Incompatible Ages for Clearwing Butterflies Based on Alternative Secondary Calibrations

Author(s)

Garzon-Orduna, Ivonne J. ^[1] ; Silva-Brandao, Karina L. ^[2] ; Willmott, Keith R. ^[3] ; Freitas, Andre V. L. ^{[4, 5]} ; Brower, Andrew V. Z. ^[1]

Affiliation

^[1] Middle Tennessee State Univ, Dept Biol, Evolut & Ecol Grp, Murfreesboro, TN 37132 - USA

^[2] Univ Sao Paulo, Ctr Energia Nucl Agr, Piracicaba, SP - Brazil

^[3] Univ Florida, Florida Museum Nat Hist, McGuire Ctr Lepidoptera & Biodivers, Gainesville, FL 32611 - USA

^[4] Univ Estadual Campinas, Inst Biol, Dept Biol Anim, Campinas, SP - Brazil

^[5] Univ Estadual Campinas, Inst Biol, Museu Zool, Campinas, SP - Brazil

• Document type: Journal article
• Source: Systematic Biology; v. 64, n. 5, p. 752-767, SEP 2015.
• Web of Science Citations: 15

Abstract

The recent publication of a time-tree for the plant family Solanaceae (nightshades) provides the opportunity to use independent calibrations to test divergence times previously inferred for the diverse Neotropical butterfly tribe Ithomiini. Ithomiini includes clades that are obligate herbivores of Solanaceae, with some genera feeding on only one genus. We used 8 calibrations extracted from the plant tree in a new relaxed molecular-clock analysis to produce an alternative temporal framework for the diversification of ithomiines. We compared the resulting age estimates to: (i) a time-tree obtained using 7 secondary calibrations from the Nymphalidae tree of Wahlberg et al. (2009), and (ii) Wahlberg et al.'s (2009) original age estimates for the same clades. We found that Bayesian clock estimates were rather sensitive to a variety of analytical parameters, including taxon sampling. Regardless of this sensitivity however, ithomiine divergence times calibrated with the ages of nightshades were always on average half the age of previous estimates. Younger dates for ithomiine clades appear to fit better with factors long suggested to have promoted diversification of the group such as the uplifting of the Andes, in the case of montane genera. Alternatively, if ithomiines are as old as previous estimates suggest, the recent ages inferred for the diversification of Solanaceae seem likely to be seriously underestimated. Our study exemplifies the difficulty of testing hypotheses of divergence times and of choosing between alternative dating scenarios, and shows that age estimates based on seemingly plausible calibrations may be grossly incongruent. (AU)

• FAPESP's process: 11/50225-3 - Natural history, phylogeny and conservation of Neotropical Lepidoptera
• Grantee: André Victor Lucci Freitas
• Support type: BIOTA-FAPESP Program - Regular Research Grants
• FAPESP's process: 12/50260-6 - Structure and evolution of the Amazonian biota and its environment: an integrative approach
• Grantee: Lúcia Garcez Lohmann
• Support type: BIOTA-FAPESP Program - Thematic Grants