Study
Evolution of character displacement in Darwin’s finches
Grant, Peter R.; Grant, B. Rosemary
Science, 2006
A finch population on Daphne Major was measured individually across decades, with beak dimensions, survival and food availability recorded through successive years. A larger-beaked competitor species established on the island during the study, and a severe drought followed.
- Studied in
- Geospiza fortis, Geospiza magnirostris
- Sample size
- a marked island population followed across decades
After the larger species established and drought reduced the large seeds both depended on, beak size in the resident species shifted downward within a generation, with survival favouring smaller-beaked birds.
What it means
The authors' reading, and ours. Where they differ, that difference is the point.
How the authors put it
Competition with a newly established species drove measurable evolutionary divergence in beak size.
How NatureHQ reads it
The rare case where character displacement was watched rather than reconstructed. The sequence matters: the competitor arrives, the shared food collapses, and the survivors are the birds least like the competitor. It is also a reminder that these events are contingent — without the drought there is no strong selection, and without the arrival there is nothing to diverge from.
- One island and one population; the strength of the episode depended on a severe drought.
- Long-term study of a small island population, where drift and immigration also act.
What this study is used for on NatureHQ
One study can inform several subjects. Here is everywhere this one is cited.
Published by: American Association for the Advancement of SciencePublished in Science or Science Advances (AAAS).
doi.org/10.1126/science.1128374
Checked against Crossref on 2026-09-28, and they agree on the title, the authors and the year.
NatureHQ summarises research in its own words and does not reproduce published text. Reviewed 2026-09-04.