New research from Cornell University has found that the evolution of bats’ wings and legs is tightly coupled, unlike birds. This discovery may have limited the ability of bats to fill as many ecological niches as birds. Researchers had initially expected to confirm that bat evolution was similar to that of birds, with wings and legs evolving independently. However, they found the opposite to be true, which was a surprising result. The study was led by Andrew Orkney, a postdoctoral researcher, and Brandon Hedrick, an assistant professor in biomedical sciences at Cornell.
The idea that the origin of flight required forelimbs and hindlimbs to evolve independently has been a widely accepted theory. Comparing bats and birds, which do not share a common flying ancestor, allows researchers to study the evolution of flight as independent replicates. The researchers found that the shapes of bones within a species’ wing or leg are correlated in both bats and birds. However, when comparing the correlation across legs and wings, the results were different. Bird species showed little to no correlation, while bats showed a strong correlation, indicating that their forelimbs and hindlimbs did not evolve independently.
The tightly coupled evolution of wings and legs in bats may limit their ability to adapt to new ecologies. When the shape of a bat’s wing changes, the shape of its leg changes in the same direction. This contrasts with birds, whose wings and legs evolve independently. Despite this limitation, bats have been able to thrive in many different environments. The researchers suggest that the coupled evolution of wings and legs may have played a role in shaping the ecological diversity of bats and birds.
The team also re-examined the evolution of bird skeletons in greater depth following their discovery about bats. They found that the evolution of birds’ wings and legs is indeed independent, which may help explain their evolutionary success. However, the researchers still do not fully understand why birds are able to evolve their wings and legs independently, or when this capability began to manifest in their evolutionary history. Further research is needed to explore these questions and better understand the evolutionary patterns and adaptations of bats and birds.
Overall, this study provides valuable insights into the evolution of flight in vertebrates, particularly bats and birds. By comparing these two groups of animals, researchers were able to uncover unique patterns of evolution that have shaped their ability to adapt to different ecological niches. The findings may have implications for understanding the limits and opportunities of evolutionary adaptations in vertebrates, and how these adaptations have influenced the diversity of species in different environments. Further research is needed to expand on these findings and explore the underlying mechanisms driving the evolution of flight in bats and birds.
