The Selfish Gene: 40th Anniversary edition (Oxford Landmark Science) — 13. The Long Reach of the Gene

1. 1. Natural selection does not work on genes directly; it works on their phenotypic effects, which can extend beyond the body.
2. 2. Segregation distorters like the t gene in mice bias meiosis to favor their own transmission, even if harmful to the organism.
3. 3. A gene's phenotypic effects include all its effects on the world, not just on the body it inhabits, as seen in caddis fly houses.
4. 4. Parasite genes can have extended phenotypic effects on host bodies, such as flukes causing snails to produce thicker shells.
5. 5. Parasites that share the same exit route (e.g., via host eggs) evolve cooperation, while those with different routes become harmful.
6. 6. Rebel DNA fragments, like plasmids, can exploit sideways transmission routes, similar to viruses, to spread without sperm or eggs.
7. 7. Cuckoo nestlings manipulate host parents using a super-stimulus, acting like an addictive drug on the host's nervous system.
8. 8. The central theorem of the extended phenotype: an animal's behaviour maximizes survival of genes 'for' that behaviour, regardless of which body they are in.
9. 9. The replicator/vehicle distinction resolves the tension between gene and individual: genes are replicators, bodies are vehicles.
10. 10. A bottlenecked life cycle (single-cell start) enables 'back to the drawing board' evolution, orderly embryology, and genetic uniformity within organisms.
11. 11. The fundamental unit of life is the replicator; individual bodies are not necessary for life to arise anywhere in the universe.