Statistical method for testing the neutral mutation hypothesis by DNA polymorphism.

Evolution of Protein Molecules

Evolutionary adaptation can be rapid and potentially help species counter stressful conditions or realize ecological opportunities arising from climate change. The challenges are to understand when evolution will occur and to identify potential evolutionary winners as well as losers, such as species lacking adaptive capacity living near physiological limits. Evolutionary processes also need to be incorporated into management programmes designed to minimize biodiversity loss under rapid climate change. These challenges can be met through realistic models of evolutionary change linked to experimental data across a range of taxa.

http://www.indiaenvironmentportal.org.in/files/climate%20change_1.pdf

Climate change and evolutionary adaptation

We redescribe the only previously known species of Myrsidea from bulbuls, M. pycnonoti Eichler. Sixteen new species are described; they and their type hosts are: M. phillipsi ex Pycnonotus goiavier goiavier (Scopoli), M. gieferi ex P. goiavier suluensis Mearns, M. kulpai ex P. flavescens Blyth, M. finlaysoni ex P. finlaysoni Strickland, M. kathleenae ex P. cafer (L.), M. warwicki ex Ixos philippinus (J. R. Forster), M. mcclurei ex Microscelis amaurotis (Temminck), M. zeylanici ex P. zeylanicus (Gmelin), M. plumosi ex P. plumosus Blyth, M. eutiloti ex P. eutilotus (Jardine and Selby), M. adamsae ex P. urostictus (Salvadori), M. ochracei ex Criniger ochraceus F. Moore, M. borbonici ex Hypsipetes borbonicus (J. R. Forster), M. johnsoni ex P. atriceps (Temminck), M. palmai ex C. ochraceus, and M. claytoni ex P. eutilotus. A key is provided for the identification of these 17 species.

A new species

What is ecological speciation

The population genetic pattern known as "isolation by distance" results from spatially limited gene flow and is a commonly observed phenomenon in natural populations. However, few software programs exist for estimating the degree of isolation by distance among populations, and they tend not to be user-friendly. We have created Isolation by Distance Web Service (IBDWS) a user-friendly web interface for determining patterns of isolation by distance. Using this site, population geneticists can perform a variety of powerful statistical tests including Mantel tests, Reduced Major Axis (RMA) regression analysis, as well as calculate F
 ST
 between all pairs of populations and perform basic summary statistics (e.g., heterozygosity). All statistical results, including publication-quality scatter plots in Postscript format, are returned rapidly to the user and can be easily downloaded. IBDWS population genetics analysis software is hosted at http://phage.sdsu.edu/~jensen/
 and documentation is available at http://www.bio.sdsu.edu/pub/andy/IBD.html
 . The source code has been made available on Source Forge at http://sourceforge.net/projects/ibdws/
 .

https://link.springer.com/content/pdf/10.1186%2F1471-2156-6-13.pdf

Isolation by distance, web service

The accuracy of gene flow estimates is unknown in most natural populations because direct estimates of dispersal are often not possible. These estimates can be highly imprecise or even biased because population genetic structure reflects more than a simple balance between genetic drift and gene flow. Most of the models used to estimate gene flow also assume very simple patterns of movement. As a result, multiple interpretations of population structure involving contemporary gene flow, departures from equilibrium, and other factors are almost always possible. One way to isolate the relative contribution of gene flow to population genetic differentiation is to utilize comparative methods. Population genetic statistics such as FST, heterozygosity and Nei's D can be compared between species with differing dispersal abilities if these species are otherwise phylogenetically, geographically and demographically comparable. Accordingly, the available literature was searched for all groups that meet these criteria ...

Dispersal, gene flow, and population structure

The genetic similarity among individuals or populations can be ascertained using a number of statistical techniques (reviewed by Bohonak 1999; Neigel 1997; Roderick 1996; Slatkin 1985). When populations can be defined a priori, one option is to analyze genetic ‘‘isolation by distance’’ (sensu Wright 1943) by plotting the genetic similarity (or distance) among population pairs as a function of the geographic distance between those pairs. Slatkin (1993) suggested the genetic distance M (1/FST 1)/4 as an appropriate similarity measure, although other approaches are possible (e.g., Epperson and Li 1996). Qualitative and statistical analyses of isolation by distance can reveal much about population genetic structure. The primary use for plots of (genetic) isolation by (geographic) distance is to assess whether more distant population pairs are more different genetically. However, these plots can also be used to test the validity of simpler models of population structure (e.g., island or hierarchical island models). Isolation by distance analyses may help separate the effects of population history from ongoing gene flow, and test the explanatory power of alternative dispersal pathways (Slatkin 1994). For example, one might assess whether the distance along a river or a topographic isocline is more biologically relevant than distance ‘‘as the crow flies.’’ The influence of geographic features or specific life-history traits on population differentiation can also be tested. Peterson and Denno (1998) contrasted isolation by distance slopes and intercepts in species with different dispersal abilities. IBD version 1.1 is a program written in C and compiled for Macintosh and Windows that can be used for analyses of isolation by distance. This program provides a number of unique features: isolation by distance slopes and intercepts are calculated using reduced major axis (RMA) regression, confidence intervals are generated based on several different assumptions regarding data structure, and statistical significance is determined using Mantel tests. The program is freely available at http:// www.bio.sdsu.edu/pub/andy/IBD.html.

/pdf/ibd-isolation-by-distance-a-program-for-analyses-of-5bvo4hwawa.pdf

IBD (Isolation by Distance): A Program for Analyses of Isolation by Distance

Traditional expectations for how widely and how often freshwater invertebrates disperse differ from empirical data. Freshwater invertebrates have been characterized as frequent, widespread dispersers, particularly those that are transported passively. Our review finds that this characterization may describe the potential for dispersal in some taxa, but it is not an accurate generalization for actual dispersal rates. High variance among habitats and taxonomic groups is a consistent theme. Advances in population genetics may help resolve these issues, but underlying assumptions should be carefully tested. Further, even unbiased estimates of gene flow may not equate with individual movement, because not all dispersers survive and reproduce. Some freshwater invertebrates may exist in classic Levins metapopulations. However, other species fit into a broader metapopulation definition, where temporal dispersal via diapause is functionally equivalent to spatial dispersal. In the latter case, local extinctions and rescue effects may be rare or absent. Finally, limited dispersal rates in many taxa suggest that theories of freshwater community assembly and structure can be made more robust by integrating dispersal and local processes as joint, contingent regulators. Recent research on freshwater invertebrate dispersal has substantially advanced our basic and applied understanding of freshwaters, as well as evolutionary ecology in general.

/pdf/ecological-and-evolutionary-significance-of-dispersal-by-3brgcyu1so.pdf

Ecological and evolutionary significance of dispersal by freshwater invertebrates

http://www.bio.sdsu.edu/pub/andy/Vandergast2008.pdf

Andrew J. Bohonak

Papers

Isolation by distance, web service

Dispersal, gene flow, and population structure

IBD (Isolation by Distance): A Program for Analyses of Isolation by Distance

Ecological and evolutionary significance of dispersal by freshwater invertebrates

Are hotspots of evolutionary potential adequately protected in southern California