Who hasn’t wanted to bring an extinct species back into
existence? Sure, there are risks, both physical (T. rex and pathogens) and
ethical (Neanderthals), and sure, we’re better off without some species
(smallpox and mososaurs), but how about the gastric brooding frog and the
thylacine and the dodo and so on? Surely the world would be a better – or at least
not worse – place if we hadn’t lost them. Enter the de-extinction
movement, which seeks to bring extinct critters back to life. It hasn’t
happened yet, of course, and it might never happen given not only the risks but
the costs and difficulties. Even better than de-extinction – and without any of the ethical baggage
– is when things thought to be extinct are found not to be (unextinction?).
Being a fish guy, one of the most inspiring unextinction
stories is the discovery of the coelacanth – though to be extinct for more than
60 million years. Found on December 22, 1938, in the bottom of a pile of fish on a
trawling ship by the young curator (Marjorie Courtenay-Latimer) of a tiny
museum in East London, South Africa, this first specimen was bundled into a cab with the
help of a very reluctant cab driver, sketched iconically and the sketch mailed to
Professor J.L.B. Smith at nearby Rhodes University. The discovery rocked the
scientific world but was less than ideal given the lack of preservative
available in East London. Then came the search for another specimen, found only
14 years later in the Comoros. Here the story only gets better, with midnight
calls to the Prime Minister of South Africa, a clandestine military evacuation,
and an indignant French establishment. And then, in 1998, a second coelacanth species
was found in Indonesia in a fish market by a couple on their honeymoon. This
one was quickly named by French scientists who hadn’t seen it, in apparent
retaliation for the loss of the Comoros specimen. (If these tidbits intrigue you, read the full coelocanth story in A Fish Caught in Time.)
Marjorie Courtenay Latimer and the famous sketch that started it all. |
De-extinction the way it should be – unextinction! This
story had always been one of my favorites and so I had long been excited to see
a coelacanth – if only in a big vat of preservative. However, few coelacanths
are in North American museums, partly because of the monopoly the French
exerted for years after the Comoros scoop by the Brits. So I didn’t get to see
one until I went to France, where every Podunk museum and aquarium in every
tiny town seems to have one – I saw mine in Biarritz. My daughter even got to
see it, although I am not sure at the age of one she had much appreciation for its
scientific significance. Truly an inspiring moment – although some day I would
love to see one in the wild (probably harder to see than nearly anything else).
The Biarritz coelacanth - a treat for me and for Aspen! |
Of course, coelacanths remain very rare, perhaps forever at
risk of re-extinction, something we should surely seek to prevent. Indeed, the goal
of preserving truly unique species is gaining steam in conservation biology.
The basic idea is that many species are likely at risk of extinction and we
need some sort of criterion for deciding which to preserve. One criterion that
has been put forth is phylogenetic distinctiveness. That is, the species that
warrant the most protection are those that represent the last remaining bits of
long isolated branches of the evolutionary tree – lose that last species and
forever lose a big chunk of the history of life. A recent incarnation of this idea is EDGE (evolutionarily
distinct globally endangered), which seeks to prioritize species conservation
based on a joint consideration of phylogenetic distinctiveness and degree of
endangerment. So far so good; finally conservation biologists are fully using
evolutionary criteria for species conservation! Something all evolutionary
biologists can get behind – or is it?
A few weeks ago, I was in College Station, at Texas A&M University, as one of
the invited speakers for the Ecological Integration Symposium organized by graduate
students (my host was Emily Rose). My talk was on ecological speciation, David
Reznick spoke on eco-evolutionary dynamics, Brian Bowen discussed marine
speciation, and Tom Lovejoy gave an overview of global climate change effects.
At the end of our plenary session, we had a panel discussion. At first, the
four of us thought it might be awkward as our talks had been on very different
things – but we quickly converged on a topic to which we could all provide
perspectives: What, precisely, should we be conserving? A large part of the
discussion focused on the importance of preserving not only species but also intra-specific
variation, but we also discussed which species should be preserved. At one
point, I went through the above rationale about phylogenetic distinctiveness being
an important criterion and then Brian grabbed the mic out of my hand.
“THE COELACANTH HAS HAD ITS DAY” was the first sentence out
of his mouth. He then went on to describe how species come and go all the time
and those old rare relicts just hanging on (coelacanths, tuataras) are probably
not long for this world (extinctive?)
regardless of human influence – so perhaps we shouldn’t bother. Instead, we
should focus our efforts on groups that are rapidly diversifying – African
cichlids was his prime example – as they are the future of biodiversity. Ok,
sure, I like cichlids as much as (probably more than) the average person, but
let the coelacanth go? Heresy. Fear. Fire. Foes. Right then and there I
excommunicated him from the pantheon of evolutionary biologists, revoked his
citizenship in a compassionate humanity, unfriended him on Facebook, and
started a smear campaign to discredit him.
Me and Brian Bowen, the most dangerous man alive - for coelacanths anyway. (Photo by Melissa Giresi.) |
On sober (actually just the opposite) subsequent refection,
however, I began to question my reaction. Try this thought experiment. How many
cichlid species is the coelacanth worth? I think we can surely say at least
one. Taking inspiration from Phil Pister’s “species
in a bucket”, if I had all of the world’s Pseudocrenilabrus multicolor in a
bucket in my left hand and all the world’s coelacanths in a bucket in my right
hand, I would probably saw through my left wrist before dropping the bucket in
my right. (I might hesitate longer if the hands were reversed.) I would
probably decide the same for 10 cichlids or maybe a hundred but what about a
thousand or ten thousand – what if it was the entire cichlid fauna of Lake
Tanganika or Malawi or Victoria? By the EDGE perspective, I expect that I would
save the coelacanth. By the de-extinction perspective, I would probably do the
same (it would be much harder to re-evolve the coelacanth than start a new
radiation of cichlids – after all, they do it all over the place). But by the
Bowen perspective, I would clearly drop the coelacanth without a second
thought. And at some level, I see the point. Coelacanths aren’t going to give
us anything new. At best, they will still be around a million years in the
future looking pretty much the same. The cichlids, however, will likely produce
many new species in that time. The future of biodiversity is perhaps better off
with the cichlids than coelacanths.
Fortunately, I am not a manager and don’t have to make such
decisions, because the truth is I want both cichlids and coelacanths! But
perhaps I could do without ticks and chiggers and dengue and AIDS and TB and
definitely poison ivy.
An amazing giant isopod in the Texas A and M invertebrate collection. (Photo by Melissa Giresi.) |
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