Archives For life

alpha centauri bb

Carbon is a great element for kick-starting life thanks to its uncanny ability to form reactive, but still stable molecules perfect for creating proteins, amino acids, and even the backbone of DNA and RNA, or their functional equivalents. And yet, according to those who argue that the reason we exist is that the universe is somehow fine-tuned for us, or that life exists as a random, one in a trillion chance, it shouldn’t even be here. You see, when the first stars started fusing hydrogen into helium-4 deep in their searing cores, the resulting helium atoms should have combined into beryllium-8 which decays so quickly that there should have been virtually no chance for another helium atom to combine with it to form carbon-12, which accounts for 98.9% of all carbon in the known universe and makes life possible. According to astronomer Fred Hoyle, whose misuse of the anthropic principle has been used to justify many an anti-evolutionary screed, since carbon based life exists, there must be a mechanism by which this beryllium bottleneck is resolved and the clue to this mechanism must lie in the conditions under which the star fuses helium.

You see, when atoms fuse into a new element, the newly formed nucleus has to be at one of its natural, stable energy levels, otherwise the combination of the protons’ and neutrons’ energies, as well as the energy of their kinetic motion will prevent the fusion. Hoyle’s insight was than any new carbon atom must have had a resonance with the process by which a beryllium and helium atom would combine, which would exert just enough energy to slow down the decay rate for the reaction with a passing helium-4 atom to happen, so the natural energy level of the result would sustain a stable carbon-12 nucleus. Imagine rolling magnetic spheres down a hill, and as these magnets roll, they collide. Some will hit each other with just enough energy to keep rolling as a single unit and absorb new spheres they run into, others combine, then break apart, or just roll on their own. The angle, the force of impact, and the speed and masses of the spheres all have to be right for them to join, and when they do, they’ll have to stay that way long enough to settle down. This is quantum resonance in a nutshell, and it’s what made carbon-12 possible.

But while this is all well and good, especially for us carbon based lifeforms, where does Hoyle’s discovery leave us in regards to the question of whether the universe was fine-tuned for life? If we assume that only carbon based life is possible, and that the only life that could exist is what exists today, the argument makes sense. However those assumptions don’t. Even if there was no quantum resonance between helium-4, beryllium-8, and carbon-12 in the earliest stars from which the first atoms of organic molecules were spawned, the first stars were massive and it’s a reasonable guess that when they went supernova, they would have created carbon, silicon, and metals like aluminium and titanium. All four elements can be useful in creating molecules which can form the chemical backbones of living organisms. In fact, it’s entirely possible that we could one day find alien life based on silicon and that in some corner of the galaxy there are microbes with genomes wound around a titanium scaffold. Life does not have to exist as we know it, and only as we know it. We didn’t have to exist either, it’s just lucky for us that we did.

When creationists try to come up with the probability that life exactly the way we understand, or have at least observed to exist, came out the way it has, against all other probabilities, they are bound to get ridiculous odds against us being here. But what they’re really doing is calculating a probability of a reaction for reaction, mutation for mutation, event for event, repeat of the entire history of life on Earth, all 4 billion years of it, based on the self-absorbed and faulty assumption that because we’re here, there must a reason why that’s the case. The idea that there’s no real predisposition towards modern humans evolving in North Africa, or that life could exist if there’s no abundant carbon-12 to help bind its molecules is just something they cannot accept because the notion that our universe created us by accident and we can be gone in the blink of a cosmic eye to be replaced by something unlike ourselves in every way, is just too scary for them. They simply don’t know how to deal with not feeling like they are somehow special or that nature isn’t really interested in whether they exist or not, just like it hadn’t for at least 13.8 billion years…

alien bacteria

One of the topics that’s been prominently featured on Weird Things has been panspermia, the hypothesis that life can originate somewhere in the galaxy and spread though asteroid or comet impacts, or even forward contamination by alien spacecraft. We know that amino acids can form all on their own when certain molecules are irradiated, that some creatures can easily survive a trip though space, and there’s evidence that molecules crucial for life here may have a strong link with primordial impacts. Now, true, the theory has been abused by those who either do not understand what it actually entails, or by those who just refuse to keep up with the science and spend most of their time accusing some secret anti-panspermia cabal trying to keep them down, but overall, it’s quite sound which is why it’s still being kept in mind by astrobiologists. Or so you would think unless you go by a Scientific American blog post which says the following…

In some ways the motivation for proposing this kind of cosmic panspermia is a little dated. It comes from a time when we felt that the origin of life of on Earth was such a mystery, and such an unlikely event, that it was convenient to outsource it. Although this didn’t actually solve the real question of life’s origins, it meant that a specific origin ‘event’ could be extremely rare among the 200 billion stars of the Milky Way yet life would still show up in other places.

These days I think our discoveries about the remarkable abundance and diversity of so-called pre-biotic chemistry […] in every nook and cranny of our solar system, and even in the proto-stellar nebula of other stars and the wilds of interstellar space – swings the pendulum back to Earth. Nature seems adept at making all the pieces for life, apparently raising the odds of local bio-genesis.

How are these two thoughts connected again? I’m not exactly sure how life being very adaptable would mean that it raises the odds of Earth being its origin because we’re talking about evolution rather than abiogenesis. Caleb Scharf, the scientist who wrote the post, seems to be making the same kind of mistake many creationists do when trying to ridicule evolutionary theory by asking how life would’ve come from non-life and nothing that evolution fails to answer this question. So it’s little wonder that whatever life gets here or starts here would fill every available nook, cranny, and environmental niche since natural selection would favor their reproduction. But whether the origin of these species is on Earth or in space is more or less a toss-up if we’re considering just how well they adapted to their current environments.

Yes, we could say that it’s more likely that life originated on Earth because space is vast and the odds of enough comets and asteroids hitting the planet at just the right conditions for life to take hold are astronomical, literally, so it makes sense to look for an explanation that makes life more likely to arise here. That explanation may not be right, but we don’t have a complete picture of how it came to be and so we’re still trying to find viable ideas that seem to fit the evidence we’ve observed so far. But an important part of the process is not to discard hypotheses without any evidence that they simply don’t fit with the observations, something that Scharf does with an odd certainty about the habitability of promising places in the solar system by hearty microorganisms that should dominate the universe based on the way natural selection works.

But the problem, and the potential paradox, is that if evolved galactic panspermia is real it’ll be capable of living just about everywhere. There should be [organisms] on the Moon, Mars, Europa, Ganymede, Titan, Enceladus, minor planets and cometary nuclei. Every icy nook and cranny in our solar system should be a veritable paradise for these ultra-tough life forms, honed by natural selection to make the most of [the] appalling conditions. So if galactic panspermia exists why haven’t we noticed it yet?

He then goes on to answer his own question by saying that we probably haven’t looked all that hard in all these places, don’t know for what we’re really looking, or possibly both, and ponders would it would mean if we kept searching and found nothing. You can tell that he’s really pushing for the Earth-centric explanation and again, as elaborated above, I can see why, but his primary reason for pushing it seems to be based on a very strange confusion between abiogenesis and natural selection with no facts to back it up. The argument seems to be: we know more extreme organisms on Earth, natural selection seems to be doing it’s job, we haven’t explored all of the promising candidates for life in our solar system in sufficient detail and we don’t really know what we’re trying to find and how we’ll know we found it, therefore, life arose on Earth. Doesn’t seem like a scientific train of thought to me, especially with all the evidence that there was at least an important role being played by organic matter or microorganisms from space…

Since yesterday I was on Skeptically Speaking, talking about the practical side of transhumanism with George Dvorsky (which was apparently such a fun show, we’re being invited back), I thought it would be fitting to take on a topic currently being covered on George’s blog and straight of Bill McKibben’s darkest fears; creating a custom baby through the latest and greatest technology that biologists and doctors can offer. Now, while you will probably never design your own custom child from the organs up and setting his ratios of IQ vs. social skills and athleticism vs. dedication to academic pursuits because this is simply not scientifically plausible to begin with, the decisions parents can already make today and would almost certainly continue making in the future could have a major impact on their children and their lives. And us our technology keeps advancing and we could make more and more of a drastic impact on a future child, the consequences will become more dire and the stakes will constantly rise, especially if the parents are behaving unreasonably, or even dangerously…

Of course just because you can do something doesn’t necessarily mean you should, and any ability to alter a developing embryo should be wielded wisely and with long term planning in mind. Humans are sill evolving, contrary to the popular pseudoscience we often hear, and when we decide to try and take evolution’s reins in an unpredictable world, we’re essentially betting that our choice for the future is the right one. And there’s a rather disturbing, but very real possibility of abuse in the future. Eugenicists didn’t just disappear after the end of the Nazis. They’re still out there, and their last major attempt to engineer “better humans” ended in 1999, an uncomfortably recent time period. What’s to say that more throwbacks to the 19th century pseudoscience that was cooked up by Francis Galton to justify racism and snobbism of the British upper class of the time, won’t decide to use the technology in question to try again? And in trying to somehow improve ourselves according to varying and often superficial standards could very well reduce our genetic diversity and make us vulnerable to new diseases, environmental changes, and even place us at a greater risk for extinction. We’re not in total control of the world around us and betting against the world is not something many would recommend.

Bioethicist Stephen Wilkinson, who wrote a book on the subject, thinks that these concerns are legitimate but not enough to necessarily forbid any particular method of customizing future children. He even goes to bat for a couple who decided they wanted their child to be born deaf because they have the same disability, doing everything possible to make it happen. And what he offers in their defense is a leap of mental gymnastics that is very difficult to follow and raises more question that Wilkinson seems willing to answer…

The strongest argument [McCullough and Duchesneau] would have to face would in all likelihood have to do with the welfare of the child created thereby: that deafness is welfare-reducing, and that it is wrong deliberately to created a child with lower welfare than it might otherwise have enjoyed. Yet, says Wilkinson, even this claim is weak. Partly this has to do with a skepticism about whether choosing for a disability is necessarily the same as choosing for a lower quality of life; partly it has to do with a claim that, even if disabled, people overwhelmingly have a life worth living… partly it is because the ‘Same Number Quality Claim’ does not reliably tell us that all examples of selecting for disability are wrong, and so, even at its strongest, will not tell us that this particular instance of choosing disability is de facto wrong.

So with the same logic we could say that if both parents are blind, they should be able to make a blind child at their pleasure and that we can’t possibly tell them otherwise since any life is better than no life at all. This not only has a strong tinge of anti-choice activists’ problematic arguments, but seems to reject the simple fact that if McCullough and Duchesneau deafened their child after he was born, they would’ve swiftly went to prison for child abuse. Quality of life claims do reliably tell us that we should choose to make sure people can enjoy life to the fullest and dictate that we should make whatever accommodations or inventions the disabled will need to do as many of the things the able-bodied do on a daily basis as possible. And when you go out of your way to make sure the future child will not even have a chance to grow up with the benefits the able-bodied take for granted because you want him or her to have the same disabilities as you, you’re being both selfish and cruel. It’s one thing to decide to give a child you know will have Down Syndrome a chance at life and prepare for this difficult task financially and mentally, but it’s completely another to seek those affected by this genetic disorder to ensure that the child will be born with the syndrome. The former is selflessness, the latter is cruelty.

Quite honestly, I’m surprised that an ethicist would actually defend a form of child abuse through technology a skilled doctor could use to fix potential health problems, arguing that we should allow people to do whatever they want to their progeny, and that quality of life is a vacuous notion, although it’s anything but that. If all life is so great, even a life of pain, misery, and frustration, there would be no concept of euthanasia, which allows an incredibly sick or debilitated person on the verge of death to pass on with dignity and end his suffering. I’m all for the transhumanists’ desire to improve the human condition through science and technology, and when we consider their platform, I seriously doubt that any transhumanist would actually support abusing technology to ensure that someone is born deaf, or blind, or mute, or with a certain ailment at the parents’ whim. Society will not allow parents to injure their children after they’re born. Why would it ever allow intentional embryonic abuse to satisfy selfish desires? And why would any ethicist argue against the qualify of life postulate?