Elisabeth Lloyd (2005), Stanford Encyclopedia of Philosophy — https://plato.stanford.edu/ENTRIES/selection-units/
Key takeaways
- The “units of selection” debate bundles four separable research questions — interactor, replicator/reproducer, manifestor-of-adaptation and beneficiary — pursued by two multilevel schools (Wrightian evolutionary-change and Fisherian adaptationist/kin-selection) with different models, so many apparent disagreements are answers to different questions.
Seeded from the abstract and a skim, before the reading in NOTE-184. What follows is what the work says about itself.
Evolution by natural selection is biology’s crowning theory, yet which entities are selected is contested. Lloyd clarifies the debates by distinguishing four research questions, often confused, and two schools of multilevel genetics. She then reviews particular debates — group selection, species selection, genic selectionism, genic pluralism, transitions in individuality, holobionts — showing which questions, alone or combined, drive each.
Standing in the record
Filed from the 2026-09-26 sweep of the papers-feed tracker for philosophy: 10 seconds of active reading over 1 session. It was filed Deferred, unread. NOTE-184 is the close reading of 2026-09-26, and it placed the work: Active — worth reading as the authoritative statement of the interactor / reproducer / manifestor / beneficiary distinction and as a dense map of the units-of-selection literature to 2023. It has to be read as one side’s case. It is not a neutral survey: it argues for the Evolutionary Change school, and it criticises by name several authors this record holds or cites.
When seeded, before the reading in NOTE-184, the entry gave a priority for a deeper reading: medium — brief visit (t = 10 s) but a load-bearing organising reference for several items in this batch; the skim captures the framework.
What the seeding asked a deeper reading to check (NOTE-184 is that reading):
- The hub reference for the units-of-selection cluster: Damuth & Heisler’s MLS1/MLS2 (LIT-201), Luque on the Price equation (LIT-205), Bourrat on reproducers (LIT-157).
- Check §4.2’s treatment of “emergent properties” for species selection against the emergence discussions (LIT-156, LIT-150).
- Check how far the four-question framework is Lloyd’s own programme (Lloyd 2015’s “logic of research questions”) rather than a neutral survey.
Access when seeded: Full SEP entry fetched directly and read by section (openings of all sections; §§2.1–2.2, 2.5, 3.3 and 5 in more depth). First published Mon Aug 22, 2005; substantive revision Wed Jun 12, 2024 (the version read); citation metadata lists Elisabeth Lloyd.