A. Biology contrasted with the other sciences
1. Soft science versus hard science
2. Other than the concept of evolution, no central dogma
3. Although many observations were made by early observers
physics developed as a science before biology
B. Evolution as the central theme of biology
1. Impact of 17th and 18th century exploration on biology
a. European flora and fauna not too diverse
b. European flora and fauna human managed
c. Explorers brought back lots of new organisms
d. Necessity to develop a classification scheme
2. Development of a classification scheme
a. Contributions of Linnaeus and Ray
1. Linnaeus formalized the concept of a binom,
genus and species name
b. First classification schemes not always biologically
based, often based on easily observed characters
3. Contributions of Darwin
a. Not the first to think in an evolutionary manner
b. Product of a well-to-do 19th century English family
c. To avoid real employment, he went on board the
Beagle as physician/naturalist
d. Beagle voyage provided a different impression of the
world and a new idea of what to do with his life
e. Acceptance of Darwin by the scientific community
1. Voyage of the Beagle
2. Monographs on barnacles
3. Correspondence with a large number of biologists
all over the world (eg., Asa Gray, Harvard)
f. Darwin's idea of change
1. Too many produced for available resources
2. Not all parents produce viable progeny
3. Those that survive have traits that make them
successful and pass those traits onto their
progeny
4. Differential survival of progeny, where the
environment does the selection
5. Therefore, he proposes the idea of "natural
selection" as the mechanism for evolutionary
change.
g. Genesis of the idea
1. First thoughts early 1840's, kept in his
notebooks
2. Circulated essays on his thoughts to a few
biologists late '40 and early 50's
3. Published formal essay of ideas when it was
brought to his attention that another biologist
Wallace, was on the same track
4. Quickly sat down and converted essay into his
book, On the Origin of Species by Means of
Natural Selection
5. Followed that book up with a number of others
on a variety of topics, including: earthworms
plants, human and animal emotions, etc.
6. Re-issued On the Origin of Species a number
of times.
h. Mixed reception of his ideas
4. Additional contributions to evolutionary ideas
a. Rediscovery of Mendelian genetics early 20th century
b. Statistical concept of populations and population
genetics
c. The modern synthesis