Yogi Berra and taxonomy's ultimate destination

Putting systematics back on course reveals distractions from its mission

Yogi Berra said that unless you know where you’re going, you might not get there.  Advocates of DNA barcoding, and other variations on molecular-based taxonomy, it seems to me, have forgotten taxonomy’s traditional destination, setting course for a different one.  Their view of taxonomy’s destination is a small one, and not just in terms of the size of molecular data points.  They aim to detect and tell apart species, to make species identifiable, so that other fields of the life sciences may advance, but do so in a manner that takes systematic biology off its own course.  There is great practical value, of course, in making identifications, but this is only a tiny part of traditional taxonomy, and not among its most interesting parts; it is a mere by-product of the lofty goals of fundamental systematics research.  Pursued as an end in itself, making species identifiable quickly and easily can be used— is being used—to justify dumbing-down the science of systematics, ignoring the most compelling evidence of evolutionary history, estimating species based on arbitrary degrees of genetic differences, and remaining ignorant of that which makes species most remarkable and interesting.

Like ships at sea, sciences must remain on course, true to their mission, if they are to reach their destinations—even if distracted by cannon fire. Image: “Battle of Cape Passaro, 11 August 1718,” oil on canvas by Richard Paton (1717-1791), Royal Museums Greenwich.

Taxonomy has had the same goal in mind for thousands of years: making sense of the wondrous pattern of similarities and differences among species.  Admittedly, this goal has evolved and gained in complexity, nuance and implications through the centuries, shaped by advances in theory, enabled by technological innovations, and reframed by astonishing discoveries, yet taxonomists remain motivated by the same deep curiosity shared by Aristotle, Linnaeus, Darwin, Hennig, and thousands of taxonomists, to explore the jaw-dropping diversity of life, interpret the astonishingly complex pattern of similarities and differences among species, and understand the multi-billion-year history of diversification of characters and species written in improbable novelties and complexity. 

Mars can be identified visually by its relative position, brightness and color, but simply identifying Mars among the planets and stars in the night sky isn’t very interesting.  Knowing that Mars has a radius of 2,106 miles; an atmosphere primarily comprised of carbon dioxide, nitrogen and argon gases; two moons; and a volcano,  Olympus Mons, three times taller than Mt. Everest, are just a few of the properties of the red planet that make it different and fascinating.  Details matter.  Knowing them, being able to compare them to Earth’s and other planets’ properties, creates perspective.  Seeking to understand the origins and significance of unique attributes expands our minds, enriches our intellectual lives, and deepens scientific understanding.  We should not constrain astronomers to simply making dots of light identifiable, but encourage and support them, as we do, to explore and discover as much as they can about the diversity and origins of each and every component of the solar system and universe.  The same is true of taxonomy.  That identifying species is necessary for credible biology and adds trillions of dollars to the global economy are icing on the cake—additional reasons to support taxonomy.  But, at its core, taxonomy remains a fundamental, curiosity-driven science that is, like basic physics, astronomy or chemistry, driven to explore the unknown.  Taxonomy done for itself is repaid handsomely in unexpected knowledge that improves our understanding of ourselves and our world, enriches our lives, and prepares us to avoid some of the worst outcomes of the biodiversity crisis, and adapt to others. Knowledge that will never be created by simply identifying species or limiting our knowledge to DNA sequences.

Taxonomy should adhere to the same heading that has guided its fantastic progress for centuries, tacking as it goes to avoid being blown off course, making steady progress toward a complete understanding of what and how many species exist; what makes each unique; how they are related; how their similarities and differences make sense in the context of evolutionary history; how they are distributed in geographic and ecological space and time; and, pulling it all together, toward a comprehensive phylogenetic classification that serves as a summary of, and gateway to, all that we have learned.

Taxonomists can and should continue to eagerly incorporate technological advances into their work as appropriate, without being distracted by winds of change from where they are going. They should be aware of the vital applications of taxonomic knowledge to problems in science and society—from ecology and conservation to agriculture and biomimicry—and deliver as much reliable data, information and knowledge as possible, in accessible form, but do so in a way that takes full advantage of, but in no way distracts from, progress toward their own destination.

Systematists should be recognized as partners by other biological disciplines, understood to have their own mission, methods, theories, and ambitions, just like every other field, and not treated as if they exist to provide identifications. Understanding the laws of physics is necessary in order that my automobile work properly, but no physicist gets out of bed in the morning motivated by that limited application of physics alone.  Taxonomy should be rewarded for the fantastic knowledge and services that it has long and proudly provided in abundance, not punished for striving, at the same time, for excellence, depth of knowledge, and realization of its own mission.

Taxonomists have, too often, gone along with wave after wave of pop science, hoping that, by appeasing fellow scientists and funders, by trying to blend in, they would keep a place at the table.  But, misunderstood and taken for granted, failing to celebrate its uniqueness, taxonomy is becoming trivialized as a mere molecular caricature of itself. And now, even worse, it is being redefined as nothing more than a source of information needed by others.  Systematics is in a precarious position having drifted off course, but it is not too late to come to our senses, restore taxonomy’s bearings and reassert its proper place among the sciences.

As species go extinct at a rate not seen in tens of millions of years; as museums and universities pander to fashions in science; as weak-kneed administrators fold to pressures to conform; as positions and funding supporting taxonomists to do taxonomy disappear; as environmental scientists demand identifications while disrespecting the needs of taxonomy to make them reliable and informative; and as the opportunity to explore, discover, describe and classify Earth’s species, and document its evolutionary history, slips through our fingers, it is imperative that we clarify and unapologetically reassert the mission, goals, needs and priorities of taxonomy.  It is urgent that we remind ourselves—and others—of where we are headed as a fundamental science and once again navigate in the right direction.  Unless we do so now—clearly and forcefully—we might never get there.