While there have been some scientific advances in genetic engineering, we are still far from successfully bringing back a species that has disappeared from the planet. But as we discussed last week, there has been some success in cloning or “back-breeding” of some species.
But what are the criteria for resurrecting an ecologically beneficial animal or plant species? What sort of impacts and risks do we need to investigate first? These are serious questions, and in-depth studies are needed on every single candidate brought up for de-extinction before moving forward.
Problems with species de-extinction 101
Resurrection or true de-extinction is impossible for a number of reasons. According to the BBC, there are currently no technologies or methods being pursued that would give us a carbon-copy of an extinct species. The best we can hope for is a proxy.
Reintroducing a species into an environment they at one time populated has its risks, both to the species and to the environment. Factors such as the stability of existing species in the region, changes in the habitat brought on by anthropogenic manipulation to the habitat and climate change need to be taken into consideration.
Another problem that needs further discussion is how would we teach a long-extinct animal to behave like its ancestor? Take for example the mammoth. Many researchers think the mammoth is an excellent candidate for de-extinction because of the role they played in the ecosystem as grazers on the Arctic steppe.
But the Arctic steppe is changing due to climate change and we are left with the problem of whether or not they would survive in this changing world. If you go one step further, baby mammoths, of at least babies closely resembling a mammoth would be bred using an elephant as the birth mother. Who or what animal is going to teach the baby how to behave like a mammoth?
Basically, we can say that while a “proxy” may be close genetically and possibly, behaviorally to the real thing, such as aurochs in the Tauros Project (above picture), they are not identical to the original animal. We can also point out that their resurrection will never undo the damage to the environment caused by human activity.
A species’ function in its ecosystem
Every animal and plant in an ecosystem has its own function. Bats eat insects, grazers keep the grasslands cropped while spreading nutrient-rich dung, while other animals spread plant seeds. And sharing the list is the predators that keep animal populations in check. Or at least, in a perfect world, that’s the way it is supposed to work.
And while some of these functions described may be redundant, shared by several species, others are fulfilled by only one or two species. This brings up one of the criteria that could be a plausible reason for bringing back certain species based on their primary function in an ecosystem.
Douglas McCauley, an ecologist at the University of California-Santa Barbara says we should select target species with unique functions that went extinct recently and focus on restoring those species to a population that would create balance within the ecosystem. This is because ecosystems have been under constant change and resurrection of a species into today’s environment could create problems.
What about the risk associated with the spread of genes?
OK, there would be little chance of a resurrected population of mammoths inadvertently breeding with an elephant in the Arctic steppes, but that doesn’t necessarily apply to say, rodent or other species. We’ve got to remember that for billions of years, the evolutionary process has given us the wonderfully diverse life forms we have in the world today.
If we look at genetically modified plants, we already have evidence of those modifications jumping into relatives, oftentimes giving us undesirable traits. “If we lose sight of the true gravity of extinction and over-zealously embrace de-extinction as a mitigation tool, it would be really easy to manufacture forests, savannas, and oceans full of Franken-species and Eco-zombies,” McCauley says.
The diversity of a species is so important in keeping a balance in the natural world. Clones or proxies of a species will need to reproduce, but will a diverse gene base be possible? A lack of genetic diversity can lead to disaster. The Irish potato famine in the 1800s is an excellent example of this.
At the time, Ireland was heavily dependent on the potato for nutrition and rather than growing potatoes from seeds, they planted sections from a parent potato. By doing this, all the potatoes produced were clones of the parent potatoes containing identical genetic material.
The lack of genetic variability led to the potato crops becoming infested with an invasive pathogen called P. infestans, in turn, wiping out a whole population. The pathogen was able to take hold because the favorable traits that would have allowed the potatoes to resist the disease had been bred out of them.
Bottom line? We will have to move with a great deal of deliberation in deciding what species should be brought back from extinction, giving thought to recently lost or near-extinct species first if we decide to go ahead with resurrection of a plant or animal.
