Physics of the Future: How Science Will Shape Human Destiny and Our Daily Lives by the Year 2100

genetically so the genome matched that of the Neanderthal. Each of these altered chunks of DNA would then be reassembled into the complete Neanderthal DNA. This cell would then be reprogrammed to revert to its embryonic state and then inserted into the womb of a female chimp.
    However, Klein of Stanford brought up some reasonable concerns when he asked, “ Are you going to put them in Harvard or in a zoo?”
    All this talk of resurrecting another long-extinct species like the Neanderthal “ will doubtless raise ethical worries,” cautions Dawkins. Will the Neanderthal have rights? What happens if he or she wants to mate? Who is responsible if he or she gets hurt or hurts someone else?
    So if the Neanderthal can be brought back to life, can scientists eventually create a zoo for long-extinct animals, like the mammoth?
    BRING BACK THE MAMMOTH?
    The idea is not as crazy as it sounds. Already, scientists have been able to sequence much of the genome of the extinct Siberian mammoth. Previously, only tiny fragments of DNA had been extracted from woolly mammoths that were frozen in Siberia tens of thousands of years ago. Webb Miller and Stephan C. Schuster of Pennsylvania State University did the impossible: they extracted 3 billion base pairs of DNA from the frozen carcasses of the mammoths. Previously, the record for sequencing the DNA of an extinct species was only 13 million base pairs, less than 1 percent of the animal’s genome. (This breakthrough was made possible by a new sequencing machine, called the high-throughput sequencing device, that allows one to scan thousands of genes at once, rather than individually.) Another trick was knowing where to look for ancient DNA. Miller and Schuster found that the hair follicle of the woolly mammoth, not the body itself, contained the best DNA.
    The idea of resurrecting an extinct animal may now be biologically possible. “ A year ago, I would have said this was science fiction,” Schuster said. But now, with so much of the mammoth genome sequenced, this is no longer out of the question. He even sketched how this might be done. He estimated that perhaps only 400,000 changes in the DNA of an Asian elephant could create an animal that had all the essential features of a woolly mammoth. It might be possible to genetically alter the elephant’s DNA to accommodate these changes, insert this into the nucleus of an elephant egg, and then implant the egg into a female elephant.
    Already, the team is looking to sequence the DNA from yet another extinct animal, the thylacine, an Australian marsupial, closely related to the Tasmanian devil, that became extinct in 1936. There is also some talk of sequencing the dodo bird. “Dead as a dodo” is a common expression, but it may become obsolete if scientists can extract usable DNA from the soft tissue and bones of carcasses of dodos that exist in Oxford and elsewhere.
    JURASSIC PARK?
    This naturally leads to the original question: Can we resurrect the dinosaurs? In a word, perhaps no. A Jurassic Park depends on being able to retrieve the intact DNA of a life-form that died out more than 65 million years ago, and this may be impossible. Although soft tissue has been found within the thigh bones of dinosaur fossils, so far no DNA has been extracted in this way, only proteins. Although these proteins have chemically proven the close relationship between the
Tyrannosaurus rex
and the frog and chicken, this is a far cry from being able to reclaim the genome of a dinosaur.
    Dawkins holds out the possibility, however, of being able to genetically compare the genome of various bird species with reptiles and then mathematically reconstruct the DNA sequence of a “generalized dinosaur.” He notes that it is possible to induce chicken beaks to grow tooth buds (and induce snakes to grow legs). Hence, ancient characteristics, which have long vanished into the sands of time, might be lingering within genomes.
    This is because biologists now realize that genes can be turned on and hence can also be turned off. This means that the genes for ancient characteristics may still exist but simply be dormant. By turning on these long-dormant genes, it might be possible to bring back these ancient traits.
    For example, in the ancient past, chicken feet once had webbing. The gene for webbing did not disappear but was simply turned off. By turning this gene back on, one can in principle create chicken with webbed feet. Similarly, humans once were covered