1. Machine learning approaches identify male body size as the most accurate predictor of species richnessKlemen Čandek, Urška Pristovšek, Matjaž Kuntner, 2020, izvirni znanstveni članek Povzetek: Background
A major challenge in biodiversity science is to understand the factors contributing to the variability of species richness –the number of different species in a community or region - among comparable taxonomic lineages. Multiple biotic and abiotic factors have been hypothesized to have an effect on species richness and have been used as its predictors, but identifying accurate predictors is not straightforward. Spiders are a highly diverse group, with some 48,000 species in 120 families; yet nearly 75% of all species are found within just the ten most speciose families. Here we use a Random Forest machine learning algorithm to test the predictive power of different variables hypothesized to affect species richness of spider genera.
Results
We test the predictive power of 22 variables from spiders’ morphological, genetic, geographic, ecological and behavioral landscapes on species richness of 45 genera selected to represent the phylogenetic and biological breath of Araneae. Among the variables, Random Forest analyses find body size (specifically, minimum male body size) to best predict species richness. Multiple Correspondence analysis confirms this outcome through a negative relationship between male body size and species richness. Multiple Correspondence analyses furthermore establish that geographic distribution of congeneric species is positively associated with genus diversity, and that genera from phylogenetically older lineages are species poorer. Of the spider-specific traits, neither the presence of ballooning behavior, nor sexual size dimorphism, can predict species richness.
Conclusions
We show that machine learning analyses can be used in deciphering the factors associated with diversity patterns. Since no spider-specific biology could predict species richness, but the biologically universal body size did, we believe these conclusions are worthy of broader biological testing. Future work on other groups of organisms will establish whether the detected associations of species richness with small body size and wide geographic ranges hold more broadly.
Ključne besede: biodiversity, lineage diversity, species traits, spiders, phylogenetic diversity, species distribution, random forest, multiple correspondence analysis
Objavljeno v DiRROS: 22.07.2024; Ogledov: 257; Prenosov: 241
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2. Biogeographical history of golden orbweavers : chronology of a global conquestEva Turk, Klemen Čandek, Simona Kralj-Fišer, Matjaž Kuntner, 2020, izvirni znanstveni članek Povzetek: Aim
A wholistic biogeographical reconstruction should combine a phylogeny with specifics of organismal biology, plate tectonics and consequent probabilities of historic dispersal events. Here, we demonstrate this approach by reconstructing the geographical origin and sequence of intercontinental colonization of the golden orbweaving spiders, a global clade. We test two alternative hypotheses about their ancestral range. Due to the highest contemporary species diversity in Africa, the ‘Out of Africa’ hypothesis predicts the Afrotropics as their most likely ancestral area. The alternative, ‘Out of West Burma’ hypothesis aims to explain a Burmese amber fossil as stem nephilid. Because the West Burma block probably detached from Australia, then rafted towards Laurasia, either on its own or with India, this hypothesis predicts either Australasia or Indomalaya (or both) as the ancestral area.
Location
Worldwide.
Taxon
Golden orbweaving spiders, family Nephilidae.
Methods
We construct an expanded phylogeny of nephilid spiders and apply RASP (Reconstruct Ancestral State in Phylogenies) to infer their global biogeographical history. We fit the data to six integrated biogeographical models: DEC, DIVALIKE, BAYAREALIKE and their +j variants. We fine-tune the analysis by evaluating varying probabilities of dispersal between geographical areas throughout the clade's evolutionary history. We use the physical distance between the areas as a proxy for dispersal probabilities, thus accounting for plate tectonics.
Results
The best supported model reconstructs both Australasia and Indomalaya as ancestral area. In several parts of the phylogeny, these areas persist for the estimated 130-million-year evolutionary history. However, numerous intercontinental shifts in nephilid biogeographical history are also inferred. Since nephilid origins are clearly Gondwanan, our study supports the interpretations that Burmese amber contains Gondwanan biota.
Main conclusions
These results are consistent with the Out of West Burma hypothesis but reject the Out of Africa hypothesis. That certain clades persist in their ancestral ranges while others may shift continents aligns well with the known nephilid biology. Our methodological approach that assesses organismal specific dispersal probabilities through concrete distances measured though time slices of the Earth's history can be applied to biogeographical reconstruction of any lineage.
Ključne besede: spiders, golden orbweavers, Nephilidae, reconstruction of lineage, biogeography
Objavljeno v DiRROS: 22.07.2024; Ogledov: 122; Prenosov: 154
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3. The Carniolan honeybee from Slovenia : a complete and annotated mitochondrial genome with comparisons to closely related Apis mellifera subspeciesAjda Moškrič, Andraž Marinč, Polonca Ferk, Branimir Leskošek, Mai-Britt Mosbech, Ignas Bunikis, Olga Vinnere Pettersson, Lucile Soler, Janez Prešern, izvirni znanstveni članek Povzetek: The complete mitochondrial genome of the Carniolan honeybee (Apis mellifera carnica) from Slovenia, a homeland of this subspecies, was acquired in two contigs from WGS data and annotated. The newly obtained mitochondrial genome is a circular closed loop of 16,447 bp. It comprises 37 genes (13 protein coding genes, 22 tRNA genes, and 2 rRNA genes) and an AT-rich control region. The order of the tRNA genes resembles the order characteristic of A. mellifera. The mitogenomic sequence of A. m. carnica from Slovenia contains 44 uniquely coded sites in comparison to the closely related subspecies A. m. ligustica and to A. m. carnica from Austria. Furthermore, 24 differences were recognised in comparison between A. m. carnica and A. m. ligustica subspecies. Among them, there are three SNPs that affect translation in the nd2, nd4, and cox2 genes, respectively. The phylogenetic placement of A. m. carnica from Slovenia within C lineage deviates from the expected position and changes the perspective on relationship between C and O lineages. The results of this study represent a valuable addition to the information available in the phylogenomic studies of A. mellifera—a pollinator species of worldwide importance. Such genomic information is essential for this local subspecies’ conservation and preservation as well as its breeding and selection.
Ključne besede: western honeybee, Apis mellifera carnica, mitochondrial genome, phylogeny, C lineage, annotation, whole genome sequencing, protection, conservation
Objavljeno v DiRROS: 06.09.2022; Ogledov: 747; Prenosov: 243
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