Sex on Six Legs_ Lessons on Life, Love, and Language From the Insect World - Marlene Zuk [29]
This is not to suggest that we shouldn't try to explore the genetic basis for behaviors such as courtship or maternal care. On the contrary, the new technologically sophisticated methods can reveal extraordinary detail about the mechanisms behind even complicated behaviors. But we should abandon, once and for all, the antiquated notion that we will ever have a catalogue of genes that can be neatly assigned to one and only one characteristic, that a gene associated with long eyelashes will have no truck with one making us more likely to prefer salty foods. Genes may dictate the production of proteins, but they do so in a maze of collaboration with other bits and particles of DNA.
What Next?
GENOME sequencing seems to induce a kind of greed in scientists, a hankering for more species with more variants of behavior and appearance. Many biologists have a favorite study organism and so often would love to have "their" animal or plant sequenced next. As the costs of processing samples decreases, the need to set priorities won't be quite so pressing, but right now several scientists have come up with justifications for "wish lists" to help guide future efforts.
Evans and Gundersen-Rindal used four criteria to evaluate groups of insects for their place on the list. First was genome size: smaller genomes are easier to sequence, and we already have an idea of genome size for many of the major categories. As mentioned earlier, flies, butterflies, and the bees and ants all have relatively small genomes, while grasshoppers and crickets, cockroaches, and silverfish, those odd little wingless pests in libraries, all have rather large ones. The central database called GenBank already has information on proteins in some of the groups, particularly flies, which also helps in starting a sequencing project. Evans and Gundersen-Rindal also ranked the insects for species diversity within each group, arguing that we would be better off working with diverse groups because they are likely to have more researchers working on them. Finally, they scored the insects for their effect on humans, where, as you might imagine, the elusive silverfish were pretty low on the scale. Overall, they plumped for more flies, more social insects such as bees and ants, and more beetles, with some moths and butterflies thrown in as well.
Beetles, particularly dung beetles, were also favorites of biologists Ronald Jenner and Matthew Wills, who suggested that the horned dung beetles in the genus Onthophagus would be particularly useful. As with antlers on deer and moose, the horns are more developed on males and are used in fights between rivals for females, allowing researchers to examine the genetic control of sexual differences. What's more, horn size is influenced by the environment in which a beetle matures, with better nourishment yielding more impressive weaponry; this could yield insights into the ways that genes are switched on and off by external factors.
Using criteria roughly similar to those of Evans and Gundersen-Rindal, myrmecologist and insect photographer Alex Wild mused about which ants would make the best candidates for genome projects. He settled on seven prospects, including the leafcutter ants of the New World tropics, which as their name implies slice off bits of vegetation that they bear off to the nest, where the material is chewed and used as a base for fungus gardens. The wood ants were another favorite, with many examples of social parasitism, potentially giving insight into the evolution of this unusual life history. One of the responses to Wild concurred with his proposal of another species, the bullet ant, which has an exceptionally painful sting, although the enthusiasm seemed to stem more from a desire for revenge by a victim