11 research outputs found
The Evolution of a Female Genital Trait Widely Distributed in the Lepidoptera: Comparative Evidence for an Effect of Sexual Coevolution
Sexual coevolution is considered responsible for the evolution of many male genital traits, but its effect on female genital morphology is poorly understood. In many lepidopterans, females become temporarily unreceptive after mating and the length of this refractory period is inversely related to the amount of spermatophore remaining in their genital tracts. Sperm competition can select for males that delay female remating by transferring spermatophores with thick spermatophore envelopes that take more time to be broken. These envelopes could select for signa, sclerotized sharp structures located within the female genital tract, that are used for breaking spermatophores. Thus, this hypothesis predicts that thick spermatophore envelopes and signa evolve in polyandrous species, and that these adaptations are lost when monandry evolves subsequently. Here we test the expected associations between female mating pattern and presence/absence of signa, and review the scant information available on the thickness of spermatophore envelopes.We made a literature review and found information on female mating pattern (monandry/polyandry), presence/absence of signa and phylogenetic position for 37 taxa. We built a phylogenetic supertree for these taxa, mapped both traits on it, and tested for the predicted association by using Pagel's test for correlated evolution. We found that, as predicted by our hypothesis, monandry evolved eight times and in five of them signa were lost; preliminary evidence suggests that at least in two of the three exceptions males imposed monandry on females by means of specially thick spermatophore envelopes. Previously published data on six genera of Papilionidae is in agreement with the predicted associations between mating pattern and the characteristics of spermatophore envelopes and signa.Our results support the hypothesis that signa are a product of sexually antagonistic coevolution with spermatophore envelopes
Unravelling the role of host plant expansion in the diversification of a Neotropical butterfly genus
Searches for Lepton flavor violation in the decays tau(+/-) -> e(+/-)gamma and tau(+/-) -> mu(+/-)gamma
Searches for lepton-flavor-violating decays of a tau lepton to a lighter mass lepton and a photon have been performed with the entire data set of (963 +/- 7) x 10(6) tau decays collected by the BABAR detector near the Y(4S), Y(3S) and Y(2S) resonances. The searches yield no evidence of signals and we set upper limits on the branching fractions of B(tau(+/-) -> e(+/-)gamma) mu(+/-)gamma) < 4.4 X 10(-8) at 90% confidence level
Search for B^{+}→ℓ^{+}ν_{ℓ} recoiling against B^{-}→D^{0}ℓ^{-}ν[over ¯]X
We present a search for the decay B+→ℓ+νℓ(ℓ=τ,μ, or e) in (458.9±5.1)×106 BB̅ pairs recorded with the BABAR detector at the PEP-II B-factory. We search for these B decays in a sample of B+B- events where one B-meson is reconstructed as B-→D0ℓ-ν̅ X. Using the method of Feldman and Cousins, we obtain B(B+→τ+ντ)=(1.7±0.8±0.2)×10-4, which excludes zero at 2.3σ. We interpret the central value in the context of the standard model and find the B meson decay constant to be fB2=(62±31)×103  MeV2. We find no evidence for B+→e+νe and B+→μ+νμ and set upper limits at the 90% C.L. B(B+→e+νe)<0.8×10-5 and B(B+→μ+νμ)<1.1×10-5