Discovering Evolution:
II. Before Darwin
"You will at once perceive," continued Professor Ichthyosaurus, "that the
skull before us belonged to some of the lower order of animals; the teeth
are very insignificant, the power of the jaws trifling, and altogether it
seems wonderful how the creature could have procured food.” – Cartoon
by H. de la Beche lampooning Charles Lyell’s non-progressionism.
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Lecture II.
Readings: Young: Ch. 2- 4; Camazine; Cuvier (Eloge), Gould
(Branching) Paley (Ch 1-3, pp. 63-67).
I.
Darwin’s Predecessors.
A. Included:
1. Buffon – homology, theory of degeneration.
2. Erasmus Darwin – wove the concept into a poem.
3. Goethe – serial homology in plants; ”1
4. Lamarck – misinterpreted and maligned.
5. Robert Grant and other “Edinburgh Lamarckians” –
perpetuated French evolutionism at a time when evolution
associated in the English mind with the excesses of French
revolution.
6. Saint-Hillaire – commonality of body plans; bested in
public debate by Cuvier for going “a phylum too far.”
7. Robert Chambers – anonymous author of Vestiges; helped
lay the groundwork for public acceptance of The Origin.
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“… Geoffroy and Goethe propounded, at about the same time, their law of compensation or
balancement of growth; or, as Goethe expressed it, ‘in order to spend on one side, nature is
forced to economise [sic] on the other side.`" – The Origin of Species, p 147.
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8. Alfred Russel Wallace.
a. Anticipated many of Darwin’s arguments: distributional
patterns, imperfection, vestigial organs, etc.
b. Independently discovered natural selection (NS).
B. In the Historical Sketch added to 3rd edition of The Origin,
Darwin acknowledged others who had previously discussed
NS.
1. Maybe not all of them – we treat this later.
2. None (save Wallace) thought of NS as a mechanism that
could account for Darwin’s “facts.”
3. Darwin-Wallace achievement not simply discovery of a
mechanism, but the realization that it could potentially explain the natural world – Darwin’s Facts.
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II. Lamarck.
A. Remembered for his advocacy of the inheritance of acquired
characters – “soft inheritance.”
1. Especially in textbooks, often contrasted with Darwin’s
more “scientific” idea of natural selection.
2. Rubbish – see Ghiselin (1894)
3. Inheritance via use and disuse accepted by
“many naturalists [who wished] who wished “to dispense, as far
as possible, with the repeated intervention of a First Cause”
(Lyell, 1836).
4. Including Darwin. Consider The Origin’s famous concluding paragraph wherein he enumerates the “laws acting
around us” that have produced life in its divers forms.
"These laws, taken in the largest sense, being Growth with reproduction; Inheritance which is almost implied by reproduction; Variability from the indirect and direct action of the conditions of life, and
from use and disuse; a Ratio of Increase so high as to lead to a
Struggle for Life, and as a consequence to Natural Selection, entailing Divergence of Character and the Extinction of less improved
forms.” [Emphasis added]
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5. Critical point: Absent variability, selection impotent.
a. As discussed by Eiseley, abundant variability became increasingly important for Darwin’s theory.
b. In later editions of The Origin and elsewhere, Darwin
placed greater emphasis on use and disuse as a mechanism for generating heritable novelty – Pangenesis.
c. Writing in Nature in 1880, Darwin remonstrated
“no one has brought forward so many observations on the effects of the use and disuse of parts, as I have done in my ‘Variation of Animals and Plants under Domestication’;”
6. Darwin and Lamarck as competing protagonists a myth.
a. Yes – Darwin was at pains to dissociate himself from his
predecessor:
“Heaven forfend me from Lamarck nonsense of a `tendency to
progression,' `adaptations from the slow willing of animals,' etc.!"
– Letter to Hooker in 1844.
b. But – Lamarck had long since gone to a pauper’s grave,
widely perceived as a crank.
7. The theories Darwin would battle were Fixity of Species and
Special Creation – legacy of Cuvier as transmitted to the
English by Kirby and Lyell.
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B. Lamarck was the first evolutionist.
1. According to Ernst Mayr (1972)
“All others before him had discussed evolution en passant … or
else in poetical or metaphorical terms. He was the first author to
devote an entire book primarily to the presentation of a theory of
organic evolution. He was the first to present the entire system of
animals as a product of evolution.”[2] – Mayr (1972).
2. In Lamarck’s words,
“Conclusion Accepted Up Until Today: Nature (or its author), in
creating the animals, anticipated all the possible sorts of circumstances in which they would have to live and gave to each species
a fixed organic structure, as well as a determined and invariable
form for its parts, which forces each species to live in those places
and climates where it is located and to maintain there the habits
which we know it has.
“My Personal Conclusion: Nature, by producing in succession all
the animal species and beginning with the most imperfect or the
simplest, gradually made the organic structure more complicated;
as these animals generally spread out into all the habitable regions
of the world, from the influence of the circumstances which each
species encountered, it acquired the habits which we know in it and
the modifications in its parts which observation reveals to us in that
2
Mayr’s observation reminds us that nowhere in The Origin is there an actual phylogeny. In
contrast, Lamarck was a systematist very much concerned with relationships amongst the various groups. He was also among, if not the, the first to recognize that the only sensible classifications are those reflective of phylogeny (Stafleu, 1971).
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species. “ [Philosophical Zoology Ch 7. Translation by Ian
Johnston
http://records.viu.ca/~johnstoi/lamarck/lamarck7.htm
C. Lamarck died blind, a pauper. Comes down to us as an almost pathetic figure. Why?
1. Politics / Religion.
a. In England, French evolutionists closely identified with Jacobin materialism and the Terror.
b. According to Kirby
(1835)
Figure 1. Playtpus eggs. So horrified were the English by Jacobin excess, that the Royal Navy
was instructed to prevent specimens of the egg-laying platypus
from falling into the hands of
French scientists (Johnston,
1998).
“Lamarck’s great error is
materialism. He seems to
have no faith in anything
but body, attributing everything to a physical … cause.
Even when, in words, he
admits the being of a God
he employs the whole
strength of his intellect to prove that he had nothing to do with
the works of creation.“ quoted by Grinell, G. 1985. The rise
and fall of Darwin’s second theory. J. Hist. Biol. 18: 5170.
`
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By the Lethean stream. Toads flee the cave as Truth’s light strikes the mask
of Reason from the Jacobin’s horid face and incinerates his volumes of
malevolance: Defamation, Libels, Sedition, Abuse, Ignorance, Anarchy and
Atheism. Above, approving seraphim bear the symbols of the British
establishment: cross, crown and the scales of justice. The caption reads “ A
peep into the Cave of Jacobinism – Magna eƒt Veritas et Prævalebit” (Great
is Truth, and it will Prevail”). For discussion, see Major, E. 2012. Madam
Britannia: Women, Church and Nation 1712-1812, Oxford Univrersity Press.
p. 267 ff. Colored etching by James Gillray, (Frontpiece of the Anti-Jacobin
Review, 1 September 1798). Reproduced from the National Portrait Gallery
(UK)
http://www.npg.org.uk/collections/search/portraitLarge/mw62486/Apeep-into-the-cave-of-Jacobinism.
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Detail from ‘A Charm for Democracy, Reviewed, Analysed, & Destroyed
Jany 1st 1799 to the Confusion of Affiliated Members’, which announces
‘Analytical Review Fallen never to rise again’ in the bottom right corner
(published by the Anti-Jacobin Review and Magazine on 1 February 1799).
The Analytical Review was seen by its detractors as providing a forum for
radical ideas – see Luisa Calé, “Periodical Personae: Pseudonyms, Authorship and the Imagined Community of Joseph Priestley’s Theological Repository”. Note allusion to Zoonomia and The Loves of Plants: “Darwin’s
topsy turvy Plants and Animals Destruction” to the left of the tailed piper.
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2. Cuvier’s Hit Job Eloge de M. Lamarck (Cuvier, 1836).
“Notwithstanding the differences of interpretation, it is interesting to
note that almost all the quotations here reproduced have their uncritical origin in only one source, sometimes un known to the authors themselves … . The thesis of Lamarck's isolation can only be
maintained if one ignores the rich … debates on natural history that
took place between 1790 and 1859, or if one accepts Cuvier's funeral commemoration of Lamarck at face value – Corsi, 1997.
[Emphasis added].
3. Choice of Language.
a. Lamarck’s views on use and disuse became animals
changing their form by force of will.
“The hypothesis of Lamarck – that progressive changes in species have been produced by the attempts of animals to increase
the development of their own organs, and thus modify their
structure and habits – has been repeatedly and easily refuted by
all writers on the subject of varieties and species, and it seems to
have been considered that when this was done the whole question has been finally settled …” – Wallace (1858) [Emphasis
added].
b. Actually, Lamarck wrote of animals’ needs – besoins – which in turn influenced their behavior, patterns of use and disuse and heritable variation.
c. He also believed in the direct effect of the environment on animal physiology and the consequent induction of heritable variants.
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d. But “needs” became “desires” in translation[3], and
Lamarck, a peddler of medieval vitalism, even though he
was a dyed-in-the wool materialist.
4. L’esprit de System. “From Cuvier’s Eloge:
“These views he began to lay before the
public as soon as he had a fixed occupation; and for twenty years he continued to
reproduce them in every variety of form
… . It is necessary to point them out, as
without them, some of his best writings
would be unintelligible. Even the charac- Figure 2. Bas-relief in the
ter of the man could not otherwise be Jardin des Plantes, Paris, of
Lamarck and the daughter
understood; for so intimately did he iden- who cared for him when he
tify himself with his systems, and such was old, blind and destitute.
was his desire that they be propagated, “Posterity will admire you,”
that all other objects seemed to him sub- she assured him, “and she
ordinate, and even his greatest and most will avenge you, my father.”
useful works appeared in his own eyes
merely as slight accessories … .” [4] [Emphasis added]
3
Mayr (1972) describes the matter thusly: “Huxley in his famous Times review of the Origin of
Species (December 1859) says that according to Lamarck ‘the new needs will create new desires, and the attempt to gratify such desires will result in an appropriate modification.’ There is
great danger that the hurried reader will only remember the word ‘desire.’ ” [Emphasis added]
4
Cuvier detested theorizing. Regarding the manifold and mutually incompatible theories of his
geological contemporaries, he remarked (Cuvier, 1825), “One will find the reason for this odd
situation if one reflects that geologists have all been either museum naturalists, who hardly ever
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5. Continuous Creation of Monads.
a. Lamarck believed the simplest life forms were continually created.
“We must be on our guard not to tread in the footsteps of the naturalists of the middle ages, who believed the doctrine of spontaneous
generation to be applicable to all those parts of the animal and vegetable kingdoms which they least understood, … ; and who, when
at length they found that insects and cryptogamous plants were also propagated from eggs and seeds, still persisted in retaining their
old prejudices respecting … minute beings, the generation of which
had not then been demonstrated by the microscope to be governed
by the same laws.” - Lyell (1836).
5. Reputation. Idiosyncratic theories in other fields – chemistry and meteorology – made him an easy target.
“Thus, while Lavoisier was creating in his laboratory a new chemistry founded on a beautiful and methodical series of experiments, M.
de Lamarck, without doing an experiment, and destitute of the
means of doing so, imagined that he had discovered another, which
he did not hesitate to set in opposition to the former, although nearly the whole of Europe had received it with the warmest approbation.” – Cuvier (1836). [Emphasis added]
examined the structure of mountains on their own, or mineralogists who have not studied with
sufficient detail the innumerable varieties of animals and the infinite complexity of their various
parts. The first have only made systems; the latter have provided excellent observations: they
have truly laid down the foundations of the science. But they have not been able to raise an edifice upon it.”
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III. The Lamarckian Balance of Nature.
A. Motivation.
1. Distinctness of species becomes blurred with increasing
numbers of specimens / examples.
“According as the productions of nature are collected and our museums grow richer, we see nearly all the gaps filled up and the
lines of demarcation effaced. We find ourselves reduced to an arbitrary decision which sometimes leads us to take the smallest differences of varieties and erect them into what we call species,
and sometimes leads us to describe as a variety … which others
regard as a separate species.” – Philosophical Zoology [1809,
p 37]
2. Progression of increasing complexity “in the arrangement
of the main groups,” though “not in that of species, nor
always even of genera.”
3. Transmutation an alternative to the extinction of fossil
species.
“I am doubtful whether the means adopted by nature to ensure
the preservation of species … have been so inadequate that entire races are now extinct or lost” (Lamarck, 1809).
B. Postulated two evolutionary forces (Figure 3).
1. Power of Life – la force qui tend sans cesse a composer
l'organisation – i.e., the inherent tendency of lineages to
increase in anatomical complexity and sophistication of
design (Table I; Figures 3, 4).
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Figure 3. Lamarck’s theory of evolution reduced to boxes and arrows. Increasing sophistication of design results from the inherent “Power of Life”;
adaptation to local environments (Conditions of Life), from changing patterns of use and disuse responding to an animal’s inner needs (Besoins).
For insensate organisms, such as polyps and plants, direct environmental
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Figure 4. Phylogenetic descent according to Lamarck in Philosophie Zoologolique (1809). Infusoria, polyps and radiaria
form one group. All other animals descend from worms (vers).
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Table I. Distribution and Classification of Animals. 5
1st Stage. No nerves; no vessels; no specialised [sic]
internal organ except for digestion.
2nd Stage. No ganglionic longitudinal cord; no vessels for
circulation; a few internal organs in addition to those of
digestion.
3rd Stage. Nerves terminating in a ganglionic longitudinal
cord; respiration by air carrying tracheae; circulation absent or imperfect.
4th Stage. Nerves terminating in a brain or a ganglionic
longitudinal cord; respiration by gills; arteries and veins
for circulation.
5th Stage. Nerves terminating in a brain which is far from
filling the cranial cavity; heart with one ventricle, and the
blood cold.
6th Stage. Nerves terminating in a brain which fills the
cranial cavity; heart with two ventricles; and the blood
warm.
5
The complete table lists 14 classes grouped into 6 levels of organization (stages). Only the latter shown here. From Philosophie Zoologique.
16
Figure 5. Phylogenetic descent according to Lamarck in Histoire Naturelle des
Animaux sans Vertebres (1815). Two ladders among invertebrates are imagined: one, “articules,” descending from primitive worms (vers) and leading to
arthropods, annelids and related forms; the other, from “infusoria” (unicells)
and leading to non-segmented forms such as mollusks. Note the independent
acquisition of “sensibility” and intelligence. As discussed by Gould [199a; b),
Lamarck would later (1820) replace multiple lineages with a single sequence in
which all life derived from a single form.
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a. As a result, the major groups could be arranged in
order of increasing complexity.
b. Extinction of fossil species only apparent – in reality they evolved into something else.
c. Because everything progressed,
i. Scala Naturae
(Chain of Being) became an
escalator.
ii. Requires continuing production of simplest
forms (monads).
Figure 6. Lamarck’s view vs.
dichotomous branching.
d. Note the difference
between Lamarck’s view and the current “tree of
life” model (Figure 6): Today’s higher forms derive from ancient “worms,” but the ancestors of today’s worms were not antecedent to living worms.
e. In short, Lamarck posited massive parallelism.
f. But, beginning in 1809, the phylogenetic trees
branch (Figures 4, 5) – see Gould (“Branching
through a wormhole”).
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2. Local adaptation, l’influence des circonstances, produced branchings of what would otherwise be a single sequence.
a. “This is, in effect, a cause whose power is absolute, superior
even to nature, since it regulates all nature’s acts … . This
cause resides in the power that circumstances have to …
change continually the laws that she [Nature] would have followed without [the intervention of] these circumstances … .
The extreme diversity of nature’s productions must also be attributed to this cause.” [Emphasis added]
b. Absent reference to the “laws that Nature would have
followed” – thoroughly modern in its emphasis on environment as the driving force in evolution.
c. This is the point at which besoins (sentiments interieur)
and the inheritance of acquired characters enter the argument, i.e., as the mechanism by which such adaptation was accomplished.
d. Doesn’t work for non-sentient species.
“Is it not strange that the author, of such a book as the ‘Animaux sans Vertebres,’ should have written that insects, which
never see their eggs, should will (and plants, their seeds) to be
of particular forms, so as to become attached to particular objects.” – Darwin (1844 letter to Hooker) [Emphasis added]
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3. Actually, Lamarck wrote of the effect of use and disuse
on the “ponderable” (colloids, cytoplasm) and “subtle”
(heat, electricity) fluids that he believed controlled animal
growth and development.
a. At the time, electricity and heat were viewed as fluids.
b. This allowed for direct action of environment on nonsensible organisms.
4. But thanks to Cuvier, Lamarck’s views on use and disuse
came to English readers as animals changing their form
by force of will – which was taken as evidence of realworld ignorance.
“M. de Lamarck reproduced this theory of Life in all the zoological
works which he afterwards published; and whatever interest these
works may have excited by their positive merits, no one conceived their systematic part sufficiently dangerous to be made the
subject of attack. It was left undisturbed like his theory of Chemistry, and for the same reason, because every one could perceive
that, independently of many errors in the details, it rested on two
arbitrary suppositions; the one, that it is the seminal vapour which
organizes the embryo; the other, that efforts and desires may engender organs. A system established on such foundations may
amuse the imagination of a poet; a metaphysician may derive
from it an entirely new series of systems; but it cannot for a moment bear the examination of any one who has dissected a hand,
a viscus, or even a feather.” [Emphasis added]
20
C. Modeling Lamarck.
1. Imagine that species can be ranked by complexity of de-
Figure 7. Increasing numbers of cell types over the past 4 billion years. Reproduced from Hedges et al. (2004).
sign, for example, by the number of cell types (Figure 7.).
2. Let xi(t) be number of species manifesting the ith level at
time t. Then
xi (t + 1) = ai −1xi −1 (t ) + (bi − ai ) xi (t ) + ci
•
•
•
•
(1)
i ranges from 0 to n – i.e., n levels of complexity;
ai is the probability of progressing from level i to i+1;
bi, the probability of diversification within level i ;
ci, the rate of spontaneous generation. Lamarck imagined that only the simplest forms are produced spontaneously, i.e., only c0 ≠ 0 .
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3. Four levels in Figure 8.
a. Given sufficient time,
proportion of progressive forms 100%
b. Reflects
assumption
that
new
species,
whether the result of
progress or local adaptation, can themselves
progress.
c. Problem: Proportions
all wrong.
Figure 8. The Lamarckian balance of nature according to
Equations (1) with four levels of
organizational complexity. The
proportions of species manifesting each level are given as x0, x1,
x2 and x3. ai = .01, i = 0,3; bi =
1.01, i = 0,3; and c0 =10. Note
the progressive dominance of
complex forms, the assumption
of high rates (10 >> .01) of spontaneous generation notwithstanding.
4. Model could be modified
by
a. Disbarring species
undergoing local adaptation from progressing – plausible.
b. Adding extinction,
especially when organisms are large, complex and
specialized – conflicts with Lamarck’s belief that
species did not go extinct, save possibly as the result
of human activity.
5. Conclusion: Science full of surprises, but even if an inherent tendency toward increasing complexity were discovered, the Lamarckian mechanism nonetheless predicts a
world quite different from the one we inhabit.
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IV. Revolutionary Upheavals of the Globe.
A. Progress in paleontology made non-extinction untenable.
1. Extant species had not changed
since antiquity.
2. Few fossil intermediates.
3. Origin species that “mystery of
mysteries.” (Darwin, 1845).
B. Champion of fixity of species was
Georges Cuvier.6
" … there is nothing which can in the
least support the public opinion “that the
new genera which I have discovered or established among the fossils, any more than
those which other naturalists have established, the palaeotheriums, anoplotheriums,
megalonyx, mastodons, pterodactyls, ichtyosaurus, and so on, could have been the ancestors of some animals today, those differentiated from them only by the influence of
time or climate.” (Cuvier, 1825)
6
Baron Cuvier. Founder
of comparative anatomy and vertebrate
paleontology; politically
adroit; the most powerful scientist in Europe.
Celebrated anatomist, and colleague of Lamarck. Among his more notable achievements was
his discovery of the correlation of parts, what he called the “Principle of Determination,” which
allows for the reconstruction of vertebrate fossils from fragmentary remains. “The entirety of an
organic being,” wrote Cuvier (1825), “forms a coordinated whole, a unique and closed system,
in which the parts mutually correspond and work together in the same specific action through a
reciprocal relationship. None of these parts can change without the others changing as well.
Consequently, each of them, taken separately, points to and reveals all the others. … Starting
with each of them, the person who possesses rationally the laws of the organic economy could
reconstruct the entire animal.” [Emphasis added]
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C. Catastrophism: Extinction the result of recurrent “revolu-
tions” – the result of forces not operative today.
“… it is vain for someone to seek in the forces which affect the surface of the earth today causes sufficient to produce the upheavals
and catastrophes whose traces the earth's surface shows us. Such
forces explain nothing, because no slow action could have produced
these sudden effects. Thus, whether there was a gradual diminution
of the waters, whether the sea carried solid material in all directions,
whether the temperature of the earth decreased or increased, none
of these has overturned the strata, enclosed in ice large quadrupeds
with their flesh and pelt, put on dry land shell fish still as well preserved today as if they had been caught while still alive, or finally
destroyed entire species and genera.” (Cuvier, 1825)
D. Revolutions Several & Abrupt – Genesis Flood the last.
“I am of the opinion that if there is something confirmed by geology,
it is that the surface of our world has been the victim of a great and
sudden upheaval, whose date cannot go back much beyond five or
six thousand years, that this revolutionary upheaval pushed down
the countries where human beings and the species of animals best
known to us today previously used to live and made them disappear,
that it, by contrast, made dry land of the bottom of the most recent
sea and from it created the countries now inhabited, that since this
revolution the small number of individuals which it spared have
spread out and propagated throughout the territories recently made
dry land, and consequently that it is only since this time that our societies have resumed a progressive development, formed institutions, raised monuments, collected facts about nature, and put together scientific systems.”
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“But these countries inhabited today … had already been inhabited
previously, if not by human beings, at least by terrestrial animals.
Consequently, at least one previous revolution had put them under
water. And if one can judge by the different orders of animals whose
remains we have found, they had perhaps undergone up to two or
three eruptions of the sea.“ [Emphasis added]
E. Regarding Environmentally-Induced Transmutation.
“… some naturalists rely a great deal on the thousands of centuries
which they add up with the stroke of a pen. But in such matters we
can hardly judge what a lengthy time would produce, except by multiplying mentally what a lesser time produces. I have therefore sought
to collect the oldest documents on the structures of animals.”
“… We can easily distinguish there the ibis, vulture, owl, falcon, Egyptian goose, … , even the hippopotamus. In the numerous monuments
engraved in the important book on Egypt7…”
“My knowledgeable colleague, Geoffroy Saint-Hilaire, impressed with
the importance of this research, has taken care to collect in the tombs
and temples of Higher and Lower Egypt as many animal mummies as
he could. He brought back embalmed cats, ibises, birds of prey, dogs,
monkeys, crocodiles, and the head of a bull. We certainly do not observe more differences between these creatures and those which we
see today than between human mummies and today's human skeletons.”
7
Ian Johnston, translator of the version of Cuvier’s Discours from which the quote is taken, observes that “The important book on Egypt … is the massive work of scholarship initially carried out on the orders of Napoleon as part of the French military expedition to Egypt … . The
military expedition was a failure, but the work completed by French scientists and published in
a number of volumes from 1809 onwards was enormously popular and influential.”
25
F. Lamarck countered that conditions in the Nile valley hadn’t
changed since the days of the Pharaohs.
“if it were otherwise; for the position and climate of Egypt are still
very nearly what they were in those times. Now the birds which live
there, being still in the-same conditions as they were formerly,
could not possibly have been forced into a change of habits.”
G. And upon his detractors, Lamarck heaped scorn:
“… every many who has any habit of reflection and at the same time
of observing the monuments of nature's antiquity will easily appreciate the import of a duration of two or three thousand years in comparison with it.
Hence we may be sure that this appearance of stability of the things
in nature will by the vulgar always be taken for reality; because people in general judge everything with reference to themselves.” [Emphasis added]
H. But –
1. Fixity of species makes same prediction.
2. As Lyell (1836) would later inquire rhetorically,
“why have other individuals of these species retained the same
characters in so many different quarters of the globe, where the
climate and many other conditions are so varied?”
26
V. Lamarck among the English.
A. By the time Darwin and the Beagle set sail, British opinion of Lamarck derived principally from Volume II of
Lyell’s Principles. His principal objections:
1. Paucity of evidence.
“It is evident, that if some well authenticated facts could have
been adduced to establish one complete step in the process of
transformation, such as the appearance, in individuals descending from a common stock, of a sense or organ entirely new, and a
complete disappearance of some other enjoyed by their progenitors, that time alone might then be supposed sufficient to bring
about any amount of metamorphosis.” [Emphasis added]
a. Lyell would later advance the same argument in correspondence with Darwin after publication of The Origin.
“… when, as I fully expect, a new edition is soon called for, you
may here and there insert an actual case to relieve the vast
number of abstract propositions.” [Letter of 3 Oct. 1859]
b. It persists to this day as “G-d in the gaps.”
2. Lamarckian mechanism implausible.
“… when Lamarck talks ‘of the efforts of internal sentiment,’ ‘the influence of subtle fluids,’ and the ‘acts of organization,’ as causes whereby animals and plants may acquire new organs, he gives us names for things, and … re-
27
sorts to fictions, as ideal as the ‘plastic virtue,’ and other
phantoms of the middle ages.” [Emphasis added]
3. Viewed proposition that habits beget organs (as opposed to
the converse) as “staggering and absurd.”
4. Rejected claim that species grade into each other.
“But in point of fact, our new acquisitions consist, more and more …
of specimens brought from foreign … countries. A large proportion
have never even been seen alive by scientific inquirers. … what is
usually the state of our information? A single specimen, perhaps, of a
dried plant, or a stuffed bird or a quadruped; a shell without the soft
part of the animal; an insect in one stage … . Such information may
enable us to separate species which stand at a considerable distance
from each other; but we have no reason to expect but difficulty and
ambiguity, if we attempt, from such imperfect opportunities, to obtain
distinctive marks for defining the characters of species, which are
closely related.”
B. Five point alternative – Theory of Special Creation.
1. “ the organization of individuals is capable of being modified to a limited extent by … external causes;”
2. “these modifications are, to a certain extent, transmissible
to their offspring;”
3. “there are fixed limits beyond which the descendants from
common parents can never deviate …;”
4. “each species springs from one original stock, and can never be permanently confounded, by intermixing with the
progeny of any other stock ;”
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5. “each species shall endure for a considerable period of
time.”
C. Aside: Finite species lifespan, i.e., extinction, necessitates
that new species be created; also a long-term balance between speciation and extinction – what we believe today
modulo mass extinction.
D. Inferences.
1. Intraspecific variation tied to environment and foresight
of the Author of Nature.
2. Man selected the most plastic species for domestication,
but domestic varieties
a. Still there are manifest limits to variation;
b. No tendency of feral individuals to revert – Lamarck’s
claimed evidence for transmutation;
c. Domestic species cannot propagate / survive in nature
– anticipates Wallace;
d. Would be out-competed by more fertile wild types –
anticipates Darwin and Wallace, i.e., stabilizing selection;
3. No hybridization in the wild – would anyway result in
deterioration, not progression.
4. No evidence of progression from fossils with exception
of the recent appearance of man.
“… in the monuments which we have hitherto examined of more
[pre-Tertiary] remote eras, in which there are as yet discovered
few fluviatile, and perhaps no lacustrine formations, and, therefore, scarcely any means of obtaining an insight into the zoology
of the then existing continents.”
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5. Man distinct from other primates.
a. Primate intelligence overrated.
b. Human variability unexceptional.
6. Recent embryological discoveries indicative of “unity of
plan” in vertebrates, but not of transmutation.
E. The barrister’s artifice: Referring to the use by indigenous
peoples of the orang to gather fruits –
“We leave it to the Lamarckians, … to explain why those same
savages of Borneo have not themselves acquired, by dint of longing for many generations for the power of climbing trees, the
elongated arms of the orang, or even the prehensile tails of some
American monkeys.”
F. Gould (1987. Time’s Arrow. Time’s Cycle) observes
that Lyell’s uniformitarianism was really four postulates:
1. Uniformity of law.
2. Uniformity of process – Lyell’s actual or observable causes (verae causae).
3. Uniformity of rate – gradualism.
4. Uniformity of state – non-progressionism.
G. Numbers 1 and 2 assumptions about process; 3 and 4
about outcome.
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H. Regarding a future warming of the climate (Volume 1 of
the Principles) Lyell mused:
“Then might those genera of animals return, of which the memorials are preserved in the ancient
rocks of our continents. The huge
Iguanodon might reappear in the
woods, and the ichthyosaur in the
sea, while the pterodactyle [sic]
might flit again through umbrageous groves of tree-ferns. Coral
reefs might be prolonged beyond
the arctic circle, where the whale
and the narwal [sic] now abound.
…”
Figure 9. Narwhales “tusking”.
The tusk is an enormously elongated canine, larger in males
than in females, which observation suggests sexual selection as
discussed by Darwin (1871).
I. Non-progressionism widely dismissed by Lyell’s contemporaries – see cartoon below – and abandoned by Lyell himself in 1868 (10th edition).
J. Lyell’s rejection of Lamarck, reflective of deep misgivings
regarding the moral implications of evolution.
“… I have long seen most clearly that if any concession is made, all
that you claim in your concluding pages will follow. It is this which
has made me so long hesitate, always feeling that the case of Man
… and of other animals, … is one and the same, and that if a "vera
causa" be admitted for one, instead of a purely unknown and imaginary one, such as the word "Creation," all the consequences must
follow.” – Letter to Darwin (10/3/1859) [Emphasis added].
31
Figure 10. Paleontology in a future age as imagined by Henry De la
Beche in 1830. The famous cartoon lampoons Lyell’s geological nonprogressionism. Professor Ichthyosaurus stands above a human skull (below rock supporting the lectern), and addresses a toothy crowd. The title
reads “Awful Changes. Man Found only in a Fossil State – Reappearance
of Ichthyosauri”; the caption, “A lecture, – ‘You will at once perceive,’ continued Professor Ichthyosaurus, ‘that the skull before us belonged to
some of the lower order of animals; the teeth are very insignificant, the
power of the jaws trifling, and altogether it seems wonderful how the creature could have procured food.’” Reproduced from Rudwick (1898)
32
VI. Charles Robert Darwin (1809-1882).
Figure 11. Darwin time line: 1825-1859. Adapted with modifications from : John van Wyhe, ed.
2002-. The Complete Work of Charles Darwin Online (http://darwin-online.org.uk/).
33
VII. Darwin and Lyell.
A. Darwin’s intellectual companions aboard HMS Beagle were
Lyell’s uniformitarianism and his rejection of transmutation.
Figure 11. Itinerary of HMS Beagle, on which Darwin served as ship’s naturalist from 1831-1836.
B. Not religion, but Lyellian Special Creation was the orthodoxy that Darwin went up against.8
“… I am almost convinced (quite contrary to the opinion I started with)
that species are not (it is like confessing a murder) immutable.” Letter to
Hooker, 1844. [Emphasis added].
8
Niles Eldredge (2005) offers a different view: “So Darwin was not just against a prevailing
scientific view – for the scientific view … fit in so nicely with prevailing religious views that to
attack one was to attack the other.”
34
C. Darwin Dithers.
1. A convert to transmutation either before or just after his
return to England in 1836 – see Sulloway (1982); Eldredge (2005).
2. Wrote three précis of what would later become The
Origin:
a. “Outline and Draft” of 1839,
b. “Sketch” of 1842.
c. “Essay” of 1844.
3. Incorporated hints of his ideas in the revised version
(1845) of his Journal of Researches first published in
1839.
4. Then nothing until he began work on Natural Selection,
his “big species book,” in the mid-1850’s.
D. It is often suggested that Lyell precipitated Darwin’s conversion
to transmutation.
“Substantial evidence indicates that Darwin was a special creationist
when he read the second volume of Lyell’s Principles and remained a
special creationist for a good long time thereafter. What Lyell did …
was to set out clearly and forcefully the species problem that Darwin
eventually solved.” (Hull, 1984)
E. But, while Lyellian uniformitarianism was a cornerstone of
Darwin’s worldview, going over to transmutation entailed the
daunting prospect of rejecting the views of Britain’s most celebrated scientist. Consider the following passages from The
Voyage of the Beagle (Ch. 17):
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1. Regarding the Galapagos:
“The archipelago is a little world within itself, or rather a satellite attached to America, whence it has derived a few stray colonists, and
has received the general character of its indigenous productions.
Considering the small size of these islands, we feel the more astonished at the number of their aboriginal beings, and at their confined
range. Seeing every height crowned with its crater, and the boundaries of most of the lava-streams still distinct, we are led to believe
that within a period geologically recent the unbroken ocean was
here spread out. Hence, both in space and time, we seem to be
brought somewhat near to that great fact – that mystery of mysteries
– the first appearance of new beings on this earth.” [Emphasis
added]
2. Regarding the finches:
“Seeing this gradation and diversity of structure in one small, intimately related group of birds, one might really fancy that from an
original paucity of birds in this archipelago, one species had been
taken and modified for different ends.” [Emphasis added]
3. His conclusion:
“Reviewing the facts here given, one is astonished at the amount of
creative force … displayed on these small, barren, and rocky islands; and still more so, at its diverse yet analogous action on points
so near each other.“ [Emphasis added]
36
4. These and other hints of Darwin’s conversion to transmutation not in the original Journal of Researches published in
1839 – see Gruber (1981).
F. The exact timing of Darwin’s conversion uncertain.
1. Eldredge (2005) cites a passage in Darwin’s Ornithological
Notes to support view that Darwin returned to England an
evolutionist.
2. Sullway (1982) argued that it was the sorting out of his collections by professional systematists after his return that
triggered Darwin’s change of mind.
3. But see Brinkman’s (2009) regarding the origins of CD’s
“law of the succession of types”
G. Whatever the truth of this, Beagle experiences were key:
“I had been deeply impressed by discovering in the Pampean formation
great fossil animals covered with armour like that on the existing armadillos; … It was evident that such facts … could only be explained on the
supposition that species gradually become modified; and the subject
haunted me.” [F. Darwin (1905) – Autobiography]
H. Darwin’s correspondence shows extraordinary concern for
the opinion of Lyell who by this time had become friend,
father figure and patron:
1. To Wallace: “No one has read it, except Lyell, with
whom I have had much correspondence. Hooker thinks
him a complete convert, but he does not seem so in his
letters to me;” [Emphasis added].”
37
2. To Lyell: “If you admit in ever so little a degree, the explanation which I have given of Embryology, Homology and Classification, you will find it difficult to say: thus far the explanation
holds good, but no further; here we must call in `the addition
of new creative forces.’ I think you will be driven to reject all
or admit all: I fear by your letter it will be the former alternative;” [Empahsis added]
3. To Hooker: “Lyell, with whom we are staying, is perfectly
enchanted, and is absolutely gloating over it [The Origin]. I
triumph to hear that he continues to approve.”
4. To Asa Gray: “Lyell highly approves of the two Geological chapters … He is nearly a convert to my views
...” [Emphasis added]
5. To Huxley: “Your letter has been forwarded to me from
Down. Like a good Catholic who has received extreme
unction, I can now sing "nunc dimittis."[9] … Exactly
fifteen months ago, when I put pen to paper for this
volume, I had awful misgivings; … I then fixed in my
mind three judges, on whose decision I determined mentally to abide. The judges were Lyell, Hooker, and yourself. It was this which made me so excessively anxious
for your verdict.”
6. Hooker and Huxley enthusiastic converts.
9
“A hymn beginning with the words ‘Nunc dimittis servum tuum’ (‘Now let thy servant depart’).
38
7. Not Lyell. Recall his plea for an “actual case inserted
here and there.” In the same letter, he wrote
“…it cannot surely be said that the most eminent naturalists have rejected the view of the mutability of species? You do not mean to ignore G. St. Hilaire and Lamarck. As to the latter, you may say, that in
regard to animals you substitute natural selection for volition to a
certain considerable extent, but in his theory of the changes of plants
he could not introduce volition; he may, no doubt, have laid an undue comparative stress on changes in physical conditions, and too
little on those of contending organisms. He at least was for the universal mutability of species and for a genealogical link between the
first and the present. The men of his school also appealed to domesticated varieties.” [Emphasis added]
I. Recall distinction between pattern and mechanism.
1. For Darwin, mechanism (NS) was key.
a. To Hooker (1844): “I think I have found out (here's presumption!)
the simple way by which species become exquisitely adapted to
various ends.”
b. To a Dutch student (1873) asking about his views on religion: “The old argument from design in Nature, as given by Paley,
which formerly seemed to me so conclusive, fails, now that the law
of natural selection has been discovered.” [Emphasis added]
c. In the Autobiography, he recollects that it was the discovery of NS that allowed him to get on with his work.
39
“It was evident that such facts [distributional patterns] … could
only be explained on the supposition that species gradually become modified; … . But it was equally evident that neither the action of the surrounding conditions, nor the will of the organisms
(especially in the case of plants) could account for the innumerable cases in which organisms of every kind are beautifully
adapted to their habits of life … and until these could be explained
it seemed to me almost useless to endeavour to prove by indirect
evidence that species have been modified.” [Emphasis added]
2. For Lyell, mutability was the issue. Viewed The Origin
as a continuation of Lamarck.
“As to Lamarck, … I remember that it was the conclusion he came to
about man that fortified me thirty years ago against the great impression that his arguments at first made on my mind, … . When I came to
the conclusion that after all Lamarck was going to be shown right, that
we must ‘go the whole orang,’ I re-read his book, and remembering
when it was written, I felt I had done him injustice. …
“Even as to man’s gradual acquisition of more and more ideas, and
then of speech slowly as the ideas multiplied, and then his persecution of the beings most nearly allied and competing with him – all of
this is very Darwinian. …
“The substitution of the variety-making power for ‘volition,’ muscular
action,’ etc. (and in plants even volition was not called in) is in some
respects only a change in names.” [3 October, 1863, Letter to
Darwin].
40
4. Lyell’s instincts proved more nearly correct. The next 150
years would witness accumulating evidence for common
descent and a succession of theories to explain it.
41