Showing posts with label human. Show all posts
Showing posts with label human. Show all posts

Wednesday, 2 May 2007

Prehistoric Location, Location, Location

Human nature doesn’t change. Tour any archeological site and you will find necessities, desires and comforts of life common to all people. In particular this applies to the place we call home. A house buyer today views properties with a mental checklist of desired features and according to recent researchers, prehistoric cave-dwelling Britons did the same thousands of years ago.

A survey of over 400 caves in Northern England shows that people living in this area from 4,000 to 2,000 B.C. selected their homes based on five important features. Caves were favoured if they

*Were located at a higher altitude
*Had an east or west facing entrances
*Had large entrances
*Included deep passages
*Had a level area just outside of the entrance

Archaeologists discovered that the Peak District, a productive area for agriculture today, attracted more prehistoric cave users than the Yorkshire Dales. But caves were also used for more transitory purposes: sometimes caves were employed like roadside motels, where travellers would stop in for a few nights to rest before continuing their journeys

The benefits of this project include the discovery of many previously unexplored caves throughout Britain, a well-practiced methodology for surveying archeological sites, and an excellent compilation of data that will aid future researchers.

Thursday, 19 April 2007

Sneezing in the Sun

After eight years and I am still learning new things my husband: we were walking down the street when the clouds parted, revealing a bright sun and he consequently sneezed! And now I realize that this phenomenon affects a significant number of other people I know. So in case you were ever wondering why looking at the sun on a bright day makes you sneeze here is the answer:

When a nerve cell is stimulated it passes on a chemical / electrical message to the next nerve cell in the chain. However, if it is a very strong message, this might also leak out and stimulate nearby nerve cells. So, when you look at the sun or a bright light, your eyes (and their nerves) suddenly have a lot of very strong information to pass to the brain. In addition to passing on their message, they also 'leak' a bit. Part of the path for the optic nerves (from your eyes) happens to be close to your sneeze reflex and so it can be triggered by accident.
-This text was originally contributed by David Hone on Ask a Biologist

Anecdotal evidence also seems to indicate that this unusual reflex has a genetic link, so may be common among members of the same family. This is confirmed by R. Eccles of the Common Cold and Nasal Research Group who says that this phenomenon (which he terms the ‘photic sneeze’) affects between 18-35% of the population. And that the photic sneeze is a well known hazard to fighter pilots when they turn towards the sun or are exposed to flares from anti-aircraft fire.

Wednesday, 11 April 2007

Arrogant scientist to represent all of humanity

American paleontologist Edward Drinker Cope, died on 12 Apr 1897.

Cope is best remembered for his rivalry with O.C. Marsh, called the Great Bone Wars; he also led many great expeditions into the American West and was prolific in the naming of dinosaur species.

When a new species of dinosaur (or any other organism for that matter) is discovered, scientists choose a holotype specimen, this is an example of the new species that will forever define it. Usually it is the first example found, for example, the holotype for T. rex was collected by Barnum Brown in 1902 and is housed at the Carnegie Museum of Natural History in Pittsburgh, Pennsylvania. It is important to remember that a holotype is usually the first example of a new species and it is not necessarily the best or typical example (although ideally it should be). Sometimes when a new species is found and the holotype named, there are only very poor or fragmentary examples available. But it is the practice that even if a better specimen is subsequently found, the holotype is not superseded.

But back to our story now, which began back in 1735 with Swedish botanist named Carolus Linnaeus. Linnaeus was fascinated by the diversity of life around him and became obsessed with categorizing it. This is very difficult to do since there are millions of species in the world but Linnaeus went about it in a very systematic way. He devised a hierarchical system for categorizing plants, animals and minerals. Interestingly, he named, described and classified human beings as a part of this system. He named humans Homo sapiens, Latin for man and wise. The concept of a holotype had not been invented yet but the humble Linneaus did consider himself to be the best example of Homo sapiens.

Then in 1897, an equally humble scientist, Edward Drinker Cope died. In his will, Cope had a final request: that his remains be used as the holotype specimen for Homo sapiens. However, Cope’s dream did not materialize. His brain was saved and preserved in a jar for future study at the Anthropometric Society. But unfortunately, when his skeleton was stripped and cleaned, taxonomists found evidence of incipient syphilis in Cope's bones, a discovery that led his suceedors to deem his remains “unsuitable” to be the type specimen for humanity. His bones were discreetly filed away and perhaps even conveniently ‘lost’ for almost 100 years.

Then in 1991, while working on a story, National Geographic photographer Louie Psihoyos discovered Cope's bones stored at the Museum of Archaeology and Anthropology at the University of Pennsylvania. Psihoyos borrowed the bones to use in his story and while out in the Western United States, he showed the bones to palaeontologist Robert Bakker who was a great admirer of Cope. Bakker began a mission to fulfill Cope’s last request: that his remains be used designated the type specimen of Homo sapiens. Bakker published his description in the Journal of the Wyoming Geological Society.

Unfortunately, Bakker and Psihoyo's efforts were not successful and Cope's remains are unlikely to receive official status for a variety of reasons: the standards for type specimens are very strict and complex and not only do Cope’s bones bear marks of syphilis, they have also suffered damage from their travels: his skull has been dropped, broken and even repaired.

To make the situation more complicated, in 1959, another palaeontologist wrote a paper declaring Carolus Linneaus the holotype of Homo sapiens, especially as his body is well-preserved in the Cathedral in Uppsala, Sweden. Well since nobody can agree, the job still remains open and there is no official holotype for humanity, but is it likely that when (if) a holotype is chosen it will be an arrogant scientist that represents humanity?

Thursday, 5 April 2007

In the News: Ancient Humans, Great Pyramids and an Antarctic Amphibian

Mystery of the great pyramids solved
Original Publication: Dassault Systems
Popular News site: CBC

Ancient human fossil from China collides with ‘Out of Africa' theory
Original Publication: PNAS
Popular News site: BBC

Antarctic amphibian
Original Publication: JVP
A synopsis of the original article will be published on this blog later today.