A friend writes to draw our attention to an interesting 2014 paper Thought Experiments in Biology, by Guillaume Schlaepfer and Marcel Weber:
Unlike in physics, the category of thought experiment is not very common in biology. At least there are no classic examples that are as important and as well-known as the most famous thought experiments in physics, such as Galileo’s, Maxwell’s or Einstein’s. The reasons for this are far from obvious; maybe it has to do with the fact that modern biology for the most part sees itself as a thoroughly empirical discipline that engages either in real natural history or in experimenting on real organisms rather than fictive ones. While theoretical biology does exist and is recognized as part of biology, its role within biology appears to be more marginal than the role of theoretical physics within physics. It could be that this marginality of theory also affects thought experiments as sources of theoretical knowledge. More.
Many of us have come to suspect that Darwinian biology is, for the most part, one big thought experiment whose speculations must be accepted as the latest truth. Getting rid of Darwinism would enable thought experiments that are distinguishable from the usual practice of the discipline, that is, interesting speculation vs. masses of (actual) findings.
No wonder so many are so dismayed when peasants protest the lack of evidence.
See also: Philosopher of science: Are there laws in biology, as in physics?
Evolutionary psychologist E. O. Wilson: Time has come for philosophy to become biology