Little ancestor, big debate: tiny islanders' identity sparks dispute.
New measurements bolster the 2-year-old claim that fossils of a half-size human ancestor found on the Indonesian island of Flores Flores, town, Guatemala
Flores (flōrəs), town (1990 est. pop. 2,200), capital of Petén department, N Guatemala. Flores was built on an island in the southern part of Lake Petén Itzá and on the site of the represent a new species, Homo floresiensis Homo floresiensis ("Man of Flores", nicknamed Hobbit) is the name for a possible species in the genus Homo, remarkable for its small body, small brain, and survival until relatively recent times. .
Comparisons of a partial Flores skeleton with bones of other human ancestors and modern people weaken recent arguments that that the island finds come either from Stone Age pygmies or from another Homo sapiens Homo sapiens
(Latin; “wise man”)
Species to which all modern human beings belong. The oldest known fossil remains date to c. 120,000 years ago—or much earlier (c. specimen with a genetic condition known as microcephaly microcephaly /mi·cro·ceph·a·ly/ abnormal smallness of the head.microcephal´ic
Abnormal smallness of the head. Also called nanocephaly. that hinders brain growth, concludes a team led by Debbie Argue of the Australian National University Australian National University, located in Canberra and state-sponsored, founded 1946 as Australia's only completely research-oriented university. Originally limited to graduate studies, it expanded in 1960, merging with Canberra University College (est. 1929). in Canberra. A separate group of researchers originally found the fossils.
Argue's group compared measurements of the Flores fossils--which range in age from roughly 12,000 to 90,000 years--with corresponding data on skull and limb bones from two people with microcephaly who died around 2,000 years ago; a roughly 4 1/2-foot-tall person previously excavated at a 3,000-to-5,000-year-old Flores site; more than a dozen human ancestors ranging in age from 1 million to 3.2 million years; and 584 modern humans, including members of especially short populations.
After considering these comparisons, Argue finds it "unlikely" that the Flores individual was a human with microcephaly or a member of any known species of human ancestors. The Flores skull displays notable anatomical differences from a pair of human skulls--one unearthed Unearthed is the name of a Triple J project to find and "dig up" (hence the name) hidden talent in regional Australia.
Unearthed has had three incarnations - they first visited each region of Australia where Triple J had a transmitter - 41 regions in all. in Greece and the other in Japan--that exhibit microcephaly, the researchers say.
The new study will appear in the Journal of Human Evolution.
Curiously, the Flores specimens relatively short limbs resemble those of a 2.5-million-year-old human ancestor, Australopithecus garhi, the team contends. The island species' skull recalls the shape of nearly 2-million-year-old Homo finds.
Argue's team determined, however, that the H. floresiensis individual probably did suffer from a type of microcephaly.
This combination of skull and limb traits raises three possible explanations for the evolution of H. floresiensis, according to Argue's group. The creature could have originated in Africa as a previously unknown Homo lineage that later migrated to southeastern Asia, or evolved on Flores from an early Homo population that had unusually short limbs, or derived from an ancient African population that was in the process of evolving from Australopithecus to Homo when it departed for Asia.
However, other researchers who have examined Flores fossils (SN: 10/15/05, p. 244) and stone tools (SN: 6/3/06, p. 341) regard them as the remains of modern humans with unusual genetic conditions (see page 46).
In a joint statement to Science News, Robert B. Eekhardt of Pennsylvania State University Pennsylvania State University, main campus at University Park, State College; land-grant and state supported; coeducational; chartered 1855, opened 1859 as Farmers' High School. in University Park and Maciej Henneberg of the University of Adelaide Its main campus is located on the cultural boulevard of North Terrace in the city-centre alongside prominent institutions such as the Art Gallery of South Australia, the South Australian Museum and the State Library of South Australia. in Australia call the report from Argue's team "incomplete and inconclusive." Eckhardt and Henneberg head a group that has submitted its own analysis of the Flores material and other bones for publication.
Argue's analysis errs by comparing a mix of pathological and non-pathological traits of the Flores skull and the two microcephalic mi·cro·ceph·a·ly
n. pl. mi·cro·ceph·a·lies
Abnormal smallness of the head.
mi skulls, Eckhardt and Henneberg contend. It also fails to account for the anatomical effects of a reduced brain size.
"The result is more numerology numerology
Use of numbers to interpret a person's character or divine the future. It is based on the assertion by Pythagoras that all things can be expressed in numerical terms because they are ultimately reducible to numbers. than objective scientific method," Eckhardt says. He suspects that the Stone Age Flores finds came from a population of small-bodied humans that reached the island, with the partial skeleton representing a case of microcephaly.