Seeking order in the natural order

Originally published 29 April 1996

It is a pop­u­lar mis­con­cep­tion that evo­lu­tion is “just a theory.”

On the con­trary, the evi­dence for the devel­op­ment of life over bil­lions of years by com­mon descent from sim­ple ances­tors is over­whelm­ing. So over­whelm­ing that most biol­o­gists and geol­o­gists would call evo­lu­tion a “fact.”

The influ­en­tial geneti­cist Theo­do­sius Dobzhan­sky said “Noth­ing makes sense except in the light of evo­lu­tion.” Nobel prize-win­ning biol­o­gist Peter Mede­war said, “The alter­na­tive to think­ing in evo­lu­tion­ary terms is not to think at all.”

What these two great biol­o­gists meant is that no oth­er sci­en­tif­ic the­o­ry present­ly offers a sat­is­fac­to­ry frame­work for mak­ing sense of what we know about the world.

Here are some things that vir­tu­al­ly all biol­o­gists hold to be true:

• Life has devel­oped on this plan­et over bil­lions of years.
• All liv­ing organ­isms share com­mon ancestors.
• Species come and go.
• Nat­ur­al selec­tion, as under­stood by Dar­win and sub­se­quent­ly extend­ed by Mendel, Weis­mann, and pop­u­la­tion geneti­cists such as Dobzhan­sky, helps shape the tree of life.

Beyond that, the sto­ry of life is up for grabs — and hot­ly debat­ed by biol­o­gists. One impor­tant bone of con­tention: Is nat­ur­al selec­tion act­ing alone enough to explain the diver­si­ty and com­plex­i­ty of life on Earth?

Many biol­o­gists would say yes. How­ev­er, a grow­ing num­ber of biol­o­gists ques­tion the exclu­siv­i­ty of nat­ur­al selec­tion as the dri­ving force of evo­lu­tion. Also at work, they main­tain, are sources of nat­ur­al order that exist in any com­plex, orga­nized system.

One sci­en­tist who advances this view is Stu­art Kauff­man of the San­ta Fe Insti­tute in New Mex­i­co. He has writ­ten a hefty, high­ly tech­ni­cal book called The Ori­gins of Order to answer the ques­tion, “What are the sources of the over­whelm­ing and beau­ti­ful order which graces the liv­ing world?”

Kauff­man sets out to show that sources of self-orga­ni­za­tion exist through­out the nat­ur­al world: The six-point­ed snowflake and spher­i­cal drop of rain are sim­ple exam­ples. In high­ly orga­nized sys­tems, such as bio­log­i­cal organ­isms, these nat­ur­al sources of order dri­ve nature towards ever more com­plex forms.

“None can doubt Dar­win’s main idea,” Kauff­man writes. “If we are to con­sid­er the impli­ca­tions of spon­ta­neous order, we must cer­tain­ly do so in the con­text of nat­ur­al selec­tion, since biol­o­gy with­out it is unthinkable.”

But Dar­win is not enough, he insists.

Life has not been cob­bled togeth­er by nat­ur­al selec­tion act­ing on ran­dom muta­tions, says Kauff­man. We are not Rube Gold­berg machines slapped togeth­er piece by piece by evo­lu­tion. Rather, life is “a nat­ur­al expres­sion of the stun­ning self-orga­ni­za­tion that abounds in very com­plex reg­u­la­to­ry net­works… Order, vast and gen­er­a­tive, aris­es naturally.”

In oth­er words, we are more than the sum of our chem­i­cal parts. Life is an emer­gent phe­nom­e­non that arose when chem­i­cal sys­tems on the ear­ly Earth increased beyond a “thresh­old of com­plex­i­ty.” The sub­se­quent his­to­ry of life unfolds at least part­ly as a con­se­quence of complexity.

Kauff­man and his col­leagues use pow­er­ful com­put­ers to explore how com­plex inter­con­nect­ed sys­tems behave. They have demon­strat­ed how com­plex sys­tems of sim­ple ele­ments can cat­alyze their own self- organization.

These com­put­er sim­u­la­tions show intrigu­ing par­al­lels with the real-world his­to­ry of life.

Kauff­man thinks laws of self-orga­ni­za­tion lie at the heart of nature. If we can dis­cov­er these laws, he says, we will under­stand how our bod­ies devel­oped from a sin­gle fer­til­ized egg, and how our species emerged over bil­lions of years from pre­bi­ot­ic chemicals.

He is a long way from find­ing the laws he is look­ing for, but the results achieved so far hint at a direc­tion­al­i­ty and inevitabil­i­ty to evo­lu­tion that may not be ful­ly account­ed for by Dar­win­ian nat­ur­al selection.

Any­one who enjoys watch­ing a bril­liant mind at work/play should glance at Kauff­man’s The Ori­gins of Order, or read his pop­u­lar book on the same sub­ject, called At Home in the Uni­verse. One catch­es a glimpse of the pow­er of the math­e­mat­i­cal way of think­ing, and also of a nec­es­sary humil­i­ty in the face of life’s great­est mysteries.

He writes: “Almost 140 years after Dar­win’s sem­i­nal book, we do not under­stand the pow­ers and lim­i­ta­tions of nat­ur­al selec­tion, we do not know what kinds of com­plex sys­tems can be assem­bled by an evo­lu­tion­ary process, and we do not even begin to under­stand how selec­tion and self-orga­ni­za­tion work togeth­er to cre­ate the splen­dor of a sum­mer after­noon in an Alpine mead­ow flood­ed with flow­ers, insects, worms, soil, oth­er ani­mals, and humans, mak­ing our worlds together.”

Kauff­man is not stingy with words like “pos­si­bil­i­ty,” “maybe,” “I do not know.” He knows we have only begun to under­stand our ori­gins. He talks about “rein­vent­ing the sacred.” He offers a vision of cre­ation wor­thy of the most resource­ful Creator.