What’s progress got to do with it?

Originally published 21 October 1996

We’ve all seen the famil­iar image of a fish wad­dling onto the shore, pre­ced­ed by a quadruped ris­ing onto its hind legs, a knuck­le-drag­ging simi­an, thick-browed Nean­derthal, and — lead­ing the parade of progress — bright-eyed Homo sapi­ens strid­ing erect.

Evo­lu­tion, as we have imag­ined it, is an ascent from the pri­mal slime, through sponges, bugs, dinosaurs, and apes to — well, to us, the cap­stone and glo­ry of creation.

Pushed from behind by the blind engine of nat­ur­al selec­tion, or drawn upwards by the guid­ing hand of God, we are the inevitable prod­uct of a thrust towards com­plex­i­ty and consciousness.

Evo­lu­tion is progress. We are its culmination.

Or so the sto­ry goes.

Stephen Jay Gould, evo­lu­tion­ary biol­o­gist, Har­vard teacher, pro­lif­ic writer, base­ball fan, and author of the provoca­tive new book, Full House: The Spread of Excel­lence from Pla­to to Dar­win, has anoth­er idea.

Gould has made some­thing of a career of pok­ing holes in our pre­sump­tion of bio­log­i­cal pri­ma­cy. It is his con­tention that the ancient idea of a Great Chain of Being, ascend­ing from the lowli­est crea­tures to humans at the apex, has noth­ing to do with the world described by science.

In the real world, says Gould, vari­a­tion, not progress, is the supreme val­ue. We evolve togeth­er — bac­teri­um, low­ly worm, and philoso­pher — arm-in-arm, so to speak, adapt­ing to our respec­tive envi­ron­men­tal nich­es, spread­ing excel­lence across the board.

In his view of things, the bac­teri­um has as much right to claim pri­ma­cy as we do. Per­haps more right, since bac­te­ria have been and will prob­a­bly always remain the most endur­ing and pop­u­lous life­form on the planet.

To illus­trate his argu­ment, Gould makes a delight­ful digres­sion into base­ball, ask­ing the ques­tion: Why we don’t have any more .400 batters?

The extinc­tion of .400 hit­ting is usu­al­ly inter­pret­ed as a sign that “they don’t make ’em like they usta.” Not so, says Gould. We no longer have .400 hit­ters because of a shrink­age in vari­a­tion from best to worst, and a spread of excel­lence among hit­ters, pitch­ers, field­ers. He mar­shals an impres­sive array of sta­tis­tics to prove his point.

What does base­ball have to do with evo­lu­tion? Gould turns the base­ball argu­ment on its head to show that the “rise of man” is no more real than the “decline of .400 hit­ting.” Rather, our appear­ance on the con­tin­u­um of life is a con­se­quence of expand­ing vari­a­tion. Progress has noth­ing to do with it.

We are one tail of a bell curve of ran­dom­ly-gen­er­at­ed vari­a­tion skewed toward com­plex­i­ty because it can’t go the oth­er way (liv­ing crea­tures can’t get much sim­pler than bac­te­ria). The peak of the bell curve, where the great­est num­bers lie, still resides, as it always did, with bacteria.

The com­mon error we make when con­sid­er­ing the “decline of .400 hit­ting” or the “rise of man” is to mis­take con­trac­tions or expan­sions in the amount of vari­a­tion for trends. Progress in evo­lu­tion is an illu­sion, says Gould. One crea­ture had to be more com­plex than the oth­ers; it just hap­pens to be us.

OK, we fig­ure, so we’re the tail of a skewed bell curve rather than the pre­or­dained glo­ry of cre­ation. But it’s our tail. The tail had to devel­op and grow. We are the most com­plex of crea­tures, the inevitable con­se­quence of vari­a­tion and the spread of excel­lence. We are still the apple of God’s eye.

Gould does­n’t even allow us this con­so­la­tion. “Humans are here by the luck of the draw, not the inevitabil­i­ty of life’s direc­tion or evo­lu­tion’s mech­a­nism,” he says. If we went back to the begin­ning and re-played evo­lu­tion, the out­come would be entire­ly dif­fer­ent. There is noth­ing inevitable about us.

What are we to make of this? Can our egos take this pum­mel­ing? Can we main­tain our con­fi­dence, our opti­mism, our faith in a mean­ing­ful uni­verse if we are noth­ing more than the quirky tail of a skewed sta­tis­ti­cal dis­tri­b­u­tion? Should we dis­miss Gould as a cur­mud­geon­ly crank and con­tin­ue bask­ing in the glow of our assumed superiority?

First of all, it is worth not­ing that many oth­er evo­lu­tion­ary biol­o­gists share Gould’s views. Indeed, his the­sis was already implic­it in Dar­win’s work.

“Nev­er say high­er or low­er,” Dar­win jot­ted in the mar­gin of a book. And again, in a pri­vate note­book: “Why is thought, being a secre­tion of the brain, more won­der­ful than grav­i­ty, a prop­er­ty of mat­ter? It is our arro­gance, our admi­ra­tion of ourselves.”

No one will deny that humans can be arro­gant, or that we are inclined to nar­cis­sism. Nev­er­the­less, I doubt many of us will warm­ly embrace Gould’s — and Dar­win’s — con­clu­sion. The notion of our pre­or­dained pri­ma­cy is deep with­in us, embed­ded in our myths and leg­ends, enshrined in our the­olo­gies, per­haps even hard­wired into our brains.

But myths and leg­ends have been found to be false. The­olo­gies have been revised. And civ­i­liza­tion depends upon the cul­tur­al sup­pres­sion of some of our ani­mal instincts. What we wish to be true is an unre­li­able guide to truth. Wish­ing our pri­ma­cy does not make it so.

We have lots more to learn about evo­lu­tion, and maybe some future Dar­win will demon­strate a built-in ten­den­cy towards com­plex­i­ty and con­scious­ness. The new math­e­mat­ics of com­plex­i­ty may throw fresh light on the subject.

But we ain’t there yet. As Gould says, “The basic the­o­ry of nat­ur­al selec­tion offers no state­ment about gen­er­al progress, and sup­plies no mech­a­nism where­by over­all advance might be expected.”