Evolutionary Path Dependency

A few colleagues and I have started to delve into Richard Dawkins The Greatest Show on Earth: The Evidence for Evolution.  Apparently, our leisure reading involves reading science based books.  For those of you who are still reading the book, this blog post goes into detail about Chapter 11 and this introduction will serve as my official spoiler alert (in case you do not want your science spoiled); for others, we can venture on.


The primary purpose of the book is to present the most compelling evidence for evolution and elaborate as to why, for all scientific intents and purposes, the theory of evolution is a fact.  Beyond this goal, the book is littered with several examples (scientific experiments, fossil records, living genome comparisons, etc.) that are quite illuminating and offer great analogies for social science studies – as an aside, the evidence for evolution is more compelling than the evidence we have for almost any theory in political science.

Chapter 11 in the book is primarily focused on the terrible "designs" that have resulted from evolution.  That is, given the current state of a creature, some of the functionality of particular organs are inefficient and, if the system was designed from a blank slate, could be quite improved upon by some sort of bio-engineer.  Unfortunately, perhaps, evolution does not work on tabula rasa like creatures and mutations that were once optimal may become less optimal in creatures that have inherited past traits.  A trait inherited may not be able to be redesigned (randomly mutated and selected as superior by conditions that encourage/prohibit breeding) as simple mutations will not allow for an animal to be overall more fit.

A relevant example of this is the Koala.  The Koala is quite an odd case since, as a marsupial, the females have a pouch that protects and feeds her young (her joey).  However sensible the marsupial pouch is, the tree-climbing Koala has a downward facing pouch, not upward facing like the Kangaroo – something that is seemingly inefficient (or potentially dangerous) for a tree-climbing species.  However, the Koala shares its ancestry with the wombat, and their common ancestor had a downward facing pouch as this common ancestor was a digging animal.  Digging from the front to the back would be quite terrible for a upward facing pouch and the downward facing pouch had excelled during this common ancestor's tenure on earth.  Some time later, as the populations diverged, the Koala, or its ancestors, began using trees as, perhaps, it provided access to its food.

Several other animals feature these seemingly inefficient designs that were the product of some sort of path dependency.  The human has terribly located sinuses with (drainage holes at their top) for an upward standing animal – however, the location and position is not so inconvenient if we are primarily moving around on all fours.  Similarly, our backs are not well designed for travel upon two feet, but we have made due with what we have. 

The chapter contains a few more such observations about the relatively inefficient body parts in other human parts, fish, giraffes, and dolphins.  This gives us quite the relevant analogy for social science discussions of path dependency.  There are quite a few business and technological analogies that have been employed over the years, especially the QWERTY keyboard, but increasing our potential pool of analogues from nature can offer more both in the classroom as well as in articles.  While often the institutions we do care about are designed with a particular focus in mind, the existence of new shocks, political movements, economic trends, technological change, and bureaucratic inertia have expanded, limited, and reshaped the role of the institutions from what they originally were.  These often minor changes leaves us with several quizzical monstrosities that would simply be more inefficient if they were redesigned from scratch – unfortunately, politics and economics tend not to work that way.

These seemingly gradual processes are interesting enough to catalogue and model, and they leave us with something radically different than we would expect – gradual change of institutions is on the equilibrium path and leads to pareto inefficient outcomes.  Perhaps this is another example of several, individual acts producing a collectively irrational outcome. In discussing the terrible performance of the human eye and all the "photoshopping" the brain must do to correct the poor image our eye produces (reverse the image, fill in blind spots, etc.), Dawkins remarks something that might be well said of many political institutions: "Blunders of this kind come not from poor design but from history." (Kindle location 4807).

There are a few other useful analogies that I will explore in an upcoming posts: the problem of biological essentialism and the collective action problems of trees.

Michael A. Allen

About Michael A. Allen

Michael is an Assistant Professor in Political Science at Boise State University with a focus in International Relations, Comparative Politics, and Methodology (quantitative and formal). His work includes issues related to military basing abroad, asymmetric relations, cooperation, and conflict. He received his Ph.D from Binghamton University in 2011.

2 Replies to “Evolutionary Path Dependency”

  1. I’ve often been disappointed with how little understanding of evolutionary theory one finds in “evolutionary” accounts of institutional change. My dissertation, which I am currently writing, attempts among other things to make use of exactly this sort of evolutionary-path-dependency thinking as applied to processes of democratization, with ideas acting in the role of random mutations.
    And if you mentioned Dawkins, I still hope to one day apply his ideas of memetics to political science topic. (I even have a title ready: “democratic contagion: memetic or mimetic?”)

  2. How do you access these changes/randomization in your dissertation? I imagine there are a few ways to potentially go about it – for example, you could do qualitative descriptions of the process, quantitative analysis of changes proposed (amendments/bills) and/or revolution/coup attempts, or perhaps work in some game theoretic attempts at change. For the latter, I would imagine Greif and Laitin’s 2004 APSR piece on endogenous institution change is apt.
    In the same vein of some of Dawkin’s work, there may be room for a simulation. His work is on birds, trees, and the like, but having a bare institution, proposed changes, and ways in which people can select particular changes might have interesting outcomes. Though, this route would require some computer programmer skills.

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