In the first part of this piece I raised the topic of bringing extinct species back to life, making such things as Tasmanian Tigers and Gastric Brooding Frogs un-extinct through DNA sequencing and clever artificial fertilisation techniques. Outside of any ethical and difficulty questions there were a couple of points that I thought were worth thinking about.
The first was that animals are not just a single species but rather complex communities of living organisms and bringing back to life the extinct animal using re-sequenced DNA therefore would only bring back the host and not the entire organism.
The second of the points that I would like to focus on is that nature is driven by opportunity. The downfall of one species will lead to the rise of another or a whole series of relative changes in success and failure. The removal of the wolf from Yosemite for example had a marked effect on the beaver population, not because they were their natural predator but rather due to the collapse in the Willow population caused by the larger than normal herds of elk which the wolves used to keep in check.
If a species therefore has been extinct for some time there will have been a general rearrangement of the remaining competitive species. Given time, all broken ground becomes colonised and all gaps in the food chain lead to a rebalancing of the whole ecosystem. Every niche becomes filled by another species and so a hole created by one extinction will have become occupied by an alternative animal.
If science is successful and manages to make a creature un-extinct it is very likely that the habitat or ecosystem in which it once existed will have either moved on or will be occupied by other competitors. And what is more these current day species will have moved on in evolutionary terms from their ancestors to be able to cope with the prevailing natural tensions in their survival market which means that the un-extinct creature is unlikely to be tuned to survive. After all an extinct creature had a problem surviving before and so why would it fair any better now when the world has moved on?
I doubt whether either of my points will deter those people who are keen to see this happen from their pursuit but I wonder if their desire is less about science and more about seeing whether or not it could be done.