I refer here to ideas about cloning extinct animal species from DNA rescued from preserved bone or tissues. Some recent species, like Dodos, might be directly clonable in some way, and in some senses could have some value--assuming that making one or a few of them is good for someone--themselves, that is, not just zoo-goers.
However, how do you do this? The best idea would be to take an entire cell, re-set its DNA/RNA status to that of a fertilized egg, and let 'er rip. But how? Unless you can make that cell develop all by itself in a Petri dish, the answer isn't obvious. The usual idea, at least for mammals, is to find a surrogate mother.
Generally the approach has been, for mammals at least, to extract a complete nuclear genome from a fossil specimen, take a surrogate mother's egg cell (from its ovary), remove its nuclear DNA, replace it with the fossil's DNA, and inject it into a hormonally prepared mother for gestation. This is basically the 'Dolly' approach and to my (clearly incomplete) knowledge it is still the basic idea. But there are problems with this, if you really want to revive a species as opposed just to getting a farm-worthy sheep or the like.
One problem is that you need the host-species' egg, and that means its mitochondrial DNA (mtDNA, which is not in the nucleus) and the RNA and other contents of the host egg cell. Even if you can use an entire intact nuclear genome, the resulting new individual is necessarily a hybrid between its mother and the other exogenous DNA. For agriculture, there are some well-known problems such as the fact that the host's cell will reflect some aspects of the host, like mutations in mtDNA or the RNA from its nucleus, and so on. The new individual is in some senses already a bit old, for example.
These problems can probably be dealt with, or perhaps have already been. But with extinct species there are other problems. Among them is that the DNA is usually not entirely intact in any cell. From fossils or extinct species, it may be degraded into very small fragments. By sequencing currently living relative species, we can identify roughly what part of the genome those fragments come from, and if we have several samples we could perhaps find in some sample each necessary fragments. That's still not the same as having intact chromosomes, and almost certainly some large subset will be missing. Then, however, you have to find the surrogate mother, and if the species is extinct you have to use a current, similar species to do this.
Mammoths and Neanderthals . . . .
Let's for the moment ignore the fact that the cloned individual in these cases really won't be a cloned individual of its original species, but some kind of hybrid or chimera. Suppose the attempt were made. What then?
Two of the favorite species that the raw, I'd say cruel Frankenstein egotism and its simplistic portrayal of the idea to the public, are Neanderthals and mammoths. Maybe the suggestions have only been publicity stunts, given the real issues in the world that serious geneticists could address, but they seem to have been offered seriously, and they show to me how science needs to be kept under control.
Neanderthals and mammoths are social beings. Real ones were gestated in mothers of their own kind, eating their natural diet, in their natural social (and hence hormonal, physiological) circumstances, and born to families and nurturing, educating, protecting, natural social groups. Once born, they were incorporated into the group in a way that they presumably evolved to be.
How should a cloned Neanderthal be treated? It would be basically human: recall that we all carry some Neanderthal inheritance through extensive inter-mating way back then. Would it have civil rights, such as to education, a home, voting? Could one experiment on it, to test aspects of its physiology? Could it be put on display in a zoo or some university museum?
What about mere mammoths? One leading Mary Shelly imitator has suggested that cloned mammoths could be plunked back into 'natural' conditions in the Arctic, where there aren't (currently) too many humans around to destroy their environment--assuming, in a fantasy way, that commercial tour groups would not be immediately organized, to go gawk at them (including by 'scientists' who want then to publish papers in Nature on their behavior), and that they wouldn't be kept in zoos or labs in our august universities. Such innocent-sounding ideas as cloning these extinct beings are far more egotism and ignorance--or willful avoidance of realities--than any sort of sound proposal.
Like humans, mammoths are social beings. The Arctic today would not be a hospitable or normal place for a mammoth. A surrogate elephant mother would not gestate a normal mammoth, in ways large or small that we can't really anticipate or even know. It would be plunked down by itself or in a pack of clones that didn't have normal social life to be raised in. Even if it had a mother who loved it rather than rejecting it as a freak, it would not be a mammoth mother, nor would its life replicate the mammoth's natural existence as a herd species. It is cruelty to suggest otherwise.
In memoriam, or a lesson never learned?
Let's not forget one Ota Benga, an African man, obtained from a slave trader, and exhibited at the St Louis World Fair in 1904 and then put on display--is there a better way to state this?--in the Bronx zoo!
|From Benga Wikipedia page|
|Baartman, from her Wikipedia page|
Nor let us forget poor Saartjie Baartman, a southern African native, put on display, naked, around Europe to exhibit her exaggerated private parts, in early 19th century Europe Traveling freak shows, might one say?
It is to be noted that the people involved were leaders of their time, and people responsible for such dehumanizing practices have included prominent scientists at major universities. Anthropologist Franz Boas requested that explorer Robert Peary bring an Inuk back from the Arctic, to be studied by scientists at Columbia.
Minik Wallace (also called Minik or Mene ) (ca. 1890 – October 29, 1918) was an Inuk brought as a child in 1897 from Greenland to New York with his father and others by the explorer Robert Peary. The six Inuit were studied by staff of the American Museum of Natural History, which had custody. The adults and one child died soon of tuberculosis (TB), and one young man was returned to Greenland. After deceiving Minik by a staged burial, the museum put the skeleton of his father on exhibit. Adopted by the museum's building superintendent, William Wallace, Minik did not return to Greenland until after 1910. A few years later, he came back to the United States, where he lived and worked until dying of influenza in the 1918 pandemic. (Wikipedia)
. . . . . and nobody to defend them
In our age of science, the idea of cloning extinct species seems exciting and appealing on the surface, a kindly sort of rescue--until you think about it carefully. As you can tell, I feel quite strongly about this. It's playing games with other sentient organisms' lives for no seriously justifiable purpose. If it's hard enough to justify or excuse what we allow to be done with mice and other species for research purposes (and I include myself among the accused), this is beyond beyond.
To me, personally, these juicy cloning suggestions reflect the cold, selfish, arrogance of science, and scientists in leading universities. The poor target species have nobody to defend them, and that is why these proposals, irresponsibly presented in the media, can get off the ground. One sees little censure of these ghoulish proposals, whose presumptive nature is essentially a continuation of the eugenics movement.
The video industry is as close as we need to get to these notions. Let us not forget our history.