Homo floresiensis

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Homo floresiensis
Fossil range: Pleistocene
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates Linnaeus, 1758
Suborder: Anthropoidea Mivart, 1864
Superfamily: Hominoidea Gray, 1825
Family: Hominidae Gray, 1825
Tribe: Hominini Gray, 1825
Genus: Homo Linnaeus, 1758
Species: H. floresiensis
Binomial name
Homo floresiensis[1]
Homo floresiensis is possibly a species in the genus Homo, characterized by an extremely small body and brain size with morphological features of both modern and more primitive members of genus Homo. H. floresiensis may have lived as recently as 18,000 years ago. When H. floresiensis hit the media in 2004, it was popularly referred to as a true Hobbit.
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Initial discovery

The primary find on the Indonesian island of Flores in 2003 included hominid bones and a nearly complete skeleton, designated LB1. LB1 was as small as a child at about 1 meter in height, but tooth wear indicated the specimen to have been 30 years of age at death. LB1 was declared female and dated at 18,000 years old.

Additional specimens from a total of eight individuals were uncovered at the same site by the same team in 2004. The team inferred dates for the specimens ranging from about 94,000 to 12,000 years ago indirectly from materials at the site. This implies that the hominids resided there for an extensive period of time and their existence overlapped with fully modern Homo sapiens on Flores.

The remains were declared to be a heretofore, unknown species, possibly a descendent of Homo erectus. Tools in the area indicated an early relation with H. sapiens in Europe and a complex culture was inferred from the evidence at the site. The specimens’ overall size was not the only diminutive aspect of their remains, they also had very small cranial capacity, indicating a brain of about 380 to 417 cm3 in size; smaller than the brain of an average chimpanzee.

The bones themselves were never fossilised and had the consistency of wet blotting paper; they were extremely fragile. [1][2]

Significance

A possible explanation for the emergence of the H. floresiensis is island dwarfism or endemic dwarfing, a condition wherein the environmental factors favour smaller size to the extent that survival favours the diminutive. This theory allows for the possibility that H. floresiensis was derived from an earlier species of the genus Homo, possibly H. erectus. If in fact the H. floresiensis is derived from another member of the genus Homo, it indicates a greater genetic flexibility endowing adaptive responses for morphological variation.[1][3]

Subsequent developments

Initially the H. floresiensis were studied on site in 2003-04, by a joint Indonesian–Australian team, digging in Liang Bua cave on the Indonesian island of Flores. Issues surrounding the discovery of the remains of H. floresiensis have revolved around the handling of the remains themselves.

Damage to the specimens

The remains were initially stored and studied in Jakarta at the Indonesian Centre for Archaeology. In November, 2004 the remains were shipped, apparently without consent of the original team, to another site: a lab in Indonesia under the control of Teuku Jacob, an eminent Indonesian palaeoanthropologist who was not a member of the original team. Jacob has maintained that the transfer was performed at the request of a member of the original team, Radien Soejono, the leader of the excavation and one of the original authors.

There have been other perceived breaches in protocol since then as well. According to Jacob, the bones would be studied in his lab by Indonesian researchers not connected with the find. Jacob then permitted Australian, US and German researchers to study the bones without permission from the discovery team members. Nothing has yet been published by Jacob's lab.

In February 2005, most of the bones were returned to the Indonesian Centre for Archaeology in Jakarta. However, the remains had been severely damaged.[4][2]

New species or pathological variant?

The issues at present involve the question of whether this represents a unique species or congenital, pathological variations of another species of the genus Homo that produced microencephaly and dwarfism.

Research published in 2004 through 2006 debated whether the remains found on Flores represented a pathological variant of another hominid, microencephaly, or a new species of genus Homo. A number of casts were made of the cranial cavity of LB1 which researchers claimed indicated telltale signs of microencephalisation.[5][6]

However newer studies show that the brain case is indicative of a smaller, well developed brain and not a pathological variant. Analysis of other bones, specifically the wrist bones, scapulae and humerus also indicate that H. floresiensis was not a variant of a modern hominid.[7][8][9]

References

  1. 1.0 1.1 1.2 A new small-bodied hominin from the Late Pleistocene of Flores, Indonesia P. Brown, T. Sutikna, M. J. Morwood, R. P. Soejono, Jatmiko, E. Wayhu Saptomo & Rokus Awe Due (2004) Nature vol. 431: 28 October |www.nature.com/nature
  2. 2.0 2.1 Skullduggery: The discovery of an unusual human skeleton has broad implications Powledge, Tabitha M. (2005) EMBO reports 6, 7, 609–612 doi:10.1038/sj.embor.7400471
  3. Human evolution writ small Lahr, Marta Mirazón, & Foley, Robert (2004). Nature, vol. 431: 28 October
  4. Culotta, Elizabeth (2005) Discoverers Charge Damage to 'Hobbit' Specimens. Science 25 March 2005: Vol. 307. no. 5717, p. 1848 DOI: 10.1126/science.307.5717.1848a
  5. /releases/2006/10/061009031321.htm Compelling Evidence Demonstrates That 'Hobbit' Fossil Does Not Represent A New Species Of Hominid. Field Museum (2006, October 9).ScienceDaily. Retrieved February 10, 2008
  6. /releases/2006/05/060519100438.htm Scientists Scuttle Claims That 'Hobbit' Fossil From Flores, Indonesia, Is A New Hominid. Field Museum (2006, May 19). ScienceDaily. Retrieved February 10, 2008
  7. New light shed on "Hobbit"Smithsonian (2007, September 25). ScienceDaily. Retrieved February 10, 2008
  8. /releases/2007/01/070129171908.htm Anthropologist Confirms 'Hobbit' Indeed A Separate Species. Florida State University (2007, January 29). ScienceDaily. Retrieved February 10, 2008
  9. Brain shape in human microcephalics and Homo floresiensis Dean Falk, Charles Hildebolt, Kirk Smith, M. J. Morwood, Thomas Sutikna, Jatmiko, E. Wayhu Saptomo, Herwig Imhof, Horst Seidler, and Fred Prior (2007). Proc Natl Acad Sci U S A. February 13; 104(7): 2513–2518.