Daily Archives: 10/28/2004

Homo floresiensis

Comparison in size between modern human and Flores Man skullsWow, just when I thought the Titan flyby would be the big science news of the week, this bombshell is released in the next issue of the journal Nature about the discovery of a new species of hominid, Homo floresiensis, on the Indonesian island of Flores. While any new hominid would be a major event, the big news about this discovery is the diminutive size of H. floresiensis. Fully grown adults were only approximately 1 meter tall. The mainstream press has already branded the species as “Hobbits” because of their small size. Labeled LB1, after the dig site of Liang Bua, Flores Man seems to be the first documented case of a hominid species exhibiting a well know adaptation to island isolation: dwarfism. Biologists already knew of dwarf elephants on Flores Island from the same time period, so the adaptation is not really that surprising. In fact, anthropologists found evidence that H. floresiensis hunted stegodon, the dwarf elephant:

The Flores people used fire in hearths for cooking and hunted stegodon, a primitive dwarf elephant found on the island. Although small, the stegodon still weighed about 1,000 kilograms (2,200 pounds), and would pose a significant challenge to a hunter the size of a three-year-old modern human child. Hunting must have required joint communication and planning, the researchers say.

Almost all of the stegodon fossils associated with the human artifacts are of juveniles, suggesting the tiny humans selectively hunted the smallest stegodons. The Flores humans’ diets also included fish, frogs, snakes, tortoises, birds, and rodents.

Liang Bua site on Flores IslandArchaeologists hypothesize that full sized Home erectus arrived by boat nearly 1 million years ago and gradually became smaller and smaller due to inbreeding and limited food supplies on the island. The youngest specimen described died about 12,000 years ago, buried in volcanic ash.

Potentially more important than the stature of H. floresiensis was its mind: It had a very small brain case, approximately the size of a chimpanzee’s brain, but made sophisticated stone tools and used fire. Anthropology has always said that brain size relates to cognition and tool making ability. H. floresiensis makes the case that brain size is not important – so what exactly are our big brains good for?

Current archaeological evidence indicates that modern H. sapiens arrived on Flores around 40,000 years ago, making contact between the two hominid species highly likely.

Even more intriguing is the fact that Flores’ inhabitants have incredibly detailed legends about the existence of little people on the island they call Ebu Gogo.

Artist's reconstruction of H. floresiensisThe islanders describe Ebu Gogo as being about one meter tall, hairy and prone to “murmuring” to each other in some form of language. They were also able to repeat what islanders said to them in a parrot-like fashion.

“There have always been myths about small people – Ireland has its Leprechauns and Australia has the Yowies. I suppose there’s some feeling that this is an oral history going back to the survival of these small people into recent times,” said co-discoverer Peter Brown, an associate professor of archaeology at New England.

The last evidence of this human at Liang Bua dates to just before 12,000 years ago, when a volcanic eruption snuffed out much of Flores’ unique wildlife.

Yet there are hints H. floresiensis could have lived on much later than this. The myths say Ebu Gogo were alive when Dutch explorers arrived a few hundred years ago and the very last legend featuring the mythical creatures dates to 100 years ago.

But Henry Gee, senior editor at Nature magazine, goes further. He speculates that species like H. floresiensis might still exist, somewhere in the unexplored tropical forest of Indonesia.

That is simply amazing. That something this close to modern man, this small, and yet making wickedly sharp little tools might have existed until just a few centuries ago – it flabbergasts me. Nature has a commentary on the discovery of Flores Man, saying how this could bring cryptozoology (the search for mythical creatures like sasquatch, the yeti and the Loch Ness Monster) in from the cold. While I think the case is pretty grim for any discovery of big foot, H. floresiensis is a welcome addition to the family tree, broadening our understanding of ourselves and our origins.

“O wonder!

How many goodly creatures are there here!

How beauteous mankind is! O brave new world,

That has such people in’t!”

-William Shakespeare, “The Tempest” Act V, Scene I

Cassini-Huygens-Multimedia-Images

False color image of Titan in UV and IR wavelengths
The first images of Saturn are streaming back in from the Cassini Orbiter, and they are beautiful.

This image shows Titan in ultraviolet and infrared wavelengths. It was taken by Cassini’s imaging science subsystem on Oct. 26, 2004, and is constructed from four images acquired through different color filters. Red and green colors represent infrared wavelengths and show areas where atmospheric methane absorbs light. These colors reveal a brighter (redder) northern hemisphere. Blue represents ultraviolet wavelengths and shows the high atmosphere and detached hazes.

I read a quote from one scientist stating that conditions on Titan are not like the ‘primordial soup’ that existed on the early planet Earth. While all the ingredients are there, it is too cold to expect the same chemistry. It is more akin to ‘primordial ice cream’ on that frozen world.

A 'petal plot' of Cassini's orbits through the Saturnian systemThe mission of Cassini-Huygens at Saturn will last several years around the planet and her satellites. The spacecraft will make 74 unique orbits around the planet, using 45 close flybys of Saturn’s largest moon Titan for gravity assist and science data acquisition. Because of the sheer size of Titan, the flybys will allow for major changes in orbital paths, allowing engineers to minimize fuel use while maximizing science data collection.

Cassini’s tour of Saturn is divided into six segments, each a different color in the orbital plot. The probe is in the white segment right now, adjusting its orbit and preparing for the release of the Huygens Lander. After the initial segment is completed early next year, a series of orbits designed to explore the rings of Saturn begins in February. That is followed by investigations of the magnetosphere, the major satellites, and a trip over Saturn’s polar regions. The entire expedition will last until 2008, and possibly longer. The world can look forward to years of discovery from Cassini.