WHEN Geerat Vermeij decided he wanted to do a PhD in biology, a university
director of graduate studies put him through his paces. Casually, he handed
Vermeij some seashells, asking him to identify each one in turn, and Vermeij
calmly trotted out the answers. This one was a Harpa, most likely
Harpa major. That one was an olive shell, most likely Oliva sayana
, the common Florida species. Right on both counts.
The director and curator of the museum where Vermeij鈥檚 grilling was taking
place were decidedly taken aback. It wasn鈥檛 that there was anything so amazing
about a student who knew a bit about shells, but this one was identifying
everything by touch. Afflicted with childhood glaucoma, Vermeij had both eyes
removed at the age of three, and spent years in special schools where a future
of basket-weaving or broom-making was considered the proper future for a
helpless blind boy.
Vermeij has lived his life a different way: leaping from skiff to shore in
the rough North Pacific seas where the water is so cold it will kill you in
minutes, clambering over rocky tropical shorelines where deadly cone shells and
stonefish display their displeasure with poisonous barbs if careless hands
disturb them.
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Ever since his childhood in the Netherlands, when his fingers first
encountered the drab, chalky shells of the North Sea, Vermeij has had a passion
for the natural world, and seashells in particular. That passion has led him on
collecting jaunts around the world, from Costa Rica, Brazil and Peru, to West
Africa and the Middle East, Hawaii, Madagascar, Singapore and the Aleutian
Islands.
鈥淚 want to expose puzzles鈥擨 want to expose things I don鈥檛 understand,鈥�
Vermeij says, as he sits in his office at the University of California, in
Davis. Vermeij wants to know why shells are the shapes they are, and why their
forms differ from one sea to the next. Over the decades, he has pondered
everything from the way shells鈥� structures differ as you move farther from the
shore, to why more species have crossed from Pacific to Atlantic than vice
versa, and the crafty bag of tricks that molluscs have evolved to ward off
shell-crushing crabs and fish. 鈥淢aybe I鈥檒l never know the answers,鈥� he says,
鈥渂ut at least I鈥檒l learn a lot of neat things along the way.鈥�
Vermeij still doesn鈥檛 understand, for instance, why the North Sea shells of
his early childhood are quite so chalky and plain compared with the flamboyant
and exquisitely-crafted shells of the tropics. He has pondered this question
since his family moved to New Jersey, where he encountered his schoolteacher鈥檚
Florida shell collection and marvelled at the contrast. 鈥淚 couldn鈥檛 believe what
I saw鈥攖hey were so much more aesthetically pleasing,鈥� he says. 鈥淭he
question why is still there as far as I鈥檓 concerned.鈥�
But Vermeij has done more than simply ponder mysteries鈥攈e has helped to
throw light on some. Most impressively, say his colleagues, he has documented
and rationalised the reason for the increasingly extreme and varied shell
designs you encounter as you travel from the Caribbean coasts to the eastern,
then western, Pacific waters. Early on his collecting trips, Vermeij noticed
that shells from the Pacific were much harder to clean than those from the
tropical Atlantic. This was because the animals have built a barrier of teeth to
guard the entrance to their shells. Pacific shells also tend to have much more
elaborate sculpture鈥攕uch as spines that stick out from the widest part of
the shell, or from the spire.
Such specialisations exist, Vermeij suggested, because predation from crabs
and fish is much more intense in the Pacific, particularly its western portion,
in effect creating an 鈥渁rms race鈥� that forces the molluscs to hole up inside
miniature Fort Knoxes. Crabs have trouble getting claws into narrower apertures.
And spines are not only sharp, they also increase the effective size of the
shell, so that crab claws and shell-crushing fish have trouble getting a good
grip. Properly shaped and positioned, they can also distribute the crushing
force over a greater area so the shell is less likely to crack.
Vermeij has also shown that Pacific crabs are indeed more fearsome, with
giant, toothed claws, and that the sturdy Pacific shells, though not immune, are
more resistant to their onslaughts. Richard Palmer, meanwhile, a marine
biologist at the University of Alberta in Edmonton, has shown that spines on
shells make them more resistant to shell-crushing fish. What neither knows for
sure is precisely why the Pacific鈥攅specially the western portion鈥攈as
created the environment for this extreme arms race, while the Atlantic has
not.
One thing that Vermeij鈥檚 forays tell him is that the days of the
specimen-collecting naturalist are far from over, no matter how much funding
agencies today frown on such 鈥渇ishing expeditions鈥� in favour of clear, testable
hypotheses. 鈥淚t鈥檚 a good thing to test hypotheses, don鈥檛 get me wrong,鈥� he says,
as he rummages through a vast assortment of shells in his office, each neatly
held in a plastic box with its strip of Braille notepaper. 鈥淏ut you don鈥檛 start
with hypotheses. You start with observations.鈥�
Vermeij abandons his search for the snail he was seeking and embarks on
something of a shell 鈥渟how and tell鈥�. He caresses each shell he is handed,
tracing its form and running his fingernails over its surface to pick up subtler
details of texture and shape. Thoughtfully, he speculates on why each shell is
the way it is. We look at a hulky Muricanthus radix from
Panama, well-covered with spines that fend off predatory fish. We look at a
helmet shell, with a massive shield on the bottom, which makes it more likely to
fall back on its base when tipped. 鈥淥therwise, if you鈥檙e upside down waving your
foot around somebody鈥檚 going to find it and chew it off.鈥�
Ridges on the inside of a left-handed whelk probably allow it to draw its
soft body back into its armour in a more efficient, orderly fashion, while
scales on a ratchet shell allow it to methodically burrow itself into the sand
and resist moving back up again. And then we reach the spectacular
Homalocantha anatomica, a shell from Guam that is covered with delicate
branching spines reminiscent of coral. Is it for camouflage? Stabilisation in
the sediment?
Mate recognition, even? Vermeij isn鈥檛 sure.
Vermeij鈥檚 colleagues admire him for his incredible wealth of knowledge: a
wall of his office is packed with a vast bank of Braille notes from scientific
books and papers he has read. But on the shore, he is awe-inspiring. 鈥淗e鈥檚 just
astonishing,鈥� says Palmer, who has been on many collecting trips with Vermeij.
鈥淥nce we got to the shore I would basically leave him, and he just scrabbles
around sort of crab-like on the rocks, feeling his way as he goes, and he comes
up with amazing collections of things. He has used collecting techniques that
would never have occurred to me鈥攍ike simply squatting down and running his
fingers through the sand鈥攚hile I would just walk around and look for
things on the surface.鈥�
Like most good friends, Palmer has not been above trying to trick his
colleague once in a while, by slipping him juvenile forms of shells and asking
him what outlandish new species they might be. 鈥淛uvenile Opeatostoma
pseudodon,鈥� concluded Vermeij, within seconds. Exotic relics from other
beachgoers can be more of a challenge. Palmer recalls catching Vermeij unusually
perplexed by a discovery. 鈥淗e was totally puzzled by it, I could tell by his
stance. He鈥檚 got this thing in his hands, he鈥檚 rolling it over and over again,
just trying to figure out what the hell it was. It turned out to be a peach
蝉迟辞苍别.鈥�
If picnic litter is one hazard of the job, Vermeij has run into enough others
to fill a whole chapter in his autobiography, Privileged Hands,
published last month. There was the time he stabbed his foot on a stingray
napping in the shallows, another when he reached under a rock and encountered a
smooth, yielding animal that turned out to be a highly poisonous stonefish that
was luckily none too alert at the time. He has been interrogated by gun-toting
soldiers, had his Braille paper turned to limp rags by the tropical humidity,
and once had his meticulous specimen labels devoured by a set of outraged snails
he had collected.
Over the years, more than one university or grant-awarding body has told
Vermeij that, frankly, they doubted a blind man could do what he was asking to
do. But, says Vermeij, the last thing a blind person needs is to be coddled. As
for the path his own life has taken, 鈥淚 knew what I wanted to do from the very
beginning.
I never had to worry about choosing a career,鈥� he says. 鈥淪hells are extremely
interesting in themselves, but I have used them to get at larger
questions鈥攓uestions about patterns in the history of life. When I look at
these things I see all kinds of characters that people haven鈥檛 noticed or paid a
lot of attention to. Oh, you start looking at something and it never ends.鈥�