Even if the new population is of a different species, it can approximately fill the niche vacated by the extinct population and keep the food web intact.

In the UK, the sale of insects for human consumption is part of what is still a niche food sector centred largely around novelty snacks.

Since those carnivorous days in the 1970s, soy foods have gone from a niche product for the vegetarian-environmentalist crowd to a four-billion-dollar-a-year food industry.