ITHACA, N.Y. – A potted scarlet monkeyflower would die within a few days without water. But multiple natural populations of the species survived an extreme, four-year drought in California, and researchers now know why: The flowers were rescued by their own rapid evolution.
In the study, under embargo until 2pm ET on March 12, 2026 in Science , researchers tracked scarlet monkeyflower populations in Oregon and California for more than a decade and found that the populations rapidly evolved in response to prolonged extreme drought, with some recovering. The results provide the first full documentation of “evolutionary rescue” from climate change in natural populations while also mapping the genetic variations that enabled, and can now even predict, recovery.
“Essentially what we found is that the populations that recovered are also the populations that evolved the fastest,” said first author Daniel Anstett , assistant professor of plant biology.
Previous studies had shown evolutionary rescue was possible in lab settings and in theoretical work, but this is the first study of natural populations to show decline due to climate change, evolution of climate adaptations across whole genomes and subsequent recovery.
“And the genetic variation we saw, even before the drought, predicted demographic recovery five, six, seven years later,” Anstett said. “That’s astounding. That’s the crystal ball we can use to predict into the future.”
The approach could help understand and forecast the survival of species endangered by climate change, as extreme events like drought are expected to increase as the planet warms.
“This is one species, but it’s a really good indicator for drought adaptation,” Anstett said. “Conservation is a complicated calculus, and this gives greater information to decisionmakers that can be integrated with other types of knowledge – it’s another arrow in our quiver to try to conserve species.”
Senior author Amy Angert from the University of British Columbia and then-Ph.D. student Seema Sheth, now at North Carolina State University, began tracking variations in monkeyflower populations in Oregon and California in 2010, without anticipating that the most extreme drought in more than 10,000 years would begin in California in 2012.
As the populations dwindled, they realized they had a time capsule, in the form of stored seeds back in the lab, to observe genetic change. Using pre-drought data, Anstett and the research team established a genetic baseline through the sequencing of whole genomes across 55 populations, including genetic variation specifically associated with the differences in climate across the populations’ range.
As the drought progressed, the team was able to track climate-associated variation as populations declined and adapted, with some populations evolving to survive while others declined or even went extinct.
“Really, this is a story of successes and failures and the different strategies that came about, some of which were more successful than others,” Anstett said. “Evolution has no foresight – it’s a process the same way gravity is a process.”
The team found that three of the populations fared particularly well – those with the most adaption at those climate-associated sites. Anstett said the genetic adaptions seem to be correlated with variations in the stomata on the plant’s leaves, how much they open or close, and how carbon is assimilated through photosynthesis, but the exact genes that control those traits remain unknown.
“That’s a starting point for further research. Identifying the genes involved in this evolution would help us understand what traits allow populations to survive these extended drought periods,” Anstett said. “There also isn’t a final verdict on whether the genetic adaption that occurred during the drought helps in the long-term. We’re still working on that.”
Anstett’s lab is currently using monkeyflower seeds from 2017 to 2025 to study what happened to the populations after recovery and how their recent evolution predisposes them to future climate events.
For Anstett, the study is the culmination of years of work and has constituted a training ground in genomics, a field he moved into over the course of the project, from more ecological research.
“It’s a highly creative process ultimately, which is not something you’d expect, but you’re always finding new ways to handle the data,” he said. “This study also just became such a big part of a lot of people’s lives – my wife is second author, so we collaborated on this, and we all worked through the pandemic. A lot of lives were intertwined with this research.”
Additional co-authors include Julia Anstett, Dylan R. Moxley, Mojtaba Jahani, Marco Todesco and Loren H. Rieseberg of the University of British Columbia; Haley A. Branch of Yale University; Kaichi Huang of Sun Yat-sen University; Miguel Lazaro-Guevara of McGill University; and Rebecca Jordan of CSIRO (Commonwealth Scientific and Industrial Research Organisation) Environment in Australia.
The study was funded by Genome British Columbia, the Natural Sciences and Engineering Research Council of Canada, the National Science Foundation and the United States Department of Agriculture’s National Institute of Food and Agriculture.
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Science
Rapid evolution predicts demographic recovery after extreme drought
12-Mar-2026