BIO 370 Lecture Notes - Lecture 8: James Hutton, Uniformitarianism, Natural Selection
Early Eolutionary Ideas and Darin’s Insight
1. Evolution at a single locus.
a) We will start with a simple null model and explore the complications that arise
with violations of the simple null model assumptions.
2. Evolution at multiple loci.
3. The Tree of Life
a) How and why we reconstruct evolutionary history.
4. Integrating 1, 2 and 3, and problem solving.
Scala Naturae - The Great Chain of Being
• From the most basic elements through perfection (i.e., God).
• A classification scheme, not necessarily tied to transformation or transmutation.
• In nature, sand, grit, dust, to soil, to metals (lead to gold), to minerals, all of which
merely exist, to living things.
• In biology, plants (non-trees > trees (demonic yew to oaks)), animals (demonic snake >
flies > useful insects > sea creatures other than fish > fish > birds > domesticated animals
> wild animals).
• Came before theory of evolution.
• The idea, however, that one level had the characteristics of the level below it, along
with novel elements, lent itself to the ideas of transformation and progression towards
perfection.
• We still fall into this trap today.
• Oaks are higher plats. Algae are loer plats.
• (I prefer taller and shorter).
• In human biology, we often think of hereditary characteristics that appear to be
maladaptie as geeti diseases.
• The issig lik oept.
• Higher plants: highly organized.
• Not all genetic diseases are maladaptive.
Today we will take a historical approach, partly to illustrate how thoughts on science itself have
changed, but also to begin to make one big point:
Evolution results not in increasing perfection, but in adaptation to local (geographically and
temporally) conditions.
The Nature of Science: Natural Versus Supernatural Explanations
What did Aristotle contribute to scientific thinking?
Extended methodological
naturalism.
Natural hypotheses can be tested.
Supernatural cannot.
What about James Hutton?
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Uniformitarianism in both geology and biology.
The earth was very old.
Hutton 1788 - The result, therefore, of our present enquiry is, that we find no vestige of a
beginning,–o prospet of a ed.
Pre-Darwinian Evolutionary Thought
Erasmus Darwin anticipated aspects of Lamarckian transformation, of natural selection, and of
surial of the fittest.
He identified fittest basically as strongest and most able. We will re-examine this later.
Lamarck: giraffe reaching up, neck gets longer, passes characteristic to offspring. Individual
improving.
Evolution: survival of the fittest.
Erasus: atiipated Dari’s atural selection. [Underline] = not what Darwinian was about.
Robert Chambers
Chambers – moved away from individuals to populations change.
Observation: Organisms are Well-Suited to Their Environments
Organisms adapted themselved to (or transformed) to better fit their
environment.
(An idea that fit well the Scala Naturae concept.)
Patrick Matthew was a businessman interested in growing better trees for shipbuilding!
• His ideas were firmly rooted in population thinking.
• Populations changed through time in terms of frequency of different inherited
characteristics.
• Individuals did not transform.
• Ideas partly based on experimental work.
• Some people argued that Matthew was the one who came up with natural selection.
• His purpose was an early application to evolutionary problems.
• Catastrophist
• Epochs of great extinctions left the landscape open for evolution of new species.
• Natural selection acted to stabilize new species.
Charles Dari’s Theory
As we have seen, many ideas about evolution preceded his publication of On the Origin of
Species. What was so special about this book?
Many ideas about evolution preceded this publication, but what was special was how he tied
everything together in terms of observations in nature and breeders, and tree of life so well.
A lot of his book had pigeon breeding.
What did pigeon breeding and artificial selection have to do with anything?
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Scala naturae - the great chain of being: from the most basic elements through perfection (i. e. , god), a classification scheme, not necessarily tied to transformation or transmutation. In nature, sand, grit, dust, to soil, to metals (lead to gold), to minerals, all of which merely exist, to living things. In biology, plants (non-trees > trees (demonic yew to oaks)), animals (demonic snake > flies > useful insects > sea creatures other than fish > fish > birds > domesticated animals. Algae are (cid:862)lo(cid:449)er pla(cid:374)ts(cid:863). (i prefer taller and shorter). In human biology, we often think of hereditary characteristics that appear to be maladapti(cid:448)e as ge(cid:374)eti(cid:272) (cid:862)diseases(cid:863): the (cid:862)(cid:373)issi(cid:374)g li(cid:374)k(cid:863) (cid:272)o(cid:374)(cid:272)ept, higher plants: highly organized, not all genetic diseases are maladaptive. Today we will take a historical approach, partly to illustrate how thoughts on science itself have changed, but also to begin to make one big point:
