Now that scientists have cloned animals, does that mean that we are ready or able to clone humans?
No. In human reproduction, it is tough to extrapolate from animal models, even primates.
If you look at the history of assisted reproductive technologies, scientists have found that techniques that didn't work in primates and mice were successful in humansthere are strange differences between the way that humans and animals produce eggs and sperm and the way fertilization happens.
The question is whether we will be able to improve cloning in animals so that it is highly efficient and safe so that we could then use it in humans with confidence.
But I'm not sure it will ever be ethical to prove that it is safe because that would involve human beings in those experimentsand is that ethical?
Will ethics questions stop the human-cloning experiments?
I think that people are just going to do itthrough conduct that is unacceptable within the current scientific or ethical norms.
Accumulation of information and perfection of method will be done along the fringes. The consequences of tinkering are devastating. The consequences of something not working correctly in cloning, or any kind of embryo manipulation, are huge.
What are the benefits of cloning humans?
The case of [human] cloning is really quite distinct because there is no clear weighing of risks and benefits. The risks to the cloned individual are enormous. The benefits to the cloned individual are not really part of the equation. The benefits are to the people who want to have a clone.
What risks do clones face?
In many species, cloned animals suffer from over-growth syndromethey grow larger than is typical of the species at birth. That presents risks and problems for the mother.
Many have organ deformities and genetic abnormalitieserrors in whether genes are turned on or offthat we don't really understand. Many of these pregnancies spontaneously abort.
Dolly also developed premature arthritis, and who knows what other health consequences she will face?
What are the potential uses of human cloning?
Cloning is not the be-all and end-all step in human reproduction. If the technology is ever proven safea big "if"it might be an option to treat infertility, though there is a vast array of other options for couples who wish to have a child, or for lesbian or gay couples who can't have children of their own.
There is a disturbing perception that you could use cloning to replace a lost son or daughter. We are much too complicated to replicate what was loved and lost.
A genetically identical individual is not going to be an identical individualto say we could clone an individual and get a copy is a mistaken perception of the roles genes play and the unique nature of human beings.
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