Conclusions and Looking Forward

Abstract

Abstract The previous chapters have shown that spiders are defined by their silk systems. From birth to death, the bulk of their behavior depends on silk production. This has apparently been true since their earliest origins and makes spiders unique, different even from other silk producing animals. Because of the centrality of silk production to spider lifestyles, we should not be surprised to find that the forces of natural selection have focused on their silk-production systems. As mentioned frequently in previous chapters, the evolution of new silk threads has correlated with major speciation events. Previous chapters discussed the molecular properties of the amino acids that make up silk, the structures of their resulting proteins, and how the genes that encode them are organized. Using these data (collected from both insects and spiders) as background information, silk proteins were studied in the context of the complex and diverse organisms that produce them, looking specifically at the physical properties of silks that are important to function, the mechanisms by which changes in silk proteins are mediated or mitigated, and the energetic demands of silk production.