The Cobweb of Life

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April 13, 2009, 7:06PM

Although "tree" is firmly enshrined as a taxonomic term of art, its aptness for taxonomic diagrams is merely conventional, because there isn't much more resemblance between real and taxonomic trees than between a man and a skeleton.

Even if we accept the skeletal "trees" in this silly metaphor, it's still grotesquely inappropriate for evolutionary taxonomy, because there's nothing in evolution remotely analogous to a trunk, and if all the many "branches" of life actually emanate from anything, it's more like a speck than a central supporting pillar.

The evolutionary connection of all living things is shaped more like a cobweb than a tree, and however inelegant this metaphorical substitution may appear to be, it nevertheless has the merit of suggesting the extreme fragility of all life, in a world which is rapidly becoming unfit for the survival of anything.

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Consider keeping the tree of life amidst the cobwebs?

Brief paper:
http://www.sbs.utexas.edu/genetics/Fall05/Handouts/PLoSbio-CobwebOfLife-Comment-10-05.pdf

Posted by Ticia
April 13, 2009 8:18 PM | Reply | Permalink

My reply below obviously pertains to your interesting comment, but I'm tagging it here just in case you're watching for replies on your dashboard.

Posted by Rutabaga Ridgepole in reply to a comment from Ticia
April 13, 2009 8:45 PM | Reply | Permalink

Thanks for that interesting link!

But I have to say that Fan Ge, Li-San Wang, and Junhyong Kim need to get out of the lab a little more often.

HGT events do not disrupt the integrity of the tree of life, contributing just small bits of genetic material, “much like cobwebs on tree branches.”

IMHO nobody in the history of the world ever saw a cobweb on the branch of a tree!

BTW do you happen to know if HGT events have been observed in non-microbial species? It's a lot more mysterious if the species involved don't conjugate.

Posted by Rutabaga Ridgepole
April 13, 2009 8:33 PM | Reply | Permalink

Here's a start:

http://en.citizendium.org/wiki/Horizontal_gene_transfer

Posted by Ticia in reply to a comment from Rutabaga Ridgepole
April 13, 2009 9:01 PM | Reply | Permalink

So apparently chloroplasts and mitochondria would be examples of massive horizontal genetic transfer.

And those cobwebs are back on the tree!

Thus the 'tree' is still a valid metaphor for microbial evolution - but a tree adorned with 'cobwebs' of horizontally transferred genes.

So is en.citizendium.org competing directly with Wikipedia, or what?

Posted by Rutabaga Ridgepole in reply to a comment from Ticia
April 13, 2009 9:22 PM | Reply | Permalink

Really interesting! And I actually 'get it'! (C'mon smile, you know your surprised!)

Thanks and rec'd.

Posted by Aunt Sam
April 13, 2009 8:50 PM | Reply | Permalink

Shocked!

(And thanks for the rec. And also thanks for that tip about Cornficker yesterday. I ran the test and all six pictures showed up.)

Posted by Rutabaga Ridgepole
April 13, 2009 9:11 PM | Reply | Permalink

Hold on to the link - test weekly. Important. And glad it is of use to you.

Posted by Aunt Sam in reply to a comment from Rutabaga Ridgepole
April 13, 2009 10:50 PM | Reply | Permalink

I prefer Borges' taxonomy:

"These ambiguities, redundancies, and deficiencies recall those attributed by Dr. Franz Kuhn to a certain Chinese encyclopedia called the Heavenly Emporium of Benevolent Knowledge. In its distant pages it is written that animals are divided into (a) those that belong to the emperor; (b) embalmed ones; (c) those that are trained; (d) suckling pigs; (e) mermaids; (f) fabulous ones; (g) stray dogs; (h) those that are included in this classification; (i) those that tremble as if they were mad; (j) innumerable ones; (k) those drawn with a very fine camel's-hair brush; (l) etcetera; (m) those that have just broken the flower vase; (n) those that at a distance resemble flies."

Posted by neoboho
April 14, 2009 2:21 AM | Reply | Permalink

And as Dr. Albert once said to Ts'ui Pen, "The book is the labyrinth."

Posted by Rutabaga Ridgepole in reply to a comment from neoboho
April 14, 2009 3:15 AM | Reply | Permalink

Check out this massive communal web in Texas. Yikes! Those spiders certainly showed those trees who's boss.

(From this original link, in case you want to avoid that place.)

Good post, R.

Posted by readytoblowagasket
April 14, 2009 9:06 AM | Reply | Permalink

Omigod!

That's nightmare material!

From this original link, in case you want to avoid that place.)

They actually use it to advertise beautiful Lake Tawakoni State Park!

And it even gets worse!

That thing is the home of the Guatemalan Long-jawed Spider!

Harharharhar!!!

And just when it couldn't possibly get any worse...

There's even a link to an even bigger Spider City near Encino California!

Posted by Rutabaga Ridgepole in reply to a comment from readytoblowagasket
April 14, 2009 3:03 PM | Reply | Permalink

Interesting. thanks- personally would have liked to see you explicate more of the salient points of analogy. But i'll waddle off and chew on this for a bit...

Posted by Obey
April 14, 2009 12:10 PM | Reply | Permalink

OT for Obey - http://tpmcafe.talkingpointsmemo.com/talk/blogs/eds/2009/04/greed.php#comment-3438004

A couple of replies there for you, and it seems you might lose track... :-)

Posted by eds in reply to a comment from Obey
April 14, 2009 4:06 PM | Reply | Permalink

web=cobweb?

Posted by Doomer252
April 14, 2009 12:38 PM | Reply | Permalink