What if this species disappeared?

What this site answers

"What if this species disappeared?" — the question sounds simple; the answer never is. Every species occupies a place in its ecosystem, and that place is not the same whether it is a predator, a pollinator, an engineer, or prey. This site maintains a reference of those roles: for each species, what its disappearance would cause, at what horizon, and with what level of certainty. The aim is not to predict the future, but to bring together what science has already observed or reasonably inferred.

What this site does not do

It does not claim what it does not know. Most sites answering "what if this species disappeared" write with the same assured tone, whether the cascade was measured over fifty years of monitoring or is a plausible extrapolation. What If Gone draws the distinction directly in the entry: a "documented" badge cites the study that observed the mechanism, an "inferred" badge shows the reasoning and says explicitly what is missing to confirm it, an "insufficient data" badge owns the gap instead of filling it with an assumption.

How to read an entry

Every entry follows the same grid, deliberately. The IUCN status and population show the risk facing the species itself. The timeline then answers the site's question: what happens one year, ten years, a hundred years, a thousand years after its disappearance? Each point carries its own confidence level — a "documented" point was observed by a published study; an "extrapolated" point starts from sourced facts but assembles a line of reasoning no one has verified as a whole; a "hypothesis" point owns a gap in the literature. The impact, finally, measures the magnitude of the cascade: it is deliberately separate from the IUCN status, because a species can be common yet indispensable, or threatened yet barely structuring.

Where the entries come from

Each species' status and population come from the IUCN Red List or an equivalent official source, with the confidence badge the IUCN itself uses (observed, estimated, projected, inferred, suspected) to qualify its own figures. The ecological cascade — the species' role and the consequence of its disappearance — is sourced separately, with its own confidence scale, because a species can have a very well-measured population and a very poorly studied ecological role, or the reverse. Every entry lists its sources and the date they were last verified; the full methodology explains the grid applied.

How species are chosen

The reference gives priority to species whose cascade is documentable — those for which a published study has observed the mechanism, or for which an explicit line of reasoning can be assembled from sourced facts. That is what rules most species out: without a study, an entry would be nothing but an assumption dressed up as science. Within that criterion, the choice favors keystone species, famous historical cases (Yellowstone, Paine's rocky shore), measured economic stakes, and species the general public knows, because that is where the question "what if it disappeared" means most to the reader.

Updates and corrections

Every entry shows the date of its last verification. Science moves: a new study can document a cascade that was only extrapolated, or disprove a hypothesis. An error on an entry, a species to add, a more recent source — write to us through our contact page, mentioning the official source, and the correction will be applied and dated on the entry concerned.

Why so few species at first

A level-1 entry (documented cascade) means finding and reading the original study, not rephrasing what a popular article says about it. It is slower than compiling a list, and it is the price for every claim to withstand the question "where does that come from".