from tree to web?

Hi!At my working place i'm confronted with some kind of muslim creationist colleague, on a daily basis. This person will not be the topic of this thread but has exposed something i had never heard or read before. Well, this person wanted to be a smartazz and showed us, with a victorious sparkle in the eye, one of the latest New Scientist weekly magazine, N2692, 24 Jan 2009. The front page offers us a quite attracting assertion: "Darwin was wrong..." and in smaller letters: "...cutting down the tree of life". The illustration is a drawing of a tree containing various animal forms.The person I mentioned did not read the article. I did, with my modest understanding of the evolution theory and of technical english. Simply put, the article in question says that Darwin first pictured a TREE to represent graphically evolution in time, as anyone interested in this matter knows, but now many seem to agree on the fact that a WEB would depict the process better, because of genetic material swapping between species (quoting: "often across huge taxonomic distances")or hybridisation. Thus, descent with modification would not have to be seen only as vertical, but in many other ways too.As i'm quite ignorant concerning many small details that can mean huge changes in the theory, i'd like to have your input and points of view about it.

Thread moved here from the Proposed New Topics forum.

This New Scientist article is probably the source. This is a secondary article. You can read the abstract from the primary source [The impact of reticulate evolution on genome phylogeny - PubMed]here[/url].What Doolittle and Bapteste are saying is that lateral gene trasfer was common early in life before animals came along. This prevents us from constructing a true, single tree for ALL life. However, the tree still stands for big, macroscopic animals because there is a lack of lateral gene transfer.For the creationists, this is a non-winner. In order for them to use this evidence they must first agree that all life evolved from unicellular organisms.Edited by Taq, : No reason given.

Indeed this still occurs today. Much of the antibiotic resistance that bacterial pathogens are evolving is actually do to the swapping of plasmids (circular pieces of DNA that are separate from the bacterial genome and are not necessary for the function of the bacterium) that carry the various genes that confer resistance. So while this makes the "trunk" of the tree more complicated, once species evolved that no longer had the ability to swap horizontally, the tree metaphor still holds.Additionally horizontal gene transfer does not refute the theory of evolution by natural selection, it only makes it more complex.

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"There are three kinds of lies: lies, damned lies, and statistics."

I prefer the metaphor "the root ball of life".The figure below is taken from Doolittle's Scientific American article "Uprooting the Tree of Life" (February 2000). Scientific American

I like it

I like it too - a very nice graphic. It illustrates very nicely how we eukaryotes don't swap genes around as much as those funky promiscuous prokaryotes do.I wish Scientific American was still as in-depth as my memory has it having been thirty years ago - the last on I bought reminded me of (urp) Popular Science.

Hi Taq, You mean to tell me that there is absolutely no horizontal/lateral gene transfer? I think there must be a little of it going on for sure somewhere....I mean look at all the experiments food engineers are running. What about retroviruses? There must be a ton of other similar such going on, no?

How about this; the coral fungus of life. For the record, I thought that the New Scientist cover was needlessly sensationalist. It came in for a lot of criticism from prominent scientists and has been waved around by gleeful creationists from the moment it was published.The tree of life hasn't been felled. It has, as one would hope for a metaphor that represents a modern theory, been refined and adapted to reflect new evidence. The discovery of phenomena like HGT don't demolish our previous knowledge, they add to it. And guess what; this is how science is supposed to work. Where's the problem?Mutate and Survive

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"The Bible is like a person, and if you torture it long enough, you can get it to say almost anything you'd like it to say." -- Rev. Dr. Francis H. Wade

Au contraire!In order for them to use it, they need only to present a graphic of the magazine's front cover, just as the OP's colleague had done, and then cite the article without ever having even looked at it. Certainly wouldn't be the first time they've even done that.Prepare yourselves for their assault with this new scientific evidence that just blows evolution out of the water!

Surely we can defend ourselves with the issue cover of a fortnight later (Feb 7-13, 2009), BORN BELIEVERS: How Your Brain Creates God.

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Genesis 2
17 But of the ponderosa pine, thou shalt not eat of it; for in the day that thou shinniest thereof thou shalt sorely learn of thy nakedness.
18 And we all live happily ever after.

It is happening with human engineered species. My favorite is the Glofish. It carries a copy of the jellyfish GFP gene which causes it to fluoresce in UV light. I haven't dug into the history behind the Glofish, but I strongly suspect that it has it's roots in the basic research lab. GFP reporter genes are common place in evo-devo studies that study transcription factors. Anyway . . .As to retroviruses, it comes close. However, this does not involve transfer of DNA from one species to the next but it does cause divergent species to share DNA not found in their common ancestor. There is also the case of mitochondrial DNA making it's way into the host genome. If you still consider mitochondria to be an endosymbiot this may count, but barely.If this were going on it would be pretty easy to spot given the wealth of genomic data that is out there.

It's also worth mentioning that the lack of a tree due to HGT has been known for quite a while. It's old news.However, this is actually a perfect trap for creationists. We should just let them run free with this for a little while. All we have to do is ask them what methodologies these scientists used in order to detect HGT. They will then have to accept common ancestry between speices that are not in the same "kind".

I've been discussing this point with another colleague involved in this funny issue and he thinks the same; according to him publishing such a cover is quite an unresponsible, dangerous thing to do. I personnally think slightly otherwise. I had read almost nothing from New Scientist until this one. I mean that some people's gullibility and, let's call it what it is, ignorance, can be a way to make ME a little less ignorant. If my fundie colleague had not put the magazine on this desk, maybe I would have never read the article. It's quite a selfish way of seeing it but it's often happening like this.One more exemple: I never was really interested in the evolution topic until i began posting in a forum, supposed to be a place mainly for musicians and music lovers. But forum are what they are and we sometimes wind up in surrealistic arguments in threads with surrealistic titles. To make it short: the one person who gave birth to my interest in the topic is a pure, obtuse, titanium-headed fundamentalist. I guess this hapens often, everywhere. If i may, i would say that "the lord works in mysterious ways"! Nice one lyx2no! Though I still BELIEVE in my favourite Zappa quote...

quote:

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One of my favorite philosophical tenets is that people will agree with you only if they already agree with you. You do not change people's minds.

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But if I can't beat a tsunami of ignorance with my tiny jug of knowledge, i will keep on filling the jug, thanks to people like you who posted on this thread. Thank you

THe new scientist the following week published a very angry by Dawkins et'al that took up half their letters section.You are so irresponsible rar rar rar, dumb load of rar rar....we have to clean up your mess rar rar.etc