Contemplating the prospect of a mass extinction reminiscent of the event 65 million years ago, one question looms: which animals would emerge as survivors and reclaim Earth? In this hypothetical scenario, rats emerge as the most adept candidates to reconquer a post-apocalyptic world.
Throughout Earth’s history, the planet has witnessed five mass extinctions, with the last one occurring 65 million years ago, attributed to an asteroid impact that led to the extinction of dinosaurs. Seizing the opportunity, our mammalian ancestors thrived in the vacated ecological niche, ultimately becoming the dominant class in the animal kingdom.
Geologist Jan Zalashewicz from the University of Leicester in London, along with colleagues, devised a theoretical experiment to identify the most resilient candidates for survival and reproduction following a mass extinction. Their hypothesis places rats at the forefront, given their widespread terrestrial presence. Despite human efforts to control their population, rats continue to exhibit successful breeding.
Historically, when animals step into vacated ecological spaces, they tend to undergo size increments, as witnessed in the case of mammals. While our ancestors adapted to living in burrows beneath the feet of dinosaurs, millions of years of evolution brought about various transformations. Zalaszewicz and team suggest that rats, too, are poised to evolve in size and other aspects over millions of years. Zalashevitzi notes, “Animals can evolve to be small or large, depending on specific circumstances and the impact of selection. This predicts a diverse future for rats, including thin, fat, slow, heavy, fast, and even aquatic rats.”
