Much has been said recently, both by the scientific community and by science fanboys like Varius and myself, about the exciting prospect of resurrecting extinct animals, such as Woolly Mammoths, with advanced (and yet-to-be-developed) cloning techniques. In a nutshell, the process involves extracting DNA from preserved remains and injecting them into the eggs of existing species. Warming up to the subject, New Scientist has published a new article entitled, “Ten Extinct Beasts That Could Walk the Earth Again,” basically a top ten list of species resurrection.

The article ranks each species on 1-to-5 scales of DNA preservation (i.e., how many good samples we have to mine genetic material from) and suitable surrogates (i.e., are there any available host animals to inject the DNA into once we’ve found it). So, for example, the Tasmanian Tiger, also known as the Thylacine, ranks a 4-out-of-5 for DNA preservation. This is because the last Thylacine died in a zoo in 1936, and they kept the body. Unfortunately, the Thylacine ranks a measly 1-out-of-5 on the surrogate scale, because it’s a marsupial, which gives it fewer relative options, and the closest living cousin is the Tasmanian Devil. Interestingly enough, though no one appears to have cloned a marsupial thus far, this may turn out to be an advantage:

“Pregnancy in marsupials typically lasts just weeks, and a simple placenta forms only briefly, meaning there might be less risk of incompatibility between an embryo and a surrogate mother of another species.”

Conversely, the Woolly Rhinoceros scores a 4-out-of-5 on preservation and a 5-out-of-5 on surrogates. The preservation is partly because of specimens preserved in permafrost, and partly because it’s apparently easier to get good DNA out of all those horns and hair. The surrogate rating is because the Woolly Rhino has some conveniently-similar relatives. Unfortunately,

“Although the woolly rhino has close living relatives that might make suitable surrogates, all contemporary rhino species are themselves on the brink of extinction. As long as this remains the case, resurrecting a woolly rhino is unlikely to be a top priority.”

Well, shit.

Surprisingly, though the Dodo is mentioned, it ranks a pathetic 1-out-of-5 on the preservation scale. Now, I knew there were preserved Dodo remains lying around in museums, but I was shocked to learn that scientists are already cutting into those specimens!

“In 2002, geneticists at the University of Oxford got permission to cut into the world’s best-preserved dodo specimen, a foot bone - complete with skin and feathers - held under lock and key… This yielded minute fragments of dodo mitochondrial DNA but nothing more.”

Apparently, though DNA is present in almost every cell in living creatures, this isn’t the case for the dead. Or maybe they just sucked at specimen preservation in the seventeenth century. Also, no one has yet managed to clone a bird, which may or may not prove to be a problem.

Oddly enough, a major hurdle raised in the article is one of scale. Several of the animals on the list are essentially gigantic versions of existing creatures, just like in the Giant Land section of Super Mario Bros. 3, and this bigness has drastically reduced their surrogate ranking. Varius summarized the problem well when I showed him the article earlier this week:

“Giant sloths, giant armadillos, giant beavers, and giant elks would all be cool by virtue of their sheer bigness, but their size means there’s a lack of viable womb-space; in a few cases, the fetus would be larger than the parent. Short of finding a way to grow these creatures in jars or something, I can’t think of a good solution. I mean, what’s the point of cloning a giant armadillo if you have to make it small?”

Happily, this problem may soon be solved by researchers more interested in human babies. A lot of research money is being pumped into the field of Ectogenesis, and specifically the invention of a functioning artificial womb. Making babies for women who can’t do it the old-fashioned way is big business, and building a machine that could safely house an embryo or a pre-term fetus is sure to rake in the cash. It’s also a gigantic slap in the face to all lonely orphans everywhere. But the upshot is that once we get a mechanical uterus for human babies, it should be easy to build a bigger one to grow a Glyptodon in.

New Scientist closes the article with a reference to The Frozen Ark, a consortium of institutions, museums, and charities working to “collect, preserve and store DNA and viable cells from animals in danger of extinction.” The idea behind this project is to get the DNA from endangered species now, before we have to cut into museum exhibits that have been stuffed with sawdust. It’s an excellent idea, and one which could probably benefit from increased funding. I think we’d all love to see us some resurrected giant armadillos, but in the short term, we probably ought to work on keeping the gorillas around. And you know how we increase the gorilla population in the 21st century, right? Yeah, baby. We clone ‘em.