In the Mojave Desert in the U.S. state of Nevada, a few hundred meters above the famous Valley of Death, in a small underwater, probably the most endangered species of fish in the world has found its home. It is a silver-blue fish smaller than your smallest finger which came after millions of years of evolution to the edge of extinction. By unusual set of circumstances Cyprinodon species Diabolis (The Devils Hole Pupfish)is today reduced to only 75 living specimens.
The Cause of The Problem
Interestingly, the greatest threat to the survival of this species comes from a rather unexpected place - its DNA. In the past, these fish lived in a relatively large lake. About 20,000 years ago, the water level in the lake dropped very quickly, the landscape began to resemble the desert and the unfortunate fish found itself trapped in small physically separated lakes. So now there are nine different types of this fish, of which at least half are at the edge of extinction. The hardest case is the type of Cyprinodon Diabolis. Its population in September this year dropped to only 75 living members. Thousands of years of evolution made this fish capable of living in a very specific environment, to survive she needs water heated at thirty degrees Celsius, low oxygen saturation and a shallow part of the lake into which they retreat in the spawning season. Being an endangered species is already difficult enough, but to be an endangered species and at the same time picky regarding conditions in the environment is a totally new level of threat.
The Bad Luck
But that's not all. Besides being compromised and picky, this type of fish is followed by bad luck. In the early seventies of the last century American biologists have built three artificial lakes in which they tried to grow the backup fish from Devil's Cave (the location where the fish are located), to save them from collapse. Valves and other mechanical components cluttered up almost daily, and most of the fish died. When we say that this is a bad luck, then we really mean it, after completed repairs remaining fish were killed by a lightning strike that destroyed a generator for electricity, and that allowed the maintenance of very specific conditions in which this little fish could survive.
However, luck smiled to the fish that were in the third lake named Point of Rocks. Specifically, in this isolated population has somehow got the other related species of small fish and its DNA soon spread through the population like a wildfire. After about 50 years, every fish that was in the lake was a descendant of "intruders" who is who knows by what combination of circumstances made it into the lake. Scientists are able to very easily conclude this, as the hybrids between the two species had one pair of gills more than original type which they had tried to preserve. After some time, biologists who worked on the project, decided to move the fish into the hatchery. Unlike Cyprinodon Diabolis, which this facility led to the edge of extinction, a new hybrid species has simply exploded. "Huge aquariums we had were filled with new fish in very short time from top to bottom. Just a few decades ago, this species was dying, and now it suddenly experiences an unexpected increase of the population, "says Andy Martin, an evolutionary biologist at the University of Colorado, head of the group of scientists who investigated the specificity of DNA in a new hybrid species.
For Martin, this fact was clear evidence of what went wrong with the species Cyprinodon Diabolis – It was a genetic mutation. On the positive side, now that the diagnosis is finally established, there is a hope is that it is possible to find a drug that could save this fish. Martin claims to have a plan to rescue "the devil fish” from collapse, but for all those people who have in the past engaged in saving the various species from extinction, this idea probably will sound like a heresy tough.
The New Logic
For many years, scientists who were trying to preserve plant and animal species kept the same simple logic: it is necessary to protect the species X, as it existed at the time Y, in the place Z. Of course, evolution does not know the logic of this type, and changing is the only thing we can expect in all living beings on the planet. And here we come to Martin's heretical idea - he thinks that, in this case, the solution is not the preservation of species X as it was at the point Z, but the "breeding" of X species genes which would enable it to do what the evolution didn’t – the change. In other words, Martin wants to enrich this endangered species with the genes of her cousins - the type Cyprinodon nevadensis. those species have the common ancestor, and, interestingly, they live in small lakes just a few kilometers away. Martin's idea is pretty simple - throw a few individuals Cyprinodon nevadensis in the lake with the remaining 75 Diabolis and - wait. These few intruders would probably allow endangered species to stop spreading defective genes, says Martin. By the introduction of new genetic material this species could be saved, but the question is whether the individuals that survive could still be considered the same species.
This way, the small fish from the Mojave Desert have made us think about the one originally philosophical question of our relationship to the nature. It is already clear that we are likely to encounter in the future a variety of other endangered species, and the way we treat the problem of fish from Devil's Valley could become a precedent for all future cases. Scientists involved in the preservation of animal species therefore could become architects of the completely new ecosystem. Approach they have used until now was restricted to the exclusion of individuals from the wild and maintaining them in controlled and less risky conditions. But with this new approach, scientists will by manipulating the genome, practically create new species, which will contain smaller or larger fragments of those species they have tried to preserve. The idea is definitely controversial and Martin currently doesn’t have the support of the institution he is employed in. However, around the world there are a lot of endangered species and some are already preserved from extinction in a manner similar to that advocated by Martin.
Written by Sasa (sale0303)