Homo floresiensis

The Homo floresiensis , nicknamed hobbit (by the characters in the novels of JRR Tolkien ) is an extinct species of the genus Homo that lived until a few thousand years on the Indonesian island of Flores. Described in 2004, it is extraordinary for the small size of its body and brain, and for its recent disappearance, since it has been contemporary with modern humans.

Summary

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  • 1 Discovery
  • 2 Origins
  • 3 Features
  • 4 When was it extinct?
  • 5 Curiosity
  • 6 Sources

Discovery

Australian scientists discovered on an Indonesian island remains of an unknown member of the human race, a species that lived on Earth 95,000 years ago and until just 13,000 to 12,000 years ago.

The group of researchers from the University of New England , in Armidale ( Australia ), found the remains on the Indonesian island of Flores , located between those of Timor and Sumbawa , where there have been legends about the existence of small beings for many years. In this case, the specimen of Homo floresiensis found is a female of about 30 years of age, less than 1 meter in height, an estimated weight of 25 kg and a cranial capacity of 380  cm³ and approximately 433 grams (less than that of a chimpanzee). This specimen must have lived approximately 18,000 years ago. But this is not the only specimen of this species found, it is added to other specimens discovered before in that same area by the team of scientists.

According to experts, the specimen unearthed from Liang Bua cave is the “dwarf” descendant of another primitive species that left Africa two million years ago.

The remains consist of a skull the size of a grapefruit and part of its skeleton. Along with the bones, stone tools were discovered. The creature would have lived at the same time as Homo sapiens , the ancestor of humans. Until now, modern humans were known to have coexisted with Neanderthals in Europe 30,000 years ago.

origins

 

Liang Bua Cave where the remains of a specimen of Homo floresiensis were found .

Although on the one hand the postcranial anatomy of Homo floresiensis is clearly that of a bipedal, the sequence of the metatarsal is similar to that of humans and the hallux is in adduction like that of all Homo , on the other hand, however, the foot is proportionally very long compared to the tibia and femur, which is not characteristic of other hominins , but it is characteristic of the great African apes. Thus, the proportions of the lower extremities mix morphologies, with a primitive design that could predate Homo erectus .

A detailed morphological and metric study of the LB1, LB2, and LB6 jaws, showed that they share a distinctive set of features that place them outside the ranges of variation, both of Homo sapiens and Homo erectus . Although the size of the molar agrees with that of one of these late Homo , the body of the symphysis and the morphology of the premolar share similarities with Australopithecus and early Homo . When the jaws are considered, in conjunction with the existing evidence on cranial and postcranial anatomy, limb proportions, and functional anatomy of the wrist and shoulder, which in many respects are closer to Homofrom Africa or Australopithecus rather than from late Homo , evidence suggests that the ancestors of Homo floresiensis left Africa before the evolution of Homo erectus .

These findings then raise the possibility that Homo erectus was not the ancestor of Homo floresiensis , which, instead, came independently of some other earlier hominin, whose dispersal in Southeast Asia is not yet documented, Homo georgicus (1.80 million years), or a branch of Homo habilis , which lived about 2 million years ago, or between Homo rudolfensis (1.86 million years) and Homo habilis, as is clear from the cladistic analysis. This adds scientific controversy since it would be the first time that the survival of a hominid of such antiquity would be demonstrated. Which would add changes that would force to remake the classic paradigm of human evolution.

features

 

Mike Morwood, one of the discoverers of the species.

Homo erectus , designated as the immediate ancestor of Homo floresiensis , was roughly the same size as modern humans. However, specialists believe that as a result of the limited food supply of the Isla de las Flores, the Homo erectus population arrived in the territory of the island of Flores ca. 500,000 years ago it suffered a strong insular dwarfism , a form of geographical speciation also present on the island in various species.

Apart from the difference in size, this hypothesis is based on the fact that the specimens appear otherwise similar in characteristics to Homo erectus , which is known to have lived in Southeast Asia at the same time as the earliest finds of Homo floresiensis . These observed similarities form the basis for the establishment of the suggested phylogenetic relationship. However, it must be taken into consideration that no remains corresponding to Homo erectus have been found on the island , and much less transitional forms; finding so far only material evidence (stone tools), attributable only presumably to a possible occupation by Homo erectus840,000 years ago; not ruling out also that they are attributable to another possible species of hominid existing at that time.

Thus, having the type specimen of this species found, a fairly complete skeleton , and an almost complete skull of a 30-year-old female and 1.06 meters high; not only is it drastically reduced compared to Homo erectus , but even somewhat smaller in size than Australopithecus , an ancestor three million years older and not previously thought to have spread beyond Africa . This tends to qualify Homo floresiensis as the most “extreme” member of the extended human family; since they would certainly be the lowest and smallest.

In relation to stature, Homo floresiensis is also quite tiny compared to the size of modern humans. The estimated height of an adult Homo floresiensis is considerably less than the average adult height of all physically smaller modern human populations, such as African Pygmies (less than 1.50 meters tall), Twa, Semang (1.37 m for adult females ) or the Andamanese (1.37 m for adult women). Mass is normally considered more biophysically important than a one-dimensional measure of height, and for that measure, due to scale effects, the differences are even greater. It has been estimated that in the type specimen of Homo floresiensis I was about 25 kg.

The Homo floresiensis also had relatively long arms, perhaps allowing this small creature to climb to the safety of the trees when needed. These arm bones make the inevitable comparisons with modern achondroplastic humans (over 1.20 m) or other dwarfs not valid, since these people are not proportionally smaller than the others as a general rule, but only have their shorter limbs .

In addition to a small body size, Homo floresiensis had an extraordinarily small brain . The type specimen, at 380 cm³, is in the same range as chimpanzees or ancient Australopithecus . Its brain is considerably reduced compared to that of the presumed immediate ancestor of this species, Homo erectus , which at 980 cm³ had more than twice the brain volume of its descendant species.

 

Comparison of the average height of various hominids from Prehistory.

Despite the law of island biogeography, it does not explain well the reduction in brain size from 800 cm³ in Homo ergaster (erectus) to 400 cc in Homo floresiensis . Thanks to the discoveries in the Dmanisi deposits of Homo georgicus , whose brain was approximately 600 cm³ and closely related to Homo habilis , which left the African continent 1.80 million years ago reaching the island of Java, we know that they existed in Asia hominins with smaller brains. A reduction of 200 cm³, that is to say from 600 cm³ of Homo geórgicus to 400 cm³ of Homo floresiensis , is not as drastic as going from 1100 cm³ ofHomo erectus at 400 cm³, which would place them closer to Homo habilis than to Homo ergaster or Homo erectus . However, the brain-body mass relationship exhibited by Homo floresiensis is comparable to that of Homo erectus , indicating that the species are unlikely to differ in intelligence. In fact, the discoverers have associated some advanced behaviors with the species.

These behaviors would be associated with the existence of evidence of the use of fire for cooking. The species has also been related to stone tools from the sophisticated Upper Paleolithic tradition typically associated with modern humans, who at 1310-1475 cm³ almost quadruple the brain volume of Homo floresiensis (with a body mass increased by a factor of 2.6) . Some of these tools were apparently used in the necessarily cooperative hunting of the Stegodon.local dwarf for this little human species. Similarly, in another site called Mata Menge, researcher Adam Brumm and his collaborators have detected that the tools found have important similarities with those found in Liang Bua; Mata Menge’s tools feature a date that yields a staggering date of “between 840,000 and 700,000 years.” These dates indicate that Homo sapiens could not manufacture the tools discovered in Mata Menge, and thus probably also those of Liang Bua; since the Homo sapiens species did not exist at that time.

Furthermore, the island of Flores remained isolated during the most recent ice age due to a deep strait, despite the low sea level that united much of the rest of Sundaland. This fact has led the discoverers of Homo floresiensis to conclude that the species or its ancestors could only have reached the isolated island by means of some maritime transport, perhaps arriving in bamboo rafts around 100,000 years ago.

This observed evidence of advanced technology and cooperation on a modern human level has prompted the discoverers to propose almost with complete certainty that Homo floresiensis would have language. These suggestions have turned out to be the most controversial of the discoverers’ findings, despite the likely high intelligence of Homo floresiensis .

When was it extinct?

 

Reconstruction of the Homo floresiensis found.

The first studies suggest that the two most possible reasons for its extinction were:

  • A volcanic eruption that occurred approximately 12,000 years ago and could kill the species.

-The fight for survival with homo sapiens, they were at a clear physical and intellectual disadvantage with what we know today as modern man and possibly little by little their population was decimating.

The case of homo floresiensis is an atypical case, it is believed that they arrived on the island about 95,000 years ago, perhaps in search of better game with which to feed. Their ancestors, probably a form of Homo erectus , may have arrived on the island hunting for the Stegodon (a primitive form of elephant, short in stature), thanks to some form of boat or by walking across a temporary land bridge.

The other big unknown is his short stature. For Stringer, “their isolation from the rest of Homo erectus and their subsequent interbreeding (in a closed community) may be what led them to develop a reduced body size. This is a verified process in other mammals. ‘

Another plausible hypothesis is that this distant cousin of modern man had to shrink in size to accommodate restricted food availability or the need to escape from predators.

Curiosity

This surprising discovery, published in the British scientific journal Nature , raises the possibility that humans are not alone on the planet, since the descendants of this specimen, which is less than one meter high, could still be alive on those islands. remote.

The new human being forces them to reconsider legends that Dutch explorers heard a century ago when they arrived in Flores. Then, the natives spoke of the « ebu gogo » (which literally means ‘grandmother who eats anything’), a strange creature with human form that, like the hominid found, was less than one meter tall and was said to eat only raw food , vegetables and meat, even human.

The legend says that these beings spoke in whispers and repeated the words of the interlocutor like parrots.

His description is consistent with that of this new species found, except for the use of tools, which the ebu gogo did not use.

According to legend, the extermination of this breed occurred in the 19th century, when the Indonesians – seized with fury over the theft of a baby – killed all of them in their caves.

There are several similarities between ebu gogo and Homo floresiensis , but they are not the only ones: many testimonies speak of similar cases in nearby islands such as the orang pendek (in Sumatra ), the batutut (in Borneo ) and the nittaewo (in Sri Lanka ). These little Indonesian yetis have been sought after many times.

For now, its existence will be another of the great enigmas of cryptozoology (a pseudoscience in vogue at the end of the 20th century in the United States).

 

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