"As Professor Owen has remarked, there is no greater anomaly in nature than a bird that cannot fly; yet there are several in this state." Charles Darwin, Origin of Species 1st edition (on Kindle)
Sir Richard Owen was mentioned in a previous post of mine when I was going through Darwin's letters. Though Owen is a prominent biologist of his time, Darwin has no respect for the man.
Brian McNab, one of my ornithological heros, has written extensively on this. It ends up that disuse is an important component of the evolution of flightlessness in birds. But not disuse per se. Up to 1/3 of a birds mass is devoted to flight muscle and is costly metabolically. There is strong selection to reduce muscle mass so if flight isn't needed then flightlessness is favored.
McNab, B. K. (1994). "Energy conservation and the evolution of flightlessness in birds." American Naturalist 144: 628-642.
"As Professor Owen has remarked, there is no greater anomaly in nature than a bird that cannot fly; yet there are several in this state." Charles Darwin, Origin of Species 1st edition (on Kindle)
Sir Richard Owen was mentioned in a previous post of mine when I was going through Darwin's letters. Though Owen is a prominent biologist of his time, Darwin has no respect for the man.
Brian McNab, one of my ornithological heros, has written extensively on this. It ends up that disuse is an important component of the evolution of flightlessness in birds. But not disuse per se. Up to 1/3 of a birds mass is devoted to flight muscle and is costly metabolically. There is strong selection to reduce muscle mass so if flight isn't needed then flightlessness is favored.
McNab, B. K. (1994). "Energy conservation and the evolution of flightlessness in birds." American Naturalist 144: 628-642.
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