Homo habilis

 

      

Nickname:      Handy Man

Where Lived:  Eastern and Southern Africa

When Lived:   2.4 million to 1.4 million years ago

Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Primates
Family:	Hominidae
Genus:	Homo
Species:	H. habilis

      

This species, one of the earliest members of the genus Homo, has a slightly larger braincase and smaller face and teeth than in Australopithecus or older hominin species. But it still retains some ape-like features, including long arms and a moderately-prognathic face.

Its name, which means ‘handy man’, was given in 1964 because this species was thought to represent the first stone-tool maker. Currently, the oldest stone tools are dated slightly older than the oldest evidence of the genus Homo.

Evolutionary Tree Information:

This species, along with H. rudolfensis, is one of the earliest members of the genus Homo. Many scientists think it is an ancestor of later species of Homo, possibly on our own branch of the family tree. Naming this species required a redefining of the genus Homo (e.g., reducing the lower limit of brain size), sparking an enormous debate about the validity of this species.

While scientists used to think that H. habilis was the ancestor of Homo erectus, recent discoveries in 2000 of a relatively late 1.44 million-year-old Homo habilis (KNM-ER 42703) and a relatively early 1.55 million-year-old H. erectus (KNM-ER 42700) from the same area of northern Kenya (Ileret, Lake Turkana) challenged the conventional view that these species evolved one after the other. Instead, this evidence - along with other fossils - demonstrate that they co-existed in Eastern Africa for almost half a million years.

Year of Discovery: 1960

History of Discovery:

A team led by scientists Louis and Mary Leakey uncovered the fossilized remains of a unique early human between 1960 and 1963 at Olduvai Gorge in Tanzania. The type speciman, OH 7, was found by Jonathan Leakey, so was nicknamed "Jonny's child". Because this early human had a combination of features different from those seen in Australopithecus, Louis Leakey, South African scientist Philip Tobias, and British scientist John Napier called these remains a new species: Homo habilis, meaning ‘handy man', because they suspected that it was this slightly larger-brained early human that made the thousands of stone tools also found at Olduvai Gorge.

Key Fossils.

KNM-ER 1813

This fossil is one of the most complete skulls of this species, best known from the Turkana Basin and Olduvai Gorge in East Africa. It is likely from a female, and had a small brain size for H. habilis.

OH 24

OH 24 is the oldest fossil skull found at Olduvai Gorge; besides OH 5, it is the most complete. Its third molars had erupted, so we know it was an adult at death, yet the molars show no sign of wear, indicating that this individual probably died soon after their eruption.

OH 8

By this time, the feet of early humans had a modern-type arch.

Height:  average 3 ft 4 in - 4 ft 5 in (100 - 135 cm)

Weight:  average 70 lbs (32 kg)

Height & Weight Supplemental Information:

Male-female body size difference is uncertain, because most post-cranial remains have not been attributed to male or female.

How They Survived:

Early Homo had smaller teeth than Australopithecus, but their tooth enamel was still thick and their jaws were still strong, indicating their teeth were still adapted chewing some hard foods (possibly only seasonally when their preferred foods became less available). Dental microwear studies suggest that the diet of H. habilis was flexible and versatile and that they were capable of eating a broad range of foods, including some tougher foods like leaves, woody plants, and some animal tissues, but that they did not routinely consume or specialize in eating hard foods like brittle nuts or seeds, dried meat, or very hard tubers.

Another line of evidence for the diet of H. habilis comes from some of the earliest cut- and percussion-marked bones, found back to 2.6 million years ago. Scientists usually associate these traces of butchery of large animals, direct evidence of meat and marrow eating, with the earliest appearance of the genus Homo, including H. habilis.
Many scientists think early Homo, including H. habilis, made and used the first stone tools found in the archaeological record—these also date back to about 2.6 million years ago; however, this hypothesis is difficult to test because several other species of early human lived at the same time, and in the same geographic area, as where traces of the earliest tool use have been found.

We don’t know everything about our early ancestors—but we keep learning more! Paleoanthropologists are constantly in the field, excavating new areas, using groundbreaking technology, and continually filling in some of the gaps about our understanding of human evolution.
Below are some of the still unanswered questions about Homo habilis that may be answered with future discoveries:

1. Was H. habilis on the evolutionary lineage that evolved into later species of Homo and even perhaps our species, Homo sapiens?
2. Are H. habilis and Homo rudolfensis indeed different species, or are they part of a single, variable species? Or was one the ancestor of the other?
3. If H. habilis is not the ancestor of Homo erectus, how does it fit into our evolutionary tree?
4. H. habilis is one of the earliest members of the genus Homo. Was there a relationship between the origin of this genus and climate change – either with an increased period of climatic fluctuations, or major episodes of global cooling and drying leading to the spread of C4 grasslands?

 References :

http://humanorigins.si.edu/evidence/human-fossils/species/homo-habilis

http://www.massey.ac.nz/~alock/175316new/lecture_notes/lecture_12/humanevollect.html

http://hjurasek.github.com/homo-habilis-physical-appearance.html

http://www.bbc.co.uk/science/cavemen/factfiles/homo_habilis.shtml

http://www.pbs.org/wgbh/evolution/humans/humankind/j.html