Charles Robert Darwin 1809-1882

Charles Robert Darwin
1809-1882
Fact 1
Potential exponential increase of
populations (superfecundity)
[Source: Paley, Malthus and others]
Fact 2
Observed steady-state stability of
populations.
[Source: universal observation]
Fact 3
Limitation of resources
[Source: observation
reinforced by Malthus
Darwin's Argument
Inference 1
Struggle for existence
among individuals
[Author of inference: Malthus]
Inference 2
Differential survival (reproduction)
through natural selection
Author of inference: Darwin
Fact 4
Uniqueness of the individual
[Source: animal breeders,
taxonomists, barnacles]
Fact 5
Heritability of much
of the individual variation
[Source: animal breeders]
Inference 3
Descent with modification
and with time new species
[Author of inference: Darwin]
Modified ever so slightly from Figure 1 in 'Darwin and Natural Selection' by Ernst Mayr in American Scientist , vol. 65, p. 321-327.
Fact 1
Potential exponential increase of
populations (superfecundity)
[Source: Paley, Malthus and others]
Fact 2
Observed steady-state stability of
populations.
[Source: universal observation]
Fact 3
Limitation of resources
[Source: observation
reinforced by Malthus
Darwin's Argument
Inference 1
Struggle for existence
among individuals
[Author of inference: Malthus]
Inference 2
Differential survival (reproduction)
through natural selection
Author of inference: Darwin
Fact 4
Uniqueness of the individual
[Source: animal breeders,
taxonomists, barnacles]
Fact 5
Heritability of much
of the individual variation
[Source: animal breeders]
Inference 3
Descent with modification
and with time new species
[Author of inference: Darwin]
Modified ever so slightly from Figure 1 in 'Darwin and Natural Selection' by Ernst Mayr in American Scientist , vol. 65, p. 321-327.
Four Reasons Why
1. Changing attitude toward the balance of nature
2. Shift to population thinking
3. Shift from soft to hard inheritance
4. Gradual loss of Christian faith
Five Works That Influenced Darwin
1. Principles of Geology (1830) Charles Lyell
2. Essay on the Principle of Population (1798) Thomas Malthus
3. Wealth of Nations (1776) Adam Smith
4. Preliminary Discourse on the Study of Natural Philosophy (1831)
5. History of the Inductive Sciences (1837) William Whewell
John F. W. Herschell
Sir Charles Lyell
1797-1875
small changes
summed
over long
periods of time
1830
He who can read Sir Charles Lyell’s grand work
on the Principles of Geology, which the future
historian will recognise as having produced a
revolution in natural science, yet does not admit
how incomprehensibly vast have been the past
periods of time, may at once close this volume.
(CRD 293)
Thomas Robert Malthus
1766-1834
In October 1838, that is, fifteen
months after I had begun my
systematic inquiry, I happened to
read for amusement Malthus on
Population, and being well prepared
to appreciate the struggle for
existence which everywhere goes
on from long- continued observation
of the habits of animals and plants,
it at once struck me that under
these circumstances favourable
var iat i o n s w o u l d te n d to b e
preserved, and unfavourable ones
to be destroyed. The results of this
would be the formation of a new
species. Here, then I had at last
got a theory by which to work.
Charles Darwin
inter- and intraspecific competition
1798
The power of population is so superior to the power of the earth to produce subsistence for man, that premature
death must in some shape or other visit the human race. The vices of mankind are active and able ministers of
depopulation. They are the precursors in the great army of destruction, and often finish the dreadful work
themselves. But should they fail in this war of extermination, sickly seasons, epidemics, pestilence, and plague
advance in terrific array, and sweep off their thousands and tens of thousands. Should success be still incomplete,
gigantic inevitable famine stalks in the rear, and with one mighty blow levels the population with the food of the
world.
Adam Smith
1723-1790
design without a designer
1776
As every individual…generally, indeed, neither intends to promote the public interest,
nor knows how much he is promoting it.…he intends only his own security; and by
directing that industry in such a manner as its produce may be of the greatest
value, he intends only his own gain, and he is in this, as in many other cases, led by
an invisible hand to promote an end which was no part of his intention.…By pursuing
his own interest he frequently promotes that of the society more effectually than
when he really intends to promote it.
Rationalist
argue to experience
analogy too limiting
consilience!
William Whewell
1794-1866
consilience in the
Origin of Species?
1837
Preliminary Discourse on the
Study of Natural Philosophy
(1831)
John F. W. Herschel
1792-1871
Empiricist
argue from experience
argue by analogy
Arguing by Analogy
use enumeration
often persuasive
never compelling
role of analogy in the
Origin of Species?
Balance of Nature
Natural Theology
• beneficial feedback device
• maintained harmony
• between species (optimistic)
from Schaller (1976)
Malthus and Darwin
• between individuals (pessimistic)
• Spencer’s ‘survival of the fittest’
• Tennyson’s ‘red in tooth and claw’
• TRM—pessimistic, steady-state
• CRD—harmony by adaptation
Uniqueness of Individual
Population Thinking*
• not typological (Platonic)
• qualitative v. quantitative
• relate to struggle for existence
from Iwago (1986)
*Not what it sounds like.
Inheritance
Darwin’s Thinking
shift from ‘soft’ to ‘hard’
changeable versus given
blending vs. particulate
Fleeming Jenkin example
mixture vs either/or
Lamarckian Mechanisms
inheritance of acquired characteristics
physiological activities of the body
direct influence of the environment
tendency to improve or progress
Loss of Christian Faith
Educated to be an Anglican minister.
Became a materialist (atheist)
mind is a product of brain
Anne Darwin
1841-1851
2/10
Natural selection replaced the hand of God.
Emma Wedgewood
Wedgewood Cameo