Questionable Motives

February 4, 2010

Is there a better explanation for origin of life than from a primordial soup?

Filed under: abiogenesis,Biology,Evolution,Science — tildeb @ 2:03 pm

Apparently so. Hot off the presses comes this hypothesis (excerpts from the article at ScienceDaily)

“Despite bioenergetic and thermodynamic failings the 80-year-old concept of primordial soup remains central to mainstream thinking on the origin of life,” said senior author, William Martin, an evolutionary biologist from the Insitute of Botany III in Düsseldorf. “But soup has no capacity for producing the energy vital for life.”

In rejecting the soup theory the team turned to the Earth’s chemistry to identify the energy source which could power the first primitive predecessors of living organisms: geochemical gradients across a honeycomb of microscopic natural caverns at hydrothermal vents. These catalytic cells generated lipids, proteins and nucleotides which may have given rise to the first true cells.

The team focused on ideas pioneered by geochemist Michael J. Russell, on alkaline deep sea vents, which produce chemical gradients very similar to those used by almost all living organisms today — a gradient of protons over a membrane. Early organisms likely exploited these gradients through a process called chemiosmosis, in which the proton gradient is used to drive synthesis of the universal energy currency, ATP, or simpler equivalents. Later on cells evolved to generate their own proton gradient by way of electron transfer from a donor to an acceptor. The team argue that the first donor was hydrogen and the first acceptor was CO2.

“Modern living cells have inherited the same size of proton gradient, and, crucially, the same orientation — positive outside and negative inside — as the inorganic vesicles from which they arose” said co-author John Allen, a biochemist at Queen Mary, University of London.

“Thermodynamic constraints mean that chemiosmosis is strictly necessary for carbon and energy metabolism in all organisms that grow from simple chemical ingredients [autotrophy] today, and presumably the first free-living cells,” said Lane. “Here we consider how the earliest cells might have harnessed a geochemically created force and then learned to make their own.”

This was a vital transition, as chemiosmosis is the only mechanism by which organisms could escape from the vents. “The reason that all organisms are chemiosmotic today is simply that they inherited it from the very time and place that the first cells evolved — and they could not have evolved without it,” said Martin.

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We can now expect at least two criticisms from creationists:

1) Darwin was wrong again and that evolution is just a theory that continues to evolve

2) There is no way we are biologically related to a geochemical gradient: where’s the transitional fossil?

January 20, 2010

Why are these theist arguments untrue?

Filed under: abiogenesis,Argument,Atheism,belief,Criticism,God,Religion — tildeb @ 2:57 pm

From Greta Christina’s Alternet article here:

Religion is a hypothesis about the world: the hypothesis that things are the way they are, at least in part, because of supernatural entities or forces acting on the natural world. And there’s no good reason to treat it any differently from any other hypothesis. Which includes pointing out its flaws and inconsistencies, asking its adherents to back it up with solid evidence, making jokes about it when it’s just being silly, offering arguments and evidence for our own competing hypotheses…and trying to persuade people out of it if we think it’s mistaken. It’s persuasion.

As long as we don’t know exactly how organic life began from non-life, then atheists’ conclusion that life almost certainly began as physical cause and effect will be called blind faith in materialism. But if we can replicate abiogenesis (the origins of life from non-life) in the laboratory—something that’s expected to happen in the next few years—this will be seen as proof that life had to be intentionally created. After all, it required people working in a lab for decades to make it happen!

Why this is untrue and unfair: This one drives me up a tree. The conclusion that life almost certainly began as a chemical process is not blind faith. It’s a reasonable conclusion based on the evidence. The overwhelming body of evidence supports the conclusion that life is a physical, biochemical process, developed into its current state of complexity and diversity by the natural process of evolution. It is reasonable to conclude that this phenomenon began as a physical, proto-biochemical process.

And when/if abiogenesis does get replicated in the lab, that’s hardly proof that life had to be designed. I’m sorry, but that’s just silly. Natural processes get replicated in the lab all the time. We grow mold in Petri dishes—does that mean mold can’t occur naturally?

When we speak out in any way about our atheism—and when we continue to organize, and to make ourselves and our ideas more visible and vocal, and to generally turn ourselves into a serious movement for social change—we are accused of being hostile, fanatical, rude, evangelical, bigoted and extremist.

But if we don’t speak out, if we don’t organize, if we don’t forge ourselves into a powerful and visible movement…then the bigotry and misinformation and discrimination against us will continue unabated.

Why this is untrue and unfair: We really can’t win on this one. Even the most mild forms of atheist activism and visibility result in believers accusing us of disrespect, intolerance and forcing our beliefs on others. If we do something as mild and unthreatening as putting up bus ads saying “You can be good without God” or “Don’t believe in God? You are not alone,” you can bet good money that plenty of believers will get worked up about how those terrible atheists are insulting Christians and other believers. The purest act of visibility—the simple act of standing up and saying out loud, “Atheists exist and are good people”—is treated as another example of the offensive, dogmatic, in-your-face extremism of the atheist movement.

But here’s the skinny:

There has never once been a marginalized group that has won recognition and rights by sitting back and waiting politely for it to happen. There has never once been a marginalized group that has won recognition and rights by doing anything other than speaking out, organizing, making itself visible and vocal. As Martin Luther King Jr. said, “Freedom is never voluntarily given by the oppressor; it must be demanded by the oppressed.”

So you’ll have to forgive us if we take the accusations of our offensive, dogmatic, in-your-face extremism with something of a grain of salt. You’ll have to forgive us if we listen to the concerned advice from believers about how our confrontational tactics are alienating people and we need to dial it back…and respond by giving it the horse laugh, and continuing to do what we’ve so successfully been doing. You’ll have to forgive us if we treat the attempts to quiet us down as attempts to shut us up.

January 11, 2010

A cautionary tale: which came first in the origin of life?

Filed under: abiogenesis,Biology,Chemistry,Science,Skepticim — tildeb @ 3:30 pm

A new study published in Proceedings of National Academy of Sciences rejects the theory that the origin of life stems from a system of self-catalytic molecules capable of experiencing Darwinian evolution without the need of RNA or DNA and their replication.

The U.S. National Aeronautics and Space Administration (NASA) defines life as a “self-sustaining chemical system capable of Darwinian evolution.” The scientific theories on the origin of life revolve around two main ideas: one focuses on genetics — with RNA or DNA replication as an essential condition for Darwinian evolution to take place — and the other focuses on metabolism. It is clear that both situations must have begun with simple organic molecules formed by prebiotic processes, as was demonstrated by the Miller-Urey experiment (in which organic molecules were created from inorganic substances).

Science more recently demonstrated that sets of chemical components store information about their composition which can be duplicated and transmitted to their descendents. This has led to their being named “compound genomes” or composomes. In other words, heredity does not require information in order to be stored in RNA or DNA molecules. These “compound genomes” apparently fulfil the conditions required to be considered evolutionary units, which suggests a pathway from pre-Darwinian dynamics to a minimum protocell.

Researchers concluded that this fundamental limitation of “compound genomes” should lead to caution towards theories that set metabolism first as the origin as life, even though former metabolic systems could have offered a stable habitat in which primitive polymers such as RNA could have evolved.

Researchers state that different prebiotic Earth scenarios can be considered. However, the basic property of life as a system capable of undergoing Darwinian evolution began when genetic information was finally stored and transmitted such as occurs in nucleotide polymers (RNA and DNA).

From the article at Science Daily here.

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