The Geometry of Hobbits

The hobbit saga continues (see these other posts) with a new report which uses the statistical analysis of the fossil remains to determine that the hobbit does indeed deserve to be labeled as a new human, Homo floresiensis. From PhysOrg.com:

Researchers William Jungers, Ph.D., and Karen Baab, Ph.D. studied the skeletal remains of a female (LB1), nicknamed "Little Lady of Flores" or "Flo" to confirm the evolutionary path of the hobbit species. The specimen was remarkably complete and included skull, jaw, arms, legs, hands, and feet that provided researchers with integrated information from an individual fossil.
The cranial capacity of LB1 was just over 400 cm, making it more similar to the brains of a chimpanzee or bipedal "ape-men" of East and South Africa. The skull and jawbone features are much more primitive looking than any normal modern human. Statistical analysis of skull shapes show modern humans cluster together in one group, microcephalic humans in another and the hobbit along with ancient hominins in a third.
Due to the relative completeness of fossil remains for LB1, the scientists were able to reconstruct a reliable body design that was unlike any modern human. The thigh bone and shin bone of LB1 are much shorter than modern humans including Central African pygmies, South African KhoeSan (formerly known as 'bushmen") and "negrito" pygmies from the Andaman Islands and the Philippines. Some researchers speculate this could represent an evolutionary reversal correlated with "island dwarfing." "It is difficult to believe an evolutionary change would lead to less economical movement," said Dr. Jungers. "It makes little sense that this species re-evolved shorter thighs and legs because long hind limbs improve bipedal walking. We suspect that these are primitive retentions instead."

The study can be found online at Wiley InterScience:

The geometry of hobbits: Homo floresiensis and human evolution

William Jungers ¹ and Karen Baab ²

   

ABSTRACT

Until quite recently modern humans shared the earth with now extinct relatives—Neanderthals and others—in Europe and Asia. Homo floresiensis—dubbed the "hobbits" in the popular press—is the most recent, and the most surprising, addition to the human family tree. Were the tiny hobbit people of Flores dwarfed descendents of known species, modern humans suffering from a skull-shrinking genetic disease or a new species entirely? William Jungers and Karen Baab look at the time, the space and the body-shape of the astonishing hobbits.

¹ Distinguished Teaching Professor and Chairman of the Department of Anatomical Sciences, Stony Brook University Medical Center in New York. He has long been interested in size and scaling in human and primate evolution.   
² Instructor and Post-doctoral Fellow in the same Department. Her expertise is in geometric morphometrics and the cranial evolution of the genus Homo.

The VPRO Beagle Moves On

The VPRO Beagle continues its journey.

The reactions of Lex Runderkamp, Dirk Draulans and Redmond O'Hanlon to the recent happenings:

Cold-blooded Goats?

The fossil remains of a prehistoric goat-like artiodactyl that once lived on Mediteranean islands over 1.5 million years ago provides evidence of how some large mammals may have survived in resource-poor ecosystems. Myotragus, a Plio-Pleistocene bovid from the Balearic Islands off the eastern coast of Spain have a particular bone structure that is shared with cold-blooded reptiles. Not cold blooded, but having a variable growth rate according to changing environmental conditions:


The Press Release from Institut Català de Paleontologia:

Mammal or reptile? Researchers from the ICP discovered that the bovidae Myotragus balearicus' metabolism was more similar to a reptile metabolism than a mammal one.

Researchers Meike Köhler and Salvador Moyà, from the Institut Català de Paleontologia (ICP-UAB) have released the results of a highly innovative research in the field of paleontology. Using paleohistological techniques, they were able to infer the physiology of extinct species. The study, based on the goat-like bovidae Myotragus from the Balearic Islands, has been published in the prestigious scientific journal Proceedings of the National Academy of Science USA (PNAS).

The Myotragus balearicus, is an extinct mammal, similar to a goat, that belongs to the family Bovidae. All the Myotragus fossil data has been found in Mallorca, Menorca, Cabrera and Dragonera. The first Myotragus balearicus was discovered in the beginning of S. XX.(sic) and since those early days, it has been center of many paleontological studies. All thanks to its remarkable characteristics, fruit of an evolution in terms of insularity.

The islands and their fossil legacy are authentic laboratories of evolution for paleontologists. In fact, we can say that they are experiments in evolution, due to the islands have many environmental factors determined: small geographic area, limited resources, and trophic (ecosystem) limited by the absence of large mammals predators. The fossil islands also give us a proper time perspective to study the evolution, thanks to the scale of geological time. A variable that the study of the actual islands can not provide us, today.

Myotragus lived more than 5 million years in an island. A very long time for a species survival, especially in an area as small as an island, which means limited resources and fluctuating. Therefore, researchers were asked how this species had been able to survive more than double the time than their mainland relatives.

The results of histological thin section of a large sample of Myotragus' bones, with which we study the bone tissue and its growth pattern, show that Myotragus were closer to a physiological crocodile (reptile) that to a mammal. The histology showed that Myotragus' bone grew unlike any other mammal, at a slow pace and flexible, stopping periodically growing, reaching maturity at very advanced ages which meant a significant increase in longevity; similar to existing crocodiles. The explanation of why this happened is simple. Mammals are endotherms (warm-blooded) and, unlike cold-blooded (cold blood) spend a lot of energy to maintain body temperature constant. When resources are scarce, some individuals chose burning less energy, ie, individuals with a lower metabolism. This implies, however, grewing at a much slower pace, reaching maturity later and living longer.

The results of the study published in the article "Physiological and life history strategies of large mammal fossils in a resource-limited environment" in the renowned scientific journal Proceedings of the National Academy of Science (PNAS) suggest that although Myotragus were an endothermic mammal, they could experience lethargic seasons when weather conditions brought a lack of resources and made life difficult for them. The abundance of Myotragus' fossil found in caves suggests the possibility of these mammals using the caves to pass the difficult seasons, lowering metabolism and reducing vital functions.

Currently, some deer or goat-like bovidae can leave the expensive maintenance of a constant body temperature (endothermy) in a very critical period, generating a temporary fluctuation of body temperature (heterotèrmia). However, the only large mammal that hibernates is the bear. Bears are dangerous animals that suffer little or no predation. In addition, during their hibernation, they can wake up at any time and their temperature never falls below 20 º C. Bears and Myotragus balearicus shared the absence of threats from predators, because Myotragus lived in an island. This enabled them, not only to reduce their metabolism in difficult moments, but also to get to stop their growth, delayed age reproduction, extend their longevity (life years) or cease feeding at critical moments.

Today, scientific experiments are conducted to study the rhythms of life and longevity. Researchers study the reactions of invertebrates and small mammals (mice) under conditions of stress and lack of resources. Observations conducted with by this type of research point to the increased longevity or duration of the life of these animals. The results presented by the ICP provide an example which supports this hypothesis and explain the evolutionary reasons for this increase in longevity. Reducing the pace of life and increased longevity are favored under conditions of stress and lack of resources. Thus, research in paleontology supports research in other fields such as medicine. Thanks to this inter-disciplinary, the study of a goat-like bovidae that evolved into a natural laboratory conditions (islands) could reveal the mechanisms that influence the physiology of humans and causes of longevity.

This scientific study is free online:
Physiological and life history strategies of large mammal fossils in a resource-limited environment. Meike Köhler and Salvador Moyà-Solà. Proceedings of the National Academy of Science (PNAS) Published online before print November 16, 2009, doi: 10.1073/pnas.081338510.

Tonight: Expedition Great White on NGC

Tonight on the National Geographic Channel, the second documentary for Expedition Week: Expedition Great White - Scientists and anglers work like a well-trained pit crew to tag a massive Great White, collect data, and get DNA samples.

Singing Wings

Male club-winged manakins vibrate their wings to create violin-like sounds to impress females, a new study says.

Video Courtesy Cornell Lab of Ornithology through National Geographic.

The internet can shrink your head...

National Geographic Channel will be kicking-off the second annual Expedition Week this Sunday at 9PM ET/PT. Opening the week will be the premiere documentary: Search for the Amazon Headshrinkers.

When I was a young lad, around the age of 10, I discovered a series of books by Willard Price that dealt with the fictional adventures of two teenage boys, Hal and Roger Hunt. Willard Price used his experiences as a traveller/adventurer (who also wrote and photographed for National Geographic) to provide the factual basis for the stories. The Hunt brothers traveled the world collecting animals for their father's wildlife farm. In Amazon Adventure (1949), his first book on the Hunt brothers, the boys see a shrunken head that is sold to them by a Jivaro chief. I can remember few details of the story, but the mental image of the luxuriant jungles of the Amazon and the people that shrinks human heads has stayed in my memory ever since.



Yesterday I watched a review copy of a new NGC documentary that shows film footage (above) taken by explorer Edmundo Bielawski. The film is purported to reveal the actual head shrinking process as practiced by the Shuar people. The program follows author and explorer Piers Gibbon as he tries to retrace Bielawski's 1960's journey. Gibbon's goal is to rediscover where the original scene was filmed and to learn more about the Shuar and their customs. He travels to Quito, Ecuador and after some difficulty, he reaches the jungle frontier and manages to locate the village where the filming had taken place. He meets the Shuar and finds that reduced heads (or 'tsantsas'), still hold a place of power and pride in the minds of the people. In the past, it was the heads of defeated warriors that were shrunk, and the eyes and lips were sealed to prevent the spirit of the dead from escaping and seeking revenge. Today rumours are still heard that head-shrinking occasionally takes place to satisfy the ready black-market for the objects. I personally have heard that some people have used the heads of monkeys as a lucrative substitute.

While my wife questioned the apparent sensationalism of the program, my 14 year-old daughter and I thought that National Geographic had successfully walked the fine line between presenting the facts and overblown sensationalism. I don't think there is subtle way to present such an amazing custom.

Search for the Amazon Headshrinkers may not be suitable for all children. The original 1960's footage of the head-shrinking process is shown, as well as a blurred re-enactment of how the skull is removed. My daughter is already familiar with the mummification practices of the Egyptians. While she was amazed by head shrinking, she did not find this documentary any more disturbing than the mummification process.

Cautionary Note: please don't try this at home...if you insist, do as I have done and shrink your own head online:

VPRO Beagle: A Terrible Accident Claims a Life

The VPRO Beagle's latest news letter reveals that a terrible accident has happened to some of the series participants:

On Wednesday night four contributors to the Beagle project were involved in a serious car crash in Argentina, near Puerto Madryn. Petra Niegeman, who was visiting her partner, soundman Charles Kersten, died in the accident. The ship's doctor Charles Boissevain and historian Jane Cameron were seriously injured and are still in hospital in critical condition. Radio reporter Marten Minkema suffered minor injuries. VPRO and the clipper Stad Amsterdam are doing everything within their means to support family, friends and colleagues.

This blog has been following this expedition since it began. I offer my condolences to the families involved and much strength to the survivors and crew.

The TV program, 'In Het Kielzog van Darwin', broadcast on Nederland 2 will not be available this Sunday, but will continue on the 22 of November.

A New Sauropodomorph Described

A species of a group of dinosaurs related to the Sauropods has been discovered in South Africa. The Sauropods, which include the popularly known 'Brontosaurus' (now correctly known as Apatosaurus), are known to have had bi-pedal ancestry due to the structure of the bones in the forearm. Aardonyx ('Earth Claw') shows characteristics shared with the Sauropods.

(Correction to title and introduction after reading Brian Switek`s article -- Introducing Aardonyx, the “Earth Claw”)



An article on the discovery can be found at Science Daily.

The original scientific description can be found free online in the Proceedings of the Royal Society B:
A new transitional sauropodomorph dinosaur from the Early Jurassic of South Africa and the evolution of sauropod feeding and quadrupedalism
Adam M. Yates, Matthew F. Bonnan, Johann Neveling, Anusuya Chinsamy and Marc G. Blackbeard
Published online before print November 11, 2009, doi: 10.1098/rspb.2009.1440

Addendum: Adam Yates, one of the authors of the paper, blogs at Dracovenator, where he describes the discovery.

A Pittance of Time - Remember