Global phylogeography of ridley sea turtles ( spp.): evolution, demography, connectivity, and conservation.

Unlabelled: Globally distributed marine taxa are well suited for investigations of biogeographic impacts on genetic diversity, connectivity, and population demography. The sea turtle genus includes the wide-ranging and abundant olive ridley (), and the geographically restricted and 'Critically Endangered' Kemp's ridley (). To investigate their historical biogeography, we analyzed a large dataset of mitochondrial DNA (mtDNA) sequences from olive (n = 943) and Kemp's (n = 287) ridleys, and genotyped 15 nuclear microsatellite loci in a global sample of olive ridleys (n  285).

Species and population specific gene expression in blood transcriptomes of marine turtles.

Background: Transcriptomic data has demonstrated utility to advance the study of physiological diversity and organisms' responses to environmental stressors. However, a lack of genomic resources and challenges associated with collecting high-quality RNA can limit its application for many wild populations. Minimally invasive blood sampling combined with de novo transcriptomic approaches has great potential to alleviate these barriers.

Innovation in a Time of Crisis: Adapting Active Learning Approaches for Remote Biology Courses.

The sudden switch from predominantly in-person to remote learning across all levels of education due to the COVID-19 pandemic posed many challenges, including transitioning in-person active learning efforts to an online format. Although active learning has increased student engagement in science, it can be challenging to effectively integrate into remote courses. Adapting in-person classroom approaches to maintain timely and effective communication, provide equitable access to course materials, and encourage class participation in remote environments proved especially difficult for many instructors engaging in remote learning during the pandemic, often for the first time.

Characterizing coral reef biodiversity: genetic species delimitation in brachyuran crabs of Palmyra Atoll, Central Pacific.

Coral reefs are highly threatened ecosystems, yet there are numerous challenges in conducting inventories of their vanishing biodiversity, partly because many taxa remain difficult to detect and describe. Genetic species delimitation methods provide a standardized means for taxonomic classification including of cryptic, rare, or elusive groups, but results can vary by analytical method and genetic marker. In this study, a combination of morphological and genetic identification methods was used to estimate species richness and identify taxonomic units in true crabs (Infraorder Brachyura; n = 200) from coral reefs of Palmyra Atoll, Central Pacific.

16S rRNA Amplicon Sequencing of Urban Prokaryotic Communities in the South Bronx River Estuary.

Biodiversity monitoring is an essential component of restoration efforts. We sequenced 16S rRNA gene amplicons from sediments and waters of Hunts Point Riverside Park and Soundview Park, located in a historically degraded but recovering urban estuary in New York. In total, 16,165 unique amplicon sequence variants were recovered, and was the dominant phylum.

Geography best explains global patterns of genetic diversity and postglacial co-expansion in marine turtles.

For many species, climate oscillations drove cycles of population contraction during cool glacial periods followed by expansion during interglacials. Some groups, however, show evidence of uniform and synchronous expansion, while others display differences in the timing and extent of demographic change. We compared demographic histories inferred from genetic data across marine turtle species to identify responses to postglacial warming shared across taxa and to examine drivers of past demographic change at the global scale.

Potential impacts of historical disturbance on green turtle health in the unique & protected marine ecosystem of Palmyra Atoll (Central Pacific).

Palmyra Atoll, in the Central Pacific, is a unique marine ecosystem because of its remarkably intact food web and limited anthropogenic stressors. However during World War II the atoll was structurally reconfigured into a military installation and questions remain whether this may have impacted the health of the atoll's ecosystems and species. To address the issue we assessed green sea turtle (n=157) health and exposure to contaminants at this foraging ground from 2008 to 2012.

Predicting connectivity of green turtles at Palmyra Atoll, central Pacific: a focus on mtDNA and dispersal modelling.

Population connectivity and spatial distribution are fundamentally related to ecology, evolution and behaviour. Here, we combined powerful genetic analysis with simulations of particle dispersal in a high-resolution ocean circulation model to investigate the distribution of green turtles foraging at the remote Palmyra Atoll National Wildlife Refuge, central Pacific. We analysed mitochondrial sequences from turtles (n = 349) collected there over 5 years (2008-2012).

Finding the 'lost years' in green turtles: insights from ocean circulation models and genetic analysis.

Organismal movement is an essential component of ecological processes and connectivity among ecosystems. However, estimating connectivity and identifying corridors of movement are challenging in oceanic organisms such as young turtles that disperse into the open sea and remain largely unobserved during a period known as 'the lost years'. Using predictions of transport within an ocean circulation model and data from published genetic analysis, we present to our knowledge, the first basin-scale hypothesis of distribution and connectivity among major rookeries and foraging grounds (FGs) of green turtles (Chelonia mydas) during their 'lost years'.

Resolving the phylogenetic history of the short-necked turtles, genera Elseya and Myuchelys (Testudines: Chelidae) from Australia and New Guinea.

Phylogenetic relationships and taxonomy of the short-necked turtles of the genera Elseya, Myuchelys, and Emydura in Australia and New Guinea have long been debated as a result of conflicting hypotheses supported by different data sets and phylogenetic analyses. To resolve this contentious issue, we analyzed sequences from two mitochondrial genes (cytochrome b and ND4) and one nuclear intron gene (R35) from all species of the genera Elseya, Myuchelys, Emydura, and their relatives. Phylogenetic analyses using three methods (maximum parsimony, maximum likelihood, and Bayesian inference) produce a single, well resolved, and strongly corroborated hypothesis, which provides support for the three genera, with the exception that the genus Myuchelys is paraphyletic - Myuchelys purvisi is the sister taxon to the remaining Elseya, Myuchelys and Emydura.

The interplay of homing and dispersal in green turtles: a focus on the southwestern atlantic.

Current understanding of spatial ecology is insufficient in many threatened marine species, failing to provide a solid basis for conservation and management. To address this issue for globally endangered green turtles, we investigated their population distribution by sequencing a mitochondrial control region segment from the Rocas Atoll courtship area (n = 30 males) and four feeding grounds (FGs) in Brazil (n = 397), and compared our findings to published data (n (nesting) = 1205; n (feeding) = 1587). At Rocas Atoll, the first Atlantic courtship area sequenced to date, we found males were differentiated from local juveniles but not from nesting females.

Mitogenomic sequences better resolve stock structure of southern Greater Caribbean green turtle rookeries.

Analyses of mitochondrial control region polymorphisms have supported the presence of several demographically independent green turtle (Chelonia mydas) rookeries in the Greater Caribbean region. However, extensive sharing of common haplotypes based on 490-bp control region sequences confounds assessment of the scale of natal homing and population structure among regional rookeries. We screened the majority of the mitochondrial genomes of 20 green turtles carrying the common haplotype CM-A5 and representing the rookeries of Buck Island, St.

DNA barcodes for globally threatened marine turtles: a registry approach to documenting biodiversity.

DNA barcoding is a global initiative that provides a standardized and efficient tool to catalogue and inventory biodiversity, with significant conservation applications. Despite progress across taxonomic realms, globally threatened marine turtles remain underrepresented in this effort. To obtain DNA barcodes of marine turtles, we sequenced a segment of the cytochrome c oxidase subunit I (COI) gene from all seven species in the Atlantic and Pacific Ocean basins (815 bp; n = 80).

Testing dispersal hypotheses in foraging green sea turtles (Chelonia mydas) of Brazil.

Testing theories of dispersal is challenging in highly migratory species. In sea turtles, population size, geographic distance, natal homing, and ocean currents are hypothesized to affect dispersal. Little is known, however, about these mechanisms in sea turtles foraging along the South American coast.