Injuries and diseases sometimes leave traces on the bones although the actual cause of death is often the most difficult to determine. Many injuries don't damage bone, their effect is just within the overlying soft tissue. Likewise many infections, without the aid of modern medicines, would have proved rapidly fatal, too swift to allow bones to develop tell tale signs and changes.

Radiocarbon dating, the analysis of ancient DNA and of isotopes locked into bones and teeth are all part of the scientific armoury that can be used to help build up a picture of our ancestors. Used together these techniques can tell us when a person died, their diet and family relationships and even their place of birth and subsequent travels.

Where the bones themselves allow it, facial reconstruction techniques can be used to allow us to come face to face with the past. The techniques used have been developed for forensic work in tracing missing persons through their often fragmentary remains and for surgical reconstruction. Both sculptural and digital images are used to create an image of a person from the past that, although not claimed to be a precise likeness, would most probably have been recognisable to that person's friends or relatives.

The excavation of human remains, of whatever date, is regulated by law and requires a licence from the Home Office.

Cemetery – кладбище

remains – останки

burial mound – могильный курган

skull – череп

DNA - ДНК