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. Bonner zoologische Monographien. Zoology. 125 continuously revolving in the scientific literature, eluded empirical documen- tation (NiLSSON 1998). According to Darwin's classical model of a co-evolutio- nary race, the sphingid moth is compelled to insert its tongue into the very base, and thus to selectively pollinate deeper flowers than its tongue reach (Nilsson 1988). Thus, long-tongued sphingid moth gain fitness advantages over those with short tongues, and deep-spurred orchids surpass the reproductive success of indi- viduals with less deep spurs (Fig. 9). Remarkably, the model of a co-
. Bonner zoologische Monographien. Zoology. 125 continuously revolving in the scientific literature, eluded empirical documen- tation (NiLSSON 1998). According to Darwin's classical model of a co-evolutio- nary race, the sphingid moth is compelled to insert its tongue into the very base, and thus to selectively pollinate deeper flowers than its tongue reach (Nilsson 1988). Thus, long-tongued sphingid moth gain fitness advantages over those with short tongues, and deep-spurred orchids surpass the reproductive success of indi- viduals with less deep spurs (Fig. 9). Remarkably, the model of a co-evolutionary race has been doubted by Wasser- thal (1997). Wasserthal assumed that X. morganii praedictds tongue elonga- tion has primarily evolved to increase distance against predators ambushing on flowers. One-sided adaptive evolution of the plant partner for pollination by long- tongued hawkmoth is the consequence of Wasserthal's model. Wasserthal DIRECTION OF EVOLUTION. Floral tube length Fig. 9: Co-evolutionary race between long-tongued sphingid moths and flowers with deep spurs. Modified after Nilsson (1988).. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Bonn, Zoologisches Forschungsinstitut und Museum Alexander Koenig
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Keywords: ., bookcentury1900, bookcollectionbiodiversity, booksubjectzoology