1. Two kinds of evolutionary
thinking
Darwinism and Lamarckism

2. John Wilkins
May 22, 2013
Some quotes
“Evolution is so simple, almost anyone
can misunderstand it” – David Hull
“Natural Selection is not Evolution ” –
Ronald A Fisher
“Nothing in biology makes sense
except in the light of evolution” –
Theodosius Dobzhansky

3. John Wilkins
May 22, 2013
Star Trek Evolution
 Why is it so
popular?
 Where does
this idea come
from?
 What should
we think about
evolution?

4. John Wilkins
May 22, 2013
The popular version
 Grades
 Direction
 Perfection
 Steady
 Humans are the goal

5. John Wilkins
May 22, 2013
The scientific version
 Branches
 Randomness + selection
 Irregular
 No direction but locally
 Humans are one animal among
many

6. John Wilkins
May 22, 2013
Names
 The popular version is called many things:
 Great chain of being
 Ladder of progress
 Lamarckism
 The scientific version is also called many
things:
 Darwinism
 Neo-Darwinism
 The Modern Synthesis

7. John Wilkins
May 22, 2013
Progress
 Depends on the “target”
 Jacob’s Ladder - God at the top,
something ugly at the bottom
 Evolution has always been thought
to be progressive
 Until Darwin (and even then)

8. John Wilkins
May 22, 2013
There are two kinds of
evolution
 The one Lamarck developed and
made known.
 The one Charles Darwin developed
and made known
 Only Darwin’s is truly novel, and yet
it is the least well known, and so it
takes the longest to really “get”.

9. John Wilkins
May 22, 2013
Before evolution
 Western thinking was historical
because of Christian theology, but
change tended to a goal
 Everything was ranked from lowest
to highest
 Higher things were “more perfect”
than lower things

10. John Wilkins
May 22, 2013
The medieval view
Stones … mere being
Fire … + motion
Plants … + growth
Animals … + sense
Man … + reason
Heaven … + incorruptibility
Angels … + knowledge of good
God … with the lot + perfection
Raymond Lull, 1512

11. John Wilkins
May 22, 2013
The chain was also moral
Bovillus 1510

12. John Wilkins
May 22, 2013
Great chain of being
 A view that goes back to the Greeks
 Everything is lined up along a scale
 Made into a time series in the 17th
and 18th centuries
 Lamarck one of the first
evolutionists, and followed this
view

13. John Wilkins
May 22, 2013
Three “Lamarckisms”
 That changes to individual
organisms are likely to be inherited
or will affect the hereditability of
traits.
 That things evolve on a
preprogrammed pathway to
perfection
 That change is predictive of the
needs (or wants) of organisms

14. John Wilkins
May 22, 2013
Lamarck’s scale from lower to
higher
 At first a single scale
 Later, two, one for invertebrates,
one for vertebrates
 Each “species” underwent change
up the scale

15. John Wilkins
May 22, 2013
Lamarck’s view of evolution

16. John Wilkins
May 22, 2013
Spontaneous generation
 Lamarck accepted the constant
generation of living things in their
simplest form, from the non-living
 Each new spontaneous generation
started a lineage
 Each lineage would evolve through the
same stages as the earlier ones had
 Later, he allowed for some branching

17. John Wilkins
May 22, 2013
Lamarck’s view of evolution 2

18. John Wilkins
May 22, 2013
Bees and brains
 “It is absurd to talk of one animal being
higher than another – We consider those
where the cerebral structures intellectual
faculties most developed, as highest. – A
bee doubtless would where the instincts
were.” Charles Darwin, Notebook B
 “Never say ‘higher’ or ‘lower’” Darwin
 What about the flowers? What would they
say?

19. John Wilkins
May 22, 2013
Darwin’s view
 Things get better locally, not globally
 Being “fitter” is a matter of being able to do
well then and there only
 Populations, not whole species, evolve
 Evolution branches all the time
 Everything has evolved as much as
everything else!

20. John Wilkins
May 22, 2013
Branching evolution
No real progress here

21. John Wilkins
May 22, 2013
The origin of species

22. John Wilkins
May 22, 2013
The tree of life is a coral tree

23. John Wilkins
May 22, 2013
Darwin used the tree metaphor
 This, too could be misused
 Although Darwin’s tree was not
directional at first, others came to
be

24. John Wilkins
May 22, 2013
Haeckel’s
mighty
oaks
Central trunk leads
directly to humans,
and everything on
the trunk is
somehow
“important”

25. John Wilkins
May 22, 2013
Indirect
progressionism
Patten (1925) makes a
direct line through
arthropods (bugs) to
vertebrates (non-bugs)

26. John Wilkins
May 22, 2013
Indirect racism
Notice how the earlier (and
“less evolved”) forms are
shown at the left of the
diagram. Now notice the
“races” of Homo - in order,
African (i.e., the “Negro”),
Australian (aboriginal),
Mongolian (the “Asiatic”),
and of course the
European.
Diagram c1920. There was
no geological evidence at
the time (or now) of any of
this.

27. John Wilkins
May 22, 2013
Direct racism (1799)

28. John Wilkins
May 22, 2013
Intelligence still
at the top of the
chain…
Despite the divergence of
evolution until now, Teilhard
(1955) still thinks that it will
all come together with humans
as the final players. At least he
isn’t racist about it – all
“socialised” humans will evolve
to the Omega Point.

29. John Wilkins
May 22, 2013
Missing links and ancestors

30. John Wilkins
May 22, 2013
Missing links and ancestors

31. John Wilkins
May 22, 2013
Any ancestors at all?
 We cannot be sure that a fossil or
living species is actually an
ancestor
 Might be a sibling of the ancestor
 Might be the ancestor, but how to
tell?
 At best, we have likelihoods

32. John Wilkins
May 22, 2013
Populations
 All evolution happens to
populations
 Not individuals (that’s “development”)
 Not entire species (that’s
“speciation”)
 Not larger groups (that’s artificial)

33. John Wilkins
May 22, 2013
Natural selection
 Does not equal “evolution”
 Is the process of adaptation (of
populations)
 Is not all that happens in evolution
(that’s called “panadaptationism”)

34. John Wilkins
May 22, 2013
Selection
Follows the fitness
peaks (available ways to
make a living).
They have to be
reachable, and they
have to be better than
what is already in place.
Changes the frequency
of genes in populations.

35. John Wilkins
May 22, 2013
Lessons to be learned
 Progress is not necessary
 There is no “next step”
 Selection is not all there is to
evolution
 Everything is as evolved as
everything else

36. John Wilkins
May 22, 2013
Further reading
 Bowler, Peter J. Evolution: The History of an Idea. Berkeley:
University of California Press, 1984.
 Dennett, Daniel C. Darwin’s Dangerous Idea: Evolution and the
Meanings of Life. New York: Simon and Schuster, 1995.
 Jordanova, L. J. Lamarck, Past Masters. Oxford; New York:
Oxford University Press, 1984.
 Lovejoy, Arthur O. The Great Chain Chain of Being: A Study of
the History of an Idea. Cambridge, Mass.: Harvard University
Press, 1964 (1936).