Biogenesis
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Biogenesis is the process of lifeforms producing other lifeforms, e.g. a spider lays eggs, which form into spiders.
The term is also used for the assertion that life can only be passed on by living things, in contrast to abiogenesis, which holds that life can arise from non-life under suitable circumstances.
Until the 19th century, it was commonly believed that life frequently arose from non-life under certain circumstances, a process known as spontaneous generation. This belief was due to the common observation that maggots or mould appeared to arise spontaneously when organic matter was left exposed. It was later discovered that under all these circumstances commonly observed, life only arises from life.
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Law of biogenesis
- "La génération spontanée est une chimère" (Louis Pasteur)
Pasteur's (and others) empirical results were summarized in the phrase, Omne vivum ex vivo, Latin for "all life [is] from life.", also known as the "law of biogenesis".
No life has ever been observed to arise from dead matter.
Controversy
Critics of said law argue:
- that it is solely rooted in empiricism.
- that it poses an instance of the fallacy of accident.
- that "Abiogenesis is not possible because it has not been observed." is an argument from ignorance.
- and that the law is tantamount to the belief in a "life spirit", a non-measurable essence that is transferred from life to life in the process of biogenesis.
Proponents counter:
- that all natural laws are rooted in empiricism, and that explanations for natural phenomena not grounded in empiricism are necessarily tentative and/or philosophical;
- that it is not a fallacy of accident, because no exception to the generalization has ever been observed;
- that a natural law should be considered universal until an example to the contrary is found.
- that the law has no relation to any belief in the "life spirit" -- it is simply an empirical fact.
Human attempts to create life
A number of efforts have been made to bring life from non-life, but none has yet succeeded. J. B. Burke attempted to produce small living cells from inorganic matter by means of radium were unsuccessful; the radiobes produced were merely bursting gas bubbles of microscopic size. Pflüger produced cyanic acid, which he compared to half-living molecules, but it was merely a dead chemical compound. The Miller-Urey experiment produced some of the organic components of life, but failed to produce a living, reproducing organism.
In 2002, scientists (http://www.cbc.ca/stories/2002/07/12/polio020712) succeeded in constructing an artificial and "functioning" (able to infect and kill mice) Polio virus. Other viruses (http://www.cbc.ca/stories/2003/11/13/phage031113) have since been synthesized. These experiments do not qualify as examples of abiogenesis, though, since viruses, fail to meet the standard biological criteria for life many do not consider them to be lifeforms (although the same criteria also discount anyone who is impotent, for the same reasons).
Still, proponents of the idea of abiogenesis cite these results in support of their position, stating that both "non-living" viruses and "living" bacteria are solely "molecular machines" of different complexity. Many of them expect scientists to be able to synthesize the latter when the necessary technology has advanced to a sufficient level, thus proving the possibility of abiogenesis.
Law of Biogenesis and Creationism
Biogenesis is the basis of Creation biology, which holds that since life cannot arise spontaneously from non-life, life must, of necessity, have been created by a "supernatural" being, typically the Christian God.
Supporters of the theory of evolution argue that creationists misuse the law of biogenesis to support their arguments. For example:
- "The spontaneous generation that Pasteur and others disproved was the idea that life forms such as mice, maggots, and bacteria can appear fully formed. They disproved a form of creationism. There is no law of biogenesis saying that very primitive life cannot form from increasingly complex molecules." [1] (http://www.talkorigins.org/indexcc/CB/CB000.html)
They also say that creationists' use of the law as an argument against theories of common descent is an example of the fallacy of false dilemma, since it is imaginable that a creator god created the LUCA or one of its ancestors, from which point on evolution occurred in a guided or unguided fashion (see Evolutionary creationism). This belief is actually held by many Christians.
Creationists respond that abiogenesis is not a form of creationism, because it holds that life arises spontaneously, while creationism holds that life was deliberately created. Further, since the development of "primitive life" from "increasingly complex molecules" has never been observed and there remains no comprehensive scientific justification for believing it has ever occurred. Finally, they argue that once it has been conceded (as is conceded by theistic evolution) that the original cell was created by a divine being, there is no reason to believe he could not have created life in a variety of forms, although there is also no reason to believe he would bother. [2] (http://www.answersingenesis.org/docs2002/dw_origin.asp)
It should be noted anything divine cannot be "proven" since it cannot be tested nor queried. Whereas possible avenues of abiogenesis can be scientifically explained and tested, but its accuracy to our ancestry will ultimately remain conjecture unless the process is observed naturally occurring.