Biological Classification systems (what are humans???)

[science_spot]

King Phillip came over for great spaghetti..........

Well that's how I learned it as a child.  Kingdom, Phylum, Class, Order, Family, Genus, Species.  Well, I think they were just starting to add "Superkingdom" into the mix, which is now known as Domain.  Am I showing my age now?  So I can offer a slight modification of King Phillip's little jingle.  Dead King Phillip came over for great spaghetti...........Can you think of anything more catchy?  Or did you learn a different way to remember the taxonomic ranks??

Taxonomy is the science of clasification.  We can really classify anything, from life forms to groceries to toys thrown about the floor.  It's actually a great activity for kids of all ages - just find a nice big pile of similar (or not-so-similar) things and figure out how you would sort them.  If you do this in the zoo, would you come up with something similar to the current biological classification system of Domain, Kingdom, Phylum, Class, Order, Family, Genus, Species?  Maybe something close??

The father of modern taxonomy, Carl Linnaeus, frst set up the scientific system called binomial nomenclature.  This is the two word scienentific name given to every plant, animal single celled organism on the planet, such as homo sapiens.  His work, Systema Naturae classified over 10,000 different species of plants and animals!!!  The classification system currently in use was derived from the system that bears his name - Linnean taxonomy.  The Integrated Taxonomic Information System  provides a database for scientific and common species names.  They focus on North American species, and currently have hundreds of thousands of listings.  This is a reflection of the millions of species, past and present, living on our Earth.  The diversity of life is an incredible thing!

Pictyre from the Integrated Taxonomic Information System  

 

I'll go through some basics of each taxonomic rank, and use humans as an example all the way through.  Check out some of the links for more details!

Domain - according to the commonly used two-domain system:

Prokayrota - organisms lacking a cell nucleus (or other organelles).  These tend to be bacteria and other single celled organisms

Eukayrota - organisms that have a cell nucleus are the multicellular organisms.  Humans are multicellular and our cells have nuclei.

Kingdom - most systems use 6 kingdoms for classification:

Animalaea - Humans are classified as animals.  That might surprise some people who contest that "humans aren;t animals".  We are not 'wild beasts', which is what people usually mean by that statement, but in terms of science, we are most certainly animals.

Plant - grass, trees and flowering plants are examples.

Fungi - yeast, mold and mushrooms are examples.

Protista - single celled motile organisms such as amoeba and paramecium, as well as single celled algae are examples.

Archaea - these are organisms similar in structure to bacteria, but they have more advanced metabolic pathways such as those found in more complex organisms.  Archaea were first found in extreme environments.

Bacteria - e coli. and streptococcus are examples.

Phylum (or in plants, called Division) - This grouping sorts the kingdom by the organisms' morphology (body appearance) or developmental similarities.  There are way too many to list here, but humans are in the phylum Chordata, meaning we have a set of characterisitcs, including the nerve (spinal) cord.  Humans are in the sub-phylum of vertebrates.

Class - This rank sorts organisms by their distinguishing anatomical characteristics, such as organs, hair, etc.  There are way too many to list here, but humans are in the class of Mammalia, which means we have mammary gland with which to nurse our young (among other characteristics).

Order - There are way too many to list here, but humans are in the order of primates, based on our large brains and advanced sense.  Monkeys and apes are also classified as primates.

Family - There are way too many to list here, but humans are in the family of hominidae (humans and great apes), based on our omnivorous diet and ability to climb. 

Genus - There are way too many to list here, but humans are in the genus homo, meaning modern human.

Species - A species is any group that is capable of interbreeding and producing fertile offspring. There are way too many to list here, but humans are in the species sapiens.

 

Have you ever wondered what all those latin words mean??  There's a great list here on Wikipedia.  It actaully makes me want to brush up on my latin again.  The 3 years I studied latin helped me in my studies of biological science, mostly due to this classification and word-relations.

There is another, newer, way of classifying life.  It isn't taking the place of the Linnean-based system (yet), because it has a different purpose.  It is based on claudistics, which is the method of classification based on phylogeny (relatedness).  There is a web-based project that is currently classifying living things according to claudistics, building a tree showing evolutionary relationships.  This project is called the Tree of Life.  Have a little fun and click on the Tree of Life webpage, and on the left, click on "random page".  What came up?  I got a spider..... http://www.tolweb.org/Mygalomorphae/2641

I think I am going to grow to love that site, just for the random page feature!!

Tonya

AKA sunmoonstars

The Science Spot

 

 

 

 

[Goodwoman614]

Apr. 16, 2009 at 12:35 AM

Wow thanks for the post!  Gotta love mnemonic devices...I remember King Philip, lol.

Now..a trivia question: what is the largest living organism detected on Earth, to date?

[science_spot]

Apr. 16, 2009 at 5:50 AM

goodwoman... do you mean dead or alive?  I am tempted to say the sperm whale, but I have a feeling it's a plant organism, not an animal......

I heard about a giant underground fungus somewhere... I think that might be it.  Or the sequia trees in Cali. 

I hope you come back to tell me the answer!!

 

(Original Poster)

[dottieanna29]

Apr. 16, 2009 at 5:07 PM

This is great.  I have  a biology degree but most of my studying was done about 20 years ago so some of the information is slightly different.  I always laugh when people insist "we are not animals".  So, what are you - a plant? or a fungus?

[PaxMommy]

Apr. 16, 2009 at 10:55 PM

Thank you!! This is excellent information. Yay for more data!!

[Goodwoman614]

Apr. 17, 2009 at 2:40 AM

aww, you're too good!  It is the giant fungus!  and here's a link to just one article you can find on it.  Freaks my mind!

[science_spot]

Apr. 17, 2009 at 9:45 AM

WOOHOO!  Thanks for the link, I totally wanted to read more about it.  I should put it on my list to write about here... it's really interesting.  Thanks :) 

 

(Original Poster)