How important is this? Let us think it over. An "organic" molecule is a molecule that contains carbon-hydrogen bonds. All earthly life depends on carbon-hydrogen bonds. The reverse is not true. Not all organic compounds are parts of organisms. Still, think of this in Bayesian probability terms. Suppose you had yesterday some reasonable guestimate as to how likely it is that the planet Mars does or has ever harbored recognizable life. Today you learn a new fact. You learn for the first time that Mars has organic molecules. It is pretty clear that your guesstimate of that probability will have to increase from its prior. NASA's Curiosity rover has discovered organic molecules such as ammonia on Mars | Daily Mail Online
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Yes, I know 'Nobel season' is over, the articles (and blog posts, including a couple here) that it regularly generates have been written and for the most part forgotten, though they might be taken out of drawers again next October when related cogitations come into play. But I want to revisit the institution of the Nobel Prize for a second, in the process harkening back to 1977. The Nobel Prize in Chemistry that year went to Ilya Prigogine "for his contributions to non-equilibrium thernodynamics, particularly the theory of dissipative structures." The fascinating thing is, not only that Prigogine's contribution was fallacious, but that it was known to be such (by researchers on the cutting edge of chemistry, if not to the members of the Nobel committee) before the prize was awarded. What is non-equilibrium thermodynamics? Well, let's take that mouthful apart. Thermodynamics is the study of heat and its relationship to matter. In chemistry (as distinct...
There is a phenomenon much discussed among biologists called "genetic load." It refers to the reduction in the mean fitness of a population caused by some genetic process. Perhaps most important is mutation genetic load Most mutations are deleterious, even if only slightly, and over geological time the effect on a gene line of the build-up of a lot of these mutations along the strands of DNA becomes serious. You might consider genetic load the biological equivalent of entropy. A population can only tolerate a certain load before going extinct, though it is difficult to quantify load and that maximum acceptable level. On a prior principles, there ought to be a highest sustainable level of mutation load. Some creationists (intelligent-design theorists, if you prefer) contend that the deleterious nature of most mutations, and thus this "load," is fatal to this damned Darwinian nonsense. They see "Darwinism" as the position that life has been gradual...
I've discovered a fascinating blog, SANDWALK , by Laurence A. Moran, a Toronto based biochemist. One of the matters under discussion there by Moran is the prevalence of "junk DNA," that is, the idea that only about 10% of a cell's DNA has a function expressed in the development of the rest of the cell. The other 90% is, so to speak, the junk. There are scientists who dispute the notion that it is all that junkie, but they are rare, and Moran emphasizes how mainstream/consensus it is that most of our DNA is superfluous. I find the whole idea odd in that it is so parallel to a common misconception about the human brain People (always who don't know neurology) have been saying do decades that we only use 10% of the brain. The implication usually is "like wow, man, if we could only use it all we'd be, like, really something." The idea has been debunked repeatedly by people who do know neurology, but it persists. Anyway Moran tells us that as ...
Watson seems to be a good sidekick sort of name. It reminds some of us of the Dr. Watson who shared a flat with Sherlock Holmes and wrote up his adventures for the world. Also, those two syllables may call the mind Thomas Watson, the fellow who worked with Alexander Graham Bell, and was on the receiving end of the first message ever transmitted by telephone. "Mr Watson, come here, I want to see you," is how I think it went. Anyway, one famous Watson who was a member of a duo and who was most definitely not a sidekick was James Watson, the biochemist who in association with Francis Crick, developed the double helix model of DNA. Watson's famous 1968 memoir of that achievement, THE DOUBLE HELIX, begins with the statement, "I have never seen Francis Crick in a modest mood." A fair reading of the book generally indicates that Watson hadn't known many modest moods himself, either. In the above photo, Crick is standing, pointing out features of the model...
I remember the following answer to that question from something that Isaac Asimov once wrote, and that I read in my teens. This is from memory: Life is a localized resistance to entropy, employing enzymes as a critical weapon in this resistance. There are at least four distinct elements to that definition. 1) Entropy is the general tendency of things to run down. Every energy exchange is a loser, with some of the energy turned to a useless form in the process of the exchange, so any closed system tends to run down. 2) Living things are a localized resistance. At certain times and places, things become more orderly (which is possible without violating physical law because they are open systems, not closed). 3) Life isn't the ONLY sort of localized anti-entropy. Volcanic activity is another example. It creates a mountain where there may previously have been a flat plain, a transition that represents a gain in potential energy. So to define life properly ...
The September issue of HARPER's included a review by David Quammen of three recent books on the subject of the Neanderthals. What caught my attention, and made me want to commonplace a bit of this, was Quammen's digression onto the two different sorts of biology in general. There are biologists who look at their field as a batter of applied chemistry -- molecules interacting and compounding. There are also biologists who look at life on the level of the organism, or on the still broader level of the whole populations or ecosystems. Reductionists versus holists, if you will, although those words are judgment freighted. Quammen speaks of organismic versus molecular biology. Here's a passage, without further comment. You may have missed this argument, unless you work in the field or are somehow involved with the allocation of university budgets and buildings. It has been quiet and internecine but bitter, and traceable back to the late 1950s and early 60s, when Edward O...