Earth’s most diverse creatures

Earth’s most diverse creatures

Collected beetle specimen • Natural History Museum, London (CC BY 2.0)

Originally published 26 November 1990

I’ve seen the British Crown Jew­els on dis­play at the Tow­er of Lon­don. I once vis­it­ed an exhib­it of gem-encrust­ed East­er eggs cre­at­ed for the Russ­ian Czars by Peter Carl Fabergé, the finest jew­el­er of Europe. I’ve browsed wide-eyed among the trea­sures at Tiffany’s.

All of these art­ful baubles pale before the nat­ur­al beau­ty of beetles.

Beetle­ma­nia! That’s the name of a [1990] exhib­it of bee­tles offered by Har­vard’s Muse­um of Com­par­a­tive Zool­o­gy. Thou­sands of spec­i­mens from the Muse­um’s vast bee­tle col­lec­tion (three-and-a-half mil­lion spec­i­mens rep­re­sent­ing 100,000 species col­lect­ed world­wide) are attrac­tive­ly dis­played and interpreted.

And they are gor­geous. Gem­stone gor­geous. Gaudy, iri­des­cent jew­el-bugs, shim­mer­ing in col­ors of turquoise, sap­phire, opal, and ruby.

One group of thumb-sized scarab bee­tles appears to have been fash­ioned from pre­cious met­als: gold, sil­ver, and plat­inum. The backs of cer­tain leaf bee­tles seem to be stud­ded with hun­dreds of tiny diamonds.

Every group of bee­tles on dis­play offers some­thing in the way of bijou beau­ty. Pearls, rhine­stones, and Indi­an beads. Pol­ished ebony and ivory. Moth­er-of-pearl brooches, lapis lazuli stick-pins, and emer­ald pen­dants big enough and rich enough to dan­gle grand­ly in Liz Tay­lor’s decolletage.

What makes the Coleoptera (bee­tles) so end­less­ly fas­ci­nat­ing is their appar­ent­ly super­flu­ous orna­men­ta­tion. They are far more flam­boy­ant­ly dec­o­rat­ed than any the­o­ry of evo­lu­tion would seem to require. What pos­si­ble advan­tage in the strug­gle for sur­vival is bestowed on the Calode­ma bee­tle by its aston­ish­ing box-of-Cray­olas col­oration? What is the rea­son for the fab­u­lous pol­ka dots and splotch­es on the backs of lady­bugs? Why do leaf bee­tles sport such a goofy pro­fu­sion of spikes, fuzz, frills, pits, and knobs, all in dec­o­ra­tor colors?

Created on the Seventh Day

Those folks who pre­fer to explain the world as the piece­work of a divine crafts­man could offer no bet­ter proof of their faith than bee­tles. It is dif­fi­cult to imag­ine any com­bi­na­tion of nat­ur­al laws cre­at­ing the bee­tles on dis­play at Har­vard. Bee­tles are pure whim­sy. Bee­tles are art for art’s sake. Bee­tles are the work of the Sev­enth Day, when the Cre­ator was just foolin’ around havin’ fun.

Of course, biol­o­gists are unwill­ing to con­cede that even the most wild­ly orna­ment­ed bee­tles don’t some­how fit into the evo­lu­tion­ary scheme. Clas­sic exam­ples of Dar­win­ian adap­ta­tion are plen­ti­ful in the Har­vard exhib­it, includ­ing bee­tles from Ari­zona that have evolved col­ors to match the rocks they live on — red for red sand­stone, black for black vol­canic rock — the bet­ter to escape predators.

But what of those thumb-sized scarabs with backs of ster­ling sil­ver or 24-carat gold? Biol­o­gists lame­ly sug­gest that in trop­i­cal rain forests these shiny metal­lic col­ors act as mir­rors, reflect­ing the veg­e­ta­tion of the for­est, there­by func­tion­ing as a kind of all-pur­pose cam­ou­flage. Small­er metal­lic bee­tles, they say, are shiny to mim­ic drops of water on a wet surface.

These Dar­win­ian expla­na­tions are, I sup­pose, rea­son­able enough, but to my inex­pert mind the spec­tac­u­lar vari­abil­i­ty of bee­tles sug­gests that nature is infect­ed by beetle­ma­nia — a sheer lunatic exu­ber­ance for diver­si­ty, a man­ic propen­si­ty to try any damn thing that looks good or works.

Every­thing, in fact, but the kitchen sink! Click bee­tles, stink bugs, fire­flies, bury­ing bee­tles, ban­jo bee­tles, stag bee­tles, whirligigs, and tum­ble bugs. They are all here, in their mind-bog­gling pro­fu­sion, glit­ter­ing like gems.

Bee­tles as tiny as the point of a pin: They don’t even need to beat their wings to fly; they sim­ply spread their feath­ery wings and float away like motes of dust in the air.

Bee­tles as big as base­balls: The Goliath bee­tle of trop­i­cal Africa, when air­borne, can shat­ter the wind­shield of a Jeep.

Bee­tles that eat dirt: Pill bee­tles found in the Israeli desert gob­ble up so much soil they recy­cle the entire desert every 15 years.

Bee­tles that scu­ba dive: Whirligig bee­tles trap a bub­ble of air under their bel­ly and use it as an aqualung to stay under water for an extend­ed peri­od of time.

Bee­tles that roll lit­tle balls of dung: Ancient Egyp­tians wor­shiped the dung-rolling scarab bee­tle, imag­in­ing it to be a suit­able image of the god that rolls the sun across the sky each day.

Beetles, beetles everywhere

And what’s on dis­play at the muse­um is only a tiny frac­tion of what lies hid­den in dark draw­ers in the nether regions of the muse­um — a Fort Knox full of coleopter­an rich­es. Bee­tles are the most diverse crea­tures on Earth. There are prob­a­bly between 5 and 50 mil­lion species of liv­ing organ­isms and bee­tles account for a quar­ter of them.

When asked what he had learned about the Cre­ator by study­ing the cre­ation, the renowned evo­lu­tion­ary biol­o­gist J. B. S. Hal­dane is said to have replied, “He must have an inor­di­nate fond­ness for beetles.”

If bee­tles are indeed the work — or play — of the Sev­enth Day, then the Cre­ator was busy from dawn to dusk.

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