AbstractThe evolution of phenotypic traits is usually studied on generational timescales or across species on million-year timescales. We bridge this conceptual gap by using high-density sampling of a species lineage, (Bryozoa, Cheilostomatida), over 2 million years of its evolutionary history, to ask whether trait-fitness associations are consistent with evolutionary trait models often applied to phenotypic time series. We use average fecundity and competitive outcome as two different fitness components, where competitive outcome is a proxy for partial survival.
View Article and Find Full Text PDFIn the realm of biological image analysis, deep learning (DL) has become a core toolkit, for example for segmentation and classification. However, conventional DL methods are challenged by large biodiversity datasets characterized by unbalanced classes and hard-to-distinguish phenotypic differences between them. Here we present BioEncoder, a user-friendly toolkit for metric learning, which overcomes these challenges by focussing on learning relationships between individual data points rather than on the separability of classes.
View Article and Find Full Text PDFThe type specimens of 42 cheilostome bryozoan species introduced by Lars Siln between 1938 and 1954 and housed at three different Swedish institutions (the Swedish Museum of Natural History in Stockholm, the Biological Museum in Lund and the Museum of Evolution in Uppsala) are here revised using scanning electron microscopy, with two exceptions, for the first time. As a result of this revision, new morphological observations were made for some species, such as ooecia in Antropora erecta, a costal pseudopore in Jullienula hippocrepis, intracolonial variation in the number of intracostal windows in Costaticella gisleni, and oral spines in Triphyllozoon mauritzoni. Some other observations confirmed the presence of structures/polymorphs in type material that had previously only been noted in non-type specimens, such as spinose interzooidal kenozooids in Retevirgula triangulata and putative brooding zooids in Bugulina kiuschiuensis.
View Article and Find Full Text PDFIncreasing amount of anthropogenic litter in the marine environment has provided an enormous number of substrates for a wide range of marine organisms, thus serving as a potential vector for the transport of fouling organisms. Here, we examined the fouling organisms on different types of stranded litter (plastic, glass, rubber, foam sponge, cloth, metal and wood) on eight beaches along the southeast coast of India. In total, 17 encrusting species belonging to seven phyla (Arthropoda, Bryozoa, Mollusca, Annelida, Cnidaria, Chlorophyta and Foraminifera) were identified on 367 items, with one invasive species, the mussel Mytella strigata, detected.
View Article and Find Full Text PDFThe zoological dry collection of the Swedish Museum of Natural History in Stockholm includes an important, historical bryozoan section that is rich in species and specimens and also diverse from a geographical point of view. This collection also contains the type specimens of the type species of some cheilostome bryozoan genera introduced by several naturalists and bryozoologists between the mid-1800s and 1900s. With a few exceptions, these have not been revised since the advent of scanning electron microscopy as a standard tool for bryozoan taxonomy.
View Article and Find Full Text PDFAllometry is vital for understanding the mechanisms underlying phenotypic evolution. Despite a large body of literature on allometry, studies based on fossil time series are limited for solitary organisms and nonexistent for colonial organisms. Allometric relationships have been found to be relatively constant across Recent populations of the same species, separated by space, but variable among fossil populations separated by thousands of years.
View Article and Find Full Text PDFPhylogenetic relationships and the timing of evolutionary events are essential for understanding evolution on longer time scales. Cheilostome bryozoans are a group of ubiquitous, species-rich, marine colonial organisms with an excellent fossil record but lack phylogenetic relationships inferred from molecular data. We present genome-skimmed data for 395 cheilostomes and combine these with 315 published sequences to infer relationships and the timing of key events among c.
View Article and Find Full Text PDFPlastic debris provides long-lasting substrates for benthic organisms, thus acting as a potential vector for their dispersion. Its interaction with these colonizers is, however, still poorly known. This study examines fouling communities on beached, buoyant and benthic plastic debris in the Catalan Sea (NW Mediterranean), and characterizes the plastic type.
View Article and Find Full Text PDFExamining the supposition that local-scale competition drives macroevolutionary patterns has become a familiar goal in fossil biodiversity studies. However, it is an elusive goal, hampered by inadequate confirmation of ecological equivalence and interactive processes between clades, patchy sampling, few comparative analyses of local species assemblages over long geological intervals, and a dearth of appropriate statistical tools. We address these concerns by reevaluating one of the classic examples of clade displacement in the fossil record, in which cheilostome bryozoans surpass the once dominant cyclostomes.
View Article and Find Full Text PDFThe Mediterranean specimens of the genus collected from shallow water habitats during several surveys and cruises undertaken mostly off the Italian coast are revised. As a result of the disentanglement of the complex and the examination of new material, three new species, , , and , are described from submarine caves or associated with seagrasses and algae. An additional species sp.
View Article and Find Full Text PDFLong-term patterns of phenotypic change are the cumulative results of tens of thousands to millions of years of evolution. Yet, empirical and theoretical studies of phenotypic selection are largely based on contemporary populations. The challenges in studying phenotypic evolution, in particular trait-fitness associations in the deep past, are barriers to linking micro- and macroevolution.
View Article and Find Full Text PDFResolution of relationships at lower taxonomic levels is crucial for answering many evolutionary questions, and as such, sufficiently varied species representation is vital. This latter goal is not always achievable with relatively fresh samples. To alleviate the difficulties in procuring rarer taxa, we have seen increasing utilization of historical specimens in building molecular phylogenies using high throughput sequencing.
View Article and Find Full Text PDFIs speciation generally a "special time" in morphological evolution, or are lineage-splitting events just "more of the same" where the end product happens to be two separate lineages? Data on evolutionary dynamics during anagenetic and cladogenetic events among closely related lineages within a clade are rare, but the fossil record of the bryozoan genus is considered a textbook example of a clade where speciation causes rapid evolutionary change against a backdrop of morphological stasis within lineages. Here, we point to some methodological and measurement theoretical issues in the original work on . We then reanalyze a subset of the original data that can be meaningfully investigated using quantitative statistical approaches similar to those used in the original studies.
View Article and Find Full Text PDFBackground: Understanding the phylogenetic relationships among species is one of the main goals of systematic biology. Simultaneously, credible phylogenetic hypotheses are often the first requirement for unveiling the evolutionary history of traits and for modelling macroevolutionary processes. However, many non-model taxa have not yet been sequenced to an extent such that statistically well-supported molecular phylogenies can be constructed for these purposes.
View Article and Find Full Text PDFThis paper describes 40 bryozoan species, comprising one cyclostome and 39 cheilostomes (8 anascan- and 31 ascophoran-grade), obtained from early Pleistocene and Holocene samples from two localities in Indonesia. Five of the cheilostomes are described as new species: Acanthodesia variegata n. sp.
View Article and Find Full Text PDFMarine biodiversity in the Coral Triangle is several times higher than anywhere else, but why this is true is unknown because of poor historical data. To address this, we compared the first available record of fossil cheilostome bryozoans from Indonesia with the previously sampled excellent record from the Caribbean. These two regions differ several-fold in species richness today, but cheilostome diversity was strikingly similar until the end of the Miocene 5.
View Article and Find Full Text PDFCompetition is an important biotic interaction that influences survival and reproduction. While competition on ecological timescales has received great attention, little is known about competition on evolutionary timescales. Do competitive abilities change over hundreds of thousands to millions of years? Can we predict competitive outcomes using phenotypic traits? How much do traits that confer competitive advantage and competitive outcomes change? Here we show, using communities of encrusting marine bryozoans spanning more than 2 million years, that size is a significant determinant of overgrowth outcomes: colonies with larger zooids tend to overgrow colonies with smaller zooids.
View Article and Find Full Text PDFEcological interactions affect the survival and reproduction of individuals. However, ecological interactions are notoriously difficult to measure in extinct populations, hindering our understanding of how the outcomes of interactions such as competition vary in time and influence long-term evolutionary changes. Here, the outcomes of spatial competition in a temporally continuous community over evolutionary timescales are presented for the first time.
View Article and Find Full Text PDFThe finding of a new species of Gephyrotes, G. moissettei n. sp.
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