PeerJ Preprints: Biodiversityhttps://peerj.com/preprints/index.atom?journal=peerj&subject=400Biodiversity articles published in PeerJ PreprintsAn introduction to phylosymbiosishttps://peerj.com/preprints/278792019-12-112019-12-11Shen Jean LimSeth R Bordenstein
Phylosymbiosis was recently formulated to support a hypothesis-driven framework for the characterization of a new, cross-system trend in host-associated microbiomes. Defining phylosymbiosis as “microbial community relationships that recapitulate the phylogeny of their host”, we review the relevant literature and data in the last decade, emphasizing frequently used methods and regular patterns observed in analyses. Quantitative support for phylosymbiosis is provided by statistical methods evaluating higher microbiome variation between host species than within host species, topological similarities between the host phylogeny and microbiome dendrogram, and a positive association between host genetic relationships and microbiome beta diversity. Significant degrees of phylosymbiosis are prevalent, but not universal, in microbiomes of plants and animals from terrestrial and aquatic habitats. Consistent with natural selection shaping phylosymbiosis, microbiome transplant experiments demonstrate reduced host performance and/or fitness upon host-microbiome mismatches. Hybridization can also disrupt phylosymbiotic microbiomes and cause hybrid pathologies. The pervasiveness of phylosymbiosis carries several important implications for advancing knowledge of eco-evolutionary processes that impact host-microbiome interactions and future applications of precision microbiology. Important future steps will be to examine phylosymbiosis beyond bacterial communities, apply evolutionary modeling for an increasingly sophisticated understanding of phylosymbiosis, and unravel the host and microbial mechanisms that contribute to the pattern. This review serves as a gateway to experimental, conceptual, and quantitative themes of phylosymbiosis and outlines opportunities ripe for investigations from a diversity of disciplines.
Phylosymbiosis was recently formulated to support a hypothesis-driven framework for the characterization of a new, cross-system trend in host-associated microbiomes. Defining phylosymbiosis as “microbial community relationships that recapitulate the phylogeny of their host”, we review the relevant literature and data in the last decade, emphasizing frequently used methods and regular patterns observed in analyses. Quantitative support for phylosymbiosis is provided by statistical methods evaluating higher microbiome variation between host species than within host species, topological similarities between the host phylogeny and microbiome dendrogram, and a positive association between host genetic relationships and microbiome beta diversity. Significant degrees of phylosymbiosis are prevalent, but not universal, in microbiomes of plants and animals from terrestrial and aquatic habitats. Consistent with natural selection shaping phylosymbiosis, microbiome transplant experiments demonstrate reduced host performance and/or fitness upon host-microbiome mismatches. Hybridization can also disrupt phylosymbiotic microbiomes and cause hybrid pathologies. The pervasiveness of phylosymbiosis carries several important implications for advancing knowledge of eco-evolutionary processes that impact host-microbiome interactions and future applications of precision microbiology. Important future steps will be to examine phylosymbiosis beyond bacterial communities, apply evolutionary modeling for an increasingly sophisticated understanding of phylosymbiosis, and unravel the host and microbial mechanisms that contribute to the pattern. This review serves as a gateway to experimental, conceptual, and quantitative themes of phylosymbiosis and outlines opportunities ripe for investigations from a diversity of disciplines.Comparative studies of Echinometra mathaei species complex (Echinoidea: Camarodonta: Echinometridae) from two sites in Western Visayas, Philippines (Taklong Island, Guimaras and Nabas, Aklan)https://peerj.com/preprints/279862019-10-282019-10-28Joseph Ricky TamayoMaria Celia D Malay
Echinometra mathaei is a species complex with its constituent reproductively-isolated species informally called A, B, C and D based on studies done in Okinawa and the Red Sea. Little research has been done on this genus, and to our knowledge no studies have been done on the E. mathaei complex in the Philippines. To help clarify species delineations in the E. mathaei complex, a comparative study was done between two localities in Western Visayas, Philippines: the Taklong Island National Marine Reserve, in Nueva Valencia, Guimaras and Barangay Unidos in Nabas, Aklan. Morphological characteristics (spine color, milled rings, and skin around the peristome) and tubefeet and gonad spicules were observed. Two or possibly three species of Echinometra were found in the two sites based on their morphology and spicules, namely: Echinometra sp. A, Echinometra sp. C, and Echinometra affinity C, which resembles sp. C but differs in the milled rings and gonad spicules. Echinometra sp. C and E. affinity C cannot be distinguished on the basis of field-visible characters, thus the two morphs are referred to as Echinometra VC for the purpose of field surveys. Echinometra VC and Echinometra sp. A exhibited differences in abundance (VC was much more common) and microhabitat (VC was restricted to rocky shores and never observed in coral communities). To study the abundance and distribution of Echinometra VC, 50 m by 2 m belt transects were surveyed along the rocky shores of both sites: two parallel transects (at 0 m and at 0.9 m) and a perpendicular transect (only in Nabas), each with three replicates. The transect data showed that the mean densities for 0 m and 0.9 m in Nabas are significantly higher in Taklong yielding p-values of 0.001 and 0.002, respectively, when analyzed using t-test.Of the two sites, only Nabas showed a significant difference between the mean densities at 0 m and 0.9 m, with the mean density at 0.9 m significantly higher than that of 0 m yielding a p-value of 0.02 when analyzed using two-sample t-test. A Poisson regression on the perpendicular transect data from Nabas showed a trend of increasing Echinometra density with increasing distance from the shore. In the future, DNA barcoding and cross-fertilization studies should be performed in order to confirm the species of Echinometra observed. Many factors can affect the density and distribution of Echinometra, so further studies must be conducted to explain observed differences in their distribution and abundance.
Echinometra mathaei is a species complex with its constituent reproductively-isolated species informally called A, B, C and D based on studies done in Okinawa and the Red Sea. Little research has been done on this genus, and to our knowledge no studies have been done on the E. mathaei complex in the Philippines. To help clarify species delineations in the E. mathaei complex, a comparative study was done between two localities in Western Visayas, Philippines: the Taklong Island National Marine Reserve, in Nueva Valencia, Guimaras and Barangay Unidos in Nabas, Aklan. Morphological characteristics (spine color, milled rings, and skin around the peristome) and tubefeet and gonad spicules were observed. Two or possibly three species of Echinometra were found in the two sites based on their morphology and spicules, namely: Echinometra sp. A, Echinometra sp. C, and Echinometra affinity C, which resembles sp. C but differs in the milled rings and gonad spicules. Echinometra sp. C and E. affinity C cannot be distinguished on the basis of field-visible characters, thus the two morphs are referred to as Echinometra VC for the purpose of field surveys. Echinometra VC and Echinometra sp. A exhibited differences in abundance (VC was much more common) and microhabitat (VC was restricted to rocky shores and never observed in coral communities). To study the abundance and distribution of Echinometra VC, 50 m by 2 m belt transects were surveyed along the rocky shores of both sites: two parallel transects (at 0 m and at 0.9 m) and a perpendicular transect (only in Nabas), each with three replicates. The transect data showed that the mean densities for 0 m and 0.9 m in Nabas are significantly higher in Taklong yielding p-values of 0.001 and 0.002, respectively, when analyzed using t-test.Of the two sites, only Nabas showed a significant difference between the mean densities at 0 m and 0.9 m, with the mean density at 0.9 m significantly higher than that of 0 m yielding a p-value of 0.02 when analyzed using two-sample t-test. A Poisson regression on the perpendicular transect data from Nabas showed a trend of increasing Echinometra density with increasing distance from the shore. In the future, DNA barcoding and cross-fertilization studies should be performed in order to confirm the species of Echinometra observed. Many factors can affect the density and distribution of Echinometra, so further studies must be conducted to explain observed differences in their distribution and abundance.Stratigraphy and Toarcian marine fauna (ammonites and brachiopods) of the South Rifian Ridges, northern Moroccohttps://peerj.com/preprints/280032019-10-022019-10-02Mohamed Benzaggagh
The South Rifian Ridges (25 km north of Meknes) corresponds to several small to medium size massifs with Triassic to Middle Jurassic (Bojocian) deposits widely covered by upper Miocene marls. Faugères (1978) has distinguished in this area three lithostratigraphic units equivalent to three paleogeographic domains, which are from the periphery to the center of the Jurassic basin: Peripheral unit, consisting of two formations: red silty clays with evaporates of Triassic (100m) and Liassic neritic limestones (100m); Intermediate unit, more complete, showing in addition of the two previous formations, a thick series (300m) of Toarcian to Middle Bajocian, constituted of silty marl-limestones, sandstones and bioclastic or oolitic limestones, often with benthic fauna; and Central unit, corresponding to the axial zone of the South Rifian basin, showing pelagic deposits from the lower Pliensbachian to the Middle Bajocian. In this unit, particularly to the east and the west of Jbel Dehar En Nsour anticline, Faugères (1974, 1978), and Elmi and Faugères (1974) reported some Toarcian ammonite specimens. For its pelagic facies often rich in ammonites, we were interested in the study of the Toarcian sequence and faunal assemblages of this unit. More than ten outcrop sections were sampled bed-by-bed. The main collected ammonite species: Calliphylloceras nilssoni, Cleviceras aff. exaratum, Dactylioceras laticostatum, D. simplex, D. (Orthodactylites) semicelatum, Juraphyllites (Meneghiniceras) lariense, Lioceratoides serotinus, Maconiceras soloniacense, Neolioceratoides schopeni, Protogrammoceras paltum and Harpoceratinae indet., allowed characterizing the Mirabile and Semicelatum subzones of the Polymorphum Zone and have already been described and illustrated in Bardin et al. (2015). Belemnite specimens: Passaloteuthis bisulcata and P. zieteni of the same stratigraphic levels were also the subject of the article, Sanders al. (2013) and a palynological study on the same sections was realized by Chahidi et al. (2016). Recent investigations allowed to collect a new interesting paleontological material composed of lower Toarcian pyritic ammonites and middle to upper Toarcian brachiopods (Rhynchonellidae, Zelleridae, and Terebratulidae), currently under study.
The South Rifian Ridges (25 km north of Meknes) corresponds to several small to medium size massifs with Triassic to Middle Jurassic (Bojocian) deposits widely covered by upper Miocene marls. Faugères (1978) has distinguished in this area three lithostratigraphic units equivalent to three paleogeographic domains, which are from the periphery to the center of the Jurassic basin: Peripheral unit, consisting of two formations: red silty clays with evaporates of Triassic (100m) and Liassic neritic limestones (100m); Intermediate unit, more complete, showing in addition of the two previous formations, a thick series (300m) of Toarcian to Middle Bajocian, constituted of silty marl-limestones, sandstones and bioclastic or oolitic limestones, often with benthic fauna; and Central unit, corresponding to the axial zone of the South Rifian basin, showing pelagic deposits from the lower Pliensbachian to the Middle Bajocian. In this unit, particularly to the east and the west of Jbel Dehar En Nsour anticline, Faugères (1974, 1978), and Elmi and Faugères (1974) reported some Toarcian ammonite specimens. For its pelagic facies often rich in ammonites, we were interested in the study of the Toarcian sequence and faunal assemblages of this unit. More than ten outcrop sections were sampled bed-by-bed. The main collected ammonite species: Calliphylloceras nilssoni, Cleviceras aff. exaratum, Dactylioceras laticostatum, D. simplex, D. (Orthodactylites) semicelatum, Juraphyllites (Meneghiniceras) lariense, Lioceratoides serotinus, Maconiceras soloniacense, Neolioceratoides schopeni, Protogrammoceras paltum and Harpoceratinae indet., allowed characterizing the Mirabile and Semicelatum subzones of the Polymorphum Zone and have already been described and illustrated in Bardin et al. (2015). Belemnite specimens: Passaloteuthis bisulcata and P. zieteni of the same stratigraphic levels were also the subject of the article, Sanders al. (2013) and a palynological study on the same sections was realized by Chahidi et al. (2016). Recent investigations allowed to collect a new interesting paleontological material composed of lower Toarcian pyritic ammonites and middle to upper Toarcian brachiopods (Rhynchonellidae, Zelleridae, and Terebratulidae), currently under study.Leveraging eDNA to detect and monitor hybrid zoneshttps://peerj.com/preprints/279962019-09-302019-09-30Kathryn StewartScott A. Taylor
Hybrid zones are important windows into evolutionary processes and our understanding of their significance and prevalence in nature has expanded quickly. Yet most hybridization research has restricted temporal and spatial resolution, limiting our ability to draw broad conclusions about evolutionary and conservation related outcomes. Here, we argue rapidly advancing environmental DNA (eDNA) methodology should be adopted for studies of hybrid zones to increase temporal sampling (contemporary and historical), to refine and geographically expand sampling density, and to collect data for taxa that are difficult to directly sample. Genomic data in the environment offer the potential for near real-time biological tracking and eDNA provides broad, as yet untapped potential to address eco-evolutionary questions.
Hybrid zones are important windows into evolutionary processes and our understanding of their significance and prevalence in nature has expanded quickly. Yet most hybridization research has restricted temporal and spatial resolution, limiting our ability to draw broad conclusions about evolutionary and conservation related outcomes. Here, we argue rapidly advancing environmental DNA (eDNA) methodology should be adopted for studies of hybrid zones to increase temporal sampling (contemporary and historical), to refine and geographically expand sampling density, and to collect data for taxa that are difficult to directly sample. Genomic data in the environment offer the potential for near real-time biological tracking and eDNA provides broad, as yet untapped potential to address eco-evolutionary questions.Inbreeding depression in one of the last DFTD-free wild populations of Tasmanian devilshttps://peerj.com/preprints/279852019-09-262019-09-26Rebecca M GooleyCarolyn J HoggSamantha FoxDavid PembertonKatherine BelovCatherine E Grueber
Background. Vulnerable species experiencing inbreeding depression are prone to localised extinctions because of their reduced fitness. For Tasmanian devils, the rapid spread of devil facial tumour disease (DFTD) has led to population declines and fragmentation across the species’ range. Here we show that one of the few remaining DFTD-free populations of Tasmanian devils is experiencing inbreeding depression. Moreover, this population has experienced a significant reduction in reproductive success over recent years.
Methods. We used 32 microsatellite loci to examine changes in genetic diversity and inbreeding in the wild population at Woolnorth, alongside field data on breeding success from females to test for inbreeding depression.
Results. We found that maternal internal relatedness has a negative impact on litter sizes. The results of this study imply that this population has entered an extinction vortex and that to protect the population, genetic rescue may be required. This study provides conservation managers with useful information for managing wild devils and provides support for the “Wild Devil Recovery Program” which is currently augmenting small, isolated populations.
Background. Vulnerable species experiencing inbreeding depression are prone to localised extinctions because of their reduced fitness. For Tasmanian devils, the rapid spread of devil facial tumour disease (DFTD) has led to population declines and fragmentation across the species’ range. Here we show that one of the few remaining DFTD-free populations of Tasmanian devils is experiencing inbreeding depression. Moreover, this population has experienced a significant reduction in reproductive success over recent years.Methods. We used 32 microsatellite loci to examine changes in genetic diversity and inbreeding in the wild population at Woolnorth, alongside field data on breeding success from females to test for inbreeding depression.Results. Wefound that maternal internal relatedness has a negative impact on litter sizes. The results of this study imply that this population has entered an extinction vortex and that to protect the population, genetic rescue may be required. This study provides conservation managers with useful information for managing wild devils and provides support for the “Wild Devil Recovery Program” which is currently augmenting small, isolated populations.On the diversity of Early Jurassic cartilaginous fishes across the Toarcian Oceanic Anoxic Eventhttps://peerj.com/preprints/279752019-09-222019-09-22Sebastian StumpfFaviel A. López-RomeroJürgen Kriwet
The Early Jurassic represents a crucial time interval in the evolutionary history of elasmobranchs, because the Toarcian witnessed a first major diversification, suggesting a profound reorganization of ecological niches of chondrichthyans, probably accompanied by a subsequent diversity decline of hybodontiforms within marine environments. Potential factors underlying the Toarcian elasmobranch radiation event not only include evolutionary novelties in ecological adaptations of swimming, feeding, and reproduction, but also abiotic factors such as increasing seawater temperatures and variations in eustatic sea level associated with the Toarcian Oceanic Anoxic Event (T-OAE). These events might have played an important role in the Toarcian elasmobranch diversification event by regulating diversity dynamics through the availability of higher speciation and dispersal rates.
In attempt to better understand macroevolutionary patterns and processes of Jurassic chondrichthyans, we analysed the generic diversity of Pliensbachian to Aalenian elasmobranchs and hybodontiforms and explored their response to the T-OAE. In doing so, we calculated the estimated mean standing diversities (EMSD) using 10 time bins of approximately 2 Myr duration and evaluated the relationships between EMSD and variations in both seawater temperature and eustatic sea level to test whether these parameters affect the observed diversity patterns.
Our data indicate profoundly different diversity dynamics of elasmobranchs and hybodontiforms. The EMSD is low in Pliensbachian to Aalenian hybodontiforms, indicating an evolutionary stasis. Conversely, a constant taxonomic increase in elasmobranchs is recorded, spanning from the Pliensbachian to the end of the Toarcian, before reaching a diversity plateau in the Aalenian. These divergent patterns might suggest that hybodontiforms were not competing with elasmobranchs, but more likely are the result of still existing taxonomic misconceptions of Jurassic hybodontiforms, mainly caused by morphological characters that are either ambiguous or broadly distributed among these anatomically rather conservative chondrichthyans. Notwithstanding this, our results indicate that variations in seawater temperature and eustatic sea level changes associated with the T-OAE were not the primary drivers underlying the observed elasmobranch diversity patterns. Therefore, it might be possible that the diversification of elasmobranchs was opportunistic, benefitting from the appearance and subsequent radiation of new food resources, probably in response of enhanced surface productivity during the T-OAE. This hypothesis, however, needs to be tested, pending the inclusion of other time-equivalent marine vertebrate groups in future diversity analyses. Moreover, a detailed re-evaluation of Jurassic hybodontiforms will contribute to our understanding of chondrichthyan diversity dynamics across the T-OAE.
The Early Jurassic represents a crucial time interval in the evolutionary history of elasmobranchs, because the Toarcian witnessed a first major diversification, suggesting a profound reorganization of ecological niches of chondrichthyans, probably accompanied by a subsequent diversity decline of hybodontiforms within marine environments. Potential factors underlying the Toarcian elasmobranch radiation event not only include evolutionary novelties in ecological adaptations of swimming, feeding, and reproduction, but also abiotic factors such as increasing seawater temperatures and variations in eustatic sea level associated with the Toarcian Oceanic Anoxic Event (T-OAE). These events might have played an important role in the Toarcian elasmobranch diversification event by regulating diversity dynamics through the availability of higher speciation and dispersal rates.In attempt to better understand macroevolutionary patterns and processes of Jurassic chondrichthyans, we analysed the generic diversity of Pliensbachian to Aalenian elasmobranchs and hybodontiforms and explored their response to the T-OAE. In doing so, we calculated the estimated mean standing diversities (EMSD) using 10 time bins of approximately 2 Myr duration and evaluated the relationships between EMSD and variations in both seawater temperature and eustatic sea level to test whether these parameters affect the observed diversity patterns.Our data indicate profoundly different diversity dynamics of elasmobranchs and hybodontiforms. The EMSD is low in Pliensbachian to Aalenian hybodontiforms, indicating an evolutionary stasis. Conversely, a constant taxonomic increase in elasmobranchs is recorded, spanning from the Pliensbachian to the end of the Toarcian, before reaching a diversity plateau in the Aalenian. These divergent patterns might suggest that hybodontiforms were not competing with elasmobranchs, but more likely are the result of still existing taxonomic misconceptions of Jurassic hybodontiforms, mainly caused by morphological characters that are either ambiguous or broadly distributed among these anatomically rather conservative chondrichthyans. Notwithstanding this, our results indicate that variations in seawater temperature and eustatic sea level changes associated with the T-OAE were not the primary drivers underlying the observed elasmobranch diversity patterns. Therefore, it might be possible that the diversification of elasmobranchs was opportunistic, benefitting from the appearance and subsequent radiation of new food resources, probably in response of enhanced surface productivity during the T-OAE. This hypothesis, however, needs to be tested, pending the inclusion of other time-equivalent marine vertebrate groups in future diversity analyses. Moreover, a detailed re-evaluation of Jurassic hybodontiforms will contribute to our understanding of chondrichthyan diversity dynamics across the T-OAE.Inventory statistics meet big data: Complications for estimating numbers of specieshttps://peerj.com/preprints/279652019-09-172019-09-17Ali KhalighifarLaura JiménezClaudia Nuñez-PenichetBenedictus FreemanKate IngenloffDaniel Jiménez-GarcíaA. Townsend Peterson
Abstract
We point out complications inherent in biodiversity inventory metrics when applied to large-scale datasets. The number of samples in which a species is detected saturates, such that crucial numbers of detections of rare species approach zero. Any rare errors can then come to dominate species richness estimates, creating upward biases in estimates of species numbers. We document the problem via simulations of sampling from virtual biotas, illustrate its potential using a large empirical dataset (bird records from Cape May, New Jersey, USA), and outline the circumstances under which these problems may be expected to emerge.
AbstractWe point out complications inherent in biodiversity inventory metrics when applied to large-scale datasets. The number of samples in which a species is detected saturates, such that crucial numbers of detections of rare species approach zero. Any rare errors can then come to dominate species richness estimates, creating upward biases in estimates of species numbers. We document the problem via simulations of sampling from virtual biotas, illustrate its potential using a large empirical dataset (bird records from Cape May, New Jersey, USA), and outline the circumstances under which these problems may be expected to emerge.Ooctonus vulgatus (Hymenoptera, Mymaridae), a potential biocontrol agent to reduce populations of Philaenus spumarius (Hemiptera, Aphrophoridae) the main vector of Xylella fastidiosa in Europehttps://peerj.com/preprints/279412019-09-072019-09-07Xavier MesminMarguerite ChartoisGuenaelle GensonJean-Pierre RossiAstrid CruaudJean-Yves Rasplus
As vector of Xylella fastidiosa (Wells, 1987) in Europe, the meadow spittlebug, Philaenus spumarius (Linnaeus, 1758) (Hemiptera: Aphrophoridae) is a species of major concern. Therefore, tools and agents to control this ubiquitous insect that develops and feeds on hundreds of plant species are wanted. We conducted a field survey of P. spumarius eggs in Corsica and provide a first report of Ooctonus vulgatus Haliday, 1833 (Hymenoptera, Mymaridae) as a potential biocontrol agent of P. spumarius in Europe. To allow species identification, we summarized the main characters distinguishing O. vulgatus from other European species of Ooctonus and generated COI DNA barcodes. We also assessed parasitism rates in several sampling sites, highlighting the top-down impact of O. vulgatus on populations of P. spumarius. Based on the geographic occurrences of O. vulgatus mined in the literature, we calibrated an ecological niche model to assess its potential distribution in the Holarctic. Our results showed that O. vulgatus potential distribution overlaps that of P. spumarius. Hence, O. vulgatus appears to be a promising biocontrol agent of the meadow spittlebug in Europe and it seems advisable to conduct research on this small parasitoid wasp to assess whether it could contribute to reduce the spread and impact of X. fastidiosa in Europe.
As vector of Xylella fastidiosa (Wells, 1987) in Europe, the meadow spittlebug, Philaenus spumarius (Linnaeus, 1758) (Hemiptera: Aphrophoridae) is a species of major concern. Therefore, tools and agents to control this ubiquitous insect that develops and feeds on hundreds of plant species are wanted. We conducted a field survey of P. spumarius eggs in Corsica and provide a first report of Ooctonus vulgatus Haliday, 1833 (Hymenoptera, Mymaridae) as a potential biocontrol agent of P. spumarius in Europe. To allow species identification, we summarized the main characters distinguishing O. vulgatus from other European species of Ooctonus and generated COI DNA barcodes. We also assessed parasitism rates in several sampling sites, highlighting the top-down impact of O. vulgatus on populations of P. spumarius. Based on the geographic occurrences of O. vulgatus mined in the literature, we calibrated an ecological niche model to assess its potential distribution in the Holarctic. Our results showed that O. vulgatus potential distribution overlaps that of P. spumarius. Hence, O. vulgatus appears to be a promising biocontrol agent of the meadow spittlebugin Europe and it seems advisable to conduct research on this small parasitoid wasp to assess whether it could contribute to reduce the spread and impact of X. fastidiosa in Europe.A preliminary bird list from Río Luis, Veraguas provides further insight into an avian suture zone in Caribbean Panamahttps://peerj.com/preprints/279402019-09-052019-09-05Jessica F McLaughlinJorge Luis GarzonOscar G Lopez Ch.Matthew J Miller
We present a preliminary list of birds collected on the Caribbean coast of the province of Veraguas, Panama. Here, we found birds not known from the area, instead they were believed to range limits ending either east or west of our collection site. These include: Cnipodectes subbrunneus, Juliamyia julie, Gymnopithys bicolor bicolor, Mionectes (oleagineus) affinis, and western phylospecies of Malacoptila panamensis and Xenops minutus. Our results reaffirm that the coast of Veraguas is an important suture zone between Mesoamerica and South America avifaunas along the Caribbean coast of Panama.
We present a preliminary list of birds collected on the Caribbean coast of the province of Veraguas, Panama. Here, we found birds not known from the area, instead they were believed to range limits ending either east or west of our collection site. These include: Cnipodectes subbrunneus, Juliamyia julie, Gymnopithys bicolor bicolor, Mionectes (oleagineus) affinis, and western phylospecies of Malacoptila panamensis and Xenops minutus. Our results reaffirm that the coast of Veraguas is an important suture zone between Mesoamerica and South America avifaunas along the Caribbean coast of Panama.The interplay between movement, dispersal and morphology in Tetrahymena ciliateshttps://peerj.com/preprints/265402019-09-032019-09-03Frank PennekampJean ClobertNicolas Schtickzelle
Understanding how and why individual movement translates into dispersal between populations is a long-term goal in ecology. Movement is broadly defined as “any change in the spatial location of an individual”, whereas dispersal is more narrowly defined as a movement that may lead to gene flow. Because the former may create the condition for the latter, behavioural decisions that lead to dispersal may be detectable in underlying movement behaviour. In addition, dispersing individuals also have specific sets of morphological and behavioural traits that help them coping with the costs of movement and dispersal, and traits that mitigate costs should be under selection and evolve if they have a genetic basis. Here we experimentally study the relationships between movement behaviour, morphology and dispersal across 44 genotypes of the actively dispersing unicellular, aquatic model organism Tetrahymena thermophila. We used two-patch populations to quantify individual movement trajectories, as well as activity, morphology and dispersal rate. First, we studied variation in movement behaviour among and within genotypes (i.e. between dispersers and residents) and tested whether this variation can be explained by morphology. Then, we address how much the dispersal rate is driven by differences in the underlying movement behaviour. Genotypes revealed clear differences in terms of movement speed and linearity. We also detected marked movement differences between resident and dispersing individuals, mediated by the genotype. Movement variation was partly explained by morphological properties such as cell size and shape, with larger cells consistently showing higher movement speed and higher linearity. Genetic differences in activity and diffusion rates were positively related to the observed dispersal and jointly explained 47% of the variation in dispersal rate. Our study shows that a detailed understanding of the interplay between morphology, movement and dispersal may have potential to improve dispersal predictions over broader spatio-temporal scales.
Understanding how and why individual movement translates into dispersal between populations is a long-term goal in ecology. Movement is broadly defined as “any change in the spatial location of an individual”, whereas dispersal is more narrowly defined as a movement that may lead to gene flow. Because the former may create the condition for the latter, behavioural decisions that lead to dispersal may be detectable in underlying movement behaviour. In addition, dispersing individuals also have specific sets of morphological and behavioural traits that help them coping with the costs of movement and dispersal, and traits that mitigate costs should be under selection and evolve if they have a genetic basis. Here we experimentally study the relationships between movement behaviour, morphology and dispersal across 44 genotypes of the actively dispersing unicellular, aquatic model organism Tetrahymena thermophila. We used two-patch populations to quantify individual movement trajectories, as well as activity, morphology and dispersal rate. First, we studied variation in movement behaviour among and within genotypes (i.e. between dispersers and residents) and tested whether this variation can be explained by morphology. Then, we address how much the dispersal rate is driven by differences in the underlying movement behaviour. Genotypes revealed clear differences in terms of movement speed and linearity. We also detected marked movement differences between resident and dispersing individuals, mediated by the genotype. Movement variation was partly explained by morphological properties such as cell size and shape, with larger cells consistently showing higher movement speed and higher linearity. Genetic differences in activity and diffusion rates were positively related to the observed dispersal and jointly explained 47% of the variation in dispersal rate. Our study shows that a detailed understanding of the interplay between morphology, movement and dispersal may have potential to improve dispersal predictions over broader spatio-temporal scales.