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More “little people” fossils found

March 11, 2008
Courtesy Public Library of Science
and World Science staff

Re­search­ers say they have dis­cov­ered more fos­sils of min­ia­ture, is­land-dwelling peo­ple, adding a new twist to the sa­ga of so-called “hob­bit” fos­sils re­ported found in In­do­ne­sia in 2004.

A sci­en­tif­ic de­bate has raged over wheth­er those came from a spe­cies of min­ia­ture hu­ma­n­s—as their disco­verers ar­gued—or just from dis­eased, or­di­nary peo­ple. 

A map indicates the relative locations of Flores, Indonesia (lower-left red arrow) and Palau (upper-right red arrow.)


If the form­er were true, this would fit in with the fact that ma­ny spe­cies of an­i­mals al­so evolve in­to small forms on is­lands. But sev­er­al stud­ies have chal­lenged the view that the In­do­ne­sian spec­i­mens rep­re­sent a new spe­cies; for ex­am­ple, a pa­per in the March 5 is­sue of the jour­nal Pro­ceed­ings of the Roy­al So­ci­e­ty B sug­gests the “hob­bits” were in real­ity mal­nour­ished cretins.

The disco­very of ad­di­tion­al, some­what si­m­i­lar fos­sils on oth­er is­lands may both re­new and com­pli­cate the de­bate.

In this week’s is­sue of the re­search jour­nal PLoS One, Lee Berger and col­leagues of the Uni­ver­s­ity of the Wit­wa­ters­rand, South Af­ri­ca, Rut­gers Uni­ver­s­ity and Duke Uni­ver­s­ity in North Car­o­li­na de­scribe new­found fos­sils of lit­tle hu­ma­ns from other is­lands. 

They lived 1,400 to 3,000 years ago, ac­cord­ing to the re­search­ers, and share some fea­tures with the ear­li­er spec­i­mens, dubbed Ho­mo flo­re­sien­sis by their disco­verers. The name came from the loca­t­ion of disco­very, In­do­ne­sia’s Flo­res Is­land.

The new find­ings comes in­stead from Palau, an is­land chain in the west­ern cen­tral Pa­cif­ic. Palau con­sists of a main is­land of Ba­bel­daob, with hun­dreds of smaller rock is­lands to the south­west. These con­tain ca­ves and rock shel­ters, ma­ny of which have yielded pre­his­tor­ic hu­man re­mains.

The new spec­i­mens from two such ca­ves, Uche­li­ungs and Ome­dokel, which seem to have been used as bur­i­al sites, re­search­ers said.

Both ca­ves, they added, yielded skele­tons of in­di­vid­u­als who would have been small even rel­a­tive to oth­er such popula­t­ions and are ap­prox­i­mately the size of H. flo­re­sien­sis or small mem­bers of the ge­nus Aus­tra­lo­pith­e­cus. These fos­sils were dat­ed to be­tween 1410 and 2890 years ago. The Ome­dokel cave en­trance al­so con­tained re­mains of larg­er peo­ple dat­ed to around a mil­len­ni­um ago, the re­search­ers said.

These ca­ves have pro­vid­ed and will con­tin­ue to pro­vide a wealth of spec­i­mens, which will need deeper stu­dy, the in­ves­ti­ga­tors added. But pre­lim­i­nar­y anal­y­sis of more than a doz­en in­di­vid­u­als in­clud­ing a male who would have weighed around 43 kg (95 lb) and a female of 29 kg (64 lb) show that these peo­ple “had ma­ny cran­io­fa­cial fea­tures con­sid­ered un­ique to H. sapi­ens,” our spe­cies, re­search­ers said.

“These in­di­vid­u­als are likely to be from a hu­man popula­t­ion who ac­quired re­duced stat­ure, for some rea­son,” the re­search­ers said in an­nounc­ing the find­ing March 10.

“It is well es­tab­lished that popula­t­ions liv­ing on iso­lat­ed is­lands of­ten con­sist of in­di­vid­u­als of smaller stat­ure than their main­land cousin­s—a phe­nom­e­non known as is­land dwarf­ism. This is true not just for hu­ma­ns but for ma­ny an­i­mals in­clud­ing ex­tinct mam­moths and ele­phants from is­lands off Si­be­ria, Cal­i­for­nia and even in the Med­i­ter­ra­nean. Al­ter­na­tively, the is­land may have been col­o­nized by a few small in­di­vid­u­als, be­tween 3,000 and 4,000 years ago who, through ex­ten­sive in­breed­ing, and oth­er en­vi­ron­men­tal drivers, pro­duced a small-bodied popula­t­ion, which con­tin­ued to in­hab­it Palau un­til at least 1,400 years ago.”

As well as hav­ing char­ac­ter­is­tics of H. sapi­ens, the Palau fos­sils al­so have fea­tures seen in H. flo­re­sien­sis, the re­search­ers said. 

Berger and col­leagues said they don’t in­fer from these fea­tures any di­rect rela­t­ion­ship be­tween the peo­ples of Palau and Flo­res. How­ev­er, they added, the ob­serva­t­ions do sug­gest that at least some of the fea­tures which have been tak­en as ev­i­dence that the Flo­res in­di­vid­u­als are mem­bers of a sep­a­rate spe­cies, may be a com­mon adapta­t­ion in hu­ma­ns of re­duced stat­ure.

Anal­y­sis of the Palau spec­i­mens probably won’t set­tle ar­gu­ments over the sta­tus of H. flo­re­sien­sis as there are fea­tures of Flo­res ma­n, such as small brain size, not found in the peo­ple of Palau, Berger and col­leagues added. Nev­er­the­less, they said, the find­ings sug­gest that at least some of the un­usu­al fea­tures seen in Flo­res are due to en­vi­ronment rath­er than an­ces­tral her­it­age. 

“Above all, the skele­tons from Palau should greatly in­crease our un­der­stand­ing of the pro­cess of is­land dwarf­ism in hu­man popula­t­ions and of the an­cient co­lon­iz­a­tions of Ocea­nia,” the re­search­ers said in their an­nounce­ment. The study was funded by the Na­tional Ge­o­graph­ic So­ci­e­ty Mis­sion Pro­grams. A doc­u­men­ta­ry on the find­ings, “Mys­tery Skulls of Palau,” pre­mieres Mon­day, March 17 at 10 PM on the Na­tional Ge­o­graph­ic Chan­nel in the U.S.


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Researchers say they have discovered more fossils of miniature, island-dwelling people, adding a new twist to the saga of so-called “hobbit” fossils unearthed in Indonesia in 2004. A scientific debate has raged over whether those came from a species of miniature humans—as their discoverers argued—or just from diseased, ordinary people. If the former were true, this would fit in with the finding that many species of animals also evolve into miniature forms on islands. But several studies have challenged the view that the Indonesian specimens represent a new species; for example, a paper in the March 5 issue of the journal Proceedings of the Royal Society B suggests the “hobbits” were in reality malnourished cretins. The discovery of additional, somewhat similar fossils on other islands is sure to complicate and reinvigorate the debate. In this week’s issue of the research journal PLoS One, Lee Berger and colleagues of the University of the Witwatersrand, South Africa, Rutgers University and Duke University in North Carolina describe newfound fossils of little humans from the Micronesian island of Palau. They lived 1400 to 3000 years ago, according to the researchers, and share some features with the earlier specimens, dubbed Homo floresiensis by their discoverers. The name came from the location of discovery, Indonesia’s Flores Island. The new findings comes instead from Palau, an island chain in the western central Pacific. Palau consists of a main island of Babeldaob, with hundreds of smaller rock islands to the southwest. These contain caves and rock shelters, many of which have yielded prehistoric human remains. The new specimens from two such caves, Ucheliungs and Omedokel, which seem to have been used as burial sites, researchers said. Both caves, they added, yielded skeletons of individuals who would have been small even relative to other such populations and are approximately the size of H. floresiensis or small members of the genus Australopithecus. These fossils were dated to between 1410 and 2890 years ago. The Omedokel cave entrance also contained remains of larger people dated to around a millennium ago, the researchers said. These caves have provided and will continue to provide a wealth of specimens, which will need deeper study, the investigators added. But preliminary analysis of more than a dozen individuals including a male who would have weighed around 43 kg (95 lb) and a female of 29 kg (64 lb) show that these people “had many craniofacial features considered unique to H. sapiens,” our species, researchers said. “These individuals are likely to be from a human population who acquired reduced stature, for some reason,” the researchers said in announcing the finding March 10. “It is well established that populations living on isolated islands often consist of individuals of smaller stature than their mainland cousins—a phenomenon known as island dwarfism. This is true not just for humans but for many animals including extinct mammoths and elephants from islands off Siberia, California and even in the Mediterranean. Alternatively, the island may have been colonized by a few small individuals, between 3,000 and 4,000 years ago who, through extensive inbreeding, and other environmental drivers, produced a small-bodied population, which continued to inhabit Palau until at least 1400 years ago.” As well as having characteristics of H. sapiens, the Palau fossils also have features seen in H. floresiensis, the researchers said. Berger and colleagues said they don’t infer from these features any direct relationship between the peoples of Palau and Flores. However, they added, the observations do suggest that at least some of the features which have been taken as evidence that the Flores individuals are members of a separate species, may be a common adaptation in humans of reduced stature. Analysis of the Palau specimens probably won’t settle arguments over the status of H. floresiensis as there are features of Flores man, such as small brain size, not found in the people of Palau, Berger and colleagues added. Nevertheless, they said, the findings suggest that at least some of the unusual features seen in Flores are a result of environment rather than ancestral heritage. “Above all, the skeletons from Palau should greatly increase our understanding of the process of island dwarfism in human populations and of the ancient colonizations of Oceania,” the researchers said in their announcement. The study was funded by the National Geographic Society Mission Programs. A documentary on the findings, “Mystery Skulls of Palau,” premieres Monday, March 17 at 10 PM on the National Geographic Channel in the U.S.