Hominid Journey Set 250,000 Years Earlier

W A S H I N G T O N, Aug. 11 -- New findings in the sediments of a dried lake bed in Israel show that early hominids migrated into the region some 780,000 years ago, bringing with them sophisticated stone tool-making skills developed in Africa.

Craig S. Feibel, a Rutgers University geologist, said that thefindings show that a hominid called Homo erectus migrated fromAfrica and settled at a site called Gesher Benot Ya’aqov some250,000 years earlier than previous studies had suggested.

Gesher Benot Ya’aqov is located in the Dead Sea rift of northernIsrael. The site is dry now, but once it was the center of a freshwater lake, surrounded by trees and lively with game, said Feibel,the co-author of a studying appearing today in the journalScience.

New Dating TechniqueFeibel said that a shift in the Earth’s geomagnetic fieldenabled the researchers to establish the new age for the GesherBenot Ya’aqov site.

The Earth’s magnetic field, for reasons not understood, willoccasionally reverse. Rocks and some soils carry the signature ofthe magnetic field that existed at the time they were formed.

The last magnetic field reversal, the one that causes compassesnow to point north instead of south, occurred 780,000 years ago.Researchers digging at the Gesher Benot Ya’aqov site preserved theorientation of sediments and then checked their magnetic polarityin the laboratory.

Feibel said they found that specimens in a middle depth of theGesher Benot Ya’aqov dig had a reverse polarity, while rock higherup in the dig had the current magnetic polarity. Fossils were foundin both the upper and lower parts of the dig. This proved that Homoerectus was living at the site when the reversal occurred, he said.

Specimens from the site include fossils of elephants, antelope,deer and other animals that the hominid used for meat, he said.There were also residues from a variety of edible plants.

Evidence of HominidThere were no actual fossils of the hominid, but Feibel said theresearchers found stone tools, principally a type of ax, that borethe same characteristic stone chipping techniques used by hominidsthat lived earlier in Tanzania.