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Genetic Creation - by Man and Nature
Genetic engineering is a technique whereby a new DNA molecule is constructed by inserting a gene into a cell from an alien source. This artificially created DNA is then introduced into a bacterial, fungal, plant or animal cell, in order that it can manufacture the desired proteins to create a modified type of organism.
Many new scientific discoveries result from analogy between technology and natural phenomena. Natural selection was believed to be analogous to artificial breeding. Now we can perceive analogy between artificial genetic and a similar process in the natural world.
One can only speculate as to where viruses come from. They only live and reproduce through living activity, and yet they seem to have always been around. They were probably responsible for the origin of Life, and for subsequent major steps in the development of the remarkable diversity of living creatures. It now seems that they may have always been arriving from outer space.
Completely novel bacteria would have been viable in the early history of this planet, when there were vast expanses of unexploited potential environment. After protists (single-celled creatures) had diversified and competed to fill every environmental niche, much less room would normally exist in the market for brash newcomers which had no time (measured in millions of years) to adapt to suitable niches. But there have been many occasions in planetary history when opportunities occurred through the diversity of living creatures was temporarily reduced by Mass Extinction.
|In nature, viruses, not men, act as the agents for genetic creation. In their independent state, they are no more than very complex chemical combinations consisting of either DNA or RNA in a protein coat, and can be stored indefinitely like any other non-living material. Viruses are everywhere, but the cells of nearly every living creature tend to have their own specific guest. [This relationship between specific viruses and specific living cells is a significant factor in the theory of genetic creation].|
|On entering its chosen cell, the virus discards its protein coat, replicates itself, and the genes encoded in its nucleic acid trick the host cell into producing new viral particles that are shed from the cell, which is normally destroyed in the process. The desperate fight of the body against these invaders accounts for most ancient common diseases, such as smallpox, polio and rabies, while recent ones like HIV appear to be due to new virus arrivals.|
|There is also a creative aspect. The introduction of viruses into a cell does not always result in destruction of the host cell, because the alien genes are absorbed into its nucleic acid, and by processes called lysogenic conversion, transduction and transformation a novel type of cell is created. Now, if every virus had its own specific host this phenomenon might be of limited interest, but some have very catholic tastes in choice of host, These can include plants fungi and animals, and, like human genetic engineers, can transport genetic material between genera, families, orders and even phyla. This does not mean that these novelties would, any more than extraordinary mutations, be viable under normal circumstances of intense competition by well-established species, but, as will shortly transpire, opportunities occur when mass extinctions leave many desirable niches vacant.|
More than thirty years ago, microwave spectroscopy identified a great variety of organic molecules in outer space Every chemical constituent of the genetic material and membranes of viruses has been found by analysis of meteorites, but, as these undergo temperatures in excess of 10,000 degrees Centigrade on entering the earth's atmosphere, complex molecules would disintegrate. Comets, however, are different, being dirty snowballs of ice, dust and chemicals. In 1996, the composition of the tail of the Hale-Bopp comet was investigated by instruments on the Hubble space telescope and the Explorer satellite. The results confirmed the presence of similar constituent materials, which, if they were viruses, could reach earth virtually intact. In the last few years, observations from NASA’s Polar spacecraft have confirmed that comet-like objects are arriving at the rate of one every three seconds, dumping tons of water into the atmosphere. In the distant past this rate was probably greater. While there is no obvious way of confirming that these imports might contain viral matter, future research and experiment will doubtless succeed in doing so.
Hubble Space telescope
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