Search results for "Intraspecific competition"
showing 10 items of 124 documents
The Stock Genetic Structure of Two Sparidae Species, Diplodus vulgaris and Lithognathus mormyrus, in the Mediterranean Sea.
2003
Abstract Polyacrilamide gel electrophoresis (PAGE) of allozymes was used to investigate the intraspecies genetic variation and the genetic stock structure of Diplodus vulgaris and Lithognathus mormyrus captured from eight localities in the Mediterranean Sea. Twenty-two and 20 putative enzyme-coding loci were examined, respectively, in D. vulgaris and L. mormyrus . Polymorphic loci at the 95% level were used to assess the allozyme variability in D. vulgaris ( AAT-2 ∗ , EST-1 ∗ , GLDH ∗ , PEPB-2 ∗ , PGI-2 ∗ , PGM ∗ , SDH ∗ ) and L. mormyrus ( AAT-2 ∗ , EST-1 ∗ , GLDH ∗ , MDH-2 ∗ , PGI-2 ∗ , PGM ∗ ). The proportion of polymorphic loci in both species ranged from 0.31 ( D. vulgaris ) to 0.30 ( …
Characterisation of four species of the genus Kluyveromyces by mitochondrial DNA restriction analysis
1997
Summary In the present work, we determine the relationships at the within-species level among strains of Kluyveromyces dobzhanskii, K. lactis, K. marxianus, and K. thermotolerans, through the restriction analysis of their mtDNAs. The three first species showed a high level of intraspecific mtDNA divergence, this polymorphism is correlated to the varieties or species defined according to the original taxonomy of the genus, which is in concordance with that shown by other phenotypic or genotypic markers codified for by the nuclear genome. In these species, the analysis of the relationships among strains based on mtDNA restriction data agrees with previous classifications based on morphologica…
Inbreeding depression in intraspecific metabolic scaling
2013
Metabolic scaling (i.e., the relationship between the size and metabolic rate of organisms) has been suggested to explain a large variety of biological patterns from individual growth to species diversity. However, considerable disagreement remains regarding the underlying causes of metabolic scaling patterns, and what these patterns are. As in all biology, understanding metabolic scaling will require understanding its evolution by natural selection. We searched for evidence of natural selection on metabolic scaling indirectly by manipulating the genetic quality of male and female Drosophila montana flies with induced mutations and inbreeding, building on the notion that mutations and inbre…
Inter- and intraspecific chromosome pattern variation in the yeast genusKluyveromyces
1998
The analysis of the electrophoretic chromosome patterns of the species of the genus Kluyveromyces, reveals a high polymorphism in size, number and intensity of bands. DiVerent sets of electrophoresis running conditions were used to establish species-specific patterns and also to detect intraspecific variation. According to their karyotypes, the species of this genus can be divided into two major groups. The first group includes the species K. africanus, K. bacillisporus, K. delphensis, K. lodderae, K. phaY, K. polysporus and K. yarrowii, composing the so-called ‘Saccharomyces cerevisiae-like’ group, because their karyotypes resemble that of the species S. cerevisiae. The second group compri…
A hierarchical analysis of genetic structure and variability in patchily distributed coexisting Chiastocheta species (Diptera:Anthomyiidae)
1996
The pattern of genetic variation in four coexisting fly species of the genus Chiastocheta was studied by allozyme electrophoresis. The fly species are confined to patches of one plant, Trollius europaeus, and thus experience very similar habitat fluctuations. Collection sites were chosen in a hierarchical fashion and F-statistics were estimated at three levels: intraregion, inter-region and total population. Population characteristic genetic parameters were compared within and among species and were related to the hierarchical level. The species were used as replicate experiments for inference of habitat history, and the hierarchical levels were used as inference for specific gene flow patt…
Assessment of genetic variation in SicilianHelichrysum(Asteraceae) and implication to germplasm conservation
2008
Some taxa of Sicilian Helichrysum related to sect. Stoeachadina have an uncertain systematic position; moreover, they are rare and endangered. In order to preserve these taxa in a genebank, a strategy to keep their genetic variation as high as possible is required. The high informative content of AFLP markers was used to assess genetic variations within and between populations and their relationships. The results show that all populations are genetically similar, even though there are two distinct groups: the first is the population referred to H. pendulum, and the second is represented by other populations belonging to several different specific and intraspecific taxa. The H. pendulum popu…
The joint evolution of learning and dispersal maintains intraspecific diversity in metapopulations
2021
The evolution of dispersal tendencies and of cognitive abilities have both been intensely studied. Yet little attention has been given to the question of how these two aspects may relate to each other, as a result of their joint evolution. On the one hand, learning abilities may help dispersers to cope with their new habitat. On the other hand, dispersal may sometimes reduce the need for learning, because local environments may differ in how much there is to learn. To get a better understanding of this relationship, we built an individual‐based simulation in which both learning speed and dispersal tendency were free to evolve. We found that both positive and negative correlations could evol…
Extensive gene flow blurs species boundaries amongVeronica barrelieri, V. orchideaandV. spicata(Plantaginaceae) in southeastern Europe
2011
Little is known about the contribution of interspecific hybridization, a frequent phenomenon in plants, to the high plant diversity in southeastern Europe, one of the continent's diversity hot spots. A good system to study the relevance of hybridization for biodiversity in this region is Veronica subg. Pseudolysimachium sect. Pseudolysimachion (Plantaginaceae). Depending on the presumed frequency of hybridization, existing taxonomic concepts in this group range from distinguishing only morphological races without explicit taxonomic status to recognizing several species each with a series of intraspecific taxa. Using genetic (plastid sequences and AFLP fingerprints), ploidy-level and morphom…
On the analysis of viability data: an example with Drosophila.
1990
Larval competition experiments involving two wild type and eight mutant strains of Drosophila melanogaster have been carried out following the substitution procedure proposed by Mather and Caligari (1981). Our main goal has been to compare the competitive abilities of two phenotypically indistinguishable strains (wild and Oregon-R) by means of their responses with eight different mutants. Prior to the analyses of viability data, we have studied the normalizing effect of several transformations in order to determine which was best suited for the analyses. The differences found among the five transformations tested and the untransformed data were not very great. The folded power transformatio…
Introduction to Symposium: Poecilogony--A Window on Larval Evolutionary Transitions in Marine Invertebrates
2012
Poecilogony is the intraspecific variation in developmental mode that has been described in some marine invertebrates. Poecilogonous species produce different larval forms (e.g., free-swimming planktotrophic larvae as well as brooded lecithotrophic or adelphophagic larvae). Poecilogony can be a controversial topic, since it is difficult to identify and characterize the phenomenon with certainty. It has been challenging to determine whether poecilogony represents developmental polymorphism with a genetic basis or developmental polyphenism reflecting plastic responses to environmental cues. Other outstanding questions include whether common mechanisms underlie the developmental variation we o…