Interesting new 'Nature' articles

[Oolon Colluphid]

From the current Nature, Vol 424, 21 August 2003 (emphases mine):
pp 928 - 931
Speciation by host switch in brood parasitic indigobirds

Michael D Sorenson, Kristina M Sefc & Robert B Payne

A growing body of empirical and theoretical work supports the plausibility of sympatric speciation, but there remain few examples in which all the essential components of the process are well understood. The African indigobirds Vidua spp. are host-specific brood parasites. Indigobird nestlings are reared along with host young, and mimic the mouth markings of their respective hosts. As adults, male indigobirds mimic host song, whereas females use these songs to choose both their mates and the nests they parasitize. These behavioural mechanisms promote the cohesion of indigobird populations associated with a given host species, and provide a mechanism for reproductive isolation after a new host is colonized. Here we show that all indigobird species are similar genetically, but are significantly differentiated in both mitochondrial haplotype and nuclear allele frequencies. These data support a model of recent sympatric speciation. In contrast to the cuckoo Cuculus canorus, in which only female lineages are faithful to specific hosts, host switches have led to speciation in indigobirds because both males and females imprint on their hosts.
pp931 - 935
Genetic mechanisms and constraints governing the evolution of correlated traits in drosophilid flies

Nicolas Gompel & Sean B Carroll

Some morphological traits differ greatly between related species, but it is not clear whether diversity evolves through changes in the same genes and whether similar, independent (that is, convergent) changes occur by the same mechanism. Pigmentation in fruitflies presents an attractive opportunity to explore these issues because pigmentation patterns are diverse, similar patterns have arisen in independent clades, and numerous genes governing their formation have been identified in Drosophila melanogaster. Here we show that both evolutionary diversification and convergence can be due to evolution at the same locus, by comparing abdominal pigmentation and trichome patterns and the expression of Bric-à-brac2 (Bab2), which regulates both traits in D. melanogaster, in 13 species representing the major clades of the subfamily Drosophilinae. Modifications of Bab2 expression are frequently correlated with diverse pigmentation and trichome patterns that evolved independently in multiple lineages. In a few species, Bab2 expression is not correlated with changes in pigmentation but is correlated with a conserved pattern of trichomes, indicating that this locus can be circumvented to evolve new patterns when a correlated trait is under different constraints.
pp 935 - 938

Regulatory evolution of shavenbaby / ovo underlies multiple cases of morphological parallelism

Elio Sucena, Isabelle Delon, Isaac Jones, François Payre & David L Stern

Cases of convergent evolution that involve changes in the same developmental pathway, called parallelism, provide evidence that a limited number of developmental changes are available to evolve a particular phenotype. To our knowledge, in no case are the genetic changes underlying morphological convergence understood. However, morphological convergence is not generally assumed to imply developmental parallelism. Here we investigate a case of convergence of larval morphology in insects and show that the loss of particular trichomes, observed in one species of the Drosophila melanogaster species group, has independently evolved multiple times in the distantly related D. virilis species group. We present genetic and gene expression data showing that regulatory changes of the shavenbaby / ovo (svb/ovo) gene underlie all independent cases of this morphological convergence. Our results indicate that some developmental regulators might preferentially accumulate evolutionary changes and that morphological parallelism might therefore be more common than previously appreciated.

There’s also a couple of interesting Nature Science Update articles:

Sea creature confused for its lunch: Worm victim of mistaken identity reclassified (http://www.nature.com/nsu/030818/030818-11.html)

Squashed embryos switch on genes: Mechanics may guide embryo growth (http://www.nature.com/nsu/030818/030818-12.html)

Cheers, Oolon

[Duvenoy]

That is interesting, Oolon. Thanks. I've only scanned it and will come back to it later for a closer reading.

You do realize of course, that it will all be summed up in those famoue, three words......... :rolleyes:

doov

[Principia]

http://www.nature.com/cgi-taf/DynaPage.taf?file=/nature/journal/v424/n6951/abs/424899a_fs.html


Nature 424, 899 - 900 (21 August 2003)

Fibre-optical features of a glass sponge

VIKRAM C. SUNDAR*, ANDREW D. YABLON†, JOHN L. GRAZUL*, MICHA ILAN‡ & JOANNA AIZENBERG*

Modern technology cannot yet compete with some of the sophisticated optical systems possessed by biological organisms. Here we show that the spicules of the deep-sea 'glass' sponge Euplectella have remarkable fibre-optical properties, which are surprisingly similar to those of commercial telecommunication fibres — except that the spicules themselves are formed under normal ambient conditions and have some technological advantages over man-made versions.

Let's see how long it takes before the CreatoIDiots connect the dots on this one. ;)

[Oolon Colluphid]

Thanks, Principia! I missed that one, or rather, overlooked it. Didn't know there was an organism called a glass sponge, thought it was some sort of technology thingummybob. :o ;)

'The more we learn, the more we learn there is to learn...'

Oolon

[Baloo]

Modern technology cannot yet compete with some of the sophisticated optical systems possessed by biological organisms.

Let's see how long it takes before the CreatoIDiots connect the dots on this one.

Ironically, modern technology will probably surpass biological organisms in designs such as these only when the practice of using genetical algorithms for mechanical design becomes much more widespread.

Intelligent design is fine for creating simple structures, like car engines. But when you need something complex, better leave it to good ole random mutation + natural selection.

[RBH]

Baloo wrote Intelligent design is fine for creating simple structures, like car engines. But when you need something complex, better leave it to good ole random mutation + natural selection.See below. :)

RBH

--------------------
"There are only two ways we know of to make extremely complicated things, one is by engineering, and the other is evolution. And of the two, evolution will make the more complex." - Danny Hillis.

[MrDarwin]

Originally posted by Baloo
Intelligent design is fine for creating simple structures, like car engines. But when you need something complex, better leave it to good ole random mutation + natural selection.

I tried to point this out over at ARN several weeks ago: they are asserting that complex systems like living cells can only be intelligently designed, but have yet to demonstrate that complex systems like living cells can be intelligently designed in the first place! Nor have IDists shown (and in fact seem oddly reluctant to make a case for) whether there is any intelligently creative force (besides humans) operating in the universe.

Thus the "design process" being postulated by IDists is a bigger, blacker box than any that Darwin ever encountered--they don't know who or what did the designing, or when, or where, or why, or how. And then they have the nerve to accuse evolutionary biologists of lacking evidence for evolution!

[dayton]

Originally posted by Oolon Colluphid
Thanks, Principia! I missed that one, or rather, overlooked it. Didn't know there was an organism called a glass sponge, thought it was some sort of technology thingummybob. :o ;)

'The more we learn, the more we learn there is to learn...'

Oolon

This is actually evidence for Creationism. Something this complex and advanced could not have formed by random mutations and natural selection.

http://www.creationism.org/

[RufusAtticus]

Originally posted by Dayton
This is actually evidence for Creationism. Something this complex and advanced could not have formed by random mutations and natural selection.

If radios can be formed by random muation and selection, then why can't fiber-based eyes?

[Valentine Pontifex]

Originally posted by RBH

"There are only two ways we know of to make extremely complicated things, one is by engineering, and the other is evolution. And of the two, evolution will make the more complex." - Danny Hillis.

I would replace evolution with history since anything with a historical contraints can make even technology more complicated than it "should" be.

[Albion]

Something this complex and advanced could not have formed by random mutations and natural selection.

Your scientific evidence being?

[Oolon Colluphid]

Originally posted by Dayton
This is actually evidence for Creationism. Something this complex and advanced could not have formed by random mutations and natural selection.
Oh? Oh? I thought you were leaving. If this is the best you can do, perhaps you should stay buggered off.

Alternatively, of course, you could ANSWER THE FUCKING QUESTIONS in the thread you started before.

In other words pal, put up or shut up.

[Heathen Dawn]

Intelligent design is fine for creating simple structures, like car engines. But when you need something complex, better leave it to good ole random mutation + natural selection.



"There are only two ways we know of to make extremely complicated things, one is by engineering, and the other is evolution. And of the two, evolution will make the more complex." - Danny Hillis.



I tried to point this out over at ARN several weeks ago: they are asserting that complex systems like living cells can only be intelligently designed, but have yet to demonstrate that complex systems like living cells can be intelligently designed in the first place! Nor have IDists shown (and in fact seem oddly reluctant to make a case for) whether there is any intelligently creative force (besides humans) operating in the universe.

Thus the "design process" being postulated by IDists is a bigger, blacker box than any that Darwin ever encountered--they don't know who or what did the designing, or when, or where, or why, or how. And then they have the nerve to accuse evolutionary biologists of lacking evidence for evolution!


:notworthy :notworthy :notworthy

I just LOVE this stuff!

[RRoman]

Originally posted by Dayton
Something this complex and advanced could not have formed by random mutations and natural selection.


Why?

[Coragyps]

This is actually evidence for Creationism. Something this complex and advanced could not have formed by random mutations and natural selection.
I just read the article itself, and then Googled a while with no success, to try to answer a couple of questions:
Do sponges have any light-sensing organs?
Is there enough light where a "deep-sea" sponge such as this one (Euplectella) lives to see anything anyway?
Do the shrimps that live within this sponge's "basket" have concerts with laser light shows so that they need fiber optics?
Or could it be coincidental that the fibers are transparent, and that their primary function is not related to light or its transmission?
Oolon, do you have a category for "overdesigned" instead of "bad design?"

[Oolon Colluphid]

Originally posted by Coragyps

Oolon, do you have a category for "overdesigned" instead of "bad design?"
Yeah, I do actually. It's from Nick Humphrey's Soul Searching (Leaps of Faith in the US), and it's his Argument from Inappropriate Design, which allows for overdesigned things, stuff with 'too much design of the wrong kind'. It works against the supernatural / paranormal / telepathy crowd, and when I get the webpage finished it will be another angle on biological 'design'. What this space... ;)

Oolon