Question for Biologists

[c0rbin]

Hey all. I had some fun playing with these two taxonomy sites and finding homo sapiens. But it created a lot of questions. Hopefully one of you fine folks can help me out with this one:

When does a sub-phylum become a new order? Or when does a sub-kingdom become a new phylum?

Refer to the lists below.

The Linnaean System
The Linnaean System classifies us with the following:

Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Primates
Family: Hominidae
Genus: Homo
Species: sapiens

Tree of Life - Web Project
But the Tree of Life seems to be a little more detailed. You can see the sub-classifications below and the source of my question (I have emphasized the corralations between the two lists with bold):

Life on Earth; Eukaryotes; Animalia; Bilateria (Triploblasts); Deuterostoma; Chordata; Craniata; Vertebrata; Gnathostomata; Sarcopterygii; Stegocephalians; Amniota; Synapsida; Therapsida; Mammilia; Eutheria; Primates; Catarrhini; Hominidea; homo sapiens

This is quite a list, and a lot of fun to go trapsing down the tree. It's somewhat of an eye-opener to see how far down the "branches" one gets before hitting vertebrates, and even farther for the mammals. Cool fun.

 

[cbish]

COrbin wrote:

When does a sub-phylum become a new order? Or when does a sub-kingdom
become a new phylum?

It sort of depends on how much "pork" is added onto the Bill.....just like Congress. Without trivializing, classification & taxonomy, as sound as we try to be, is still a man-made enterprise. It just sort of depends on what people want to go with, obviously as a result of criteria & debate.

The Linnean system is more traditional and more widely used. However, through such studies such as Cladisitics and with further info from DNA & protein sequencing, modifications & changes are being proposed.

This Tree of Life grouping is a little confusing to me as you have posted it. Are you sure you read it correctly? Sarcoptergyii is an extinct Family of fish that is considered to be a transitional fossil to Amphibians. Similarly, Synapsida & Therapsida are mammal-like reptiles; also considered to be transitional. In my mind, it looks like they took an umbrella, folded it, and called it a linneage!

 

[c0rbin]

I will admit that I am a n00b when it comes to taxonomy

I worked from the Linnean taxonomy for homo sapiens and tried to follow it on the Tree of Life page.

I started from more general (kingdom) and tried to navigate my way to "us." But I got lost after chordata and ended up having to work my way back from homo sapiens.

That is when my question arose. I went through a lot of sub-groups until I got back on the Linnean track. I probably made any errors there, connecting in the middle.

The new technology and specialization in the field makes sense for having all the sub-groups. My interest is purely diversionary, but what a cool diversion!

Thanks.

 

[athon]

The whole Linnean system is being revised slowly due to recent movements in molecular biology.

I studied under one of the world's leading (well, going on his credits and his research) molecular evolutionists at university, Dr. Phil Giffard. Many bacteria have been reclassified after a genetic analysis has determined point os relationship.

I see a day when this will happen with much of the system, where 'points of genetic difference' will determine where one belongs in the system.

Athon

 

[c0rbin]

Athon,

can you recommend any titles for a lay-person like myself to read up on this field.

I love this kind of stuff.

 

[arcticpenguin]

Tree of Life web site