Evolutie. Deel XIV

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Op donderdag 14 juni 2007 01:58 schreef barthol het volgende:
Even nog een artist impression van die Gigantoraptor,
Zo groot als een T-rexx maar meer bird-like
Echt een vreemde vogel.

[afbeelding]

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An international research consortium today published a set of papers that promise to reshape our understanding of how the human genome functions. The findings challenge the traditional view of our genetic blueprint as a tidy collection of independent genes, pointing instead to a complex network in which genes, along with regulatory elements and other types of DNA sequences that do not code for proteins, interact in overlapping ways not yet fully understood.

In a group paper published in the June 14 issue of Nature and in 28 companion papers published in the June issue of Genome Research, the ENCyclopedia Of DNA Elements (ENCODE) consortium, which is organized by the National Human Genome Research Institute (NHGRI), part of the National Institutes of Health (NIH), reported results of its exhaustive, four-year effort to build a parts list of all biologically functional elements in 1 percent of the human genome. Carried out by 35 groups from 80 organizations around the world, the research served as a pilot to test the feasibility of a full-scale initiative to produce a comprehensive catalog of all components of the human genome crucial for biological function.

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Op zondag 27 mei 2007 22:36 schreef Invictus_ het volgende:
[afbeelding]

Hét museum is open en de blogosphere trakteert ons op commentaar onder redactie van PZ.

http://scienceblogs.com/p(...)_creation_museum.php

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In May of 2005, a 3-member subcommittee of the Kansas State Board of Education held hearings to determine whether Darwin's long-held Theory of Evolution should be challenged in public-school science curriculum. At stake was, in effect, the definition of science for Kansas schoolchildren.

Kansas vs. Darwin takes you inside the hearings to meet the characters who captured the world's attention: school board members who believe their literal interpretation of the Bible trumps modern scientific evidence, and members of the Intelligent Design Network who believe mainstream science is conspiring to suppress evidence that would overturn evolution. You'll also get face to face with an organization of Kansas scientists, educators, and citizens that organizes a worldwide response to put an end to what they see as a religiously-motivated kangaroo court.

Kansas vs. Darwin is a heady, absorbing swirl of politics, science, religion, education and emotion in which the filmmakers unflinchingly race from one, compelling point of view to its polar opposite in order to challenge the viewer's own opinions. Audiences may experience discomfort as they plunge to the heart of one of mankind's most central questions of existence - and to the epicenter of the American culture war.

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In the corner of a laboratory at Michigan State University, one of the longest-running experiments in evolution is quietly unfolding. A dozen flasks of sugary broth swirl on a gently rocking table. Each is home to hundreds of millions of Escherichia coli, the common gut microbe. These 12 lines of bacteria have been reproducing since 1989, when the biologist Richard E. Lenski bred them from a single E. coli. “I originally thought it might go a couple thousand generations, but it’s kept going and stayed interesting,” Dr. Lenski said. He is up to 40,000 generations now, and counting.

*snip*

“It’s fun for us, because we can watch the game of life at the molecular level,” said Bernhard Palsson of the University of California, San Diego. “Many features of evolutionary theory are showing up in these experiments, and that’s why people are so excited by them.”

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Op woensdag 27 juni 2007 00:11 schreef wijsneus het volgende:
An irreducibly complex system has evolved in bacteria within the past 70 years.

http://www.talkdesign.org/faqs/icdmyst/ICDmyst.html#how2eatpcp

--
http://www.biology.mcgill(...)Harrison/schmidt.pdf

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Op woensdag 27 juni 2007 08:56 schreef Rumboon het volgende:

De huidige westerse mens heeft echter niet meer te maken met deze natuurlijke selectie. Dankzij medische ingrepen kunnen zelfs geestelijk gehandicapten langer leven en zich voortplanten. Hierdoor kan ik toch aannemen dat wij niet meer evolueren? Hoe moet ik dit zien...?

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Op woensdag 27 juni 2007 07:55 schreef bigore het volgende:

[..]

Auw, als dit waar is en op de juiste manieren getoetst is/word kan dit een gigantische klap in de bek voor creationisten worden. Hopelijk horen we hier meer over.

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Op woensdag 27 juni 2007 00:11 schreef wijsneus het volgende:
An irreducibly complex system has evolved in bacteria within the past 70 years.

http://www.talkdesign.org/faqs/icdmyst/ICDmyst.html#how2eatpcp

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Op woensdag 27 juni 2007 09:47 schreef Dwerfion het volgende:

[..]

Noemt de ID-beweging iets wat uit 3 enzymen bestaat al IC?

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Op woensdag 27 juni 2007 09:47 schreef Dwerfion het volgende:

[..]

Noemt de ID-beweging iets wat uit 3 enzymen bestaat al IC?

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Op woensdag 27 juni 2007 10:08 schreef wijsneus het volgende:

[..]

Dat is de _letterlijke_ definitie van IC. Minimaal drie delen waarbij het verwijderen van 1 van de delen het functioneren van het geheel stopt.

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Op woensdag 27 juni 2007 07:55 schreef bigore het volgende:

[..]

Auw, als dit waar is en op de juiste manieren getoetst is/word kan dit een gigantische klap in de bek voor creationisten worden. Hopelijk horen we hier meer over.

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Op woensdag 27 juni 2007 11:10 schreef Monolith het volgende:
Of natuurlijk het feit dat Muller al in 1918 publiceerde over het idee dat evolutie zeer waarschijnlijk tot 'irreducible complexity' (hij noemde het interlocking complexity) zou moeten leiden.
Genetic Variablity, Twin Hybrids and Constant Hybrids, in a Case of Balanced Lethal Factors", by Hermann J Muller, in Genetics, Vol 3, No 5, Sept 1918, pp 422-499.

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Op woensdag 27 juni 2007 10:23 schreef Dwerfion het volgende:

[..]

Waar haal je die drie vandaan? Ik zie wel ergens 'several' staan.

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Op woensdag 27 juni 2007 12:01 schreef wijsneus het volgende:

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Behe zegt inderdaad 'several' maar komt met voorbeelden van 'drie': Een kruk met drie poten is IC omdat hij niet functioneerd met twee poten. Een flagellum is 'motor, connector, and paddle'.

Ik heb dit verkeerd begrepen, i stand corrected

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Op donderdag 28 juni 2007 17:38 schreef Monolith het volgende:
[afbeelding]

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Scientists take step to making synthetic life

By Maggie Fox, Health and Science Editor
Thu Jun 28, 4:04 PM ET



WASHINGTON (Reuters) - Scientists have taken a first step toward making synthetic life by transferring genetic material from one bacterium into another, transforming the second microbe into a copy of the first.

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They intend to use their technique to custom-design bacteria to perform functions such as producing artificial fuel or cleaning up toxic waste, the researchers report in Friday's issue of the journal Science.

"This is equivalent to changing a Macintosh computer to a PC by inserting a new piece of software," Craig Venter, a genome pioneer who now heads his own institute in Rockville, Maryland, told reporters in a telephone briefing.

"I think eventually we could make artificial cells," Venter added. "This is a first step."

Venter has been trying for years to create a microbe from scratch. This is not quite it, but his team re-programmed one species of bacteria by adding in the genetic material from a closely related species.

They gene-engineered the replacement chromosome to resist an antibiotic and then flooded their experiment with the drug. The bacteria that survived all carried only the genes that had been spliced in.

They believe all the others simply died, but they are in fact not sure how the new DNA re-programmed some of the bacteria or what happened to the original DNA.

"I think that we don't know for certain how the donor genome takes over," Venter Institute researcher Ham Smith told reporters.

Nonetheless, Venter's team has applied for a patent on the process and they hope to exploit it industrially. Venter believes it will be relatively straightforward to build a new chromosome from scratch, one that performs the desired functions, to create a custom-made bacterium.

"What we are reporting in this Science paper is not anything about a synthetic organism," Venter said.

BOOTING UP LIFE

"It's a key enabling step so that once we have a synthetic chromosome we know it is now possible to boot that up. So synthetic biology itself and synthetic genomics is much closer to being proven," Venter added.

"We look forward to having fuels from genetically modified organisms within the next decade and perhaps in half that time."

The key to the experiment was using a very simple bacterium called Mycoplasma capricolum, which often infects goats. Bacteria do not have a nucleus as do cells from more complex organisms.

The research team injected a chromosome from a related species called Mycoplasma mycoides.

They do not know how well it worked but at least some of the M. capricolum were transformed into what looked and acted like M. mycoides.

The scientists concede it will be much more difficult to do this with more complex organisms, even bacteria, that have cell walls and all sorts of defensive mechanisms to keep out foreign

DNA.

A non-profit Canadian organization called the ETC Group expressed concern about the experiment and Venter's patent application. "We are extremely concerned about the breadth and implications of this patent and of its monopoly claims," the group's Jim Thomas said in an e-mail.

"We will be requesting that patent offices worldwide refuse this patent."

But Venter defended the patent. "At every stage of what the team has done here over the past several years, we have had to develop novel technologies and approaches that have not existed before because the field has not existed before," he said.