“Hobbits” may owe their peculiarities to genetic mutations

January 4th, 2008 - 4:39 pm ICT by admin  

A file-photo of National Geographic

Washington, January 4 (ANI): Scientists have discovered that a rare disease called microcephaly, characterized by small brain and body size but near normal intelligence, is caused by mutations in a gene coding for the protein pericentrin.

The new finding has led the researchers to speculate that the condition may explain the tiny, hobbit-like people that occupied a remote Indonesian island about 18,000 years ago.

It has also fuelled the debate over whether the unusual creatures were a new species, or just diseased modern humans.

Pericentrin helps separate chromosomes during cell division, which is needed for growth.

“The whole body loses its capacity to grow, because cell division is so difficult for people with this defect,” National Geographic quoted study co-author Anita Rauch of the Institute for Human Genetics at the University of Erlangen in Germany, as saying.

It is said that microcephaly sufferers on average grow about three feet tall, and have a brain the size of a three-month-old baby. They also exhibit subtle bony anomalies in their hands and wrists, skull asymmetry, small chins, abnormal teeth, and abnormal shoulders. However, their intelligence is near normal.

Rauch said that the description of the hobbit-like people is very similar to that of modern humans with this genetic defect.

Upon being discovered in 2004 on the Indonesian island of Flores, the hobbit was hailed as a new species, Homo floresiensis, by the scientists. Since then, it is being debated whether the hobbit are a new species or a modern human with microcephaly.

The new study links the genetic mutations to a type of microcephaly.

“We think it is very likely that Homo floresiensis indeed had a pericentrin mutation,” Rauch said.

Richard Potts, director of the human origins program at the Smithsonian Institution in Washington, D.C., said that the new study’s link between genetics and human growth was “neat”.

He, however, disagreed with the suggestion that Homo floresiensis represents a modern human with a genetic disorder. He said that evidence of the hobbit being a unique species was found in recent detailed studies of its wrist and upper arm bone, which showed that its wrist bones were very similar to that of gorillas or chimpanzees.

He insisted that genetic diseases, including any type of microcephaly, do not result in an apelike wrist similar to the hobbit’s.

“For many of us in the field, we have taken those studies, especially the one [on the wrist bone] as really being the death blow to the idea that we’re dealing with a modern human,” Potts said.

He further said that even if a gene associated with dwarfism was found in the hobbit, the researchers would “still have to go down to the details of the morphology and try to explain (them).” (ANI)

Related Stories

Tags: , , , , , , , , , , , , , , , , , , ,

Posted in Health Science |