Adaptive radiation is an evolutionary process in which a single ancestral species rapidly diversifies into many new species, each adapted to exploit different ecological niches. This usually occurs when new habitats become available, after mass extinctions, or when organisms acquire new adaptations that open up opportunities for diversification.
- Rapid diversification of species from a common ancestor
- Each new species adapts to a different ecological niche
- Often triggered by new environmental opportunities, mass extinctions, or key innovations
Adaptive radiations occur when new niches become available, after mass extinctions, or when organisms develop new adaptations—conditions that promote rapid diversification.
Darwin's finches and cichlid fishes are textbook examples of adaptive radiation.
Adaptive radiation involves rapid diversification into many new species, unlike the slower, steady change seen in gradual evolution.
Adaptive Radiations in Dinosaurs
Dinosaurs experienced several adaptive radiations, particularly during the Triassic and Jurassic periods. Following the Permian mass extinction, early archosaurs—ancestors of dinosaurs—radiated rapidly to fill vacant niches. This led to the emergence of diverse dinosaur lineages adapted for herbivory, carnivory, and various modes of locomotion. New adaptations like upright posture and efficient respiratory systems enabled them to exploit resources better than competitors, fueling their evolutionary success.
- Dinosaur adaptive radiations began after the Permian mass extinction
- Early archosaurs diversified rapidly into multiple forms
- Innovations like upright stance and advanced respiration aided niche exploitation
Key factors in dinosaur adaptive radiation included upright posture, advanced respiratory systems, and varied diets.
Dinosaurs underwent their major adaptive radiation during the Triassic period.
Theropods, sauropodomorphs, and ornithischians emerged as major dinosaur groups during adaptive radiations.
Conclusion
Adaptive radiations are bursts of evolutionary creativity that explain how dinosaurs and many other organisms became so diverse and successful.
- They require new opportunities—like empty niches or new traits—to spark rapid change
- Dinosaur adaptive radiation explains their dominance for over 160 million years
- Modern examples (like finches and cichlids) reveal the ongoing power of this process
Adaptive radiation occurs when new niches, key innovations, or mass extinctions provide opportunities for diversification.
The major adaptive radiation of dinosaurs occurred during the Triassic.
Key adaptations included upright posture, efficient respiration, and varied diets.