Category: origin of life

Philae finds organic molecules on comet: what’s the big deal?

November 19, 2014 • 8:53 am

Everyone is excited that organic molecules have been detected by the probe Philae on the comet 67P/Churyumov-Gerasimenko.  This, people say, could explain the origin of life on Earth: the planet was seeded by the carbon-containing molecules on comets, and those organic seeds help create the first replicators that eventually became things that were indubitably “alive.”

But wait: we already had carbon-containing molecules on Earth, and we have no idea what molecules Philae found. The cometary compounds could, for example, be methane (a simple molecule with one carbon and four hydrogen atoms)—a molecule unlikely to have played a major role in the origin of life. Ditto for carbon monoxide or carbon dioxide (CO and CO2 respectively). The early Earth already had carbon in those molecular forms in the atmosphere, so why did we need to get them from a comet or asteroid? There were also physical forces on Earth, like heat and pressure around thermal vents, that could synthesize more complex organic molecules like amino acids. We also know that peptides (small proteins composed of amino acids) might have formed under early-Earth conditions.

Given that the constituents of early life could have formed under early Earth conditions (granted, as Matthew mentioned yesterday, we have little idea of how it happened), why invoke life being helped along by molecules on comets, molecules that haven’t even been identified yet?

I’ll be more impressed if they find complex amino acids or—even better but even more unlikely—proteins on the comet.  But until they do, at present I would echo Laplace and say that there’s no real need for a “cometary theory of abiogenesis.” Did the comet have geophysical conditions, or come from some planet with those conditions, that were even more favorable to the formation of complex organic molecules than the conditions on Earth?

What I’m saying, then, is that all the heated speculation that life on Earth might have been catalyzed by stuff on comets like  is a very premature speculation. Let’s wait and see what they found on comet 67P.

h/t: Melissa

Where did life come from: God or naturalism? The data from the U.S. vs. the U.K.

November 17, 2014 • 9:32 am

This disparity between our two related and Anglophonic lands is even worse than I expected. U.S. and U.K. citizens were polled just last wee about how they think life on Earth began. The question and choices were virtually identical for the two countries.

First the good news:

YouGov poll on the origin of life taken in the U.K. (2003 adults), Nov. 12-13 of this year. Figures are percentages:

UK

If you lump the third and fourth answers as “naturalistic origin,” then 59% of the respondents think life occurred as an outcome of the laws of chemistry and physics.  And if you go to the page, you’ll see the results don’t vary much with age, gender, region, or political affiliation.

Before you look below, guess what the answer is for the U.S.

*
*
*
*
*

Here’s the bad news, then: the YouGov poll from the U.S., taken Nov. 12-14:
US 1 US2

Less than half of the respondents were naturalists: 25%, while 53% thought life was created by God (and by that I suspect direct intervention, not just that God made sure the right chemicals were there.  That is more then threefold the number of Brits assuming God’s work (15%).

Breaking the U.S. data down by gender, age, and politics, we see that, as is often found, females are more religious than males, older people are more religious than younger (this reflects, I suspect, more a clinging to one’s upbringing than an age-related conversion), and the damn Republicans are goddier than the Democrats.

Republicans are the bane of science in the U.S.:

Screen Shot 2014-11-17 at 10.29.42 AM

Now I haven’t looked at all the survey data (there are more questions on other stuff like the possibility of intelligent life elsewhere in the Universe), but once again we see how hyperreligious the U.S. is, even compared to the U.K., where faith schools are rife. I don’t think Americans are dumber than the inhabitants of Great Britain; they’re just blinkered by faith.

h/t: Dom