Why Darwin was wrong about the tree of life

New Scientist ^ | 21 January 2009 | Graham Lawton

[Lorianne]

IN JULY 1837, Charles Darwin had a flash of inspiration. In his study at his house in London, he turned to a new page in his red leather notebook and wrote, "I think". Then he drew a spindly sketch of a tree.

As far as we know, this was the first time Darwin toyed with the concept of a "tree of life" to explain the evolutionary relationships between different species. It was to prove a fruitful idea: by the time he published On The Origin of Species 22 years later, Darwin's spindly tree had grown into a mighty oak. The book contains numerous references to the tree and its only diagram is of a branching structure showing how one species can evolve into many.

The tree-of-life concept was absolutely central to Darwin's thinking, equal in importance to natural selection, according to biologist W. Ford Doolittle of Dalhousie University in Halifax, Nova Scotia, Canada. Without it the theory of evolution would never have happened. The tree also helped carry the day for evolution. Darwin argued successfully that the tree of life was a fact of nature, plain for all to see though in need of explanation. The explanation he came up with was evolution by natural selection.

So what happened? In a nutshell, DNA. The discovery of the structure of DNA in 1953 opened up new vistas for evolutionary biology.

[B-Chan]

RANDOMCHANCERANDOMCHANCERANDOMCHANCELALALALA

[stormer]

Wow. It must be late where you are. Get some rest.

[Zero Sum]

Thank you for your thoughtful and informative post.

[aliquando]

The good thing about science is that it changes. New discoveries change old belief's. Why people view this as a confrontation is beyond me. When I die, G_d will let me know how he did it. That is my faith in my Creator. Not an individual discovery, but a body of work. You may disagree, but this my faith.

[smokingfrog]

     

"The affinities of all the beings of the same class have sometimes been represented by a great tree... As buds give rise by growth to fresh buds, and these if vigorous, branch out and overtop on all sides many a feebler branch, so by generation I believe it has been with the great Tree of Life, which fills with its dead and broken branches the crust of the earth, and covers the surface with its ever branching and beautiful ramifications."

Charles Darwin, 1859

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Sounds very poetic, but not very scientific.

[count-your-change]

If a tree falls in the forest, will an evolutionist hear it?

[Mogwai]

bump

[Does so]

If a tree falls in the forest, will an evolutionist hear it?

I didn't hear it fall, but I have a 50-pound piece of fossilized wood which silently represents a species from which evolved a tree species we know today as the Norfolk Pine.

The discovery of the structure of DNA in 1953 opened up new vistas for evolutionary biology.

"Be there or be square."

:)

[count-your-change]

What sort of DNA were you able to recover from the fossil?

[Darwin Fish]

Very informative post.

[Inappropriate Laughter]

This has been posted before and I'll repost my earlier comment:

---

I read that crappy NS article after it was cited in a creationist piece as proof that evolution is wrong on another thread...and I tried to figure out what was "news" here...horizontal gene transfer between microbes has long been known about, as well as hybridization of plants, but for the most part the "Tree of Life" metaphor still works pretty well, especially for animals. Here is a comment on the NS article:

The Trouble With Science Journalism by Jason Rosenhouse

From Rosenhouse's article:

The cover sports a big green tree with the words “Darwin Was Wrong.” I hope they sell a lot of magazines with that load of tripe, since they certainly were not thinking about the generations of school kids and church-goers who will now be treated to that cover in every creationist power point presentation between now and the Rapture. How many people do you think will actually read the article to discover what it was, precisely, that Darwin got wrong?

If the article, by Graham Lawton, had some real news to report that would justify such a headline, then that would be one thing. In reality, though, the article has only the yawn-worthy old-news that horizontal gene transfer among single-celled organisms means that the metaphor of a tree of life must be modified. Scientific American published a far more informative version of the same article back in February of 2000.

The basic idea here is simple. The tree metaphor, which famously appears as the sole diagram in The Origin of Species, is based on the assumption that genes are only transferred vertically. That is, genes pass from parent to offspring, but not from sibling to sibling. If unrelated organisms are nonetheless swapping genes back and forth, then the tree does not capture much of what is important in the evolutionary process. The prevalence of horizontal gene transfer among single-celled organisms implies that the base of the tree looks more like a web.

Like I said, this is old news, and is not anything that is relevant in our little dust-ups with the creationists. Quite the contrary. Recognizing the importance of HGT has opened up exciting new avenues of research for biologists, and has shown that evolutionists of the past had been unnecessarily limiting their options in explaining the evolutionary process.

[Lorianne]

Recognizing the importance of HGT has opened up exciting new avenues of research for biologists, and has shown that evolutionists of the past had been unnecessarily limiting their options in explaining the evolutionary process.

What is wrong with writing about that excitement? The article does not say anywhere that creationists are right and evolution is wrong ... only what you said above.

[Does so]

"...What sort of DNA were you able to recover from the fossil...?

It's not what I do and wouldn't attempt it, but it's done every day!

Quote:

"A mass of rocks (about 0.5 m3) was removed using a pick and shovel from the Clarkia fossil beds and subsequently transported to Washington State University Pullman, Washington, USA, and stored at 4°C. Rocks were cleaved, and fossil leaves of good quality were selected for DNA extraction."

http://www.amjbot.org/cgi/content/full/91/4/615

[SunkenCiv]

Rethinking The Genetic Theory Of Inheritance: Heritability May Not Be Limited To DNA
Science Daily | Jan. 20, 2008 | Unknown
Posted on 01/21/2009 4:17:24 AM PST by decimon
http://www.freerepublic.com/focus/f-chat/2168676/posts