BACKGROUND Charles Darwin’s Descent of Man, and Selection in Relation to Sex tackled the two main controversies arising from the Origin of Species: the evolution of humans from animal ancestors and the evolution of sexual ornaments. Most of the book focuses on the latter, Darwin’s theory of sexual selection. Research since supports his conjecture that songs, perfumes, and intricate dances evolve because they help secure mating partners. Evidence is overwhelming for a primary role of both male and female mate choice in sexual selection—not only through premating courtship but also through intimate interactions during and long after mating. But what makes one prospective mate more enticing than another? Darwin, shaped by misogyny and sexual prudery, invoked a “taste for the beautiful” without speculating on the origin of the “taste.” How to explain when the “final marriage ceremony” is between two rams? What of oral sex in bats, cloacal rubbing in bonobos, or the sexual spectrum in humans, all observable in Darwin’s time? By explaining desire through the lens of those male traits that caught his eyes and those of his gender and culture, Darwin elided these data in his theory of sexual evolution. Work since Darwin has focused on howmore »
Habitat complexity and complex signal function – exploring the role of ornamentation
Animals often communicate in complex, heterogeneous environments, leading to hypothesized selection for increased detectability or discriminability in signaling traits. The extent to which secondary sexual ornaments have evolved to overcome the challenges of signaling in complex environments, however, remains understudied, especially in comparison to their role as indicator traits. This study tested the hypothesis that the condition-dependent secondary sexual ornamentation in the wolf spider Rabidosa rabida functions to increase detectability/discriminability in visually complex environments. We predicted that male ornamentation would interact with the complexity of the signaling environment to affect male mating success. In particular, we expected ornaments to confer a greater mating advantage when males courted in visually complex environments. To test this, we artificially manipulated male foreleg ornamentation (present/absent) and ran repeated-measures mating trials across laboratory microcosms that represented simple versus complex visual signaling environments. Microcosm visual complexity differed in their background pattern, grass stem color, and grass stem placement. We found that ornamented males mated more often and more quickly than unornamented males across both environments, but we found no support for an ornament-by-environment interaction. Male courtship rate, however, did interact with the signaling environment. Despite achieving the same level of mating success across signaling environments, more »
- Publication Date:
- NSF-PAR ID:
- 10362984
- Journal Name:
- Behavioral Ecology
- Volume:
- 33
- Issue:
- 1
- Page Range or eLocation-ID:
- p. 307-317
- ISSN:
- 1045-2249
- Publisher:
- Oxford University Press
- Sponsoring Org:
- National Science Foundation
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