I just finished reading Your Inner Fish by Neil Shubin and he spends a lot of time offering examples of how shared structure in animals can tell us about their ancestors. There’s a prime example of this in the news today: alligators and birds share a common lung structure. Specifically, alligators breathe in only one direction, like birds, instead of in two, like mammals. Why is this important?
The researchers believe the similarity in lung structure may explain why some animals were better able to adapt after the extinction, when oxygen levels dropped.
“We know that birds are really good at breathing in hypoxic conditions. They can fly at altitudes that would kill a mammal,” said Dr Farmer.
“Many archosaurs, such as pterosaurs, apparently were capable of sustaining vigorous exercise. Lung design may have played a key role in this capacity.
“That’s been a puzzle, why do birds have these very different lungs? But now we can date it back to the common ancestor of birds and crocodilians.
From the BBC article. (See also NewScientist.)
Tags: alligators, archosaurs, birds, breathing, Evolution, lungs
