Science Literature

Students of evolution are taught to avoid incorporating the idea of progress to the theory. Law + Chance do not allow the incorporation of an over-riding goal. One Evolution 101 course expresses it this way: "It is tempting to see evolution as a grand progressive ladder with Homo sapiens emerging at the top. But evolution produces a tree, not a ladder - and we are just one of many leaves on the tree." The Darwinian mechanisms of mutation + natural selection emphasise Chance over Law, with the corollary that the evolutionary process is unpredictable. Readers of Stephen Jay Gould will know that this was one of his favourite themes, to which he repeatedly returned. In a recent paper, Simon Conway Morris consciously challenges the status quo and points a way to a different perspective on evolutionary transformation:

"Specifically, I argue that far from its myriad of products being fortuitous and accidental, evolution is remarkably predictable."

Are humans an "evolutionary inevitability" or just one of many leaves on the Tree of Life? (Source here)

Conway Morris has wrestled with the question: why, if evolution is fortuitous and accidental, are there so many evidences of convergence? Over-specialisation has meant scientists escape the overwhelming evidence for convergence being ubiquitous. Their research "tends to track the particularities and peculiarities of a given group and seldom enquires whether there are any wider or deeper sets of explanations". This needs to change, and the advocates of neo-Darwinism need to acknowledge the deficiencies of their theory.

"Here, I will suggest that one central tenet of the current neo-Darwinian synthesis, that evolution is for all intents and purposes open-ended and indeterminate in terms of predictable outcomes, is now open to question. Thus, not only is life suspended between permanently uninhabitable regions that are either locked into crystalline immobility or in continuous and chaotic flux, but that the lines of evolutionary vitality thread through a landscape that leaves evolution with surprisingly few choices. The basis of this view relies on the phenomenon of evolutionary convergence."

We can commend Conway Morris for his willingness to support "the heterodox idea" that there is more predictability in evolutionary biology than the Darwinians will admit. We need scholars who are prepared to think rather than operate within a theoretical straitjacket. However, what Conway Morris does not do is to critique the paradigm that makes "fortuitous and accidental" mechanisms the key to the mystery of life's origins. He thinks that "something is missing" and that he can bolt on something that will somehow turn these stochastic components into an engine for delivering "ubiquitous evolutionary convergence". He wants to do this by bringing in contributions from developmental biology and epigenetics. Key words for the new way of thinking include: emergent phenomena, self-organisation and nonlinear systems.

"[T]hese concepts can be melded with the currency of evolution in the form of developmental constraints (the role of which may be exaggerated) and epigenetics to suggest that indeed something is missing in the Darwinian synthesis."

Is something missing? Hardened Darwinists will interpret this as merely a refinement of their essential mechanisms: with an acknowledgment that living things are products of history: genetic variations and natural selection can only work with the source material that is there. This is how structuralism can be integrated within the evolutionary synthesis. But Darwinists are not showing any signs of acknowledging that anything significant is missing from their theory! The evolution of life is still essentially fortuitous, but the options open for transformation are constrained by history.

Conway Morris does not talk about mechanisms that challenge the "fortuitous" thesis. Rather, he gives numerous examples of striking convergences that allow him to suggest that evolutionary trajectories are predictable. However, the argument presupposes common ancestry and the early (existing in the Precambrian) appearance of life forms that exhibit "an extraordinary degree of complexity". His story effectively starts with complexity and it is this complexity that is transformed as the Tree of Life extends its branches. The process is described as an apparently "baffling series of self-organizations".

"In many cases, we also see that the particular molecules show a remarkable versatility of function in what appear to be unrelated contexts. It is most probable that these molecules are homologous, but in many cases the overall architecture and the iron constraints of active sites (or equivalents) suggest that convergence should not be automatically dismissed. It is also striking how in general the idea that primitive groups are simple, almost skeletal constructions in comparison to their descendants, is simply incorrect and in precursors as diverse as the last common ancestor of the eukaryotes or choanoflagellates we either infer or see an extraordinary degree of complexity. Rather than imagining that this arose by a series of conveniently cryptic prior stages, we may have to face the possibility that evolution involves what to us seem to be a baffling series of self-organizations."

None of the above is understood at the level of mechanism - Conway Morris is developing a theoretical model that tries to make sense of twigs without being able to trace the branches. "What we do not understand is how organisms assemble as exceedingly complex functional entities nor why they repeatedly navigate to convergent solutions." There is no insight here as to how complexity is built from simple precursors - just an appeal to self-organisation. This, however, is the weak point of the argument. The origin of biological information cannot be a matter of self-organisation because DNA is a code. The precursor molecules have physical and chemical bonds that permit all possible different codes to be carried. There is no innate process of organisation that can generate information.

Nevertheless, Conway Morris has put his finger on data that needs an explanation. Working within his adopted paradigm, Law (rather than Chance) must be invoked if there is to be predictability. This is the hope behind the appeal to self-organisation, developmental constraints and epigenetics. Will this deliver predictability? I think the answer to this is "yes" - but in a more limited sense than that intended by Conway Morris. Developmental biology has taken us beyond the genocentric view of organisms. For example, concentration gradients of morphogens regulate tissue differentiation and morphogenesis in multicellular organisms. Where a pattern of development can be described mathematically, the application area is limited to a limited range of organisms. These ideas can be applied, in principle, to predict diversification within the basic types of life, but beyond this, the empirical base is speculative.

This is where design thinking has enormous potential to move the discussion forward. If we allow Design to stand alongside Law and Chance, there are ways to move the discussion of biological information forward and to ensure theoretical ideas are both informed and constrained by empirical research. Conway Morris' descriptions of ID as "anti-evolutionary dogma" and "scientific fiction" fail to do justice to scholars who "in any other respect fail to manifest any obvious sign of mental instability".

How do we know that "convergence" is the right description of the phenomena described in this paper? Could some of them be design motifs? How can the different explanations of Law and Design be evaluated? This is a contribution ID scientists can bring to the table.

Evolution: like any other science it is predictable
Simon Conway Morris
Philosophical Transactions of the Royal Society B, (January 12) 2010 365, 133-145 | doi:10.1098/rstb.2009.0154

Abstract: Evolutionary biology rejoices in the diversity of life, but this comes at a cost: other than working in the common framework of neo-Darwinian evolution, specialists in, for example, diatoms and mammals have little to say to each other. Accordingly, their research tends to track the particularities and peculiarities of a given group and seldom enquires whether there are any wider or deeper sets of explanations. Here, I present evidence in support of the heterodox idea that evolution might look to a general theory that does more than serve as a tautology ('evolution explains evolution'). Specifically, I argue that far from its myriad of products being fortuitous and accidental, evolution is remarkably predictable. Thus, I urge a move away from the continuing obsession with Darwinian mechanisms, which are entirely uncontroversial. Rather, I emphasize why we should seek explanations for ubiquitous evolutionary convergence, as well as the emergence of complex integrated systems. At present, evolutionary theory seems to be akin to nineteenth-century physics, blissfully unaware of the imminent arrival of quantum mechanics and general relativity. Physics had its Newton, biology its Darwin: evolutionary biology now awaits its Einstein.