Sunday, November 1, 2015

Why are we still searching for evidence of natural selection?

During the last century, especially the second half, many biologists (including myself) spent their careers in search of supporting evidence for Darwin’s theory of natural selection. It was exciting to witness the seemingly endless accum-ulation of published data from both laboratories and natural habitats everywhere, and for everything from bacteria to flowering plants to mammals.  We couldn’t get enough. Drunk on the exuberance of the ‘modern synthesis’, we all embraced an unquestioned faith in a new and exciting mantra:  “Nothing in biology makes sense except in the light of evolution” (Dobzhansky 1973).   It was true.

And so … Darwin was right:  natural selection works.
It’s everywhere.  Like gravity.

But the exuberance still has an oddly powerful hold for many evolutionists. Even more than a century and a half after publi-cation of the ‘The Origin’, they seem never to tire of hearing another new report (added to the now brimming pile) showing that natural selection works — even showing it exactly how most researchers already expect it to.  
Hypothesis:  The insects are mostly green because the lizard is better at spotting the brown ones.  'Eureka!  Let's do an experiment to show this!  We could even check on the physiology and genes involved.  It's bound to show that Darwin was right!' 

It’s like they are addicted to the buzz of another discovery ‘fix’, because they know in advance that it always delivers.  [After all, Darwin was right].  With each new testimonial for an apparent consequence of natural selection — e.g. with details of how a particular trait is adaptive, or the mechanism for how genes inform it — there is continuing praise and blessing from the fellowship. It doesn't matter that (as is often the case) essentially the same interpretation for the same trait (in different species or from different habitats) had already been published previously — all fitting neatly in line with standard predictions of accepted theory.  These testimonials take place at annual conferences, and weekly study groups and meetings with guest speakers for evolutionary biology congregations, attended faithfully by many followers within university departments everywhere.  Even without prayers and hymns, the atmosphere is not unlike a worship service — for Darwinism — with a sea of heads nodding in approval, frothing at the mouth.

The cherished convictions of the congregation are especially strengthened when the newly reported study involves a particularly elegant experimental design, an application of new technology, a novel or expensive method of data collection, or complex and rigorous data analyses.  Hallelujah!  Praise the Lord!  A new, more potent fix with a stronger buzz!  It doesn’t even seem to matter that the evidence presented often involves a study design from which alternative results or interpretations would have been implausible, or essentially impossible to obtain.  If a study does happen to turn up negative results, they normally end up in a file drawer, unpublished — because the only acceptable explanation is that the experimental design or data collection must have been improperly carried out.  [After all, Darwin was right].  And so, routinely, investigations are conducted for which the answers (positive ones) are already known in advance.  [... not a great track record for bolstering integrity and public confidence in science].

From Darwinism itself, I suppose, we should expect nothing less.  For our ancestors, identification and alignment of one’s views and beliefs with those of a growing contingent of others not only rewarded their intrinsic need for a sense of belonging and self-esteem.  It also undoubtedly provided assurance — often grounded in truth — that this conspicuous group of contemporaries was probably on to something important (without needing to know why) that ended up rewarding reproductive success.  [Today, of course, researchers know why, in terms of strategy for rewarding tenure, promotion, and status from an expanding publication record that corroborates the cherished convictions of the congregation].

But surely we need to move on in the 21st Century. We don’t need new reports showing that gravity works, or showing that the earth revolves around the sun.  Similarly, when a new report arrives showing essentially nothing but another example of how natural selection works in ways that we all could have guessed — consistent with what established theory predicts — I am so not impressed.

Is there any valuable research left to do on natural selection?  Certainly.  This happens when there are convincing reasons to hypothesize (with potential to test) that natural selection may (or does) work in ways that would be (or is) surprising, (or, surprisingly, isn't working at all) — i.e. running counter to expectations based on published theory (or without being readily predicted by that theory). It can also happen when the research is placed conspicuously in the context of contributions that have potential to address needs or goals that are important to society at large.  In many cases, the latter is easy to do, but commonly ignored (usually because it is regarded as uncool by the elites).

Please, if you must search for more evidence that Darwin was right about natural selection, at least make sure it passes the test for conspicuous and meaningful valuation branding. Otherwise, it runs a growing risk of looking like something stuck in the 20th Century.  I need regular reminders of this myself; as an ardent evolutionist, I can be as rabid as they come.


Dobzhansky T (1973) Nothing in biology makes sense except in the light of evolution. American Biology Teacher 35 (3): 125–129.