scholarly journals Reevaluating claims of ecological speciation in Halichoeres bivittatus

2021 ◽  
Author(s):  
Dan L. Warren ◽  
Ron I. Eytan ◽  
Alex Dornburg ◽  
Teresa L. Iglesias ◽  
Matthew C. Brandley ◽  
...  
Keyword(s):  
Gene Flow ◽  
Population Biology ◽  
Florida Keys ◽  
Ecological Speciation ◽  
Habitat Types ◽  
Ecological Processes ◽  
Marine Population ◽  
Speciation Event ◽  
Primary Driver ◽  
Mitochondrial Locus

AbstractUnderstanding the role of ecological processes in speciation has become one of the most active areas of research in marine population biology in recent decades. The traditional view was that allopatry was the primary driver of speciation in marine taxa, but the geography of the marine environment and the dispersal capabilities of many marine organisms render this view somewhat questionable. One of the earliest and most highly cited empirical examples of ecological speciation with gene flow in marine fishes is that of the slippery dick wrasse, Halichoeres bivittatus. Evidence for this cryptic or incipient speciation event was primarily in the form of a deep north-south divergence in a single mitochondrial locus, combined with a finding that these two haplotypes were associated with different habitat types in the Florida Keys and Bermuda, where they overlap. Here we examine habitat assortment in the Florida Keys using a broader sampling of populations and habitat types than were available for the original study, and find no evidence to support the claim that haplotype frequencies differ between habitat types, and little evidence to support any differences between populations. These results severely undermine claims of ecological speciation with gene flow in Halichoeres bivittatus. We argue that future claims of this type should be supported by multiple lines of evidence that illuminate potential mechanisms and allow researchers to rule out alternative explanations for spatial patterns of genetic differences.

scholarly journals Reevaluating claims of ecological speciation in Halichoeres bivittatus

2021 ◽  
Author(s):  
Dan Warren ◽  
Ron Eytan ◽  
Alex Dornburg ◽  
Teresa Iglesias ◽  
Matt Brandley ◽  
...  
Keyword(s):  
Gene Flow ◽  
Population Biology ◽  
Florida Keys ◽  
Ecological Speciation ◽  
Habitat Types ◽  
Ecological Processes ◽  
Marine Population ◽  
Speciation Event ◽  
Primary Driver ◽  
Mitochondrial Locus

Understanding the role of ecological processes in speciation has become one of the most active areas of research in marine population biology in recent decades. The traditional view was that allopatry was the primary driver of speciation in marine taxa, but the geography of the marine environment and the dispersal capabilities of many marine organisms render this view somewhat questionable. One of the earliest and most highly cited empirical examples of ecological speciation with gene flow in marine fishes is that of the slippery dick wrasse, Halichoeres bivittatus. Evidence for this cryptic or incipient speciation event was primarily in the form of a deep north-south divergence in a single mitochondrial locus, combined with a finding that these two haplotypes were associated with different habitat types in the Florida Keys and Bermuda, where they overlap. Here we examine habitat assortment in the Florida Keys using a broader sampling of populations and habitat types than were available for the original study, and find no evidence to support the claim that haplotype frequencies differ between habitat types, and little evidence to support any differences between populations. These results severely undermine claims of ecological speciation with gene flow in Halichoeres bivittatus. We argue that future claims of this type should be supported by multiple lines of evidence that illuminate potential mechanisms and allow researchers to rule out alternative explanations for spatial patterns of genetic differences.

scholarly journals Genetic structure and diversity of the mustard hill coral Porites astreoides along the Florida Keys reef tract

2021 ◽  
Vol 51 (4) ◽  
Author(s):  
Dominique N. Gallery ◽  
Michelle L. Green ◽  
Ilsa B. Kuffner ◽  
Elizabeth A. Lenz ◽  
Lauren T. Toth
Keyword(s):  
Genetic Diversity ◽  
Gene Flow ◽  
Genetic Relatedness ◽  
Florida Keys ◽  
Genetic Population ◽  
High Genetic Diversity ◽  
Western Atlantic ◽  
Porites Astreoides ◽  
Single Well ◽  
Reef Tract

AbstractIncreases in local and global stressors have led to major declines in coral populations throughout the western Atlantic. While abundances of other species have declined, however, the relative abundance of the mustard hill coral, Porites astreoides, has increased. Porites astreoides is relatively resilient to some stressors, and because of its mixed reproductive strategies, its populations often recover quickly following disturbances. The ability for P. astreoides to continue as a potential “winner” in western Atlantic reefs relies on maintaining sufficient genetic variation within populations to support acclimatization and adaptation to current and future environmental change. Without high genetic diversity and gene flow within the population, it would have limited capacity for adaptation and the species’ competitive advantages could be short-lived. In this study, we determined the genetic relatedness of 37 P. astreoides colonies at four shallow reefs along the offshore Florida Keys Reef Tract (FKRT), a region particularly hard-hit by recent disturbances. Using previously designed microsatellite markers, we determined the genetic diversity and connectivity of individuals among and between sites. Our results suggest that the FKRT likely contains a single, well-mixed genetic population of P. astreoides, with high levels of gene flow and evidence for larval migration throughout the region. This suggests that regional populations of P. astreoides likely have a higher chance of maintaining resilience than many other western Atlantic species as they face current and future disturbances.

scholarly journals Ecological Divergence and the Origins of Intrinsic Postmating Isolation with Gene Flow

2011 ◽  
Vol 2011 ◽  
pp. 1-15 ◽  
Author(s):  
Aneil F. Agrawal ◽  
Jeffrey L. Feder ◽  
Patrik Nosil
Keyword(s):  
Linkage Disequilibrium ◽  
Gene Flow ◽  
Natural Selection ◽  
Theoretical Models ◽  
Ecological Speciation ◽  
Divergent Selection ◽  
Postmating Isolation ◽  
Divergent Natural Selection ◽  
Mathematical Exploration ◽  
Neutral Gene

The evolution of intrinsic postmating isolation has received much attention, both historically and in recent studies of speciation genes. Intrinsic isolation often stems from between-locus genetic incompatibilities, where alleles that function well within species are incompatible with one another when brought together in the genome of a hybrid. It can be difficult for such incompatibilities to originate when populations diverge with gene flow, because deleterious genotypic combinations will be created and then purged by selection. However, it has been argued that if genes underlying incompatibilities are themselves subject to divergent selection, then they might overcome gene flow to diverge between populations, resulting in the origin of incompatibilities. Nonetheless, there has been little explicit mathematical exploration of such scenarios for the origin of intrinsic incompatibilities during ecological speciation with gene flow. Here we explore theoretical models for the origin of intrinsic isolation where genes subject to divergent natural selection also affect intrinsic isolation, either directly or via linkage disequilibrium with other loci. Such genes indeed overcome gene flow, diverge between populations, and thus result in the evolution of intrinsic isolation. We also examine barriers to neutral gene flow. Surprisingly, we find that intrinsic isolation sometimes weakens this barrier, by impeding differentiation via ecologically based divergent selection.

scholarly journals NASA-NPS Landscape Climate Change Vulnerability Project (LCCVP) Team Meeting at AMK Ranch

2013 ◽  
Vol 36 ◽  
pp. 183-184
Author(s):  
Andy Hansen ◽  
Tom Oliff
Keyword(s):  
Climate Adaptation ◽  
Monitoring Program ◽  
Landscape Conservation ◽  
State University ◽  
Habitat Types ◽  
Management Options ◽  
Ecological Processes ◽  
Montana State University ◽  
University Of Montana ◽  
Landscape Conservation Cooperatives

A NASA-funded research team met May 19-22 at the AMK Ranch for a semi-annual team workshop. Participants included: Montana State University – Andy Hansen, Tony Chang, Regan Nelson, Nate Piekielek Woods Hole Research Center – Patrick Jantz, Scott Zolkos NPS Inventory & Monitoring Program – John Gross, Bill Monahan Great Northern LCC – Tom Olliff NASA Ames – Forrest Melton, Jun Xiong Guest – Steve Running (University of Montana) Chef – Jodi Stevens The goal of the project is to demonstrate the four steps of climate adaptation planning in two US Department of Interior Landscape Conservation Cooperatives (LCCs) using NASA and other data and models. Objectives are: 1. Hindcast and forecast future climate and land use scenarios. 2. Assess the vulnerability of ecological processes and key habitat types. 3. Evaluate management options. 4. Design and implement management adaptation strategies. 5. Facilitate decision support.

Fish Habitat: Essential Fish Habitat and Rehabilitation

1999 ◽  
Keyword(s):  
Field Experiment ◽  
Fish Habitat ◽  
Spiny Lobster ◽  
Basic Research ◽  
Florida Keys ◽  
Ecological Processes ◽  
Juvenile Recruitment ◽  
Before And After ◽  
Individual Survival ◽  
Concrete Blocks

<em>Abstract</em> .—Basic research on the settlement and postsettlement ecology of spiny lobster <em>Panulirus argus </em> has led to an application with the potential to replace lost natural refuge with artificial shelters intended for the vulnerable small juvenile stages. We began investigating ecological processes regulating juvenile spiny lobster recruitment in the Florida nursery in the mid-1980s. An unprecedented massive die-off of sponges in the middle Florida Keys followed cyanobacterial blooms in 1991–1993, ultimately affecting about 300 km2 of a region providing approximately one-fifth of total juvenile recruitment. Before 1991, crevices in sponges provided diurnal refuge from predators for about 70% of juveniles <50 mm carapace length. On the basis of sampling done before and after sponge loss, we estimated that juvenile abundance declined by 30–50% on spongeless sites without alternative shelter, resulting in a decrease of annual nurserywide potential of up to 10%. Results of a field experiment evaluating the relative influences of the magnitude of settlement and availability of crevice shelter on juvenile recruitment, fortuitously begun before the sponge die-off, showed that juvenile survival and abundance were sustained on small 0.02- to 0.07-ha test sites provided with supplemental artificial shelters (slotted concrete blocks). In the absence of sponges, survival of microwire-tagged juveniles on the shelter-supplemented sites was about six times higher than that on unsupplemented sites. On the basis of our earlier ecological findings, we devised a feasibility study to test whether the artificial shelters could replace lost sponge shelter for juvenile lobsters on a large scale. It took the form of a field experiment using 240 shelters spread over 1-ha sites located amid hard substrate denuded of sponges. The shelters provided substitute crevices, supporting juvenile lobster recruitment approximating that in areas with good sponge cover. This outcome exemplifies the essential value of initial basic research that provides understanding of the ecological processes regulating individual survival and, ultimately, the character and dynamics of the fishery population. Such an approach, and the information it provides, is necessary to successful rehabilitation of essential habitat or restocking of natural populations. Moreover, conducting basic research can help prevent the waste of precious time, funds, income, and human effort that typically has occurred in past failed attempts that were undertaken with insufficient knowledge. We urge the fisheries-ecology discipline and support agencies to promote strongly the primacy of research on basic processes.

Landscape Connectivity

2019 ◽  
pp. 206-238
Author(s):  
Kimberly A. With
Keyword(s):  
Invasive Species ◽  
Gene Flow ◽  
Landscape Pattern ◽  
Landscape Structure ◽  
Pattern Analysis ◽  
Landscape Connectivity ◽  
Ecological Processes ◽  
Independent Variable ◽  
Ecological Flows

Landscape connectivity is essential for maintaining ecological flows across landscapes. Processes as diverse as dispersal; gene flow; the flow of water, materials and nutrients; the spread of invasive species, diseases, or pests; or the spread of disturbances like fire, are all potentially influenced by the connectivity of different land covers and land uses. Landscape connectivity can be defined structurally as well as functionally. Landscape connectivity may therefore be treated as either an independent variable, in terms of studying how landscape connectivity influences ecological flows, or as a dependent variable in which landscape connectivity emerges as a consequence of how species or ecological flows interact with landscape structure. This chapter thus explores the different scales and ways in which connectivity can be measured and studied, providing a bridge between the previous chapter on landscape pattern analysis and the chapters that follow on the effects of landscape pattern on ecological processes.

scholarly journals Genetic Structuring Among Migratory Populations of the Black-Whiskered Vireo, with a Comparison to the Red-Eyed Vireo

The Condor ◽  
2001 ◽  
Vol 103 (3) ◽  
pp. 439-448
Author(s):  
Patrick W. Zwartjes
Keyword(s):  
Puerto Rico ◽  
Gene Flow ◽  
Random Amplified Polymorphic Dna ◽  
Florida Keys ◽  
The United States ◽  
Genetic Structuring ◽  
Vireo Olivaceus ◽  
La Florida ◽  
Southern Florida ◽  
Los Grupos

AbstractThe Black-whiskered Vireo (Vireo altiloquus) breeds from coastal southern Florida in the United States through the islands of the West Indies, and thus consists of several populations separated by large regions of uninhabitable space. I examined genetic variation within and among six migratory populations in the Florida Keys, Jamaica, and Puerto Rico, using random amplified polymorphic DNA (RAPD) markers and analysis of molecular variance (AMOVA). Calculations of variance components revealed that over 90% of the variance was among individuals; a significant portion also occurred among regional groups (Florida, Jamaica, and Puerto Rico). Variance between subpopulations within the regional groups was not significantly different from zero. This contrasts with the closely related Red-eyed Vireo (V. olivaceus) of continental North America, in which analyses of three widely separate geographic localities revealed that over 99% of the genetic variance was among individuals, with no significant variance detectable among localities. The greatest differences in V. altiloquus were detected between the Florida Keys populations and the populations from Jamaica and Puerto Rico; the latter two showed no significant differentiation. Estimates of gene flow from the AMOVA analog to Wright's F-statistics suggest that there is enough gene flow among regions to prevent differentiation by genetic drift. Although not strongly isolated, the Florida population of V. altiloquus is sufficiently differentiated to suggest reduced genetic exchange with the populations on Puerto Rico and Jamaica.Estructura Genética entre Poblaciones Migratorias de Vireo altiloquus con una Comparación con Vireo olivaceusResumen. Vireo altiloquus se reproduce desde la costa del sur de la Florida en los Estados Unidos hasta las islas de las Antillas, y por lo tanto presenta varias poblaciones separadas por extensas regiones de espacio no habitable. Examiné la variación genética dentro y entre seis poblaciones migratorias en los Cayos de la Florida, en Jamaica y en Puerto Rico, usando marcadores polimórficos de ADN amplificados al azar (RAPD) y análisis de varianza molecular (AMOVA). Los cálculos de los componentes de la varianza indicaron que más del 90% de la varianza se presentó entre individuos; una porción significativa también estuvo presente entre los grupos regionales (Florida, Jamaica y Puerto Rico). La varianza entre subpoblaciones dentro de grupos regionales no fue significativamente diferente de cero. Esto contrasta con los resultados para V. olivaceus de Norteamérica continental, donde los análisis de tres localidades alejadas revelaron que más del 99% de la varianza genética se registró entre individuos, sin varianza significativa detectable entre localidades. Las mayores diferencias en V. altiloquus fueron detectadas entre las poblaciones de los Cayos de la Florida y las poblaciones de Jamaica y Puerto Rico; las últimas dos no mostraron diferencias significativas. Las estimaciones de flujo génico a partir del AMOVA, análogo al estadístico F de Wright, sugieren que hay suficiente flujo génico entre las regiones para evitar diferenciación por deriva génica. Aunque no está muy aislada, la poblacion de V. altiloquus de la Florida se diferencia lo suficiente como para sugerir un intercambio génico reducido con las poblaciones de Puerto Rico y Jamaica.

Factors affecting resistance to insecticides in house-flies, Musca domestica L. (Diptera: Muscidae). IV. The population biology of flies on animal farms in south-eastern England and its implications for the management of resistance

1985 ◽  
Vol 75 (1) ◽  
pp. 143-158 ◽  
Author(s):  
I. Denholm ◽  
R. M. Sawicki ◽  
A. W. Farnham
Keyword(s):  
Gene Flow ◽  
Musca Domestica ◽  
Population Biology ◽  
Marker Gene ◽  
House Fly ◽  
Factors Affecting ◽  
House Flies ◽  
Resistance Selection ◽  
South Eastern ◽  
Brown Body

AbstractWays in which the bionomics and dynamics of populations of Musca domestica L. can influence the development of insecticide resistance, and how resistance genes spread within and between farms was investigated in a three-year study of the biology and movement of flies on 63 pig-rearing farms in south-eastern England. House-flies survived winter only on 12 ‘overwintering’ farms where they bred in heated pig-rearing houses (‘closed buildings’) throughout the year. In late spring they appeared out doors, and their descendents founded populations on neighbouring ‘summer’ farms where pigs breed only in unheated (‘open’) buildings. There, flies reached peak numbers in August–September and died out by mid-November. Gene flow within and between farms was studied indirectly by mark-release-recapture of colour-marked adults, and directly by monitoring the diffusion of the visible marker gene bwb (brown body) introduced into indigenous house-fly populations. Although movement between open buildings within a farm was unrestricted, dispersal between farms was limited, and gene flow between even adjacent closed buildings was indirect, and required more than one generation. Likewise, indirect and gradual gene flow during summer probably accounted for the similarity in type and frequency of other independent genetic markers of local overwintering populations. Thus closed buildings played a key role in house-fly ecology and population genetics. Unfortunately, control with persistent insecticides in these buildings ensures efficient resistance selection, ultimately resulting in its spread to all pig farms. Less selective control practices are needed at these sites.

The influence of visitors on intertidal biodiversity

2005 ◽  
Vol 85 (2) ◽  
pp. 263-268 ◽  
Author(s):  
Eunice H. Pinn ◽  
Michelle Rodgers
Keyword(s):  
Statistical Analysis ◽  
Multivariate Statistical Analysis ◽  
Human Impacts ◽  
World Heritage Site ◽  
Habitat Types ◽  
Ecological Processes ◽  
Multivariate Statistical ◽  
Heritage Site ◽  
Wildlife Reserve ◽  
Marine Wildlife

The Purbeck Marine Wildlife Reserve lies within the boundary of the Dorset and East Devon World Heritage Site on the south coast. This study investigated the influence of visitors on intertidal biodiversity at Kimmeridge Bay, the only accessible part of the reserve. The assemblages present on two rock ledges were compared: Washing Ledge, which is regularly visited and utilized by people, and Yellow Ledge, which is more isolated and visited much less regularly. At each ledge, three habitat types were investigated: open rock, rockpools and the fucoid zone. Multivariate statistical analysis revealed significant differences in assemblages between ledges and among habitat types. The differences observed in the communities of the two ledges can be explained to some extent by natural ecological processes, but human impacts were also detected. The most obvious contrast associated with trampling was a reduction in the larger, branching species of algae and an increase in ephemeral and crustose species in the more heavily utilized areas.

ORIGIN AND BIOGEOGRAPHY OF THE WEEVILS OF SOUTHERN FLORIDA (COLEOPTERA: CURCULIONIDAE)

1994 ◽  
Vol 126 (3) ◽  
pp. 819-839 ◽  
Author(s):  
Robert S. Anderson ◽  
Stewart B. Peck
Keyword(s):  
Florida Keys ◽  
Habitat Diversity ◽  
South Florida ◽  
Habitat Types ◽  
Species Origin ◽  
Naturally Occurring ◽  
The Caribbean ◽  
Southern Florida ◽  
Unintentional Action ◽  
Important Site

AbstractThe naturally occurring weevil (Curculionidae) fauna of Dade and Monroe counties in southern Florida is composed of 100 genera and 222 species. Another 20 species are adventive; their presence is due to the unintentional action of humans. Twenty-eight species occur only on the islands of the Florida Keys, 118 species occur only on mainland south Florida, and 76 species are shared by the mainland and the islands. Greater habitat diversity on the mainland accounts for its higher species diversity. The species distributions and faunal affinities are 60% Nearctic and 40% Neotropical or West Indian. Thirty-five species are known to occur only in southern Florida. This probably reflects poor knowledge of their distribution in the Caribbean rather than southern Florida as an important site for species origin. Most of the weevil species (133; 60%) are habitat specific and few species (22; 10%) are found in three or more habitat types. Wetland-inhabiting species are predominant (76; 34%), followed by hardwood hammock species (47; 21%). Flightlessness in adults is uncommon (35 species; 16%), but more prevalent in the species endemic to southern Florida (12 species; 34%). Extrapolation from data on weevil diversity yields a conservative estimate of over 5000 species of insects in southern Florida.

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