Patterns, Mechanisms and Genetics of Speciation in Reptiles and Amphibians.

In this contribution, the aspects of reptile and amphibian speciation that emerged from research performed over the past decade are reviewed. First, this study assesses how patterns and processes of speciation depend on knowing the taxonomy of the group in question, and discuss how integrative taxonomy has contributed to speciation research in these groups. This study then reviews the research on different aspects of speciation in reptiles and amphibians, including biogeography and climatic niches, ecological speciation, the relationship between speciation rates and phenotypic traits, and genetics and genomics.

Habitat use in eight populations of Sceloporus grammicus (Squamata: Phrynosomatidae) from the Mexican Plateau.

Studies on habitat use have often helped explain observed variation in morphology, behavior and reproductive characteristics among populations within a single species. Here we analyze morphological and ecological characteristics of individuals from the Sceloporus grammicus species complex from 7 different localities (CER, El Cerezo; PAC, Pachuca; HUI, Huichapan; EZA, Emiliano Zapata; SMR, San Miguel Regla; LMJ, La Mojonera; and LMZ, La Manzana) in the state of Hidalgo, and one locality (Cahuacán) in the State of Mexico. A canonical correspondence analysis (CCA) showed that females from PAC, EZA, LMZ, HUI, SMR and CAH populations use similar microhabitats characterized mostly by bare soil, in females from LMJ and CER use microhabitats characterized primarily by vegetation and rocks.

Female preference for sympatric vs. allopatric male throat color morphs in the mesquite lizard (Sceloporus grammicus) species complex.

Color polymorphic sexual signals are often associated with alternative reproductive behaviors within populations, and the number, frequency, or type of morphs present often vary among populations. When these differences lead to assortative mating by population, the study of such polymorphic taxa may shed light on speciation mechanisms. We studied two populations of a lizard with polymorphic throat color, an important sexual signal.

Anopheles immune genes and amino acid sites evolving under the effect of positive selection.

Background: It has long been the goal of vector biology to generate genetic knowledge that can be used to "manipulate" natural populations of vectors to eliminate or lessen disease burden. While long in coming, progress towards reaching this goal has been made. Aiming to increase our understanding regarding the interactions between Plasmodium and the Anopheles immune genes, we investigated the patterns of genetic diversity of four anti-Plasmodium genes in the Anopheles gambiae complex of species.

Phylogenetic assessment of the earthworm Aporrectodea caliginosa species complex (Oligochaeta: Lumbricidae) based on mitochondrial and nuclear DNA sequences.

The Aporrectodea caliginosa species complex includes the most abundant earthworms in grasslands and agricultural ecosystems of the Paleartic region. Historically this complex consisted of the following taxa: A. caliginosa s.

Exploring the origin and degree of genetic isolation of Anopheles gambiae from the islands of São Tomé and Príncipe, potential sites for testing transgenic-based vector control.

The evolutionary processes at play between island and mainland populations of the malaria mosquito vector Anopheles gambiae sensu stricto are of great interest as islands may be suitable sites for preliminary application of transgenic-based vector control strategies. São Tomé and Príncipe, located off the West African coast, have received such attention in recent years. This study investigates the degree of isolation of An.

The molecular evolution of four anti-malarial immune genes in the Anopheles gambiae species complex.

Background: If the insect innate immune system is to be used as a potential blocking step in transmission of malaria, then it will require targeting one or a few genes with highest relevance and ease of manipulation. The problem is to identify and manipulate those of most importance to malaria infection without the risk of decreasing the mosquito's ability to stave off infections by microbes in general. Molecular evolution methodologies and concepts can help identify such genes.

Patterns of selection in anti-malarial immune genes in malaria vectors: evidence for adaptive evolution in LRIM1 in Anopheles arabiensis.

Background: Co-evolution between Plasmodium species and its vectors may result in adaptive changes in genes that are crucial components of the vector's defense against the pathogen. By analyzing which genes show evidence of positive selection in malaria vectors, but not in closely related non-vectors, we can identify genes that are crucial for the mosquito's resistance against Plasmodium.

Methodology/principle Findings: We investigated genetic variation of three anti-malarial genes; CEC1, GNBP-B1 and LRIM1, in both vector and non-vector species of the Anopheles gambiae complex.

Delimiting species: comparing methods for Mendelian characters using lizards of the Sceloporus grammicus (Squamata: Phrynosomatidae) complex.

Species form the fundamental units of analysis in many areas of biology and, therefore, rigorous delimitation of this unit is important to a broad array of researchers. Recently, many new empirical methods have been proposed to delimit species in nature, and a large literature exists on the theoretical merit and superiority of each method. However, few empirical studies actually compare the results of these methods applied in the same study system.

Genetic divergence of Connecticut Melanoplus femurrubrum populations.

We surveyed Melanoplus femurrubrum populations within the state of Connecticut for genetic diversity at multiple genetic markers, including three mitochondrial [cytochrome oxidase subunit 1 (COI), reduced form of nicotinamide adenine dinucleotide dehydrogenase subunit 2 (ND2), and AT rich] and one nuclear [internal transcribed spacers of the ribosomal DNA cluster (ITS1)] gene regions. All markers were variable, and the AT-rich gene showed the highest sequence divergence. Analysis of molecular variance (AMOVA), fixation index (Fst) analysis, and phylogeographic patterns showed little divergence between northern and southern regions.

Short report: Phylogenetic relationships of the anthropophilic Plasmodium falciparum malaria vectors in Africa.

Malaria kills more than one million people a year, and understanding the historical association between its most notorious causative agent, Plasmodium falciparum, and its mosquito vectors is important in fighting the disease. We present a phylogenetic analysis of a number of species within the mosquito subgenus Cellia based on a selection of mitochondrial and nuclear genes. Although some of these relationships have been estimated in other studies, generally few species were included and/or statistical support at many nodes was low.

The impact of species concept on biodiversity studies.

Species are defined using a variety of different operational techniques. While discussion of the various methodologies has previously been restricted mostly to taxonomists, the demarcation of species is also crucial for conservation biology. Unfortunately, different methods of diagnosing species can arrive at different entities.