Rus Hoelzel

Durham University | DU · Department of Biosciences

Estimates of whale mutation rates contribute to understanding evolutionary processes.

Half a century after its foundation, the neutral theory of molecular evolution continues to attract controversy. The debate has been hampered by the coexistence of different interpretations of the core proposition of the neutral theory, the 'neutral mutation-random drift' hypothesis. In this review, we trace the origins of these ambiguities and sug...

The designation of units for conservation has been a necessary but challenging objective since conservation efforts began. Most species are divided, typically by environment, into populations with independent evolutionary trajectories. There are practical conservation objectives for defining these boundaries. Separate genetic clusters provide futur...

In oceanic ecosystems, the nature of barriers to gene flow, and the processes by which populations may become isolated are different from the terrestrial environment, and less well understood. In this study we investigate a highly mobile species (the sperm whale, Physeter macrocephalus) that is genetically differentiated between an open North Atlan...

Prediction of future ice-sheet behavior in Antarctica and its contribution to sea-level rise depends on accurate understanding of ice-sheet response to a warm climate. Examination of how the ice sheet reacted to past warm episodes affords a means of assessing its tolerances to climate change. The West Antarctic Ice Sheet (WAIS), in particular, is t...

The Saimaa ringed seal (Pusa hispida saimensis) is endemic to Lake Saimaa in Finland. The subspecies is thought to have originated when parts of the ringed seal population of the Baltic region were trapped in lakes emerging due to postglacial bedrock rebound around 9000 years ago. During the 20th century, the population experienced a drastic human-...

Aim The Saimaa ringed seal ( Pusa hispida saimensis ) is endemic to Lake Saimaa in Finland. The subspecies is thought to have originated when parts of the ringed seal population of the Baltic region were trapped in lakes emerging due to post-glacial bedrock rebound around 9,000 years ago. During the 20 th century, the population experienced a drast...

This Topic Issue will focus on cetaceans (including whales, dolphins and porpoises), investigating various aspects of these charismatic and ecologically important megafauna. Cetaceans are recognised as flagship animals of aquatic biodiversity and are the main target of aquatic research and conservation efforts worldwide. However, there are still ga...

Global warming is affecting the population dynamics and trophic interactions across a wide range of ecosystems and habitats. Translating these real-time effects into their long-term consequences remains a challenge. The rapid and extreme warming period that occurred after the Last Glacial Maximum (LGM) during the Pleistocene–Holocene transition (7–...

Local adaptation and adaptive radiations are typically associated with phenotypic variation suited to alternative environments. In the marine environment, the nature of relevant ecological or environmental transitions is poorly understood, especially for highly mobile species. Here we compare three genetic lineages in the genus Tursiops (bottlenose...

adaptation - divergence - Indian Ocean - morphology - speciation

The ancestors of marine mammals once roamed the land and independently committed to an aquatic lifestyle. These macroevolutionary transitions have intrigued scientists for centuries. Here, we generated high-quality genome assemblies of 17 marine mammals (11 cetaceans and six pinnipeds), including eight assemblies at the chromosome level. Incorporat...

Many marine species exhibit fine-scale population structure despite high mobility and a lack of physical barriers to dispersal, but the evolutionary drivers of differentiation in these systems are generally poorly understood. Here we investigate the potential role of habitat transitions and seasonal prey distributions on the evolution of population...

We use genomics to identify the natal origin of a grey whale found in the South Atlantic, at least 20 000 km from the species core range (halfway around the world). The data indicate an origin in the North Pacific, possibly from the endangered western North Pacific population, thought to include only approximately 200 individuals. This contributes...

In this letter, we revisit a study we published in 2017, following comment in a paper by Marchesini et al. published in this volume. We provide some further analyses that help us to reinforce the original conclusions of our earlier paper, and to address the points raised by Marchesini et al. We conclude that the concerns raised in their review do n...

Marine mammals can play important ecological roles in aquatic ecosystems, and their presence can be key to community structure and function. Consequently, marine mammals are often considered indicators of ecosystem health and flagship species. Yet, historical population declines caused by exploitation, and additional current threats, such as climat...

Understanding the genomic basis of adaptation is critical for understanding evolutionary processes and predicting how species will respond to environmental change. Spinner dolphins in the eastern tropical Pacific (ETP) present a unique system for studying adaptation. Within this large geographic region are four spinner dolphin ecotypes with weak ne...

Founder populations are of special interest to both evolutionary and conservation biologists, but the detection of genetic signals of selection in these populations is challenging due to their demographic history. Geographically separated founder populations likely subjected to similar selection pressures provide an ideal but rare opportunity to ov...

SNP data sets can be used to infer a wealth of information about natural populations, including information about their structure, genetic diversity, and the presence of loci under selection. However, SNP data analysis can be a time-consuming and challenging process, not in the least because at present many different software packages are needed to...

Background: SNP datasets can be used to infer a wealth of information about natural populations, including information about their structure, genetic diversity, and the presence of loci under selection. However, SNP data analysis can be a time-consuming and challenging process, not in the least because at present many different software packages ar...

Marine organisms face relatively few barriers to gene flow, and yet even highly mobile species such as dolphins often show population structure over regional geographic scales. Understanding the processes that promote this pattern of differentiation helps us understand the evolutionary radiation of this group, and to promote more effective measures...

Species that evolved in temperate regions during the Pleistocene experienced periods of extreme climatic transitions. Consequent population fragmentation and dynamics had the potential to generate small, isolated populations where the influence of genetic drift would be expected to be strong. We use comparative genomics to assess the evolutionary i...

The impact of inbreeding on fitness has been widely studied and provides consequential inference about the adaptive potential and the impact on survival for reduced and fragmented natural populations. Correlations between heterozygosity and fitness are common in the literature, but they rarely inform about the likely mechanisms. Here, we investigat...

The impact of inbreeding on fitness has been widely studied and provides consequential inference about adaptive potential and the impact on survival for reduced and fragmented natural populations. Correlations between heterozygosity and fitness are common in the literature, but they rarely inform about the likely mechanisms. Here, we investigate a...

Phylogeographic inference has provided extensive insight into the relative roles of geographical isolation and ecological processes during evolutionary radiations. However, the importance of cross-lineage admixture in facilitating adaptive radiations is increasingly being recognised, and suggested as a main cause of phylogenetic uncertainty. In thi...

The chance discovery of an 18th-century knuckle-bone floor at the National Trust property of Belton House in Lincolnshire prompted a review of all known post-medieval knuckle-bone floors in Britain to examine their date, context of creation and species composition. The identification of fallow deer bones within the Belton floor became the focus of...

The accurate identification of conservation units is central to effective management strategies. However, marine environment populations often have large census sizes and few obvious boundaries to gene flow. Poorly understood species in the deep sea are especially at risk of being erroneously managed as a single interbreeding stock (panmictic). How...

The conservation of adaptive potential to enable populations and species to respond to environmental change is one of the cornerstones of conservation genetics. To date, however, most work has by necessity focused on neutral markers and demographic questions. Now, with the rapid development of genomic technologies, we have new tools with which to a...

We report on an accumulation of mummified southern elephant seals (Mirounga leonina) from Inexpressible Island on the Victoria Land Coast (VLC), western Ross Sea, Antarctica. This accumulation is unusual, as elephant seals typically breed and molt on sub‐Antarctic islands further north and do not currently occupy the VLC. Prior ancient DNA analyses...

Evaluating how populations are connected by migration is important for understanding species resilience because gene flow can facilitate recovery from demographic declines. We therefore investigated the extent to which migration may have contributed to the global recovery of the Antarctic fur seal (Arctocephalus gazella), a circumpolar distributed...

R-code for “A global cline in a colour polymorphism suggests a limited contribution of gene flow towards the recovery of a heavily exploited marine mammal.”

The bottlenose dolphin, genus Tursiops is one of the best studied of all the Cetacea with a minimum of two species widely recognised. Common bottlenose dolphins (T. truncatus), are the cetacean species most frequently held in captivity and are known to hybridize with species from at least 6 different genera. In this study, we document several intra...

We investigated Heterozygosity Fitness Correlations (HFC) for a marine mammal known to be subject to epizootic episodes, the striped dolphin (Stenella coeruleoalba). Dolphins included in the study varied with respect to their parasite burden of a highly pathogenic lung nematode (Skrjabinalius guevarai). Genetic diversity assessed for nuclear SNP lo...

Aim The heterogeneity of the marine environment is thought to be the origin of marine biodiversity, often delineated in marine biogeographical provinces. Cetaceans are highly mobile aquatic mammals, but even those species inhabiting seemingly boundary‐free open waters are found to exhibit degrees of population structure, often attributed to ecologi...

The Anglo-Normans first introduced fallow deer (Dama dama) to Ireland in the thirteenth century, however no biomolecular research has previously been undertaken to examine the timing, circumstances and impact of the arrival of this species. This study combines historical, zooarchaeological, genetic and isotopic data from both medieval and post-medi...

For highly mobile species that nevertheless show fine-scale patterns of population genetic structure, the relevant evolutionary mechanisms determining structure remain poorly understood. The bottlenose dolphin (Tursiops truncatus) is one such species, exhibiting complex patterns of genetic structure associated with local habitat dependence in vario...

Intraspecific diversity promotes evolutionary change, and when partitioned among geographic regions or habitats can form the basis for speciation. Marine species live in an environment that can provide as much scope for diversification in the vertical as in the horizontal dimension. Understanding the relevant mechanisms will contribute significantl...

This study investigated taxonomic validity of the pale ghost shark Hydrolagus pallidus Hardy & Stehmann, 1990, which was described as a species distinct from the smalleyed rabbitfish H. affinis (de Brito Capello 1868). While few morphological characters distinguish the two taxa, a striking difference in sex ratio and fixed differences (1·1–1·6% div...

Until recently, little was known about the distribution and species occurrence of marine cetaceans in Pakistani waters, an area which needed to be addressed exigently given its inclusion in the Indian Ocean Whale Sanctuary. Boat-based surveys (2005-09) carried out along the coast of Pakistan identified 12 species of cetaceans. Although these survey...

Phylogeography can provide insight into the potential for speciation and identify geographic regions and evolutionary processes associated with species richness and evolutionary endemism. In the marine environment, highly mobile species sometimes show structured patterns of diversity, but the processes isolating populations and promoting differenti...

The evolutionary processes that shape patterns of diversity in highly mobile marine species are poorly understood, but important towards transferable inference on their effective conservation. In this study, bottlenose dolphins (Tursiops sp.) are studied to address this broader question. They exhibit remarkable geographical variation for morphology...

Aim We investigated the population genetic structure of a highly mobile marine species, the striped dolphin, Stenella coeruleoalba (Meyen, 1833), along a geographical range with habitat transitions and historical dynamics to identify the causes of genetic divergence, and to assess the effect of past climate change on demography and population conne...

The South American sea lion (Otaria flavescens) is widely distributed along the southern Atlantic and Pacific coasts of South America with a history of significant commercial exploitation. We aimed to evaluate the population genetic structure and the evolutionary history of South American sea lion along its distribution by analyses of mitochondrial...

List of individuals that bear each mitochondrial DNA control region haplotype, and the respective GenBank number. Absolute frequency in the sample and geographic distribution of haplotypes for South American sea lion. (DOCX)

List of individuals that bear each mitochondrial DNA cytochrome b haplotype. Absolute frequency in the sample and geographic distribution of haplotypes for South American sea lion. (DOCX)

Extended Bayesian skyline plot showing the effective population size fluctuation of South American sea lions populations throughout time based on the mtDNA control region. Internal dashed lines are median estimates and thin lines and coloured areas are the 95% Central Posterior Density (CPD) intervals. Nef, effective female population size (log sca...

Extended Bayesian skyline plot showing the effective population size fluctuation of South American sea lions populations throughout time based on the mtDNA control region. Internal black dashed lines are median estimates and thin lines are the 95% CPD intervals. Thin green lines are the individual population trajectories. Nef, effective female popu...

Species and access number of sequences downloaded from GenBank used to estimate the Bayesian phylogeny (Fig 3). (DOCX)

Genetic diversity of South American sea lions for each locus per clustered localities and for the species as whole. (A) Number of alleles, (E) = exclusive alleles, (Ho) observed heterozygosity, (He) expected heterozygosity.* Loci that deviated from HW equilibrium after Bonferroni correction. (DOCX)

Plots from STRUCTURE HARVESTER performed with Evanno’s method. (A) Highest value of (ΔK) = 79.20 on K = 2. (B) Mean of estimated Ln probability of data (± sd) averaging ten runs from K = 1 to K = 10. (TIF)

STRUCTURE bar plot from the test for migrants or hybrids between oceans using the sampling locations (in this case the ocean basin) and the USEPOPINFO model. Each bar is one individual and each colour represents the assignment probability of the individual to belong to that genetic cluster. (TIF)

Barbuda and Antigua's national animal is the fallow deer, Dama dama dama, a species native to the eastern Mediterranean that has been transported around the world by people during the last 8,000 years. The timing and circumstances by which fallow deer came to be established on Barbuda are currently uncertain but, by examining documentary, osteologi...

Species that have been translocated and otherwise manipulated by humans may show patterns of population structure that reflect those interactions. At the same time, natural processes shape populations, including behavioural characteristics like dispersal potential and breeding system. In Europe, a key factor is the geography and history of climate...

Social structure is a core element of population biology, influenced by intrinsic and environmental factors. Intra-taxon comparisons of social organization are useful in elucidating the role of such ecological determinants of sociality. Killer whales Orcinus orca are widely distributed, social delphinids with diverse morphology, diet, behaviour, an...

Foote and Morin (2016) reanalyse data published in our recent RADseq studies (Moura et al., 2014a, 2015) to address questions about the likelihood of differentiation in sympatry among killer whale populations in the North Pacific. However, they describe a demic version of sympatric differentiation, requiring reproductive isolation to evolve by ‘eco...

Some species, such as the giraffe or bottlenose dolphin, are immediately recognizable and might seem immutable. In fact, their evolutionary stories are often more complicated. Regional populations of giraffe with distinct pelage patterns have only recently been recognized as four different species ( 1 ), and the number of species represented by wha...

The archaeological record concerning the distribution and timing of fallow deer translocation across the Mediterranean has been growing in the last years. This knowledge has provided important insights into the movement, trade patterns and ideology of past societies. Unfortunately, the dispersal of fallow deer to the western part of the Mediterrane...

The role of ecological and changing environmental factors in the radiation of species diversity is a fundamental question in evolutionary biology. Of particular interest is the potential for these factors to determine the boundary between what we would consider differentiation among populations and incipient speciation. Dolphins in the genus Delphi...

This paper presents the results of the first comprehensive scientific study of the fallow deer, a non-native species whose medieval-period introduction to Britain transformed the cultural landscape. It brings together data from traditional zooarchaeological analyses with those derived from new ageing techniques as well as the results of a programme...

Here we consider the role of depth as a driver of evolution in a genus of deep-sea fishes. We provide a phylogeny for the genus Coryphaenoides (Gadiformes: Macrouridae) that represents the breadth of habitat use and distributions for these species. In our consensus phylogeny species found at abyssal depths (> 4000 m) form a well-supported lineage,...

Diet seems to be a key factor driving diversity and isolation among killer whale populations. Killer whales at Marion Island, Southern Ocean, have been observed preying on seals and penguins but are also know to depredate Patagonian toothfish from longline fishing vessels. However, their diet is poorly known especially when they occur offshore. We...

Understanding observed patterns of connectivity requires an understanding of the evolutionary processes that determine genetic structure among populations, with the most common models being associated with isolation by distance, allopatry or vicariance. Pinnipeds are annual breeders with the capacity for extensive range overlap during seasonal migr...

The letter by Garner et al. [1] continued an important discussion regarding the role genomics might play in conservation biology. In general, we do not see a dichotomy between our point of view [2] and that put forth by Garner et al. [1]. At the heart of the issue is how to define an actual impact of genomics on applied conservation and find suitab...

In How to Clone a Mammoth , Beth Shapiro tackles to the topic of de-extinction, carefully considering the technological, ecological, and ethical challenges that such an endeavor would entail. Reviewer A. Rus Hoelzel recounts Shapiro's arguments (Can we? Should we?) and applauds the book as "rich in anecdote and scientifically precise."

Protecting wildlife helps to sustain ecosystems and the services they provide, but beyond that, wildlife species have an intrinsic value. It is hard to imagine a world without iconic species such as the African elephant. However, elephants carry with them an appendage of great commercial value: their tusks. Conservation efforts struggle to keep pac...

An official journal of the Genetics Society, Heredity publishes high-quality articles describing original research and theoretical insights in all areas of genetics. Research papers are complimented by News & Commentary articles and reviews, keeping researchers and students abreast of hot topics in the field.