Archive for June, 2013
I was watching yet another presentation about the possibility of reviving extinct life forms (http://www.ted.com/talks/hendrik_poinar_bring_back_the_woolly_mammoth.html). Now that we appear to have the technology, at least in theory, to extract DNA from long dead animals and place it in currently extant species there seem to be more and more articles about how terrific it would be to bring them back from oblivion. This particular talk concerned reviving the woolly mammoth but I have seen similar ones suggesting restoring the thylacine, or Tasmanian tiger, to life.
Technology has been astonishingly uninspiring when it comes to saving the world’s current long list of endangered species. While there have been a few cases of successful artificial insemination or an embryo from an endangered species being reared to term by a surrogate (http://www.scientificamerican.com/article.cfm?id=cloning-endangered-animals), the majority of effective conservation programs have relied on natural breeding to create enough animals to sustain a population, along with addressing the causes why the species became endangered in the first place. There are too many unknowns when it comes to artificially breeding wild animals: how best to harvest the eggs and collect sperm, how to freeze gametes and embryos, synchronising reproductive cycles, carrying a foreign species to term, providing appropriate milk, etc, etc. All these difficulties, and more, apply to the resurrection of extinct species.
If we are able to successfully impregnate a surrogate that takes the pregnancy to term, then what? We have a single individual being reared by an individual of a different species. If this works what do we then do with our mammoth or thylacine? Apparently appropriate mammoth habitat exists in Siberia. But what would our solitary mammoth do in such a place? We would need to produce at least 50 mammoths (probably more like 500: http://www.eoearth.org/article/Minimum_viable_population_size?topic=58074), to create a self-sustaining population. Given the paucity of genetic material available to play with, these mammoths would be virtual clones with very little genetic diversity. All conservation programs seek to maximise genetic diversity to avoid the problems that now occur in inbred populations e.g. Tasmanian devils and their contagious cancer.
What would be the point of bringing back one species? The mammoth will be no more than a curio, devoid of any real value, unless you bring back its entire ecosystem. This ecosystem would need to include not just all the extinct animals but also all the plants it shared its former existence with.
There is more logic in restoring the thylacine as it only became extinct in the 1930s, not 4000 years ago, but even there the Tasmanian ecosystem has changed in the past 70 years. Would it not make more sense to invest all that time, money and expertise into preventing other species from heading down the same extinction path, instead of wasting it on frivolous projects whose only purpose seems to be to let scientists marvel at their own cleverness?
Dr. F. Bunny
If I was hungry and my family was hungry and a tasty looking antelope skipped past it would be hard to resist the temptation to stuff it into the pot for dinner just because my government or a foreign NGO told me not to. Family comes first after all and, while I appreciate the need to conserve biodiversity and protect endangered species, I also appreciate the need to put a bit of protein on the table.
In many ways I don’t have a problem with this subsistence approach to bush meat harvesting. People need to eat and why shouldn’t they avail themselves of their country’s natural resources? It becomes a problem when the meat is taken, not for local subsistence, but for a wealthy foreigner who wants to eat it because it’s a bit different and a status symbol he can show off to his friends.
The global bush meat trade is now estimated to be at least $1 billion annually (http://www2.macleans.ca/2013/04/15/gorillas-in-our-midst/). As much as 25 million kilograms of meat is smuggled into the US each year, 30% of it primate, while 11,000 tons find their way into the UK (http://www.independent.co.uk/life-style/health-and-families/health-news/african-monkey-meat-that-could-be-behind-the-next-hiv-7786152.html). That’s a lot of illegal, probably endangered, meat. The irony is that because bush meat has now become a luxury food item that fetches high prices internationally (hundreds of pounds per kilogram of gorilla and chimpanzee meat in the UK, apparently) the very people who used to hunt it for subsistence can no longer afford it.
Primate meat in particular also carries with it a significant disease risk. Simian Immunodeficiency Virus (SIV) is closely related to HIV and one theory is that SIV passed to humans where it mutated into HIV because of the close contact that occurs during hunting. Numerous outbreaks of Ebola virus infections are also likely connected to the harvesting of wild primates, as are Simian Foamy Virus infections and yellow fever. The potential is certainly there for these diseases to leave their African homes and pop up in other countries via smuggled meat. “Outbreak” here we come.
Of course, it is not just meat that is the problem. Smuggled wildlife destined for the pet trade can be just as dangerous, as shown by the 2003 outbreak of monkeypox in the US, courtesy of some infected prairie dogs who caught it from imported Gambian giant rats (http://www.cdc.gov/ncidod/monkeypox/qa.htm).
Unfortunately as long as we continue to desire the exotic, and are prepared to pay for it, and keep moving species around the world without adequate controls some sort of global pandemic is a very real possibility, not just a science fiction scenario.
Dr. F. Bunny