An illustration of Archaeopteryx
Mark Witton.
About 150 million years ago, a small, feathered dinosaur was negotiating one of the most consequential transitions in vertebrate evolution: getting airborne and remaining there under its own power. Archaeopteryx, with its feathered wings, toothed jaws, clawed fingers and long, bony tail, combined features that creationists prefer to imagine belong in separate, independently created categories. It also lived almost 150 million years before the supposed ‘Creation Week’ of young-Earth creationism. Both its anatomy and its antiquity present awkward problems for anyone trying to compress the history of life into a literal reading of Genesis.
Now, a paper in Developmental Biology, by Erik A. Meilak and colleagues, addresses a particularly interesting question: how could an animal with a less specialised flight apparatus than that of modern birds get off the ground? Their modelling suggests that powerful hindlimbs could have supplied the answer. A succession of forward leaps, potentially assisted by a wingbeat between jumps, could have built up sufficient speed for flapping flight.
For a modelled Archaeopteryx weighing about 400 grams, the researchers calculated that three leaps using both legs, or two with an intervening downward wingbeat, could have brought it to a sustainable flight speed of approximately seven metres per second. This provides a plausible route into the air without requiring the powerful, explosive take-off of many living birds. It is a proposed biomechanical solution, rather than direct evidence of an observed Jurassic behaviour, but it makes a specific evolutionary possibility testable.
That distinction matters because evolution does not require a modern bird’s entire flight apparatus to appear in one miraculous event. Existing structures can acquire additional functions, and useful intermediate combinations can precede the more specialised arrangements found in descendants. Legs already capable of propelling an animal across the ground could also launch it into the air; feathered forelimbs could contribute to that movement before acquiring all the refinements of modern wings. No foresight is required, only advantages available to the animal at the time.
Nor does describing Archaeopteryx as transitional mean it was an unfinished creature waiting for evolution to complete it. It was an animal in its own right, with a revealing combination of ancestral and derived features. Birds are themselves theropod dinosaurs, so the transition concerns the emergence of avian specialisations within the dinosaur lineage, not a magical crossing between unrelated ‘kinds’. Calling Archaeopteryx “just a bird” does nothing to explain away its dinosaurian anatomy or its position in evolutionary history.
The study does not settle every question about the origin of flight, and it need not do so to expose the weakness of the creationist alternative. Science can investigate how a transitional animal functioned, compare competing explanations and refine its conclusions. A literal Genesis chronology cannot even accommodate the time in which that animal lived. In the following article, reproduced from The Conversation, co-author Neil J. Gostling explains how the research brings us closer to understanding the steps — or, in this case, leaps — by which early birds took to the air. His article is reformatted for stylistic consistency:
