Menzel (1985) claimed that the information available to a foraging bee comes from two sources: its own individual experience, and the "species experience" which is derived from evolutionary history and which is written into the species' genome. The implication here is that the "species memory" is identical in all members of the species. This is strictly true only when there is no genetic variability for the trait in question, either because ofconstraint, or because selection or drift have eliminated variance in the past. However, recent studies have shown that there is heritable variation in learning speed (Brandes 1988), and several other foraging related traits (see references in Waddington, this volume) which means that the limitations of the plasticity discussed elsewhere in this chapter are variable and subject to selection. Thus, just as much as foraging is shaped by individual experience, it is also determined by individual genetic histories.
We hope for more studies of heritable variation of sensory and behavioral traits related to foraging. To confirm a hypothesis that a trait is adaptive, we should ideally show that animals with that trait have greater fitness than animals without that trait, or with a different quantitative expression of the trait. Is traplining adaptive, for example.? Is flower constancy a strategy (Menzel, this volume) or a suboptimal solution (Gegear & Laverty, this volume)? Do bumble bees with red preference perform better on some islands than on the mainland, whereas bumble bees without such preference outcompete those with red preference in European mainland habitats (Chittka et al., this volume).? We need to exploit heritable variation to understand whether the cognitive, behavioral, and sensory attributes of pollinators are truly sitting on narrow adaptive peaks, as many workers assume.
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