Evolution Writ Small
This is a preliminary draft of one chapter of a book-in-progress
tentatively entitled, “Evolution As It Was Meant To Be — And the Living Narratives That Tell Its Story”.
You will find
a fairly lengthy article serving as a kind of extended abstract of major
parts of the book. This material is part of the
Biology Worthy of Life
Project. Copyright 2017-2021
The Nature Institute.
All rights reserved. Original publication: May 7, 2019.
Last revision: April 30, 2021.
One might think that the natural place to look for an understanding
adequate to the evolutionary history of life would be the powers of
self-transformation we observe in the evolving organisms themselves. But
it can be dangerous to look in a clear-eyed manner at the creative
potentials of living beings. One risks having to acknowledge the evident
wisdom and agency so vividly on display. In an era of institutionalized
materialism, any suggestion that these inner powers are vital to the
entire evolutionary story can only produce the sort of discomfort
associated with a taboo and what I have been calling the biologist’s
On the other hand, Stephen Jay Gould ran afoul of no taboo when he
effectively ascribed this same wisdom and agency to natural selection.
Countering the questions we heard voiced in
about what sort of creative principle could explain the “arrival of the
fittest”, he asked (referring to several giants of twentieth-century
evolutionary biology), “Why was natural selection compared to a composer
by Dobzhansky; to a poet by Simpson; to a sculptor by Mayr; and to, of all
people, Mr. Shakespeare by Julian Huxley?”
The answer, Gould said, is that the allusions to poetry, musical
composition, and sculpture helpfully underscore the “creativity of natural
The essence of Darwinism lies in its claim that natural selection creates
the fit. Variation is ubiquitous and random in direction. It supplies
the raw material only. Natural selection directs the course of
evolutionary change. It preserves favorable variants and builds fitness
On its face, Gould’s argument was a puzzling one. His answer to the
question how creative variation arises amounted to saying nothing more
than “It is everywhere” (“variation is ubiquitous”) — which, one might
have thought, only added urgency to the need for an explanation. He
seemed to suggest that, because organisms are so expert and prolific at
producing new possibilities of life, the evolutionist can simply take
their powers of achievement for granted. Because organisms so
abundantly provide raw materials for creative work, we are somehow free to
declare natural selection the agent performing this work. It need
only preserve all those wonderfully effective new traits.
How easy it is, apparently, to forget that the so-called “raw materials”
being preserved are never merely raw materials! At the first appearance
of any beneficial change, the creative work has already been accomplished.
We find ourselves looking, not at random raw materials, but at a viable
feature harmoniously incorporated into all the tightly interwoven
complexity of a living being. The only power we know to be capable of
such incorporation is that of the organism telling its own
a story always reflecting the qualitative, dynamic character and
developmental potentials of a particular species.
This harmonious incorporation of new features, founded upon whole-cell
inheritance and manifested in whole-organism processes of development, is
the only place where we see creative evolutionary change originating. The
spreading of an already-existing change through a population — almost the
only thing those dominant evolutionary theorists known as “population
geneticists” have attended to — is not where we see evolutionary novelties
So Gould’s response shows us that one of the evolutionist’s strategies for
coping with taboo agency is immediately to turn the question, “How does
creative change arise?” into the different question, “How does creative
change, once arisen, spread through a population?” The switch of topics
is not hidden, but occurs in plain sight. Only a habit of
relative to the organism’s agency seems able to explain the prevailing
inattention to such an obvious evasion of a real biological question.
None of this means we need to doubt whatever is true in the idea of
natural selection. As philosopher Ronald Brady summed it up, “simple
selective pressure has never been seriously in question. That certain
conditions can cause selective mortality means only that some alleles
[genes] can be weeded out, not that this action can combine with variation
in order to optimalize adaptation”
Eliminating problematic traits (or defective organisms) is not the same
thing as profoundly transforming the integral unity that every organism
The point is not terribly subtle. There is simply nothing in the idea of
natural selection that points to the creative capacities necessary for
producing new adaptive features — for producing, say, a four-chambered
heart (with all its organism-wide implications) from a three-chambered
one. There is only the living being whose agency and activity natural
selection necessarily assumes and which, as a result of
evolutionists have unconsciously transferred to a mystical “mechanism” of
selection somehow operated by the inanimate world.
So here is our main question for this chapter: What do organisms show us,
directly, compellingly, and uncontroversially, about their own powers of
organic transformation? Much of the first half of this book contributes
to an answer, especially at the physiological and molecular levels of
observation. But in the present, evolutionary context, it will be well to
look at the organism from a new angle.
A ‘magical’ power of
If I were to tell you that scientists have sequenced the genomes of two
entirely distinct organisms — say, a flying creature such as a bird or
bat, and a crawling one such as an earthworm or snake — and had found the
two genomes to be identical, you would probably think I was joking.
Surely such differently structured forms and behaviors could not possibly
result from the same genetic instructions! A genome, we’ve been told time
and again, comprises a blueprint for, or otherwise corresponds to, a
phenotype — that is, the manifest form and functions of an organism. And
what could be more different than the phenotypes of snake and bird?
And yet a good reason for jettisoning the entire notion of “genetic
instructions” is that there are flying and crawling creatures with
the same genetic sequence. A monarch butterfly and its larva, for
example. Nor is this kind of thing rare. A swimming, “water-breathing”
tadpole and a leaping, air-breathing frog are creatures with the same
inherited DNA. Then there is the starfish: its bilaterally symmetric
larva swims freely by means of cilia, after which it settles onto the
ocean floor and metamorphoses into the familiar form of the adult. This
adult, carrying the genome passed on from its larval stage, exhibits an
altogether different, radially symmetric (star-like) body plan.
Metamorphosis of an Insect
The goliath beetle
(Goliathus goliatus), larva and
The British physician and evolutionary scientist, Frank Ryan, described
the goliath beetle’s metamorphosis this way:
“Rather than a den of repose, we see now that the enclosed chamber of the
goliath’s pupa really is a crucible tantamount to the mythic pyre of the
phoenix, where the organic being is broken down into its primordial
elements before being created anew. The immolation is not through flame
but a voracious chemical digestion, yet the end result is much the same,
with the emergence of the new being, equipped with complex wings,
multifaceted compound eyes, and the many other changes necessary for its
very different lifestyle and purpose.
“The emerging adult needs an elaborate musculature to drive the wings.
These muscles must be created anew since they are unlike any seen in the
larva, and they demand a new respiratory system — in effect new lungs — to
oxygenate them, with new breathing tubes, or tracheae, to feed their
massive oxygen needs. The same high energy needs are supplied by changes
in the structure of the heart, with a new nervous supply to drive the
adult circulation and a new blood to make that circulation work.
“We only have to consider the dramatic difference between a feeding grub
or caterpillar and a flying butterfly or a beetle to grasp that the old
mouth is rendered useless and must be replaced with new mouthparts, new
salivary glands, new gut, new rectum. New legs must replace the
creepy-crawly locomotion of the grub or caterpillar, and all must be
clothed in a complex new skin, which in turn will manufacture the tough
new external skeleton of the adult. Nowhere is the challenge of the new
more demanding than in the nervous system — where a new brain is born.
And no change is more practical to the new life-form than the newly
constructed genitals essential for the most important new role of the
adult form — the sexual reproduction of a new generation.
“The overwhelming destruction and reconstruction extends to the very cells
that make up the individual tissues, where the larval tissues and organs
are broken up and dissolved into an autodigested mush … To all
intents and purposes, life has returned to the embryonic state with the
constituent cells in an undifferentiated form”
(Ryan 2011, pp. 104-5).
Millions of species consist of such improbably
distinct creatures, organized in completely different ways at different
stages of their lives, yet carrying around the same genetic inheritance.
This is something to reflect on. How could the
transformation possibly be orchestrated, and where lies the
power of orchestration?
To speak of the “power of orchestration” will
perhaps trigger accusations of “mysticism”. And yet the expression of
some power is right there before our eyes. It is hardly
anti-science to let ourselves come up against questions we cannot yet
answer. They are what science is for.
One way or another we must come to terms with the
fact that the organism and its cells actively play off the genomic
sequence and all the other available resources within a huge space of
profoundly creative possibility. No identifiable physical force compels
or directs the cell-by-cell and molecule-by-molecule dissolution and
refashioning described in Box 18.1. It is only healthy that such
difficulties for our understanding should be acknowledged.
Looking at the pupal case of a fly, the
developmental biologist and evolutionary theorist, Wallace Arthur, asked:
“What on earth is going on in there to turn one animal into another? If
we didn’t know better, we might venture ‘magic’ as our best attempt at an
(Arthur 2004, p. 45).
Arthur’s wonder is justified. And he surely expects, as we must, that a
more satisfactory answer than “magic” will be forthcoming. Meanwhile, it
is worth keeping in mind that the “magical” impression of a phenomenon
becomes more powerful in direct proportion to the inadequacy of our
existing explanatory resources.
Metamorphosis of cells
Frogs and butterflies aside, we are brought up against the same
perplexities even when we consider the more “routine” developmental
processes in complex organisms. Take, for example, the radical cellular
transformations following from a single, fertilized human egg cell. As
adults, we incarnate ourselves in trillions of cells, commonly said to
exemplify at least 250 major types. And when we count subtypes and
transient types, we may well find that — as cell biologists Marc Kirschner
and John Gerhart tell us — there are “thousands or tens of thousands of
kinds representing different stable expression states of the genome,
called forth at different times and places in development”
(Kirschner and Gerhart 2005, pp. 179-81).
As researchers hone their ability to investigate single cells, they are
finding that even neighboring cells, “identical” in type and occupying the
same tissue or niche, reveal great heterogeneity. Every cell is, in
whatever degree, “doing its own thing”. The path from the zygote through
the many intermediate stages of cell differentiation to a particular
mature cell type is a path that, for every cell, takes a novel course. It
is a distinct cellular “evolution”, or active unfolding of potential.
Strikingly, however, the cell is not only doing its own thing; it is also
heeding the “voice” of the surrounding context, which is in turn an
expression of the unity of a particular kind of organism. So each cell is
disciplined by the needs of its immediate cellular neighborhood as well as
those of the entire developing organism, which in turn is conditioned by
the larger environment. We are looking at a remarkable diversity within
an overall, integral unity.
In humans there are, for example, cells (neurons) that send out extensions
of themselves up to a meter or more in length, while being efficient at
passing electrical pulses through the body. There are contractile cells
that give us our muscle power. There are the crystalline-transparent fiber
cells of the lens of the eye; their special proteins must last a lifetime
because the nucleus and many other cellular organelles (prerequisites for
protein production) are discarded when the fibers reach maturity. There
are cells that become hard as bone; as easily replaceable as skin; as
permeable as the endothelial cells lining capillaries; and as delicately
sensitive as the various hair cells extending into the fluids of the inner
ear, where they play a role in our hearing, balance, and spatial
Many of these cells are as visibly and functionally different, in their
own way, as the phenotypes of any two organisms known to us. This,
you might think, would interest the evolutionary biologist.
Organisms manage their
own germlines expertly
Of all the cellular phenotypes, it would be hard to find one whose
differentiation and specialization is more distinctive, or more expertly
and intricately contrived, or more purposively managed, than the germ
cells of sexually reproducing organisms. We can hardly help acknowledging
that parental organisms, in carrying out meiosis, genetic recombination,
and mating, play a massive role, not only in preserving and re-purposing
the genome, but also in transforming it. Deeply embedded in time and
always facing the future, every sexually reproducing animal expresses its
future orientation most immediately and vividly in the gametes whose full
“self-realization” belongs to the next generation.
A gamete is at least as specialized as any other cell of the body. At the
same time, this gamete, along with the entire lineage leading up to it,
must retain the potential to yield the totipotent zygote. That is,
despite its commitment to a highly specialized, reproductive function
unlike that of any other cell type in the body, the germline cell must at
the same time preserve within itself the flexibility and freedom that will
be required for producing every cellular lineage of a new organism.
It is an extraordinary mandate, and our bodies must focus extraordinary
powers of development upon it. For example, the chromosomes of both sperm
and egg will have been modified by epigenetic “marks”
ensuring that certain genes in the offspring will be active, or repressed,
depending on which parent the gene was inherited from. Other widespread
marks imposed by the parents will (for the most part) be erased
immediately after fertilization. This leaves space for the new organism
to structure the spatial, electrical, and chemical characteristics of its
chromosomes (and therefore also its gene expression) according to its own
And, of course, there is the elaborately orchestrated “meiotic ballet”
(Page and Hawley 2003)
that produces both sperm and egg, each with only half the number of
chromosomes found in somatic cells, and with those chromosomes reshuffled
and otherwise modified according to a logic and via activities that are
still largely beyond any comprehensive understanding.
But one thing is sure: the body’s rearrangement (“recombination”) of its
chromosomes during meiosis is now showing itself to be highly regulated.
Multiple protein complexes and epigenetic modifications of chromosomes
function combinatorially, with synergism, antagonism, and redundancy: “The
new-found multiplicity, functional redundancy and [evolutionary]
conservation” of these regulatory factors “constitute a paradigm shift
with broad implications”
(Wahls and Davidson 2012).
So we are given no choice but to think of the germline as an expression of
that same agency — that same, end-directed transformative power — through
which our body subtly, elaborately, and adaptively directs each of its
other cell lineages toward a distinctive form and functioning within the
unity of the whole. We have seen that this power of transformation comes
to expression in the entire cell, quite apart from any mutations in its
DNA. And it is just a fact that an entire cell is what each parent passes
on as an inheritance to its offspring.
It would be strange indeed if the organism’s ability to proceed adaptively
and creatively along paths of developmental transformation were to become
frozen at the very point where, via the most sophisticated activity
imaginable, it prepares its whole-cell bequest for the next generation.
Can we reasonably claim that this is the one cell lineage in which the
organism’s normal, future-oriented activity goes silent? Or that, with
all the organism’s expertise at producing, adapting, and stably
maintaining diverse phenotypes even without changes in DNA sequence, it
“refuses” to employ this expertise when it comes to the preparation of
inheritances? Or that the power with which the organism conforms all its
cells, tissues, and organs to a unified and integral whole adapted as far
as possible to current conditions is a power lost to it in the management
of its own germline?
If every organism is a living agent, as we all know it to be (whether
or otherwise), then surely that agency — whatever its nature, and however
conditioned and constrained — is the decisive thing passing between
generations. If every organism is an activity, a power of becoming, then
the inheritance preparing the way for a new life must first of all be an
inheritance of this active power, not of some fixed, already achieved,
material result of it. And yet our science has not even addressed the
problem of this formative power, let alone asked what role its unfolding
expression — its development of its own potentials — might play in
A strangely absolute
demand for stable
There could hardly be a more frequently stated requirement for natural
selection than this: any beneficial genetic or other variation
occurring in an organism, if it is to be evolutionarily relevant, must be
stable, heritable, and long-lasting down through the generations. If
a given variation is likely to pass away after a generation or two, or if
it quickly suffers further change, then the normally long and slow process
of selection will not have time to spread the variation (“fix it”)
throughout a population.
We should note that here we have already left behind the question about
the origin of new traits in favor of the question about their
widespread establishment in a population. But the conventional answer to
this second question, with its call for stable variation, is highly
problematic — and revealing — in its own terms.
Richard Dawkins approaches the matter with his customary verve and ability
to highlight the core defects of evolutionary theory as if they were its
chief assets. In order for a genetic variation to be useful, he says, it
must be “potentially eternally heritable”. “I’m not wedded to DNA”, he
adds, but “I am wedded to this operational criterion that alterations in
it go on forever
What he means is that useful variations are the ones selected for —
maybe not eternally, but at least for a long time. The ones that are less
than useful are selected against, and therefore are not eternal.
But the truly beneficial adaptations can be selected and selected again,
generation after generation, without any in-principle limitation. They
are in this sense “potentially eternally heritable”, which can only be the
case if they are extremely stable.
And yet, this stability criterion is wholly dependent upon the biologist’s
unmindfulness of the organism’s agency. In contradiction to everything we
know about organic activity, the assumption is made that variation results
from processes altogether lacking the kind of coordination and adaptation
to circumstances, the end-directedness and future-orientation,
characteristic of all living activity we have ever observed. Variation,
on this view, originates in more or less random rearrangements of
Once this sort of mindless rearrangement is substituted in our minds for
living agency, there is, so the thinking goes, only one way a new trait,
appearing first in just one or a few organisms, can become distributed
throughout a large population: it requires a prolonged and more or less
chancy play of life, competition, and death. Any transgenerational
instability in the trait would make its fixation in the population via
this process highly unlikely.
Unfortunately for the consistency of this point of view, the organism’s
ignored as far as possible, is still assumed at every point of the theory.
In their mere existence — let alone in their struggles for life, their
mating, and their generation of inheritances — organisms display all the
features of purposive, future-oriented beings. Only by means of these
features can there be anything remotely like a “play of life, competition,
and death”. But, at the same time, these features hardly support the idea
that this play is merely “chancy”.
And, in fact, virtually every statement about the “mechanisms” of
evolution in the literature today is rooted in the unspoken, unnoticed
conviction that organisms routinely exercise the agency and purposive
initiative central to their life. The conviction is so clearly
underwritten by everyday perception that it need not even be mentioned.
But when the failure to mention it turns into a “conspiracy of silence”,
so that our theories of evolution must ignore the obvious, then something
has gone badly wrong.
Moreover, a principle of stability looks rather odd as a
fundamental principle of evolutionary change. When we trace a
differentiating cell lineage in a developing organism, we watch one cell
generation succeeding another, not by stably preserving change, but by
compounding it — changing again what has just been changed. This
is the change of a transformative, organic
not a mere rearrangement of Newtonian particles being pushed about by
But think what this means. If many developmental changes are not stable
and heritable over any large number of cellular generations, it is because
they had better not be. After all, the cell lineage is on the
way to somewhere, proceeding directionally along a pathway of
integral, holistic transformation. This suggests how differently we may
have to look at evolutionary processes when we are willing to acknowledge
the nature of organic change and agency.
For example, the usual criticism of epigenetic factors as evolutionary
causes — namely, that they often are not preserved endlessly down through
subsequent generations — simply misses the whole character of organic
change. It does so because the agency working through integral, living
populations — whether those populations consist of the trillions of cells
in our bodies or the myriad organisms in a community — has been
out of the picture.
I understand that some may view my rather casual transition in that
previous sentence — the transition from cells in a body to organisms in a
population — as a rather startling attempt to bridge an impassable gulf
between development and evolution. To those concerned about this, I can
only advise: read further.
Meanwhile, summing up the present chapter: the powerful adaptive
plasticity whereby organisms undergo concerted developmental change looks
like exactly the sort of change — the only sort of change we know about —
that might translate, upon a wider stage, into the diverse organic
transformations of evolution. The bare logic of natural selection, after
all, makes no reference to the specific potentials concretely realized in
the distinctive evolutionary trajectories leading from the simplest cells
to redwoods and wildebeest, crayfish and cormorants. On the other hand,
do we not discover something very like those potentials playing out in the
distinctive developmental trajectories leading from a single-celled zygote
to osteoblast and endothelium, neuron and neutrophil? And also when we
watch the goliath beetle larva (or human embryo) metamorphosing into the
Only when we ignore the living powers required for such
transformations can we subconsciously transfer our ineradicable sense of
these powers to the working of a blind evolutionary algorithm
Once having learned to avoid such a mistake, we may reflect that, just as
individual cells participate in the life of a complex organism, so, too
individual organisms participate in the life of a population, or species.
In neither case is it always easy to distinguish what is individual from
what is collective. And this suggests that the agency we recognize in
individual organisms cannot be cleanly separated from the agency at work
in the species — surely an idea the evolutionary theorist might run with.
I will now pick up this idea — not because it is a speculation worth
exploring, but because its mundane truth is forced upon us by everything
in front of our eyes, if only we will see it.
By the time Gould completed his
masterwork, The Structure of Evolutionary Theory, he would offer a
richly nuanced qualification of these statements. But his fundamental
belief in the creative role of natural selection — or, as he would say,
its “efficacy” — remained.
Goliath beetle larva and adult photo credit: Frantisek Bacovsky.
My quotations are transcribed from the conclusion of part 3 of a
three-part recording of a debate, “Homage to Darwin”, held at Oxford
University, May 8, 2009. Participants in the debate included Richard
Dawkins, Lynn Margulis, Steve Bell, and Martin Brasier. The event was
chaired by Oxford’s Denis Noble.
Arthur, Wallace (2004). Biased Embryos and Evolution. Cambridge
UK: Cambridge University Press.
Brady, Ronald H. (1979). “Natural Selection and the Criteria by Which a
Theory Is Judged”, Systematic Biology vol. 28, pp. 600-21.
Available online at the
Nature Institute website
Dawkins, Richard (2009). Comments during “Homage to Darwin” debate,
Balliol College, Oxford University (May 8). Audio of part 3 of the debate
(from which my quotations are transcribed) is available at
(downloaded October 25, 2019). The quoted remarks by Dawkins begin at
about 1:31:20 of the recording. Links to all three of the parts can be
Gould, Stephen Jay (1976). “This View of Life: Darwin’s Untimely Burial”,
Natural History vol. 85, pp. 24-30.
Gould, Stephen Jay (2002). The Structure of Evolutionary Theory.
Cambridge MA: Harvard University Press.
Kirschner, Marc W. and John C. Gerhart (2005). The Plausibility of
Life: Resolving Darwin’s Dilemma. New Haven CT: Yale University
Page, Scott L. and R. Scott Hawley (2003). “Chromosome Choreography: The
Meiotic Ballet,” Science vol. 301 (Aug. 8), pp. 785-9.
Ryan, Frank (2011). The Mystery of Metamorphosis: A Scientific
Detective Story. Foreword by Dorion Sagan and Lynn Margulis. White
River Junction VT: Chelsea Green Publishing.
Wahls, Wayne P. and Mari K. Davidson (2012). “New Paradigms for
Conserved, Multifactorial, cis-Acting Regulation of Meiotic
Recombination”, Nucleic Acids Research vol. 40, no. 20, pp.
Steve Talbott :: Evolution Writ Small