Original title: Speciation, extinction and explosions induced by sudden environmental changes
Larissa G. Landucci, Marcus A. M. de Aguiar · September 2026
How do sudden environmental changes shape the variety of life? Researchers investigated this question using a computer simulation of sexually reproducing populations. They abruptly changed three environmental factors: carrying capacityThe maximum number of individuals the environment can support. (the population size an environment can support), mating range, and assortativityHere, the requirement that two individuals be similar enough before they are allowed to mate. (how genetically similar two mates must be). They found that suddenly boosting the carrying capacity can lead to new species forming, or it can trigger widespread extinctions until only a single species dominates. Sudden changes to the mating range cause a similar outcome. The key factor deciding between speciationThe process by which one population splits into separate species. or extinction is genome lengthThe number of genes involved in reproduction and similarity requirements., meaning the number of reproduction-controlling genes. Finally, making mating more restrictive sparks a temporary burst of new species that settles above the original level.
A small town runs a weekly mixer where single people meet. When the town suddenly changes—a new highway makes one neighborhood much more popular—the usual matchmaking breaks down: either small tight circles form all over town, or everybody flocks to that one neighborhood and the rest empty out. In this paper, the town is a population, the sudden change is an environmental shock, and the matchmaking rule is how similar two individuals must be to pair off and reproduce.
Sudden environmental changes are real and can hit a population before it adapts. For species that need a mate to reproduce, the same shock can generate new species or collapse the system down to one. The outcome seems to hang on how many genes control who counts as similar enough to mate. That points to a concrete measurement for predicting biodiversity after a sudden shift.
The abstract reports results from a specific individual-based model and gives no explicit caveats. It describes qualitative outcomes—speciation, extinction, bursts—without exact parameter values, effect sizes, or generation counts beyond "a few generations." The environmental changes are single sudden shocks, so gradual or repeated changes are not addressed. The abstract also says nothing about whether the results generalize to natural populations or other mating systems.
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Speciation, extinction and explosions induced by sudden environmental changes — Larissa G. Landucci, Marcus A. M. de Aguiar
Abstract licence: CC0
Explanation generated by Synthesis from the abstract — it is not the original paper. This is a preprint, so it hasn't necessarily been peer reviewed.