Spreading Through Asia
Homo erectus, was one of the world's most successful hominids. This species appears to have evolved in eastern Asia and lived there for perhaps as long as 1.5 million years--10 times longer than modern humans have been around. Some of the oldest--and youngest--fossils of Homo erectus have been found in Southeast Asia, in particular on the island of Java in Indonesia. This region is very far from Africa, suggesting that once our ancient relatives moved out of that continent, they quickly spread east.
Numerous ancient fossils of the species Homo erectus have been found on the Indonesian island of Java. The first was discovered at Trinil in 1891.
How Old Is It?
Geologist Carl Swisher collects data to determine the age of a hominid site at Sangiran, Java. Researchers can sometimes date a layer of rock or soil by studying the orientation of its iron particles, which shift with changes in Earth's magnetic field.
A Long History
Our species has been around for a relatively short time--200,000 years at most. The species Homo erectus survived in Asia for much longer--some 1.5 million years. The skull to the right is one of the oldest Homo erectus fossils, possibly dating back 1.8 million years. The skull below it may be no more than 40,000 years old.
Type Specimen: Homo erectus
The young Dutch doctor Eugene Dubois set out for the Dutch East Indies in 1887, determined to find ancient hominid fossils. A strong supporter of Charles Darwin and his work on evolution and natural selection, Dubois felt that human evolution could be demonstrated only with fossil evidence. In 1891, Dubois miraculously found this skullcap of what is now described as a member of the species Homo erectus.
This skull from the island of Flores, Indonesia, belonged to a hominid so small it is nicknamed "the Hobbit." Found with a partial skeleton in 2004, it has sparked a furious debate. Although the Flores hominid seems to have lived only 18,000 years ago--at the same time as modern humans--it had a tiny brain, similar in size to the brains of our earliest, apelike relatives. The scientists who discovered the fossils classify the Flores hominid as its own species, Homo floresiensis. Others maintain it was the victim of a disease.
When researchers first discovered this tiny skull from 18,000 years ago, they thought it was the remains of a modern human child. But it had the teeth of an adult--they were very worn, and the wisdom teeth had come in. The partial skeleton found with the skull indicated an individual about one meter (three feet) tall. Scientists later found fossils of more Flores hominids with the same diminutive form.
Why is the Flores Hominid so small?
Biologists have observed that species isolated on islands tend to change size as they evolve over the course of many generations. Fossil remains of pygmy elephants have also been found on Flores. These elephants likely evolved into smaller forms in response to limited food resources. Perhaps the small size of the Flores hominid reflects similar pressures during hominid evolution.
The huge cave known as Liang Bua has been used for thousands of years by residents of the island of Flores. Researchers had to dig down some six meters (20 feet) before finding the fossil remains of the tiny Flores hominids.