Contrary to what Darwin once proposed, the pace of evolution can unfold in years rather than epochs. In some scenarios, rapid genetic shifts emerge as species respond to environmental change. A broad, international collaboration has demonstrated how quickly evolution can occur, highlighting its potential as a tool in addressing global warming. This line of research shows that natural selection can drive meaningful genetic changes in short time frames, not just across deep time, and it opens doors to understanding how organisms adapt to shifting habitats.
Darwin described evolution as a slow process driven by natural selection that alters traits over long periods. Yet contemporary studies reveal many instances where noticeable evolutionary changes arise within just a few years. Recent findings from a global effort with the Leibniz Institute for Zoo and Wildlife Studies have shown that the raw material for evolution in wild populations is larger than once assumed. The results, reported in a prominent science journal, underscore that populations harbor substantial genetic variation that enables adaptation and survival under changing conditions.
In early discussions, scientists asked how quickly birds and mammals could adapt to environmental shifts. The English pepper moth is a classic example where the frequency of color forms shifted dramatically over decades due to shifts in pollution levels that altered selective pressures. While this case demonstrated rapid change, questions remained about higher turnover rates in long‑lived species. New research now provides evidence that even longer-lived animals can undergo substantial evolutionary shifts within relatively short time spans when the ecological context favors certain traits.
Evolution of certain animal families and the roles of different species have become clearer through ongoing observations. A team led by Timothée Bonnet from the Australian National University, together with researchers from 27 institutions, explored how much evolutionary fuel is present in wild bird and mammal populations. The striking answer: many species possess two to four times more capacity for evolution than previously believed. This insight reshapes expectations about how quickly species can respond to environmental change.
One reason earlier estimates fell short is that generations that do not produce offspring were not fully accounted for. Addressing this required new statistical methods and rigorous data selection. Researchers needed precise life histories: birth dates, mates, offspring, and deaths. Despite the challenge, the team compiled millions of hours of field data and integrated genetic analyses across 19 populations spanning 15 species from various regions.
Among the populations studied, the spotted hyenas of the Ngorongoro Crater in Tanzania stood out. Leibniz-IZW researchers have studied this group for more than 26 years, building a genetic pedigree that covers thousands of individuals over multiple generations. Other studied populations included wrens from Australia, songbirds from Canada, and red deer from Scotland.
When the study quantified evolutionary fuel, the results showed notable differences among species. Spotted hyenas emerged as the species with the greatest reservoir of evolutionary potential among the 15 studied. This surprised the research team, as hyenas are known for remarkable adaptability across diverse habitats. The lead investigators emphasized that the finding does not imply a guaranteed adaptation for every species, but it highlights the flexibility present in nature.
Social learning and genetic change
Beyond the vast data collection and methodological advances, the team confronted a key question in social species: can social learning influence traits that affect survival and reproduction? In animals that live in tightly knit groups, changes in important traits may arise not only through heredity but also through social processes. The approach required careful control for potential biases from social inheritance, which can mimic genetic effects.
To separate these influences, researchers designed computer simulations that modeled a population where heredity was purely social. They then compared the estimated evolutionary fuel in these simulated hyenas with the real data. The additional simulations did not alter the main conclusions, reinforcing the view that, in hyenas, a substantial portion of the observed genetic variation is tied to heritable material within the natural gene pool.
These findings carry implications for predicting how species might adapt to rapid environmental changes, including those driven by climate disruption. The study’s authors stress that evolution could be a principal driver enabling populations to persist as habitats transform. As habitats shift at accelerating rates, the capacity for rapid genetic and behavioral adjustment becomes increasingly important for long-term survival.
For further context, the study is documented in the journal Science, with the research team emphasizing the broader relevance of their results for understanding how populations respond to environmental pressures. The Science publication marks a significant contribution to the field by detailing how much evolutionary fuel exists in natural populations and how this fuel varies across species.
Environment departments and research institutions continue to advance this area of study, building on long-term field programs and rigorous genetic analyses to refine our understanding of adaptive potential in the wild. The evolving narrative suggests that evolution may play a more substantial and immediate role in shaping species’ responses to our rapidly changing world, beyond what earlier expectations had suggested.