A little less than a week ago, a team of Russian scientists announced a startling find in the frozen wastes of Siberia: the complete carcass of a woolly mammoth, a relic from the most recent ice age over 10,000 years old. Although mammoths have been unearthed from the permafrost before, they are rarely recovered in such pristine condition, and never have they been found with liquid blood. Of course, there are only two words that come to mind when the blood of extinct species is mentioned: “Jurassic Park.” The central conceit of Michael Crichton’s novel is that dinosaur DNA from blood trapped in amber-preserved mosquitoes is used to resurrect the Mesozoic beasts, with dire consequences.
While it’s unlikely that a herd of woolly mammoths will go rampaging through an ice age theme park anytime soon, it is becoming increasingly feasible that the genetic resources necessary to clone a mammoth will be developed. Blood itself is actually a rather poor medium from which to extract ancient DNA: red blood cells, or erythrocytes, do not contain any genetic information, and white blood cells, or leukocytes, are fairly fragile. In the words of Stephen Schuster, the biologist behind the sequencing of the mammoth genome, the genetic material in the mammoth blood is probably “as shattered as if you took a mirror and threw it on the floor.” Research is already in progress to clone a mammoth from bone marrow cells, which are more resilient and have better-preserved DNA.
Considerable amounts of effort are being invested in this project, but why (or is it even) a worthwhile investment? The “wow” factor of bringing back an extinct species is certainly a large part of the rationale. The sense of reaching back into the past, of letting people see something that hasn’t been seen for millenia, excites the imagination and draws attention to science in general. Conservation biology has a similar concept in the “flagship species,” a charismatic large animal that serves as a focus for the ecological concerns of the general public. The plight of the manatee, for example, draws in attention and funding for the preservation of the Florida Everglades. Bringing back a mammoth would encourage a new generation of young scientists to explore the fields of molecular biology and paleontology. This kind of project may also put a more favorable public light on genetic technology, which has recently received a lot of negative attention due to the fight over GMO labeling and a recent Supreme Court case involving the agribusiness giant Monsanto.
Some scientists, like Jose Folch, see a bioethical imperative for work on de-extinction. Folch, whose team successfully cloned the extinct Pyrenean ibex (albeit one with a lifespan of seven minutes), believes that his work may serve as a basis “for future cloning-based conservation.” There is a sort of inherent justice in the thought that species wiped out by direct human impacts, like the passenger pigeon and the Steller’s sea cow, might one day be restored by direct human effort. However, there are many steps remaining between cloning an individual and reestablishing a population of an extinct species. Clones are genetically identical, and therefore rather vulnerable to disease or ecological stresses. Evolution and migration have shaped ecosystems in the absence of extinct species, even over the short timespans some have been extinct, and it is likely that not all species would fit comfortably back into their niches. A less obvious danger is the thought that with this sort of technology, the importance of traditional conservation is somehow reduced. Why bother with protecting existing species if we can call them back at will? Yet as scientists have continually learned, all species are connected; the loss of one obvious organism could have unforeseen effects on countless others, and it’s best to conserve as many as possible while we try to understand the web of life.