"Molecular Machines" -- Proof of Evolution at Cellular Level

"Our cells, and the cells of all organisms, are composed of molecular machines. These machines are built of component parts, each of which contributes a partial function or structural element to the machine. How such sophisticated, multi-component machines could evolve has been somewhat mysterious, and highly controversial."

Trevor Lithgow of Australia's Monash University.

An international team of biochemists have discovered evidence at the molecular level in support of one of the key tenets of Darwin's theory of evolution that provides a blueprint for a general understanding of the evolution of the "machinery" of our cells.

"Our research shows that these machines although complete and complex, were a result of evolution. Simple ''core'' machines were established in the first eukaryotes by drawing on pre-existing proteins that had previously provided distinct, simplistic functions" -proof that Darwin's theory of evolution is valid at the molecular level, Professor Lithgow added refuting non-Darwinian explanations of Intelligent Design that propose that these complex machines to be so "irreducibly complex" that they must have been designed by an intelligent entity.


As a model system, the research focussed on one specific molecular machine, the TIM complex, which transports proteins into mitochondria. Mitochondria are a compartment of human cells that serve as the energy-producing 'powerhouses'. At a very early stage in evolution, mitochondria were derived from bacteria that lived within the first eukaryotic cells.

"Our cells literally are chimeras of a "host" cell and these intracellular bacteria. Yet bacteria don't have TIM complexes – to understand where the TIM complex came from we simply applied scientific reasoning and looked at a modern-day bacterium akin to the organism that gave rise to mitochondria." Professor Lithgow said.

The group looked at the bacterium Caulobacter crescentus and found bacterial proteins related to the components of the mitochondrial TIM complex. They then showed that these bacterial proteins are not found as part of protein transport machines.

"François Jacob described evolution as a tinkerer, cobbling together proteins of one function to yield more complex machines capable of new functions." Professor Lithgow said.

"Our work describes a perfect example of Jacob's proposition, and shows that Darwin's theory of evolution beautifully explains how molecular machines came to be."

Casey Kazan via Monash University

Comments

[intelligent_tinkerer]

The problem with the François Jacob analogy, is that while a 'Tinkerer' may cobble things together from material available at hand, they generally do it with a goal, which suggests an intelligence.
To argue that incredibly complex individual molecular machines, evolved in a steady progression not only to benefit themselves as molecular machines but complementing an ongoing beneficial development of an entire organism outside it's own functioning (to an astonishingly symbiotic degree despite evidence that mutations generally are not beneficial) puts it so far beyond the mathematics of probability that is makes the whole 'given enough time' notion begin to look absolutely absurd. Gentlemen we are running out of 'time'.

Professor... Stating that something is 'proof' when it flies in the face of logic, does not make it true nor scientific. We call that dogma.

[Wot ZOo]

Wowthat makes a lot of sene dude.

www.online-privacy.no.tc

[Zorba]

@intelligent_tinkerer:
The allusion to evolution performing some tinkering is just a bit of metaphor to make one of the main ideas of evolutionary biology more accessible to the public. Jacob is not actually invoking a Tinkerer.

The truth is that emergent complexity (where complex results are born from simple forces) happens all the time in the universe. The biochemical dance of life can emerge from simple physical laws.

The only reason your Intelligent Design movement exists is because you're trying to deny scientific evidence because it conflicts with your religious mindset. If intelligence is necessary to create something complex, then what greater intelligence created your supposed Designer?

[Wade]

According to Buddhism, our awareness becomes attached to physical matter and in continually reborn over and over again, during which we are guided by a simple bifurcation of "this is beneficial" or "this is not beneficial". So, yes, it is guided evolution. It is not merely a random cobbling together of molecular parts given enough time.

[stephen]

evolution does not in fact always progress- at least not to better designs. Many random possibilities are born but fail to survive. Likewise, are pressures are removed, "bad" or older designs can reappear. There has been plenty of time.

[bijuterii argint]

every interesting and non-useless research creates controverses ar a moment... maybe that is why not every information is accesible for the general public... but the show must go on because the evolution is in scientific results of this kind of research

[SB]

@zorba:
"The biochemical dance of life can emerge from simple physical laws"
Life does follow the laws of physics but to have life spontaneously form from non-life is not simple nor does it explain why life is programmed with the "will" of survival and reproduction. Chemical reactions are simple but they aren't "aware".

[SB]

Here's a link with a video to help visualize the complexity of the chemistry and the physics of what transpires inside a living cell.

http://www.studiodaily.com/main/technique/tprojects/6850.html

Credits to Harvard

[Agha Sohail Mirza]

Evolution will become revolution with nanotechnology. Nice post.

[rap]

nice post thank u admin

[TJ]

If it is found that this is in fact proof of Darwin's theory of evolution, it does not rule out the Intelligent Design theory. Despite anything that science discovers or comes up with, it will never disprove the intelligent design theory.

[bijuterii online]

Thanks for posting this article. I am tired of struggling to find relevant and intelligent commentary on this subject. Also i love the debate created.