2007-05-23

Classifying species

There's been a lot of articles, blog posts and news about the 300 year anniversary of Carl von Linné (Carolus Linnaeus) lately. He was born today, May 23:rd 1707 in Älmhult, Småland in southern Sweden as the son of a preacher.

In 1735 he published the first version of his now world famous Systema Naturae. It was 11 large pages that classified the natural world and humans were for the first time grouped together with other primates. The eleven pages in the first edition grew to three thousand pages in the final and thirteenth edition, published in 1770.

The system that made him famous was a simple two part naming system based on the physical attributes of the organisms. The two terms are the genus name and the specific descriptor.
The so called Linnaean taxonomy is the base for the system of scientific classification used in modern biology. Linnaeus hierarchy started with the division into three kingdoms, Animals, Plants and Minerals. The Kingdoms were divided into Classes and the Classes into Orders, which were divided into Genera, which were divided into Species. The classifications have changed a lot since Linnaeus' first version and only the groups in the Animal kingdom remain to this day, although heavily updated.

There have been some discussions about improving this centuries old classification style to something more modern, like a tree based nomenclature based on the recent discoveries from DNA studies. It's quite clear that even if animals or plants look the same, they can come from families very far apart. A classic example is the Hyrax that looks like a big guinea pig, but the closest relative is actually the Manatee. (It's also closely related to the Elephant but that's not the closest relative, even if they share the same ancestor.)

A system called PhyloCode grew out of a workshop at Harvard University in 1998 and it's still in the draft stage. Maybe the simplicity of the Linnaean system will prevail anyway. It seems to have worked quite well for the last 272 years...

1 comment:

Claes Mogren said...

A well written article on wired about making an online database of all species on the planet:
http://www.wired.com/science/planetearth/news/2007/05/hanken_qanda