Publications by authors named "SR Palumbi"

Symbiont genotype plays a vital role in the ability of a coral host to tolerate rising ocean temperatures, with some members of the family Symbiodiniaceae possessing more thermal tolerance than others. While existing studies on genetic structure in symbiont populations have focused on broader scales of 10-100 s of km, there is a noticeable gap in understanding the seascape genetics of coral symbionts at finer-yet ecologically and evolutionarily relevant-scales. Here, we mapped short reads from 271 holobiont genome libraries of individual colonies to protein coding genes from the chloroplast genome to identify patterns of symbiont population genetic structure.

View Article and Find Full Text PDF
Article Synopsis
  • Coral bleaching has raised interest in improving heat resistance in coral species, but this may come with fitness trade-offs that affect their overall health.
  • Research in Palau categorizes corals into different heat resistance levels based on pigmentation loss during heat stress, exploring both their resistance and recovery over a 6-month period.
  • Findings show that while heat resistance reduces early mortality, moderate-resistance corals excel in skeletal growth over time, indicating complex trade-offs between heat resistance and recovery that should be considered in coral management strategies.
View Article and Find Full Text PDF

The ability of local populations to adapt to future climate conditions is facilitated by a balance between short range dispersal allowing local buildup of adaptively beneficial alleles, and longer dispersal moving these alleles throughout the species range. Reef building corals have relatively low dispersal larvae, but most population genetic studies show differentiation only over 100s of km. Here, we report full mitochondrial genome sequences from 284 tabletop corals () from 39 patch reefs in Palau, and show two signals of genetic structure across reef scales from 1 to 55 km.

View Article and Find Full Text PDF
Article Synopsis
  • Stony corals exhibit a unique reproductive process where they may produce gametes from somatic tissue, challenging the typical separation of germline and somatic cells.
  • Researchers sequenced genomes from parent coral branches and their sperm pools, revealing a significant number of post-embryonic single nucleotide variants (SNVs) that were unique to either the parent branches or the sperm.
  • The findings suggest that self-renewing stem cells in corals contribute to both germ and somatic cells throughout the colony’s life, highlighting potential insights into coral adaptation and evolution in response to climate change.
View Article and Find Full Text PDF

Widespread mapping of coral thermal resilience is essential for developing effective management strategies and requires replicable and rapid multi-location assays of heat resistance and recovery. One- or two-day short-term heat stress experiments have been previously employed to assess heat resistance, followed by single assays of bleaching condition. We tested the reliability of short-term heat stress resistance, and linked resistance and recovery assays, by monitoring the phenotypic response of fragments from 101 Acropora hyacinthus colonies located in Palau (Micronesia) to short-term heat stress.

View Article and Find Full Text PDF

The pervasive loss of biodiversity in the Anthropocene necessitates rapid assessments of ecosystems to understand how they will respond to anthropogenic environmental change. Many studies have sought to describe the adaptive capacity (AC) of individual species, a measure that encompasses a species' ability to respond and adapt to change. Only those adaptive mechanisms that can be used over the next few decades (e.

View Article and Find Full Text PDF
Article Synopsis
  • Interest in coral reef conservation is increasing due to challenges like climate warming and coral bleaching, leading to strategies such as ex situ propagation and transplantation of corals to restore degraded areas.
  • Current methods, including demographic restoration and assisted evolution (like selective breeding), show limited effectiveness in preventing severe coral decline under climate change unless there’s a significant, long-term input of resilient colonies.
  • The study suggests that fostering natural genetic diversity in coral populations may be more effective for long-term adaptation to warming than solely relying on introducing heat-tolerant corals.
View Article and Find Full Text PDF
Article Synopsis
  • - At Rowley Shoals, the exposed reef flat and warm lagoon waters create an ideal setting to study how coral species adapt to climate change by analyzing genetic and environmental factors.
  • - Researchers collected samples from various habitats and used advanced techniques like whole-genome sequencing and heat stress experiments to investigate genetic variations and resilience in corals.
  • - Findings showed that lagoon corals are more resistant to bleaching and exhibit distinct gene expression patterns, indicating that different environments influence coral evolution and their ability to withstand climate-related stressors.
View Article and Find Full Text PDF

Recent warm temperatures driven by climate change have caused mass coral bleaching and mortality across the world, prompting managers, policymakers, and conservation practitioners to embrace restoration as a strategy to sustain coral reefs. Despite a proliferation of new coral reef restoration efforts globally and increasing scientific recognition and research on interventions aimed at supporting reef resilience to climate impacts, few restoration programs are currently incorporating climate change and resilience in project design. As climate change will continue to degrade coral reefs for decades to come, guidance is needed to support managers and restoration practitioners to conduct restoration that promotes resilience through enhanced coral reef recovery, resistance, and adaptation.

View Article and Find Full Text PDF
Article Synopsis
  • Reef-building coral species are declining due to severe marine heatwaves and bleaching, leading to high mortality rates.
  • Research on 114 coral colonies during a 2015 bleaching event identified genetic differences among four closely related species (HA, HC, HD, HE), particularly in heat tolerance and symbiont relationships.
  • The species HE showed significant genomic differences related to bleaching resistance, with two key loci (HES1 and HES2) linked to resilience, highlighting the genetic factors contributing to coral survival during increasing environmental stress.
View Article and Find Full Text PDF

Climate change is dramatically changing ecosystem composition and productivity, leading scientists to consider the best approaches to map natural resistance and foster ecosystem resilience in the face of these changes. Here, we present results from a large-scale experimental assessment of coral bleaching resistance, a critical trait for coral population persistence as oceans warm, in 221 colonies of the coral across 37 reefs in Palau. We find that bleaching-resistant individuals inhabit most reefs but are found more often in warmer microhabitats.

View Article and Find Full Text PDF

Corals are experiencing unprecedented decline from climate change-induced mass bleaching events. Dispersal not only contributes to coral reef persistence through demographic rescue but can also hinder or facilitate evolutionary adaptation. Locations of reefs that are likely to survive future warming therefore remain largely unknown, particularly within the context of both ecological and evolutionary processes across complex seascapes that differ in temperature range, strength of connectivity, network size, and other characteristics.

View Article and Find Full Text PDF

Global environmental change is challenging species with novel conditions, such that demographic and evolutionary trajectories of populations are often shaped by the exchange of organisms and alleles across landscapes. Current ecological theory predicts that random networks with dispersal shortcuts connecting distant sites can promote persistence when there is no capacity for evolution. Here, we show with an eco-evolutionary model that dispersal shortcuts across environmental gradients instead hinder persistence for populations that can evolve because long-distance migrants bring extreme trait values that are often maladaptive, short-circuiting the adaptive response of populations to directional change.

View Article and Find Full Text PDF

DNA metabarcoding has been increasingly used to detail distributions of hundreds of species. Most analyses focus on creating molecular operational taxonomic units (MOTUs) from complex mixtures of DNA sequences, but much less common is use of the sequence diversity within these MOTUs. Here we use the diversity of COI haplotypes within MOTUs from a California kelp forest to infer patterns of population abundance, dispersal and population history from 527 species of animals and algae from 106 samples of benthic habitats in Monterey Bay.

View Article and Find Full Text PDF

Progress in global shark conservation has been limited by constraints to understanding the species composition and geographic origins of the shark fin trade. Previous assessments that relied on earlier genetic techniques and official trade records focused on abundant pelagic species traded between Europe and Asia. Here, we combine recent advances in DNA barcoding and species distribution modelling to identify the species and source the geographic origin of fins sold at market.

View Article and Find Full Text PDF

The study of local adaptation in the presence of ongoing gene flow is the study of natural selection in action, revealing the functional genetic diversity most relevant to contemporary pressures. In addition to individual genes, genome-wide architecture can itself evolve to enable adaptation. Distributed across a steep thermal gradient along the east coast of North America, Atlantic silversides () exhibit an extraordinary degree of local adaptation in a suite of traits, and the capacity for rapid adaptation from standing genetic variation, but we know little about the patterns of genomic variation across the species range that enable this remarkable adaptability.

View Article and Find Full Text PDF

High pCO habitats and their populations provide an unparalleled opportunity to assess how species may survive under future ocean acidification conditions, and help to reveal the traits that confer tolerance. Here we utilize a unique CO vent system to study the effects of exposure to elevated pCO2 on trait-shifts observed throughout natural populations of Astroides calycularis, an azooxanthellate scleractinian coral endemic to the Mediterranean. Unexpected shifts in skeletal and growth patterns were found.

View Article and Find Full Text PDF

One challenge for multicellular organisms is maintaining genome stability in the face of mutagens across long life spans. Imperfect genome maintenance leads to mutation accumulation in somatic cells, which is associated with tumors and senescence in vertebrates. Colonial reef-building corals are often large, can live for hundreds of years, rarely develop recognizable tumors, and are thought to convert somatic cells into gamete producers, so they are a pivotal group in which to understand long-term genome maintenance.

View Article and Find Full Text PDF

Moderate- to high-density genotyping (100 + SNPs) is widely used to determine and measure individual identity, relatedness, fitness, population structure and migration in wild populations.However, these important tools are difficult to apply when high-quality genetic material is unavailable. Most genomic tools are developed for high-quality DNA sources from laboratory or medical settings.

View Article and Find Full Text PDF

Kelp forest ecosystems dominate 150,000 km of global temperate coastline, rivalling the coastal occurrence of coral reefs. Despite the astounding biological diversity and productive ecological communities associated with kelp forests, patterns of species richness and composition are difficult to monitor and compare. Crustose coralline algae are a critically important substrate for propagule settlement for a range of kelp forest species.

View Article and Find Full Text PDF
Article Synopsis
  • Humans are driving significant evolutionary changes in nature, particularly in the Anthropocene, but the genetic mechanisms behind these changes are still not fully understood.
  • In a study of fish populations, researchers observed rapid adaptations in growth rates due to size-selective harvesting over just four generations, revealing consistent allele frequency shifts in growth-related genes across different populations.
  • However, one specific group of genes underwent a rapid increase in frequency in one population, highlighting how similar physical changes can mask different underlying genetic responses, emphasizing the unpredictable nature of rapid adaptation under strong human influence.
View Article and Find Full Text PDF

As climate change progresses and extreme temperature events increase in frequency, rates of disturbance may soon outpace the capacity of certain species of reef-building coral to recover from bleaching. This may lead to dramatic shifts in community composition and ecosystem function. Understanding variation in rates of bleaching recovery among species and how that translates to resilience to recurrent bleaching is fundamental to predicting the impacts of increasing disturbances on coral reefs globally.

View Article and Find Full Text PDF

Ecological restoration of forests, meadows, reefs, or other foundational ecosystems during climate change depends on the discovery and use of individuals able to withstand future conditions. For coral reefs, climate-tolerant corals might not remain tolerant in different environments because of widespread environmental adjustment of coral physiology and symbionts. Here, we test if parent corals retain their heat tolerance in nursery settings, if simple proxies predict successful colonies, and if heat-tolerant corals suffer lower growth or survival in normal settings.

View Article and Find Full Text PDF