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Many endangered species are already evolutionarily extinct

 

This is a blog that might be difficult for some of you to take on board, but it is the blunt truth about many highly endangered species in the world. My message is ultimately that we should not have let them become that way, and we still might have the choice to do right for many. But also for many species, we might have to accept, based on our complacency in the past, extinction in the near future because they are already dead as species. They are the ghosts of a world that once was, and while we might catch the occasional glimpse of an individual, we have taken away a defining characteristic of what it is to be a species – their future evolutionary potential.

 

We have come to accept that conservation is about saving individuals as that is all we have left. We have been led to believe that biodiversity is served by having a few Sumatran tigers and Javan rhinos clinging to individual survival, the hope that a few Ivory-Billed woodpeckers (pictured above) still elude eager spotters, and that we might just find a hidden stronghold among mammals for the Bawean deer, the Namdapha flying squirrel, the Blond Titi monkey and the Blonde Capuchin, the Black-bearded Saki and the Andaman white-toothed Shrew, the Social Tuco-tuco and the Wondiwoi tree kangaroo. Among plants,for the Pokemeboy, Brown’s Pigweed, Troodos Rockcress and the Maltese rock-centaury. Among birds for the Sulu Hornbill, the Honduran Emerald, and the sadly named Medium tree-finch. Among freshwater molluscs for the Ouachita Rock Pocketbook, the Tar River Spiny Mussel and the False Spike, the Shiny Pigtoe and the Cracking Pearly Mussel. Hidden strongholds? Not a chance. Extinction is not about the last individual, it is a process.

 

Our species, Homo sapiens, now numbers seven billion. We have effectively taken over the planet  some time ago in terms of our demand for natural resources. Those resources include wood from forests in existence for hundreds of years, bush meat, hunting trophies, fragile marine resources, fossil fuels. We have, and will increasingly contribute to climate change as carbon emissions are now ever more accepted as a necessity of economic growth instead of careful consideration of environmental consequences. Due to demand from our numbers, we increasingly and ceaselessly require an array of biological products that cannot (despite their supposedly “renewable” status) keep up with our demands. We destroy forests for wood, to open up temporary fields to grow a few crops, and to plant oil palms to fuel our cars. We believe in the biofuel concept (for those same cars) that fuels the expansion of sugar cane plantations at the expense of natural habitats.

 

Economic demands at present levels, and at probably increasing levels in the future, are completely out of synchrony with any means of supply from our wild species, whether they be tunas, deep sea corals, leopards, lions, mahogany trees, or any of the increasing number of species on the IUCN Red List of endangered animals and plants. Those of you who own Chippendale furniture are looking at wood from an extinct tree. It has come to the point that anyone who claims that sustainable offtake of vulnerable species is possible should gently be conveyed to an institution specializing in the treatment of delusionals.

 

Let’s face it. We have eradicated biodiversity on this planet to the extent that we are now faced (or actually have been faced for some time but nobody was paying attention) with a big and growing crisis. And now let me get to some meat some of you might find indigestible, but still needs to be served.

 

Darwin, a progressive thinker who struggled with his religious issues and potential competition from Alfred Russel Wallace, eventually published his Origin of Species. Darwin, truth be told, had no inkling of how inheritance actually worked, and it is said an unopened letter from Mendel was found on his desk after he died. But nevertheless he proposed a principle that still guides evolutionary thinking 150 years later.

 

Darwin was a proponent of “evolution by descent”.  That meant variation in species could lead to new varieties, hence evolution. Wallace opined that changing environments could select for new species, by implication again due to genetic variation present among populations.

 

Genetic variability is accumulated within a species by substantial numbers of individuals over many generations, and relies on a variety of different processes, not only the slow mutation as was once thought. We now acknowledge species “need” genetic diversity to ensure their survival in shifting environments, and also to allow speciation in the future.  Species are dynamic entities, and thus we must realize that we have by our past actions taken the evolutionary potential (at least) away from many species by destroying their numbers. Therefore, many species are now already evolutionarily extinct while some few individuals might remain. 

 

We do not seem to realize that by the time we classify a species as endangered, or critically endangered, that it is already dead in an evolutionary sense. Perhaps we need to accept that for those species evolution is dead, and that all we can do now is be concerned with the survival of a few remaining individuals. Maybe that is the best we can do given a dire situation. Maybe we should celebrate apparent success stories where numbers of individuals are somewhat resurrected by timely intervention. The black-footed ferret in the USA comes to mind. There are many programmes in zoos to breed animals in captivity either gone from the wild or present in such low numbers to cause great concern. Reintroduction into the wild is a pesky detail for such programmes, but some progress has been made.

 

Still, we have not learned from our mistakes. Endangered species are given special status by CITES and the IUCN, and once designated, trade and consumption is suddenly subject to a great number of regulations, guidelines, decrees and directives. The same should be best proactively extended to species currently listed as “vulnerable”, as those, in many cases, are still proper species in an evolutionary sense. We tend to wait until it is too late for species by saying “enough is enough”, and then we are down to numbers that cannot sustain evolution. The IUCN criteria to “become” an endangered species are rigid, and strictly speaking they only get on the list and get urgent protection when it is far too late.

 

A species is not a bunch of individuals in scattered and isolated populations added together. A species needs to be seen as a genetically variable and evolutionarily viable entity. We should put all species now classified as “vulnerable” on the endangered species list – after all, we should be talking about species, not individuals in terms of intelligent conservation.  Lions should not “wait” to become endangered, though those in western Africa and India already are. Time to pay attention to genetics, evolution, and intercede in a timely fashion. What’s more important to maintaining biodiversity - a species that is still viable or a sadly lingering ghost? It will require a sea change in our muddled thinking, but conservation needs to accept Darwinian principles if we are to be truly effective in the future.

 

Picture credit: http://training.fws.gov/History/Articles/IvoryBilledWoodpecker.html

 

 

Add a comment | Posted by Pieter Kat at 14:38