Evolution of the X chromosome

Posted 18 March 2005 by

↗ The current version of this post is on the live site: https://pandasthumb.org/archives/2005/03/evolution-of-th-3.html

This week's Nature has an article summarizing the sequencing of the human X chromosome by Ross et al. (that should be Ross ET AL.!!!; see the author list at the end). There is an impressive wealth of quantitative and genetic detail here, but I'm not going to reiterate it. Mostly, I want to outline the evolutionary story.

And it really is an obligate evolutionary story they're telling. A paper on the sequence of a chromosome is not just a recitation of As, Gs, Cs, and Ts—it is about extensive analyses, comparisons of genomes from different species, reconstructions of past translocations, inversions, and mutations, and about the logical and mathematical modeling of the history of transformations that produced a particular arrangement of genes. What we have in the X chromosome is a text that shows the smudges and strike-outs and rearrangements of hundreds of millions of years of editing.

Continue reading "Evolution of the X chromosome" (on Pharyngula)

20 Comments

Andy Groves · 18 March 2005

Excellent post, Dr. Meyerz.

Chromosomal evolution is a rather nice example of a "lift the rock and see which way they scurry" - type question for ID proponents. Given the sequences of the human, chimp, mouse, chicken and pufferfish chromosomes, do they suggest that:

- The human X chromosome is the result of millions of years of evolutionary changes

or

- The human X chromosome is the result of a specific design event

or

- The vertebrate chromosomes are the result of an ancestral design event, followed by evolution.

If Dembski, Nelson, Johnson, Behe, Remine or Cordova are reading, it would interestign to hear your answers.......

Greg · 18 March 2005

282 authors, and not a single "Steve"?! Talk about improbable. It's a bloody conspiracy! If you took 282 people off the street, I bet at least a couple of them would be Steves. Heck, I have a "Steve" sitting not 20 feet from me right now.

Partial credit for a Steffen?

Seriously, great piece. Utterly fascinating.

Nic George · 18 March 2005

Very interesting but some pictures summarizing the steps that took place would make it more comprehensible.

Jim Harrison · 19 March 2005

The absence in these comments of the usual suspects shows that real science is, anong other things, a superior insecticide.

On a less snarky note: one of the obstacles to a general understanding of evolution is vast complexity of the real explanations as opposed to the utter simplicity of the false ones. Worse, living science mostly appears in the form of research papers in journals, which makes it hard to see the state of the science as a whole. I read SCIENCE and other publications regularly, but I've found that it is revelatory to acquire up-to-date textbooks on cell biology and other subjects and flog myself through them. 21st Century biology is truly monumental. It's too bad that viewing it requires such a strenuous climb to the top of the pyramid.

PZ Myers · 19 March 2005

I've noticed the same thing: they never try to grapple with the science, and when they do comment on it, it is to try and derail the conversation in the direction they want, away from the data.

Luke · 20 March 2005

Greg.

That may be because the authors are only identified by their surnames.

:-P

John A. Davison · 20 March 2005

s m pst ws dltd. Cngrtltns P.Z. Mrs.

Jhn . Dvsn

John A. Davison · 20 March 2005

Lt th rcrd shw tht P.Z. Mrs dlts pst tht h fnds nccptbl.

[ for the record, I haven't deleted any comments in this thread. I will if people can't resist the siren song of the troll ]

Ed Darrell · 20 March 2005

Unfortunately the Dallas Morning News killed its award-winning science section a few months ago.

But even they covered this story, with the Associated Press version. You can see it here, with a free registration required (which will get you into all Belo Corp. sites, which includes the Providence Journal, and a few other good outlets):
http://www.dallasnews.com/s/health/stories/031605cccahealthchromosome.1451a51bf.html

John A. Davison · 20 March 2005

P.Z. Mrs s trsh nd f tht s th w mngmnt cts hr t Pnd's Thmb s s Pnd's Thmb. rqst n plg frm th mngmnt f Pnd's Thmb; tht s f Pnd's Thmb s mngd. Mrs dd xctl th sm thng t DvSct nd sspct fr xctl th sm rsn.

[ if you can't discuss the topic of the article, shut your pie-hole. I will not put up with creationist trolling any further.
Hugs & kisses,
pzm ]

John A. Davison · 20 March 2005

Fr th rcrd, Mrs hs nt nl dltd psts n ths thrd bt grbld thm s wll b dltng vwls. H dd th sm thng rlr t DvSct. Wht bttr prf cld n sk fr dmnstrtng th bnkrptc f th Drwnn fr tl? f Mrs dns h hs dltd psts Mrs s lr: smpl s tht.

Jhn . Dvsn

PZ Myers · 20 March 2005

Listen, people, and consider this a formal declaration: among the last couple of articles I've posted here, there have been some extremely annoying attempts by creationist trolls like DvSct and Jhn Dvsn to derail what should be interesting discussions with their pretentious caterwauling. I appreciate input from readers, but I will not tolerate any more of this crap from fckng mrns. OK?

If you want to disagree with my interpretations, that's one thing, but whining about unfairness or dredging up old, tired idiocies that are trivially refuted if you would just read Mark Isaak's Index to Creationist Claims are going to get cut short or disemvoweled.

Davison has complained in e-mail that if I continue to gut his comments he will "stop wasting [ his ] time with Pandas Thumb." I consider that a promise. Goodbye, Mr Davison. We won't miss you.

John A. Davison · 20 March 2005

r s f th mprl W s s rvlng tht r nthng bt Drwnn grpthnk. Pnd's Thmb shld gt rd f f t xpcts t mntn n crdblt whtsvr. pprntl R th mngmnt. f tht s tr thn s mch fr Pnd's Thmb. hv gn t f m w n n ttmpt t cmmnct m thghts n smthng nbd knws nthng bt fr crtn. S gt ths n t bg g. Shw th wrld wht bgt rll r.

John A. Davison · 20 March 2005

Cm n P.Z. Mrs. Flx ths bgtd mscls f rs. Dmnstrt rslf gn fr ll t s.

John A. Davison · 20 March 2005

Tht's th sprt. Tht's wht wntd t s. r crdt t th dclrd prpss f Pnd's Thmb. ndd, s wll s m bl t dtrmn, R Pnd's Thmb. Jst fr fn, s thr nn ls n ths ntr frm wh wld gr wth m tht P.Z. Mrs' tctcs r dspcbl? B sr t rd ths bfr th grt cnsr rndrs t nntllgbl.

Wh dn't s r pwrs t hv m bnnd r s tht bnd r cpct? Dn't b sh. Fllw r nflng nstncts nd d wht knw s bst fr gd ld Pnd's Thmb. Gt crckng.

Michael Rathbun · 20 March 2005

Why don’t you use your powers to have me banned or is that beyond your capacity?

— Jhn . Dvsn
What precisely do you imagine that you are contributing? Could it possibly be that nobody would find your abrupt and complete disappearance a desirable relief if you did not act so consistently as if you were a thorough jerk? Perhaps your hypotheses possess merit. Your method of presentation of them and of yourself have guaranteed a tiny market for them. My only disagreement with PZM's tactics involves his patient tolerance, which so far exceeds the level that I could muster that he has gained my respect on that score. Were it up to me, every IP address that had ever been at any time been associated with a post signed by you would be denied access at the border routers.

DaveScot · 20 March 2005

Mrs tctcs rn't dspcbl. Th'r prdctbl. Wht dd xpct, Jhn, frm scntsts wh s th jdcl sstm t stfl crtcsm f thr thst fth? H's gng t d whtvr t tks t sht p.

DaveScot · 20 March 2005

R0FLM@0!!!!!!!!!!!

PvM · 20 March 2005

Somehow, both Dvsct and Dvsn make much more sense now that they have been disemvoweled. Cngrts

PZ Myers · 20 March 2005

Once again, I am compelled to close all comments on a thread because two creationist jackasses are incapable of actually saying anything intelligent on the topic. It's a despicable tactic--polluting a conversation with noise--but it's what I've come to expect from creationists.