Monday, May 15, 2006

Follow the nitrogen to extraterrestrial life

Follow the nitrogen to extraterrestrial life: [Graphic: "Nitrogen Cycle," United States Environmental Protection Agency]
The narrow search for water may miss important clues, say USC geobiologists, EurekAlert!, 4-May-2006, Carl Marziali, University of Southern California [Also at & ScienceDaily] The great search for extraterrestrial life has focused on water at the expense of a crucial element, say geobiologists at the University of Southern California. Writing in the Perspectives section of the May 5 issue of Science, four USC researchers propose searching for organic nitrogen as a direct indicator of the presence of life. Nitrogen is essential to the chemistry of living organisms. Even if NASA were to find water on Mars, its presence only would indicate the possibility of life, said Kenneth Nealson, Wrigley Professor of earth sciences in the USC College of Letters, Arts and Sciences. "It's hard to imagine life without water, but it's easy to imagine water without life," Nealson said. [This is a very good point. Presumably NASA is fixated on water because it knows that water is likely to be found on planets and moons and then when it is found it can talk up the possibility of life?]

The discovery of nitrogen on the Red Planet would be a different story. "If you found nitrogen in abundance on Mars, you would get extremely excited because it shouldn't be there," Nealson said. The reason has to do with the difference between nitrogen and carbon, the other indispensable organic element. Unlike carbon, nitrogen is not a major component of rocks and minerals. This means that any substantial organic nitrogen deposits found in the soil of Mars, or of another planet, likely would have resulted from biological activity. [Agreed. This is so elementary (harking back to my geology and ecology units) that it is hard to believe no one at NASA had thought of it. But then, as astrophysicist, turned science writer John Gribbin observed, James Lovelock of later Gaia fame (or should that be infame?), showed in 1965 (i.e. 41 years ago), when he was working for NASA, that it could be deduced from Earth by a spectroscope that, based on the lack of oxygen in its atmosphere, there was no existing life on Mars, but presumably NASA did not want to know:

"Lovelock tells how the realization came to him as a flash of insight in 1965, when he was working for NASA, designing instruments that would eventually be used by the Viking Mars probes to sniff the Martian air and look for traces of life products. He saw that there was no need to go to all the trouble and expense of sending a probe to Mars to make these subtle tests, because astronomers already knew that the atmosphere of Mars is inert and must therefore, he reasoned, signify a dead planet ... The fact that the Earth has an atmosphere rich in oxygen, full of chemical potential energy and highly reactive, is a sign that something out of the ordinary, in chemical terms, is happening on our planet. If the atmosphere of Mars resembles exhaust gases from an internal combustion engine, the atmosphere of the Earth resembles (in fact, in large measure it is) the mixture of gases that goes into such an engine. But this is only possible because plants can steal energy from the Sun. ... So a visitor from another star, entering our Solar System, could use a simple spectroscope to investigate the atmospheres of the planets, and conclude that while Venus and Mars, which both have carbon dioxide atmospheres, do not have life, Earth, with its oxygen-rich atmosphere, must have life. In the mid-1960s, Lovelock's view met with a cool response. If it had been taken seriously, it would have pulled the rug from under the whole Viking project. After all, the main purpose of the project was to look for life on Mars, and Lovelock confidently asserted that there was no life on Mars. ... In 1977 the Viking landers confirmed that Mars was indeed as lifeless as Lovelock had predicted more than ten years previously." (Gribbin, J., "In The Beginning: The Birth of the Living Universe," [1993], Penguin, London, 1994, reprint, pp.118, 120-121)

Again presumably the last thing NASA wants is a simple test(s) to show there is no (and never has been any) life on Mars!]

Dimming the hopes of life-on-Mars believers is the makeup of the planet's atmosphere. The abundant nitrogen in Earth's atmosphere is constantly replenished through biological activity. Without the ongoing contribution of living systems, the atmosphere slowly would lose its nitrogen. The extremely low nitrogen content in the Martian atmosphere suggests that biological nitrogen production is close to zero. However, the authors write, it is possible that life existed on Mars at some hypothetical time when nitrogen filled the atmosphere. Co-author Douglas Capone, Wrigley Professor of environmental biology in USC College, said NASA should establish a nitrogen detection program alongside its water-seeking effort. He noted that next-generation spacecraft will have advanced sampling capabilities. "What we're suggesting here is basically drilling down into geological strata, which they're going to be doing for water anyway," Capone said. "The real smoking gun would be organic nitrogen." Said Nealson: "If your goal is to search for life, it would be wise to include nitrogen." ... [But if your goal is more Mars missions (the "search for life" being a pretext to extract money out of Congress), then it would be "wise to" not "include nitrogen"!]

PS: The following unrelated long `tagline' quote is part of anthropologist the late Loren Eiseley's meticulously detailed case see this quote for an overview) that Darwin plagiarised (i.e. used without acknowledgment and indeed covered up) the ideas of a contemporary Edward Blyth. I will include this in my `Evolution Quotes Book' under a section on Darwin's dishonesty.

Stephen E. Jones, BSc (Biol).
`Evolution Quotes Book'

"In Blyth's paper of 1835 occurs a statement concerning Ancon sheep. A little later in the same paragraph occurs a list of odd mutations, including `donkey-footed swine, tailless cats, back-feathered, five-toed, and rumpless fowls, together with many sorts of dogs....' This odd little concentration of mutative types is duplicated in almost the same order in Darwin's essay of 1844. Like Blyth, Darwin is discussing `sports' or hereditary monsters. Like him, Darwin mentions Ancon sheep, rumpless fowls, and tailless cats. It is true that the solid ungular swine and five-toed fowls have disappeared; but they occur in later pages of Darwin's essay. They have merely been dispersed. In the matter of claws, two pages farther on we encounter the phrase, `breeds, characterized by an extra limb or claw as in certain fowls and dogs.' In the Origin this curious sequence has vanished, though the Ancon sheep is still mentioned. Blyth, in his discussion of food and its effects on animals, comments that `herbivorous quadrupeds which browse the scanty vegetation on mountains are invariably much smaller than their brethren which crop the luxuriant produce of the plains....' Darwin in turn holds that `external conditions will doubtless influence and modify the results of the most careful selection; it has been found impossible to prevent certain breeds of cattle from degenerating on mountain pastures....' Blyth, in his discussion of hybridity, recognized dominance (i.e., prepotency) and the possibility of the re-emergence of suppressed characteristics in the third generation. In the essay of 1844 Darwin once again expresses similar views. The use and disuse concept is brought into play by Blyth in his discussion of domestic forms where `an animal...supplied regularly with ...abundance of foods without the trouble and exertion of having to seek for it...becomes, in consequence, bulky and lazy ... while the muscles of ... locomotion ... become rigid and comparatively powerless, or are not developed to their full size .' Darwin in his second essay devotes a section to this subject and comes once more to similar conclusions, which are re-expressed in the Origin. Blyth devotes considerable attention to protective coloration and the utilitarian advantages gained by such devices in the struggle for existence. In the course of this discussion Blyth, in his paper of 1835, quoted from Mudie's Feathered Tribes of the British Islands the metaphor `grouse are brown heather.' In the Origin Darwin utilizes the same device, picturing `the red grouse the color of heather.' Further on in the same section, and this time in his own words, Blyth speaks of the ptarmigan as `snow in winter.' In the same section in Darwin `the alpine ptarmigan [is] white in winter.' The discussion of protective coloration is more extended in Blyth, but his and Darwin's views of it are the same. Blyth has a vivid description of the relation of the falcon to its prey. He dwells at length upon the bird's great powers of sight. In the corresponding Darwinian passage hawks are mentioned as `guided by eyesight to their prey .' Like Blyth, Darwin then dwells upon the pruning effect exercised by these carnivorous birds in keeping the cryptic coloration of small mammals and ground-dwelling birds, such as grouse, uniform and constant through natural selection. The variant animal is unable to conceal itself successfully and is thus more subject to destruction. Although Darwin's treatment of the idea is not as lengthy as Blyth's, the descriptive material cited above is powerfully suggestive of a direct connection, particularly when it is taken in conjunction with the other evidence I have been at some pains to assemble [`such as Blyth's reference to the variation manifested in the beaks of finchlike birds']. Turning to Blyth's paper of 1837, it will be recalled that in discussing his localizing principle he touched upon the homing instinct in animals. During the course of his discussion Blyth asserted this capacity was `not wholly absent from the human constitution.' He referred to the Australian aborigines and other savages as being subject to this `intuitive impulse.' Although Darwin almost totally avoided reference to man in the Origin it is of interest to note that the homing instinct in man receives attention in both of the trial essays. It is mentioned briefly in the first essay and twice in the second. Here the Australian savage reappears. The instinctive shamming of death is also mentioned by Blyth as characteristic of certain animals. Once more Darwin treats of it briefly but critically in the essay of 1842 and again in the lengthier essay of 1844. When Blyth's papers are subjected to extended and minute analysis there is no doubt that a few additional items pointing toward a connection between the two men might be established. Even making some allowance for accidental use of the same sources, the effect is cumulative and, in the present writer's view, unexplainable by chance. Furthermore, there is ample evidence that Blyth's restrictions on divarication beyond the species level troubled Darwin and that he was forced to spend considerable time and ingenuity in finding his way around this barrier. After an investigation of this effort, it will be possible to see more clearly than heretofore why Darwin approached the subject of variation in wild nature with such timidity." (Eiseley, L.C., "Charles Darwin, Edward Blyth, and the Theory of Natural Selection," in "Darwin and the Mysterious Mr. X," E.P. Dutton: New York NY, 1979, pp.60-62, 241n. References omitted)


Anonymous said...

"Dear Webmaster,
I was reading and I noticed the link to wasn't working but I have found it at if you want to update it for your readers.
Kind regards
Nizam Uddin"

Stephen E. Jones said...


>I noticed the link to wasn't working

Thanks. I have updated the Nitrogen Cycle graphic with one from Wikipedia: The Nitrogen Cycle but for some reason Blogger won't or can't update the page.

I will keep trying but if there is a permanent problem in updating a 6year old post, then it will have to stay as is.

Stephen E. Jones