| | One of Sam's Points:
"If, for example, a significant amount of human brain tissue were to displace that of a dog, the hybrid will not be able to process the huge olfactory organs of a dog, and conversely, the cerebral capability to talk and process language would not be matched with the physical ability to enunciate. The hybrid would be a relative genius in one respect and a complete idiot in another."
This is a very complicated matter given the epistatic interactions of genes and the fact that most versions of a gene will either work suitably well or not at all. Epistatic regulation is the fact that one gene, often a "regulator" will interact with other genes to change the expression of one or more traits, which my be expressed normally or abnormally or not at all. Imagine that a person gets a particularly dark melanin gene from his mother, but gets a regulator gene from his father that turns all pigment genes off, or, more likely, turns off the gene that makes the precursor for melanin? Then, even though the child has a dark gene from his mother he may end up an albino, because his father's gene in effect "stepped in" and "shut the process down." Now such effects are extremely complex, so we find such phenomena as blue eyed dogs tending toward deafness, and so on, because genes long down the production line or genes that only interact indirectly cause effects that are not simple arithmetic summations.
Most animal genes when transplanted across species will either work out okay (but possibly with some efficiency loss) and thus allow the normal activity to proceed (although perhaps with the build up of physical flaws, toxins or such over time) or they will simply fail to work entirely, and if the gene is vital, the animal will die. The idea of women with viper fangs or dog men will not occur simply because we replace the bone or saliva gene of one animal for the other. The genes must work together as an integrated organism or probably not at all. Such manipulations to a phantasmagorical extent would seem quite a long long way off.
As for having mice with human brain genes, since the mice will not have human vocal or sense organs, which are the seat of language and thus conceptualization, the mice will probably function close to norm as mice, perhaps with slower brain maturation if regulator genes that are slower to act in humans are transplanted. The gene expression program is strongly feedback-governed and redundant, and many essential hormones and molecules can even be made by various different pathways, so even if a few genes are not working right, the organism is designed to overcome the failures. (Most people are said to carry at least 10 lethal genes, but having two copies of each, the good copy usually steps up to the plate, as in sickle cell carriers or as in dwarves who have one normal and one dwarf type growth regulator gene. Two copies of the dwarf gene are fatal.) The special purpose for scientists to make mice which seem just like regular mice but have human brain genes is that the human proteins that they do express can be tested using medicines designed to work on human tissue, not mouse tissue, so experiments can be done on mice rather than on human corpses and ill volunteers who provide less helpful subjects given their otherwise unhealthy state. This will help in say, Alzheiner's research, where we don't want to cut up live people or do potentially deadly tests on a medicine that will attack just one human protein.
Nonviable monsters will self-select out (i.e., die off) and workable chimeras will have to be workable organisms. If they are capable of voluntary reason, they would presumably have rights, but not the "right" to violate the laws of chemistry or biology. And the ability to sue without cause does not require alien DNA now, so what would change with Chimerae running around would seem to be more of a political question to ask now, rather than a biological question to ask for later.
Frankly, I'd be happy with an anti-aging suite of genes and less of the Irish tendency towards diabetes, and maybe the head of hair I had at 17. I have little interest, concern or fear about my future ability to procreate with cows.
Ted Keer (Edited by Ted Keer on 11/16, 2:00am)
(Edited by Ted Keer on 11/16, 10:51am)
(Edited by Ted Keer on 11/16, 10:15pm)
(Edited by Ted Keer on 11/16, 10:25pm)
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