Niche construction
Niche construction is the observation that organisms do not only adapt to their environment, they change it, and their descendants then inherit the changed version. Selection and environment become a loop rather than a one-way pressure.
The idea
In the standard picture, the environment poses a problem and populations adapt to it. Niche construction, developed in detail by Odling-Smee, Laland and Feldman, points out that this misses half the traffic. Earthworms rework soil chemistry and drainage, and worm populations then evolve in soil their ancestors made. Beavers flood valleys and their descendants are born into ponds. Plants put oxygen into the atmosphere, and every aerobic organism since is adapted to a world plants created.
What makes it more than a footnote is the inheritance. Genes are not the only thing passed on. A modified environment is passed on too, sometimes to unrelated species, and it can persist far longer than any individual. This is often called ecological inheritance.
A world where organisms cannot change anything gives evolution a fixed problem to solve, which is one of the standard explanations for why simulated evolution stalls. See open-ended evolution. Niche construction is one of the few mechanisms that makes the problem move on its own.
The claim to be careful with
Niche construction is often illustrated with beaver dams and termite mounds, which are dramatic and which make it easy to slide into a much bigger claim. Changing the environment does not require intending to change it, planning a structure, or having any representation of the result. A worm is not building anything. It is eating, moving, and excreting, and the soil changes as a side effect.
That distinction is the whole difficulty in reporting it from a simulation. Persistent environmental modification is measurable. Deliberate construction is a far stronger claim, and measuring modification does not get you there.
What has actually been measured here
Organisms in Emergent Life can move material. Ground is a conserved quantity: it can be excavated, carried and deposited, but not created or destroyed, which is described in reshaping the world. Because it is conserved, a hole somewhere is a mound somewhere else, and the world's total does not drift.
Two things have been measured directly. Environmental states produced by organisms persist beyond the lifetimes of the organisms that produced them. And on the current experimental candidate, measurable amounts of the map have been physically reworked relative to genesis. Disturbed ground does not stay disturbed forever: ecological succession lets worked ground recover, which was added after an earlier candidate turned the world into a permanent scar.
None of that is evidence of building. There is no build action, no reward for construction, and no sensory channel that favours it. No structure has been shown to be built deliberately, and no organism has been shown to gain from a modification made by an ancestor. The measurements and the reasoning are in research notes, and the general rule this site follows about not upgrading an interpretation into a fact is in methodology.
References and further reading
Primary sources for the claims on this page. Where this project's own results are referred to, they link to the page carrying the evidence instead.
- Odling-Smee, F. J., Laland, K. N., & Feldman, M. W. (2003). Niche Construction: The Neglected Process in Evolution. Princeton University Press.
- Laland, K. N., Odling-Smee, F. J., & Feldman, M. W. (1999). Evolutionary consequences of niche construction and their implications for ecology. PNAS, 96(18), 10242-10247. doi:10.1073/pnas.96.18.10242
- Laland, K., Matthews, B., & Feldman, M. W. (2016). An introduction to niche construction theory. Evolutionary Ecology, 30, 191-202. doi:10.1007/s10682-016-9821-z