Homo floresiensis

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Homo floresiensis
Temporal range: Late Pleistocene
Skull with associated mandible.
A cast of a Homo floresiensis skull, American Museum of Natural History
Scientific classification (disputed)
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Family: Hominidae
Tribe: Hominini
Genus: Homo
Species: H. floresiensis
Binomial name
†Homo floresiensis
Brown et al., 2004

Homo floresiensis ("Flores Man", also called "hobbit") is a possible species (type) in the genus Homo, the biological family to which humans belong. The remains were found in 2004 on the island of Flores in Indonesia. Parts of the skeletons of nine individuals were found, including one complete cranium (the bones that form the head).[1][2]. The most important and obvious identifying features of H. floresiensis are its small body and small size of the space for the brain inside the skull. This is why the discoverers have called members of the species "hobbits", after J.R.R. Tolkien's fictional race of roughly the same height.

A lot of research is done to find out if they are a different species to modern humans.

Contents

Discovery [change]

The remains were discovered on the Indonesian island of Flores by an Australian-Indonesian team of archaeologists in 2003. Archaeologist Mike Morwood and colleagues were looking for evidence of the original human migration of H. sapiens from Asia to Australia.[1][3] They were not expecting to find a new species. They were surprised at the recovery of a nearly complete skeleton of a hominin (the name of the tribe (like a biological family) to which humans also belong). They called it LB1 because it was unearthed inside the Liang Bua Cave. Excavations done after that recovered seven additional skeletons, dating from 38,000 to 13,000 years ago.[2] An arm bone which they think belongs to H. floresiensis is about 74,000 years old. The specimens are not fossilized and have been described as having "the consistency of wet blotting paper"; once exposed, the bones had to be left to dry before they could be dug up.[4][5]:86

Researchers hope to find preserved mitochondrial DNA to compare with samples from similarly unfossilised specimens of Homo neanderthalensis and H. sapiens.[4]

This hominin (human-like being) is remarkable because it has a small body and brain. There are also a lot of stone tools found in the cave. The tools are of a size that could be used by the 1 meter tall human. They are dated from 95,000 to 13,000 years ago. They are found in the same archeological layer as an elephant of the extinct genus Stegodon. They think that LB1 might have hunted this elephant. The elephant would have been very common throughout Asia during the Quaternary[2]. Other animals that lived on the island at that time were giant rats, Komodo dragons, and even larger species of lizards.[6] Homo sapiens reached the region by around 45,000 years ago.[7]

A new species or not? [change]

Archaeologist Mike Morwood and colleagues who found the remains published research to say that they think the individuals belong to a new species, H. floresiensis, within the taxonomic tribe of Hominini. Other members of this tribe are human (the only living member of the genus Homo), bonobo (genus Pan), and chimpanzee (genus Pan); their ancestors; and the extinct line of their common ancestor.[1][3] The discoverers also say that H. floresiensis might have lived at the same time as modern humans (Homo sapiens) on Flores.[8]

Not everyone agrees that this is a new species. Indonesian anthropologist Teuku Jacob suggested that the skull of LB1 was a modern human with microcephaly. This is a disorder that causes the bones of the head to stop growing. Another study says that perhaps the individuals were born without a working thyroid (a hormone gland), which would result in the small size of the hominins because of a disorder called Myxedema, ME.[9]

Two studies of the bones published in 2007 both reported evidence to support species status for H. floresiensis. A study of three bits of bones from the hand (or carpal bones) showed that they were similar to the carpal bones of a chimpanzee or an early hominin such as Australopithecus. They were also different from the bones of modern humans.[10][11] A study of the bones and joints of the arm, shoulder, and legs also concluded that H. floresiensis was more similar to early humans and apes than modern humans.[12][13] In 2009, the publication of a cladistic analysis[14] and a study comparing body sizes[15] gave further support for the theory that H. floresiensis and Homo sapiens are separate species.

Cave on Flores Island where the specimens were discovered.
Flores Island in Indonesia, shown highlighted in red

Recent survival and Ebu Gogo [change]

They believe that the species has survived on Flores at least until 12,000 years before present. This makes it the longest lasting non-modern human. It also lived longer than the Neanderthals (H. neanderthalensis), which became extinct about 24,000 years ago.[2]

Because of a deep neighboring strait, Flores remained isolated during the Wisconsin glaciation (the most recent glacial period). Because of this, the discoverers of H. floresiensis think that the species, or its ancestors, must have reached the isolated island by water transport around 100,000 years ago (or, if they are H. erectus, then about 1 million years ago).

Local geology suggests that a volcanic eruption on Flores approximately 12,000 years ago was responsible for the end of H. floresiensis and animals that lived on the island. The elephant Stegodon also became extinct at this time.[3] Gregory Forth hypothesized that H. floresiensis may have survived longer in other parts of Flores to become the source of the Ebu Gogo stories told among the local people.

The stories say that Ebu Gogo were small, hairy, language-poor cave dwellers that are the same size as the Homo Floresiensis.[16] It is said that they were there at the time of the arrival of the first Portuguese ships during the 16th century. These creatures are claimed to have existed as recently as the late 19th century.[17] Gerd van den Bergh, a paleontologist working with the fossils, reported hearing of the Ebu Gogo ten years before the fossil discovery.[18] On the nearby island of Sumatra, there are reports of a 1-1.5m tall humanoid, the Orang Pendek which might be related to H. floresiensis.[19] Henry Gee, senior editor at Nature magazine, speculates that species like H. floresiensis might still exist in the unexplored tropical forest of Indonesia.[20]

Notes [change]

  1. ↑ 1.0 1.1 1.2 Brown et al. 2004
  2. ↑ 2.0 2.1 2.2 2.3 Morwood, Brown et al. 2005
  3. ↑ 3.0 3.1 3.2 Morwood, Soejono et al. 2004
  4. ↑ 4.0 4.1 Nature 2004
  5. ↑ Morwood and van Oosterzee 2007
  6. ↑ The Age 2004-10-27
  7. ↑ Smithsonian July 2008
  8. ↑ McKie, Robin (February 21st, 2010). "How a hobbit is rewriting the history of the human race". The Guardian. http://www.guardian.co.uk/science/2010/feb/21/hobbit-rewriting-history-human-race. Retrieved February 23st, 2010.
  9. ↑ Obendorf et al. 2008
  10. ↑ Tocheri et al. 2007
  11. ↑ New Scientist 2007-09-20
  12. ↑ Larson et al. 2007 (preprint online)
  13. ↑ Guardian 2007-09-21
  14. ↑ Argue, Morwood et al. 2009
  15. ↑ Jungers and Baab 2009
  16. ↑ Forth 2005
  17. ↑ Telegraph 2004-11-02
  18. ↑ Sereno, M.I. (2005). "Language Origins Without the Semantic Urge" (PDF). Cognitive Science Online 3.1: 1–12. http://cogsci-online.ucsd.edu/3/3-1.pdf.
  19. ↑ Nature 2004-10-27
  20. ↑ "'Hobbit' joins human family tree". BBC News. October 27, 2004. http://news.bbc.co.uk/1/hi/sci/tech/3948165.stm.

References [change]

Further reading [change]

  • Linda Goldenberg (2007). Little People and a Lost World: An Anthropological Mystery. Minneapolis, Minnesota: Twenty-First Century Books. p. 112. ISBN 978-0-8225-5983-2. OCLC 62330789.
  • Maciej Henneberg; John Schofield (2008). The Hobbit Trap:Money, Fame, Science and the Discovery of a 'New Species'. Kent Town: Wakefield Press. p. 159. ISBN 978-1-86254-791-9.

Other websites [change]

Wikinews has news related to this article: Bones of "small-bodied humans" found in cave
Wikispecies has information on: Homo floresiensis.
Wikimedia Commons has media related to: Homo floresiensis

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