An artist’s interpretation of life and death after the asteroid impact that wiped out the dinosaurs. The three hair-covered forms (left) represent species of plankton found inside the crater made by the impact. The geometric form (bottom left) is a species of algae. The bones belong to an extinct marine reptile.
The University of Texas at Austin Jackson School of Geosciences/John Maisano.
That life on Earth eventually recovered after the Chicxulub impact—the asteroid strike that wiped out the non-avian dinosaurs and much of the planet’s megafauna—is hardly surprising. If it had not, mammals and birds would not be the dominant land vertebrates today. What may be more surprising is how quickly that recovery appears to have begun, according to new research led by Assistant Professor Chris Lowery of the University of Texas Institute for Geophysics (UTIG) at the Jackson School of Geosciences.
Their findings have just been published in the journal Geology.
For creationists, the study presents yet another awkward problem. Not only did these events occur 66 million years ago — tens of millions of years before primates evolved, let alone the humans that some creationists insist lived alongside dinosaurs — but the results also show evolution proceeding exactly as evolutionary theory predicts.
The mass extinction at the end of the Cretaceous — known to geologists as the K–Pg boundary, after the distinctive global layer preserved in sedimentary rocks — was followed by a rapid diversification of new species as surviving organisms evolved to fill the ecological niches suddenly left vacant. This pattern is precisely what evolutionary biology predicts following a mass extinction: with competitors gone and environments destabilised, natural selection quickly favours new adaptations.
According to this new study, that evolutionary response may have begun remarkably quickly. Some entirely new species appeared within a few thousand years. New species of plankton, for example, emerged within about 2,000 years of the Chicxulub impact.
The research also provides a good example of the self-correcting nature of science, one of its greatest strengths. Earlier studies had suggested that recovery took tens of thousands of years before new species appeared. Those estimates, however, relied on the assumption that sedimentation rates after the K–Pg boundary were the same as they had been before the impact.
Lowery and his colleagues argue that this assumption was probably incorrect. The global catastrophe triggered by the asteroid—mass extinction, widespread wildfires, and dramatic climatic disruption—would also have altered vegetation cover and erosion patterns, which in turn would have changed the rate at which sediments accumulated.
To test this, the team analysed the isotope helium-3 (3He), which accumulates in marine sediments at a roughly constant rate from extraterrestrial dust. Because of this steady input, the concentration of 3He acts as a natural clock: higher concentrations indicate slower sediment accumulation, while lower concentrations indicate faster deposition.
By measuring 3He levels on either side of the K–Pg boundary in sediment samples from Europe, North Africa, and the Gulf of Mexico, the researchers were able to refine the timing of events recorded in the rocks. In particular, they examined the first appearance of a tiny planktonic foraminiferan, Parvularugoglobigerina eugubina (P. eugubina), one of the earliest new species to appear after the impact. Their analysis indicates that this species—and several others—evolved within roughly 2,000 years of the Chicxulub event.
In other words, even after one of the most devastating catastrophes in Earth’s history, evolution resumed quickly, producing new species as surviving lineages adapted to the radically altered environment. Far from the static world imagined by creationist mythology, the fossil record once again reveals life responding dynamically to changing conditions.
The K–Pg Mass Extinction and the Rapid Recovery of Life. Around 66 million years ago, a large asteroid about 10–12 km in diameter struck what is now the Yucatán Peninsula in Mexico, creating the Chicxulub crater, roughly 180 km across. This impact released an immense amount of energy—equivalent to billions of nuclear bombs—and triggered one of the most severe mass extinction events in Earth’s history.The research team describe their findings in more detail in a news release from Texas Geosciences:
The catastrophe marks the boundary between the Cretaceous (K) and Palaeogene (Pg) periods, commonly called the K–Pg boundary. This boundary is preserved in sedimentary rocks worldwide as a thin layer rich in the element iridium, which is rare in Earth’s crust but common in meteorites. The presence of this global iridium layer was one of the first clues that an asteroid impact caused the extinction event.
The environmental consequences were dramatic. The impact blasted enormous quantities of dust, soot, and sulphur into the atmosphere, blocking sunlight and causing a sudden global cooling often described as an “impact winter.” Wildfires ignited across vast areas, ecosystems collapsed, and photosynthesis was severely disrupted.
As a result, about 75% of all species on Earth disappeared. Among the most famous victims were the non-avian dinosaurs, along with many marine reptiles, ammonites, and numerous plankton species that formed the base of ocean food webs.
However, the extinction did not wipe out all life. Many smaller organisms survived, including mammals, birds (the surviving lineage of dinosaurs), reptiles, amphibians, and various marine organisms. Once the dust settled and environmental conditions stabilised, these surviving groups began to expand into ecological niches left vacant by the extinction.
This process is known as adaptive radiation — a rapid diversification of species as populations evolve to exploit newly available habitats and resources. The fossil record shows that many modern groups of mammals and birds began their major evolutionary expansions during the early Palaeogene, following the disappearance of the dinosaurs.
In the oceans, microscopic plankton such as foraminifera played a key role in rebuilding marine ecosystems. Because these tiny organisms evolve relatively quickly and leave abundant fossil shells in marine sediments, they provide a particularly detailed record of ecological collapse and recovery after the Chicxulub impact.
Recent research suggests that some new plankton species appeared within only a few thousand years of the extinction event—far faster than previously thought—showing just how quickly evolution can respond when major ecological opportunities arise.
Together, these discoveries illustrate a central principle of evolutionary biology: mass extinctions reshape ecosystems, but they also create opportunities for rapid evolutionary change.
Evidence of ‘Lightning-Fast’ Evolution Found After Dino-Killing Asteroid Impact
The asteroid that struck the Earth 66 million years ago devastated life across the planet, wiping out the dinosaurs and other organisms in a hail of fire and catastrophic climate change. But new research shows that it also set the stage for life to rebound astonishingly quickly.
New species of plankton appeared fewer than 2,000 years after the world-altering event, according to research led by scientists at The University of Texas at Austin and published in Geology.
Lead author Chris Lowery, a research associate professor at the University of Texas Institute for Geophysics (UTIG) at the Jackson School of Geosciences, said that it’s a remarkably quick evolutionary feat that has never been seen before in the fossil record. Typically, new species appear on roughly million-year time frames.
It’s ridiculously fast. This research helps us understand just how quickly new species can evolve after extreme events and also how quickly the environment began to recover after the Chicxulub impact.
Assistant Professor Christopher M. Lowery, Lead author.
University of Texas Institute for Geophysics
University of Texas at Austin
Austin, Texas, USA.
Although previous studies that Lowery and his team have conducted on the Chicxulub crater in the Gulf of Mexico have shown that surviving life returned quickly after the catastrophic event, it has been widely accepted that it took tens of thousands of years for the first new species to appear after impact.
This timeline assumed that sediments accumulated at the same rate after the impact as they did before the extinction. Researchers mark the beginning and end of the extinction with a global geologic layer created by fallout from the impact called the K/Pg boundary. However, Lowery and his co-authors note that the massive die-offs happening on land and sea altered sedimentation rates for the boundary and made this assumption incorrect.
The decline in the numbers of calcareous plankton that sink to the seafloor, which mostly went extinct, combined with increased erosion from land after the death of most vegetation caused big changes in how quickly sediment piled up in different places. This made it difficult to determine the true ages of small fossils in this layer based on the sedimentation rate alone.
In their study, the researchers drew on previously published data on an isotope marker present in the K/Pg boundary that provides a more accurate measure of time captured in the geologic layer — and used it to more precisely determine when different species of plankton appear in the fossil record.
The isotope marker is called Helium-3. It accumulates in ocean sediments at a constant rate. That means if sediment accumulated slowly, it should have lots of Helium-3, and if it accumulated quickly, it should have less Helium-3, which allowed the team to more accurately calculate the passage of time.
The Cretaceous/Paleogene (K/Pg) boundary at El Kef, Tunisia, and the overlying interval covered by this study. The white ruler is ~53 cm long. 50 cm above the K/Pg boundary, the white arrow shows the level of the lowest occurrence of the foraminifera species Parvularugoglobigerina eugubina, which Lowery et al. calibrated at Kef to be 6,600 years after the Chicxulub impact.Outcrop photograph from Julio Sepúlveda, annotated by Chris Lowery.
The research team used the more accurate sedimentation rates calculated using Helium-3 from six K/Pg boundary sites from Europe, North Africa and the Gulf of Mexico to mark the age of the sediments where a new species of plankton, a foraminifera called Parvularugoglobigerina eugubina (P. eugubina), first appears. The appearance of P. eugubina is a commonly used marker of recovery following the extinction.
A scanning electron micrograph of the planktic foraminifera Parvularugoglobigerina eugubina.Scan by Chris Lowrey.
Lowery’s team found that this plankton evolved between 3.5 and 11 thousand years after the Chicxulub impact, with the exact timing differing across sites. The researchers also identified other plankton species that evolved in this interval, with some appearing fewer than 2,000 years after the Chicxulub impact, kicking off a recovery of biodiversity that would continue over the next 10 million years.
The speed of the recovery demonstrates just how resilient life is, to have complex life reestablished within a geologic heartbeat is truly astounding. It’s also possibly reassuring for the resiliency of modern species given the threat of anthropogenic habitat destruction.
Professor Timothy J. Bralower, co-author.
Department of Geosciences
The Pennsylvania State University
University Park, Pennsylvania, USA.
Between 10 and 20 new species of foraminifera appeared within about 6,000 years of the impact, according to the research. Paleontologists still debate which should be classified as distinct species.
This new timeline demonstrates how quickly new species can appear under the right conditions and highlights how even after devastating losses, life can bound back relatively quickly — a few thousand years later new species were already emerging.
Publication:
In other words, even one of the most catastrophic events in the history of life did not halt evolution—it accelerated it. With ecosystems shattered and many competitors gone, surviving lineages quickly diversified to exploit the ecological opportunities that suddenly became available. The appearance of new plankton species within a few thousand years of the Chicxulub impact is exactly the sort of evolutionary response predicted by the Theory of Evolution: rapid change following major environmental disruption.
For creationists, however, this presents yet another uncomfortable reality. Not only does the event itself sit 66 million years outside their preferred 6,000–10,000-year timeline, but the pattern of recovery recorded in the rocks shows evolution working precisely as evolutionary biology says it should. New species arise, ecosystems reorganise, and life adapts to changing conditions—all without any need to invoke supernatural intervention.
Once again, the fossil record and the geological record tell a consistent story: life on Earth has been shaped by deep time, environmental upheaval, and the continual process of evolution. Even global catastrophes do not stop that process. They simply set the stage for the next chapter in the long and dynamic history of life on our planet.
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