Homo habilis



Homo habilis is the species name given to a reputed hominid that is believed to be an evolutionary intermediate between the australopithecines (apes) and ancient humans (i.e. Homo erectus). Its name means "Handy-man" referring to its supposed ability to make tools. It was discovered by Louis Leakey in 1960 who was convinced that this was the Olduvai toolmaker he had searched for most of his life. Leakey then asserted that H. habilis was a direct human ancestor.

Characteristics
The specimens attributed to habilis vary widely, as are the measurements of specific fossils taken by different researchers, making it very difficult to describe the accepted characteristics of the species. Instead many sources simply describe the specimens that are generally accepted to belong to this taxa. Rather than having distinct attributes the species seems to instead be a conglomerate of African fossils that paleontologists are unable to classify or put in any other group.

The cranial capacity of fossils assigned to H. habilis range from just under 500 cubic centimeters (cc) to approximately 800 cc. The first specimen attributed to the species was a 12 or 13 year old male known as OH 7, which was discovered by the Leakey team in Olduvai Gorge, Tanzania. It consisted of a nearly complete left parietal bone, a fragmented right parietal, most of the mandible (including thirteen teeth), an upper molar, and twenty-one hand bones. It is considered the type specimen for H. habilis. The brain size attributed to this specimen varies widely among the various researches that performed measurements (ranging from 590 all the way up to 710 cc). Tobias gives an estimate of 647 cc, Holloway gives an estimate of 710 cc, and Wolpoff has estimated it at 590 cc.

Controversy
There is much debate among paleontologists as to whether the fossil specimens assigned to this taxa all belong to the same species. According to Wolpoff, habilis has been used ‘as a garbage bag’ for fossils by some scientists. Tattersall and Schwartz have described it similarly as an ‘all-embracing “wastebasket” species into which a whole heterogeneous variety of fossils could be conveniently swept’.

ArchaeologyInfo.com summarizes the habilines as follows: Homo habilis is a very complicated species to describe. No two researchers attribute all the same specimens as habilis, and few can agree on what traits define habilis, if it is a valid species at all, and even whether or not it belongs in the genus Homo or Australopithecus. Hopefully, future discoveries and future cladistic analyses of the specimens involved may clear up these issues, or at least better define what belongs in the species.

Some have argued to split the taxa into two groups and reclassify some as a new species called Homo rudolfensis.

The differences in morphological features of the fossil species included in Homo, excluding the invalid taxon Homo habilis, are believed to represent, among other factors, genetic variation within the one human kind. Homo habilis is believed to represent a collection of assorted fossils that either were human (e.g. Homo erectus) or were australopithecine apes. If fossils such as those categorized as Homo erectus and Neandertals were all fully human, then the case for human evolution essentially collapses, as there is an unbridgeable morphological gap between the australopithecine apes and these humans.

The ability to make tools was inferred from several specimens that were found in the presence of tools. The existence of tools reveals that men occupied these sites, however, Malcolm Bowden suggests that the ape skulls at the site were probably broken open for food

Additional information

 * Homo habilis hacked from the family tree, New hominid fossils have ‘completely changed the story’ of human evolution by Phillip Bell, Creation Ministries International, September 14, 2007.