Publications by authors named "Michael Calonje"

Background And Aims: Cycads are a key lineage to understand the early evolution of seed plants and their response to past environmental changes. However, tracing the evolutionary trajectory of cycad species is challenging when the robust relationships at inter- or infrageneric level are not well resolved.

Methods: Here, using 2901 single-copy nuclear genes, we explored the species relationships and gene flow within the second largest genus of cycads, i.

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The cycad genus Ceratozamia comprises 40 species from Mexico, Guatemala, Belize, and Honduras, where cycads occur throughout climatically varied montane habitats. Ceratozamia has the potential to reveal the history and processes of species diversification across diverse Neotropical habitats in this region. However, the species relationships within Ceratozamia and the ecological trends during its evolution remain unclear.

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butterflies are obligate herbivores of , the most diverse neotropical genus of cycads. interactions have been characterized mainly for species distributed in North and Central America. However, larval host plant use by the southern clade remains largely unknown, precluding a comprehensive study of co-evolution between the genera.

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Studies of pollination biology often focus on visual and olfactory aspects of attraction, with few studies addressing behavioral responses and morphological adaptation to primary metabolic attributes. As part of an in-depth study of obligate nursery pollination of cycads, we find that Rhopalotria furfuracea weevils show a strong physiological response and behavioral orientation to the cone humidity of the host plant Zamia furfuracea in an equally sensitive manner to their responses to Z. furfuracea-produced cone volatiles.

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Coevolution between plants and insects is thought to be responsible for generating biodiversity. Extensive research has focused largely on antagonistic herbivorous relationships, but mutualistic pollination systems also likely contribute to diversification. Here we describe an example of chemically-mediated mutualistic species interactions affecting trait evolution and lineage diversification.

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Color vision has evolved multiple times in both vertebrates and invertebrates and is largely determined by the number and variation in spectral sensitivities of distinct opsin subclasses. However, because of the difficulty of expressing long-wavelength (LW) invertebrate opsins in vitro, our understanding of the molecular basis of functional shifts in opsin spectral sensitivities has been biased toward research primarily in vertebrates. This has restricted our ability to address whether invertebrate G protein-coupled opsins function in a novel or convergent way compared to vertebrate G opsins.

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Premise Of The Study: The Bahamas archipelago is formed by young, tectonically stable carbonate banks that harbor direct geological evidence of global ice-volume changes. We sought to detect signatures of major changes on gene flow patterns and reconstruct the phylogeographic history of the monophyletic complex across the Bahamas.

Methods: Nuclear molecular markers with both high and low mutation rates were used to capture two different time scale signatures and test several gene flow and demographic hypotheses.

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Several individuals of the Caribbean Zamia clade and other cycad genera were used to identify single-copy nuclear genes for phylogeographic and phylogenetic studies in Cycadales. Two strategies were employed to select target loci: (i) a tblastX search of Arabidopsis conserved ortholog sequence (COS) set and (ii) a tblastX search of Arabidopsis-Populus-Vitis-Oryza Shared Single-Copy genes (APVO SSC) against the EST Zamia databases in GenBank. From the first strategy, 30 loci were selected, and from the second, 16 loci.

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Background And Aims: Despite a recent new classification, a stable phylogeny for the cycads has been elusive, particularly regarding resolution of Bowenia, Stangeria and Dioon. In this study, five single-copy nuclear genes (SCNGs) are applied to the phylogeny of the order Cycadales. The specific aim is to evaluate several gene tree-species tree reconciliation approaches for developing an accurate phylogeny of the order, to contrast them with concatenated parsimony analysis and to resolve the erstwhile problematic phylogenetic position of these three genera.

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Premise Of The Study: This study of Zamia in Puerto Rico is the most intensive population genetics investigation of a cycad to date in terms of number of markers, and one of few microsatellite DNA studies of plants from the highly critical Caribbean biodiversity hotspot. Three distinctive Zamia taxa occur on the island: Z. erosa on the north coast, and Z.

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Article Synopsis
  • The study investigates how cyclones influence natural selection on palm species, focusing on their resistance to wind load.
  • Using New World palms as a model, the researchers assessed cyclone damage on plants from both cyclone-prone and cyclone-free areas to compare mortality rates.
  • Results indicate that palms from cyclone-prone areas have lower mortality and less variation in wind tolerance, suggesting that cyclones exert selective pressure leading to natural selection for cyclone tolerance.
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