For the non-specialist, especially myself, things can get confusing when scientific

theories have bearing on our understanding of ourselves as biological creatures and on the nature

of the human condition itself. Certain evolutionary concepts can capture the imagination and,

often in public discourse, a theoretical insight can lose the context that gives it meaning in the

first place. Thought about natural selection out of context seems to imply “selection” in a

physiological sense rather than an evolutionary sense. Theories about the survival of the fittest

captures the imagination as something occuring in lifetimes rather than in evolutionary time, or

in societies rather than populations. Indeed the very idea of evolution invokes an image about

direction towards an “ideal.” While this usually does not change the original science behind an

idea it can change its future development; scientists and science do not exist in a vacuum outside

of the social, political, and even ideological realms. Historically, ideologies have best thrived

when they make a malleable social construction appear to be an absolute natural law. Biological

constructions, especially those used in evolutionary theories, are especially prone to

misunderstanding and therefore succeptible to misuse.

A chief difficulty, then, arises from the contradiction between scientific concepts

needing to be sufficiently fuzzy to be meaningful to good science but sufficiently clear to be

truthfully and practically communicable. To this end, Evolution in Four Dimensions (henceforth

E4D) is remarkably successful in promoting multiple dimensions of inheritance. The emphasis

on theoretical perspectives rather than a particular world view as embodied in E4D is important

to further any understanding of the complex dynamical systems inherent in biology and

evolution. Jablonka and Lamb highlight what is missing from a modern gene-centred view of

evolution to great effect. However, it may be interesting to contemplate whether Evolutionary

Biology has been a profoundly fruitful science in spite of its neglect of epigenetic, behavioural,

and symbolic inheritance or because of it. While E4D makes a strong case for the possibility of

epigenetic inheritance systems having important evolutionary implications, what is lacking is

applicable theoretical models with the predictive success on the scale of Mendelian genetics.

Epigenetic inheritance, even when observed empirically, does not have the theoretical

framework behind it to tell us whether an induced change, or even which kind of induced

change, actually persists or has persisted on an evolutionary scale. The dual role of epigenetics

as a response system and an inheritance system furthers the difficulty of creating a working

model. On the other hand, it is not immediately clear whether learned behavioural and symbolic

inheritance, which are important factors of development, can be usefully employed to

demonstrate evolutionary processes. For example, the ability to read and write is an evolved

trait, but there is a possibility for literacy to be lost within one generation because, in a sense,

symbolic and behavioural evolution exists on the level of the population as a cultural artifact.

That this has the ability to change the physiology of our brain blurs the distinction. But our

biology retains the capacity for literacy regardless, and so that may not be a fair argument.

Nevertheless, the gene-centred view abounds at least in part because it is sufficiently narrow

(and exculsionary) for the purposes for which it was invoked.

Perhaps these features explain, to some extent, our genetic obsession and the dominance

of the Modern Synthesis. Of the four dimensions, the genetic dimention is the one with the most

robust theoretical framework both in terms of explanatory power (natural selection) and

predictive success (Mendelian genetics). Now it may be important to recall the notion that a

theory makes an excellent servant but a terrible master. The genetic dimension helps us

understand much about biology, but not every facet of evolution can be explained in terms of

genetics alone. One could argue that the genetic dimension is the basis of evolution while the

epigenetic, behavioural, and symbolic dimensions form bases of lasting development, but this is

a matter of semantics that does not aid much in advancing a truly useful understanding of what is

a complex system in which change is pervasive. If the genetic dimension is likened to a sieve

through which we isolate certain aspects of evolution for the purpose of understanding, it

wouldn’t make much sense to retroactively define evolution as everything that can be filtered

through that sieve.

At the other end of semantic confusion are ideas of the form “what is ______.” “What is

a gene?” “What is an epigenome?” “What is a meme?” Philosophical questions abound. In any

philosophy course, someone inevitable asks a question of this form: “What is the colour of this

table?” Perhaps at a certain level, this is interesting to philosophize about. However, for

practical purposes, the colour of the table is really whatever the practical purpose dictates. To a

disinterested student, it may be an indiscriminate brown; to a painter it may be a certain mixture

between burnt umber and yellow ochre; for an interior designer the colour may be Jacobean; to a

camera it may be a certain pattern of red, green, and blue pixels; etc. In short, it must be asked,

“To what end?” In physics, the question, “What is light?” elicits a response in terms of what one

aims to understand or explain about light. For much observed phenomena, it is useful to think of

a wave. For photoelectric effects, one must invoke the concept of a particle. For many useful

purposes the question of precise definition is largely irrelevant and stands in the way of

understanding rather than deepening it. Similarly, a conceptual understanding of the gene or

meme or epigenome changes depending on what one aims to understand and which conceptual

tools are used to aid in a useful understanding. This should not provoke doubts about their

existence any more than the wave-particle duality provokes doubts about the existence of light.

Context matters.

The difficulty in evolutionary studies is that the context includes the nature of our own

existence. One could argue that the question, “What is a gene?” is more important than “What is

light” because of the medical applications of genetics or the social imagination captured by

genetics. Nevertheless, it may be the case that a gene for the purposes of medical applications

may be different than a gene for the purpose of evolutionary understanding. So context still

matters.

The question, “To what end?” also highlights two features important to our understanding

of evolution – models and metaphors. Functional understanding requires models and intelligible

insight requires metaphor. A model is necessarily false. However, the simplifying assumptions

of models hold back inexplicable complexity in order to reveal potentially important

relationships, ideally predictable and causal relationships, thereby producing practical

applications. This is also a chief feature of lab work – simplifying assumptions are made by

holding other factors constant, often to reveal practical applications in areas such as medicine.

Scientific metaphor is a powerful tool for comprehension and insight, despite being literally

false. The genes in a cell are not a switchboard, but it is useful to think them as such when we

imagine their being “turned on” or “switched off.” Likewise, Waddington’s epigenetic

landscape does not mean there is a literal landscape – it is a metaphor invoked to understand

canalization so that we can make sense of the confounding fact that identical genes can produce

differing phenotypes while diverse genes can produce identical phenotypes. The insight that it is

not possible to “average out” the effects of changing genes on the scale of a population to

understand any one individual is important in order to make intelligible the fact that genes are

not single causal agents. Perhaps the importance of models and metaphors can explain, to some

extent, the level of success in a science which, incidentally, is itself a product of path-dependent

change.

Jablonka and Lamb state early on in E4D that it is “quite wrong to think about heredity

and evolution solely in terms of the genetic system. Epigenetic, behavioral, and symbolic

inheritance also provide variation on which natural selection can act.” However, the genetic

basis determines strict limits within which this variation is possible, even though we may not

always be able to define these limits exactly. Epigenetic, behavioural, and symbolic dimensions

greatly increase the possibilities of variation, but how do we go about creating good models and

metaphors for determing what is and isn’t possible in terms of these dimensions of heredity and

evolution? More empirical research is required. Is it even theoretically sound to make the leap

from heredity to evolution? Working models are needed. The thought experiment of speciation

on Jaynus gives us the ability to imagine such a possibility, but evolution, heredity, and

development are so inextricably linked that it sometimes does not make sense to separate

observed phenomena into theoretical categories that exist solely on the basis of our own

conceptual frameworks1. Once again, the problem of forcing observable “truths” into

unobservable and quite plausibly arbitrary categories arises. If evolution can be thought of in at

least four overlapping dimensions, what happens when we try to factor in the interdependence of

evolution alongside development and heredity? We could, once again, ask, “To what end?” on a

case-by-case basis until a more fitting theoretical framework is developed. But, like evolution

itself, scientific progress is a case of path-dependent change (for which selection might not be

necessarily adaptive). It often will not be possible to accurately force all new discoveries into

1 Specialization in the sciences can magnify the problem – for example, if molecular biologists don’t engage with evolutionary anthropologists, or philosophers of science propagate theories of paradigm shifts without attempting to open a sincere dialogue with practicing scientists, it would severely limit the quality of scientific progress can be made?

existing paradigms, but it often doesn’t serve the interest of understanding to have a complete

paradigm shift, either. Perhaps the idea of multiple dimensions can be employed to bridge the

gap, as Jablonka and Lamb do when they incorporate epigenetic inheritance systems into a “neo-

Darwinian” framework while simultaneously referring to certain ideas as “neo-Lamarckian.” In

identifying different theoretical frameworks with which to study a complex reality, as long as it

is clear that the framework is a lens of our own construction and not a literal feature of that

reality, it is possible to have a deeper, richer, and more fruitful understanding of both the world

we live in and ourselves.

In truth the “level” and “dimension” perspectives in E4D only appear revolutionary in the

sense that E4D advocates until one realizes that our understanding of anything in nature is

comprised of “levels” of understanding. When we categorize biological organisms into plants

and animals; animals into mammals, fish, birds, reptiles, amphibials, invertebrates; or celestial

bodies into planets and moons; and even sciences into biology and chemistry and physics, it is

not to propose that these are the literal categories of nature, but categories adopted to suit our

evaluative and conceptual purposes at any given time for a given function deemed important at a

particular level, and are therefore possible to change over time even at their most fundamental

levels. This doesn’t mean that everything is relative and reality exists as a result of our

theoretical constructs. One can study a tree to different purposes using biology, chemistry, and

ecology – but this does not mean that the tree itself changes based on which theories we use to

understand it. Rather, our theoretical frameworks shape the way in which we view the reality

that exists outside of our minds and for practical purposes, and – I would argue – for the

purposes of understanding, it is not terribly important whether a single “objective reality” exists

or not.

For example the important questions in mathematics are not of the type “Do numbers

exist?” but “How can we use certain numerical concepts to effectively explain and ideally predict

the relationships we observe in the world?” The latter is an equally useful question whether the

answer to the former is yes or no. Perhaps it is useful to think of numbers as existing for the

purpose of doing mathematics, just as it is useful to think of the genetic and epigenetic, or

behavioural and symbolic, dimensions as existing for the purpose of understanding certain

evolutionary truths. However, these are lenses through which to oberve evolutionary

phenomena. The fuzzy categories only hinder understanding when one focuses on the nature of

the category rather than the nature it seeks to explain. Our framework will necessarily change

depending on our levels of understanding, and there may be right and wrong ways (or, more

practically, useful and unuseful ways) to construct a theoretical level.

Returning to the first questions posed in this commentary, the lens metaphor may prove

useful in understanding certain difficulties posed by the biological sciences. Sciences provide us

with conceptual lenses through which to observe worldly phenomena for a specific purpose of

understanding. The danger lies in the fact that a lens fashioned to observe that which is

considered external can be employed to look back upon ourselves. The image has been altered

but its scientific association implies objective reality. A distinction made for one purpose is

bound to be used for another. Here philosophers and biologists have an important role and,

arguably, an ethical duty to carefully consider the social implications of a theoretical framework.

Constructions such as race, gender, fitness, and selection – through their association with nature

and science– can be and, indeed have been, propounded as objective truths to harmful effect.

Because of this the realms of science and philosophy should be clear about theoretical constructs.

The trouble lies in the fact that scientists and philosophers are not objective arbiters of reality

either, being themselves part of a socio-political historical narrative. Indeed the skepticism of

the generalist or layperson may be traced to historical abuses of scientific, or pseudo-scientific,

authority. Does this mean that we have worked ourselves into a corner out of which insight and

understanding cannot arise? It would if science existed in a world unto itself, and specialized

fields were separated from one another. However, insightful understanding requires an

unspecialized approach that involves cooperation, debate, discussion, and meaningful dialogue

between everyone with an interest in truth. The possibilities for understanding are only as

limited as the divisions we maintain between disciplines that have been divided for a different

purpose – a division that exists to serve one end may hinder in serving another. So while our

ends may differ, the most this layperson can contribute to scientific understanding is to continue

to ask of any theoretical framework, “To what end is this useful for the purpose of

understanding?”