Are there genes for practically everything? For being gay? For being mean? For being a philosopher? Does modern science show that we are largely the product of our genes --- or not? Join Ken and John and famed philosopher of biology John Dupre to see how trapped you are by your genes.
What role do genes play in how organisms develop? John begins by distinguishing the genotype from the phenotype. Genetic determinism says that the genotype completely determines the phenotype, that is, the genes completely determine how an organism turns out. We often read about "a gene for intelligence" and "genes for homosexuality", but what does that mean? Doesn't that support the idea of genetic determinism?
John introduces the guest, John Dupre. Dupre distinguishes between various senses of the word "gene". But, John asks, haven't we found a gene for Down syndrome? Dupre explains what that phrase means. Ken says that he learned about the genetic code in school that spells out how each organism will develop. Dupre replies that that use of the phrase "genetic code" is incorrect. The genetic code is very basic and the phenotypic traits depend on more than just the genes. For example, Dupre says, a family may have a common nose shape, but that is determined by biology, not just the genes. Dupre gives some reasons for looking at the genome, as a whole, rather than individual genes. Ken summarizes: using the phrase "gene for X" does not mean that someone that has that gene will necessarily have X.
Ken asks aren't genes distinctive, extra-powerful causes? The genome is important but overemphasized. Dupre criticizes the idea that all the information that is passed from parents to offspring is in the DNA. Dupre gives some reasons for looking at the genome as a whole rather than individual genes. Then, John, Ken, and Dupre discuss what it means when people talk about the number of genes in the human genome and what "junk DNA" is.
Dupre thinks that genetic determinism is false. Does this mean that anyone can become anything? What does his view entail? There are limits, but they are not imposed solely by genes. Dupre thinks we should shift from focusing on the genome to concentrating on development.
- Ian Shoales the Sixty Second Philosopher (Seek to 51:30): Ian Shoales provides many quotes from various philosophers, authors, and poets in favor of donating to public radio to help out the donation drive.
- Amy Standen the Roving Philosophical Reporter does not have a piece in this episode.
John Dupré, Professor of Philosophy of Science, University of Exeter
- The Stanford Encyclopedia of Philosophy entry on the genotype-phenotype distinction
- There are some excellent chapters on genetic determinism in Kim Sterelny's and Paul Griffiths's book, Sex and Death: An Introduction to Philosophy of Biology.
- Stephen Jay Gould's article critical of genetic determinism called "Humbled by the Genome's Mysteries".
- Richard Dawkins's book, The Extended Phenotype, was the subject of an email question addressed by John Dupre
- John Dupre's book mentioned at the start of the show: Human Nature and the Limits of Science.
- Daniel Dennett has a good essay called "The Mythical Threat of Genetic Determinism" in his collection, Freedom Evolves.
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