Re: [isml] Re: Differences between clones baffles science
- Hilary A. Thomas <standingrock@...> wrote on Saturday, January 01,
2000 3:25, > >From: "Dan S" <ds2000@...>
> >>From The Ottawa Citizen Online,
> >If such cloning worked exactly they should, theoretically, have been
> >copies of each other. In reality, a host of other factors have conspiredto
> >make them into unique individuals. Mr. Campbell is unable to say exactlyamong
> >the animals differ: research into the causes has not been done. High
> >the possibilities is the fact that the four-cell nuclei from which theyThis is not as much as a "Duh!" as you think. It is was currently believed
> >created were placed into egg cells taken from different female sheep.
> Duh! I don't think you have to look further...
that DNA defines an animal's appearance and much of its personality. These
clones had identical DNA and different egg cells. The egg cells were
thought to be empty containers to hold the DNA. Now that the animals look
and act different, it appears that DNA is not the end-all blueprint that we
thought it was. Apparently, much of the animals definition comes from
This throws much of our assumptions about genetics out the window. It means
that characteristics of children come from the parents via other mechanisms
in addition to DNA. It means that a complete mapping of human DNA genome
still won't give us complete control over a child's characteristics.
Scanning fetal DNA won't be able to detect all birth defects, or even all
birth defects inherited from the parents.
This is a major problem for genetics and biology. We have to develop an
extension to genetics that track trait inheritance outside of DNA. This
also is a problem for cloning replacement organs. What if we get an exact
DNA match, and the organs are still rejected by the body as being alien? We
thought we were very close to understanding most of genetics, with the
mapping of the human genome. It now appears that there are more inheritance
pathways to map, and we don't even know where they are or how they work.
Harvey Newstrom <http://harveynewstrom.com>
Certified Consultant, Legal Hacker, Engineer, Research Scientist, Author.
- Hmm... Insterestings. =)
On the subject of other inheritance paths the first that comes to mind is that
of mitochondreal DNA which comes with the egg and may not be completely
compatable with a completely foreign neucleus.
If we are just looking at percentage error factors then we can look at
everything from slight variations in the chemestry of the womb. Another is "Toss
of the dice" kind errors and other such things that aren't generally important
to non-cloned orgainisms where things can be good enough and exactness isn't put
under the microscope.
Other factors could be introduced by the cloning technique, that is when the egg
is assembled naturally it has a relatively orgainized anatomy in that teh
Rhybosomes are just to the left of the nucleus and the orgainelles are
orgainized such that the cytoplasm tends to flow in relatively regular patterns.
It is possible that the dissruption of this system, though recoverable in many
cases, can still have an effect on the later stages of embryology measured in
asymetries in later cell devisions.
Drugs are good.
They automatically screen the deltas and gammas from the alphas and betas.