Unformatted text preview: • One must not confuse the fact that a structure is used in some way with the primary evolutionary reason for its existence and conformation Black Carp—Exotic molluscivore Black Carp’s pharyngeal teeth are indeed well suited for its diet Snail Darter ( Percina tanasi ) “…has no adaptations for snail eating.” • Really? – Grabs snail – Forces it against bottom – Swallows whole Digests soft tissue yielding energy Snail Darter ( Percina tanasi ) – Digests soft tissue, yielding energy – Partially digests hard tissue, yielding minerals – Defecates remnant shell • Well suited anatomically, behaviorally, and physiologically • An integrated whole...
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- Spring '08
- Proc. R. Soc, Snail Darter, Digests soft tissue, regards natural selection, energy soft tissue