Evolutionary suicide
Encyclopedia
Evolutionary suicide is an evolutionary mechanism where adaptation
An adaptation in biology is a trait with a current functional role in the life history of an organism that is maintained and evolved by means of natural selection. An adaptation refers to both the current state of being adapted and to the dynamic evolutionary process that leads to the adaptation....

at the level of the individual results in a situation where the entire population goes extinct. This process is different from group selection
Group selection
In evolutionary biology, group selection refers to the idea that alleles can become fixed or spread in a population because of the benefits they bestow on groups, regardless of the alleles' effect on the fitness of individuals within that group....

, and arises where individual fitness is coupled with the fitness of the population.

An example of this would be an individual animal who learns to eat buds or seedlings of a food crop, destroying the normal supply of food that would later be available from mature plants. The adaptation of a single animal would cause the entire group to starve to death.

Models of evolutionary suicide have generally come from scientists using the mathematical model
Mathematical model
A mathematical model is a description of a system using mathematical concepts and language. The process of developing a mathematical model is termed mathematical modeling. Mathematical models are used not only in the natural sciences and engineering disciplines A mathematical model is a...

ing technique known as adaptive dynamics, where models of evolution can be combined with models of population dynamics
Population dynamics
Population dynamics is the branch of life sciences that studies short-term and long-term changes in the size and age composition of populations, and the biological and environmental processes influencing those changes...

. This allows the scientist to predict how population density
Population density
Population density is a measurement of population per unit area or unit volume. It is frequently applied to living organisms, and particularly to humans...

will change as a given trait invades the population.

Evolutionary suicide has also been referred to as "Darwinian extinction", "Runaway selection to self-extinction" or "Evolutionary collapse". The idea is similar in concept to the Tragedy of the Commons
Tragedy of the commons
The tragedy of the commons is a dilemma arising from the situation in which multiple individuals, acting independently and rationally consulting their own self-interest, will ultimately deplete a shared limited resource, even when it is clear that it is not in anyone's long-term interest for this...

.

As such, evolutionary suicide remains a theoretical possibility. Very few studies have actually demonstrated it, either in the laboratory or in nature, but this is due to the difficulties associated with observing the exact causes of an extinction.