Lecture #18 Tuesday April 8, 2008: Evolution and SF
The theme of our class: Science is not mythology. But it often is used as if it were mythology. No greater example than evolution. Evolution (natural selection) is a firmly established, fundamental phenomenon. It has also become a powerful and provocative metaphor and myth.
Two distinct (and broadly incorrect) metaphors from evolution: Perpetual progress: organisms “always evolve to state of higher complexity” (WRONG)
Success in competition as inherent moral stamp-of-approval, e.g., “Social Darwinism”
Examples of evolution in SF: The Eloi and the Morlocks in Wells’ The Time Machine:
economic pressures leads to two distinct species.
Two facets:
1. Evidence for common origin and change through time (or descent with modification ) of species http://www.talkorigins.org/faqs/comdesc/ (Otherwise, each species had to arise or be created independently http://www.trueorigin.org/theobald1a.asp )
2. The mechanism for change through time is natural selection.
Phylogeny = origin of a type of organism (e.g, a species, genus, family, etc.) (Greek, phylon = tribe, genesis = birth )
Evidence for common phylogeny:
The fossil record provides enormous evidence for evolution of species as well as descent from common ancestors. The fossil record provides a remarkably complete picture. New “missing links” are found all the time.
parahomology: similar structures but different functions
Anatomical parahomology:similar structures in anatomy in related species
Molecular parahomology: similar molecular structures (genes, enzymes, etc.)
We deduce “family trees” consistent from three different pieces of evidence:
What causes the change over time? Natural selection.
Evolution in a nutshell
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2. Not all offspring are equal: variation in inherited traits
= competition for resources, or “Survival of the most reproductively fit”
“May the most successful inherited traits win!”
Evidence for evolution:
New species have been observed occuring, usually in fast-reproducing, geographically isolated organisms (mice on islands, fish in isolated lakes)
see http://www.talkorigins.org/faqs/speciation.html
The vehicle for inherited traits is the genetic code. Therefore, we expect fingerprints of evolution in genomes. We predict a correlation between detailed morphological
relationships and genetic relationships (that is, anatomical and molecular parahomology should be correlated), which we find!
Summary: natural selection (evolution) is not “just-a-theory” (a wacky hypothesis without evidence). It is a “theory-with-lots-and-lots-and-lots-of-evidence”
Evolution and science fiction
Three broad categories of evolution subtext in SF:
* “Just-so” stories about alien biology and evolution
* Teleological stories about future human evolution: implicitly assumes all organism naturally evolve to “higher” state (which is false):
Arthur C. Clarke’s Childhood’s End
Greg Bear’s Darwin’s Radio
* Parables about the blind nature of evolution:
C. M. Kornbluth’s short story “The Marching Morons.” (1957) An accident puts realtor John Barlow into a state of suspended animation (much like in Woody Allen’s Sleeper). He wakes in the far future and finds the average human IQ is 45.
Pseudo-evolutionary explanation in the story: more intelligent and educated people have smaller families. Therefore, lower intelligence and education is a reproductive advantage.
To discuss in your small groups about your theses:
Is it a thesis (and not a topic)? Does it have a point to persuade?
Is the thesis relevant to the class?
Analysis of narratives about science, technology, and/or scientists.