A population bottleneck is an event corresponding to the fact that a substantial proportion of the population of a species disappears or is prevented from reproducing. There is a significantly different type of demographic bottleneck called the founder effect, which occurs when a subset of a population is, at least as far as reproduction is concerned, isolated from the main group (it does not disappear The two groups will be independent of each other).
In population genetics, the founder effect is the loss of genetic variation that occurs when a new population is established by a very small number of individuals belonging to a larger population.
Agriculture is the cultivation of crops for human consumption. Synonymous terms are farming, crop-growing, and growing food. I hope this helps!