Law of biogenesis

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Law of biogenesis

-->recapitulation theory

The theory formulated by E.H. Haeckel that individuals in their embryonic development pass through stages similar in general structural plan to the stages their species passed through in its evolution; more technically phrased, the theory that ontogeny is an abbreviated recapitulation of phylogeny. The theory has been discredited in the light of the modern science of genetics. even at the time, there was much reason to doubt its validity. Especially as Haeckel himself was ordered to appear before a university court in Jena were he was accused of faking the evidence for recapitulation. He finally admitted that his evidence had been 'doctored'.Synonym: biogenetic law, haeckels theory, embryonic recapitulation.

Law of biogenesis. The law which states that life arises from existing life. The ancient greeks believed that living things could originate from nonliving matter (abiogenesis) and that the goddess Gea could make life arise spontaneously from stones. aristotle disagreed, but still believed that creatures could arise from dissimilar organisms or from soil. variations of this concept of spontaneous generation still existed as late as the 17th century, but towards the end of the 17th century a series of observations, experiments, and arguments began that eventually discredited such ideas. This advance in scientific understanding was met with much opposition, with personal beliefs and individual predjudices often obscuring the facts.

Francesco Redi, an Italian physician, proved as early as 1668 that higher forms of life did not originate spontaneously, but proponents of abiogenesis claimed that this did not apply to microbes and continued to hold that these could arise spontaneously. attempts to disprove the spontaneous generation of life from non-life continued in the early 1800s with observations and experiments by Franz Schulze and Theodor Schwann.

In 1864, Louis Pasteur finally announced the results of his scientific experiments. In a series of neat experiments, pasteur demonstrated that life today did not arise in areas that had not been contaminated by existing life. Pasteur's empirical results were summarized in the phrase, Omne vivum ex ovo, latin for "all life [is] from eggs". Thus Dr. Louis Pasteur finally overcame the longstanding belief in spontaneous generation of life.

It is worth noting that Louis Pasteur's research dealt with what can be observed to happen in the present day and says nothing about what may have happened on earth in the past. Indeed, both advocates of evolution and advocates of creationism both endorse abiogenesis as the means by which life began on earth, the latter group simply claiming that god did it. Young Earth creationists even go so far as to claim that fully grown creatures were created in their present form some six to ten thousand years ago, an idea which would seem to be completely discredited by Pasteur's research.

See http://en.wikipedia.org/wiki/Biogenesis#Law_of_biogenesis for more information.