scholarly journals Contrasting evolutionary responses in two co-distributed species of Galaxias (Pisces, Galaxiidae) in a river from the glaciated range in Southern Chile

2020 ◽  
Vol 7 (7) ◽  
pp. 200632 ◽  
Author(s):  
P. F. Victoriano ◽  
C. P. Muñoz-Ramírez ◽  
C. B. Canales-Aguirre ◽  
A. Jara ◽  
I. Vera-Escalona ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Life History ◽  
Population Size ◽  
Life History Traits ◽  
Genetic Differences ◽  
Southern Chile ◽  
Haplotype Networks ◽  
Galaxias Maculatus ◽  
Biological Differences ◽  
Over Time

Life-history traits are among the most important factors affecting population abundance and genetic diversity of species. Here, we analysed the genetic patterns of two Galaxias species with different life-history traits to investigate how these biological differences impacted their evolution in the Valdivia River basin, Southern Chile. We analysed mitochondrial DNA (mtDNA) sequences from 225 individuals of Galaxias maculatus and 136 of G. platei to compare patterns of genetic diversity, structure and demographic growth across the basin. Galaxias maculatus presented higher genetic diversity and higher genetic structure than G. platei . Demographic analyses showed G. maculatus kept a higher population size over time, with a signal of demographic expansion in the last 250 kyr. Whereas Galaxias platei , exhibited lower, but constant population size over time. Furthermore, haplotype networks revealed higher lineage diversity in G. maculatus with a tendency to occupy different areas of the basin. Coalescent simulations ruled out that genetic differences between species could be explained by stochastic processes (genetic drift), suggesting species-specific biological differences as responsible for the observed genetic differences. We discuss how differences in life-history traits and past glaciations interact to shape the evolutionary history of the two Galaxias species.

scholarly journals The Rate of Spontaneous Mutation for Life-History Traits in Caenorhabditis elegans

Genetics ◽  
1999 ◽  
Vol 151 (1) ◽  
pp. 119-129 ◽  
Author(s):  
Larissa L Vassilieva ◽  
Michael Lynch
Keyword(s):  
Life History ◽  
Caenorhabditis Elegans ◽  
Mutation Rate ◽  
Life History Traits ◽  
Deleterious Mutation ◽  
Spontaneous Mutation ◽  
Spontaneous Mutations ◽  
Homozygous State ◽  
Mutational Effect ◽  
Biological Differences

Abstract Spontaneous mutations were accumulated in 100 replicate lines of Caenorhabditis elegans over a period of ∼50 generations. Periodic assays of these lines and comparison to a frozen control suggest that the deleterious mutation rate for typical life-history characters in this species is at least 0.05 per diploid genome per generation, with the average mutational effect on the order of 14% or less in the homozygous state and the average mutational heritability ∼0.0034. While the average mutation rate per character and the average mutational heritability for this species are somewhat lower than previous estimates for Drosophila, these differences can be reconciled to a large extent when the biological differences between these species are taken into consideration.

scholarly journals Estructura genética de poblaciones de Eriocaulon bilobatum (Eriocaulaceae): una especie amenazada de humedades temporales

2019 ◽  
Vol 85 ◽  
pp. 81
Author(s):  
Fabiola Magallán Hernández ◽  
Mahinda Martínez ◽  
Luis Hernández Sandoval ◽  
Ken Oyama
Keyword(s):  
Genetic Diversity ◽  
Life History ◽  
Genetic Structure ◽  
Gel Electrophoresis ◽  
Life History Traits ◽  
Aquatic Environments ◽  
Starch Gel Electrophoresis ◽  
Temporary Wetlands ◽  
Sexual And Asexual Reproduction ◽  
Starch Gel

<em>Eriocaulon bilobatum</em> is an aquatic species that inhabits temporary wetlands in central Mexico. It is annual, herbaceous, emergent, with sexual and asexual reproduction, monoecious and insect pollinated. It is a rare and vulnerable species due to its endangered habitats. The objectives of this study were to determine the diversity and genetic structure of <em>E. bilobatum </em> and to know if there is a correlation with genetic diversity and its ecological and life history traits. Using horizontal starch-gel electrophoresis, we screened 160 individuals from four populations. <em>E. bilobatum</em> has a higher genetic diversity (A=2.32, Ae=1.31, P=69.65, Ho=0.134, He=0.197, HT=0.221) than species with similar ecological and life history traits, moderate levels of inbreeding (FIS = 0.312) and low genetic differentiation among populations (FST = 0.053 y GST = 0.048). Its diversity and genetic structure are determined by the mating system and life history traits, more than by inhabiting aquatic environments.

scholarly journals Evolution and seed dormancy shape plant genotypic structure through a successional cycle

2021 ◽  
Vol 118 (34) ◽  
pp. e2026212118
Author(s):  
Anurag A. Agrawal ◽  
Amy P. Hastings ◽  
John L. Maron
Keyword(s):  
Genetic Diversity ◽  
Life History ◽  
Environmental Change ◽  
Seed Dormancy ◽  
Life History Traits ◽  
Rapid Evolution ◽  
Insect Herbivory ◽  
Oenothera Biennis ◽  
The Face ◽  
The Impact

Dormancy has repeatedly evolved in plants, animals, and microbes and is hypothesized to facilitate persistence in the face of environmental change. Yet previous experiments have not tracked demography and trait evolution spanning a full successional cycle to ask whether early bouts of natural selection are later reinforced or erased during periods of population dormancy. In addition, it is unclear how well short-term measures of fitness predict long-term genotypic success for species with dormancy. Here, we address these issues using experimental field populations of the plant Oenothera biennis, which evolved over five generations in plots exposed to or protected from insect herbivory. While populations existed above ground, there was rapid evolution of defensive and life-history traits, but populations lost genetic diversity and crashed as succession proceeded. After >5 y of seed dormancy, we triggered germination from the seedbank and genotyped >3,000 colonizers. Resurrected populations showed restored genetic diversity that reduced earlier responses to selection and pushed population phenotypes toward the starting conditions of a decade earlier. Nonetheless, four defense and life-history traits remained differentiated in populations with insect suppression compared with controls. These findings capture key missing elements of evolution during ecological cycles and demonstrate the impact of dormancy on future evolutionary responses to environmental change.

scholarly journals The systematics and biology of Cotesia nonagriae (Olliff) stat. rev. (Hymenoptera: Braconidae: Microgastrinae), a newly recognized member of the Cotesia flavipes species complex

Zootaxa ◽  
2008 ◽  
Vol 1846 (1) ◽  
pp. 35 ◽  
Author(s):  
KATE MUIRHEAD ◽  
ANDREW AUSTIN ◽  
MOHAMED SALLAM
Keyword(s):  
Biological Control ◽  
Life History ◽  
Phylogenetic Relationships ◽  
Species Complex ◽  
Life History Traits ◽  
Cotesia Flavipes ◽  
Taxonomic Study ◽  
Australian Species ◽  
Taxonomic History ◽  
Biological Differences

The Australian species Cotesia nonagriae Olliff stat. rev. (Hymenoptera: Braconidae) is redescribed and formally removed from synonymy with C. flavipes based on molecular, morphological and biological differences. The taxonomic history and phylogenetic relationships of C. nonagriae with other members of the C. flavipes complex are presented and underscore the importance of molecular-based identification within this group. The biology of C. nonagriae on the native noctuid stemborer host, Bathytricha truncata (Walker), is compared with previously recorded C. flavipes life history traits. The implications of this taxonomic study relative to biological control and importation of stemborer parasitoids into Australia are discussed.

Body size and segmentation patterns in free-living and parasitic polychaetes

2001 ◽  
Vol 79 (5) ◽  
pp. 741-745 ◽  
Author(s):  
Robert Poulin
Keyword(s):  
Life History ◽  
Body Length ◽  
Life History Traits ◽  
The Body ◽  
Free Living ◽  
Body Segments ◽  
The Family ◽  
Body Sizes ◽  
Number Of Segments ◽  
Over Time

Taxa that include both free-living and parasitic lineages present opportunities to examine if and how the life-history traits of parasitic organisms have diverged from those of their free-living relatives. In a comparative analysis the body sizes and numbers of body segments of parasitic polychaetes of the family Oenonidae were compared with those of free-living polychaetes from closely related families. There was no difference in body length between oenonids and free-living polychaetes. However, the parasitic oenonids attain, on average, a much higher number of body segments than their free-living counterparts. The number of segments per unit body length is also much higher in oenonids than in related free-living polychaetes. This suggests that new segments are produced at a higher rate or for longer periods in oenonids than in free-living polychaetes, in which the proliferation of new segments slows down over time to allow for the segments to grow in size. Given that each segment can produce gametes late in the life of the worm, the proliferation of segments in oenonids may be an adaptation to their parasitic life-style.

Pedigree-based analysis of genetic variability in the registered Normande cattle breed in Colombia

2017 ◽  
Vol 57 (3) ◽  
pp. 422
Author(s):  
Derly Rodríguez Sarmiento ◽  
Emanuela Tullo ◽  
Rita Rizzi
Keyword(s):  
Genetic Diversity ◽  
Genetic Variability ◽  
Population Size ◽  
Cattle Breed ◽  
Inbreeding Coefficient ◽  
Mating Strategies ◽  
Effective Population ◽  
Significant Difference ◽  
Genealogical Information ◽  
Over Time

Genetic variability and structure of the population were studied in 7949 registered Normande cattle in Colombia. The pedigree was deep with 18 traced generations, but there were some incomplete genealogical information for the cattle born in the more distant past. The average number of complete and equivalent complete generations was 2.42 and 5.21, respectively. The average pedigree completeness index for five generations was 0.62, which increased over time, and a significant difference between sexes was found (males: 0.82 ± 0.11; females: 0.62 ± 0.38). The average generation interval was 7.57 years. The number of founders, effective founders, ancestors, and founder genomes were 575, 115, 47, and 22.22, respectively, which suggests that an unequal use of founders and a random loss of alleles from founders occurred over time. The level of inbreeding was 0.019 and increased to 0.023, when the inbreeding coefficient was calculated by assigning inbreeding of contemporaries to founders. These levels of inbreeding lead to an effective population size of 138.5 and 117.9 and to a 0.36% and 0.42% rate of inbreeding, respectively. Out of 267 herds with more than five registered breeding animals, only one nucleus herd was present, whereas 117 and 119 were classified as multiplier and commercial herds, respectively. About 92% of calves were sired by French bulls; but the use of Colombian bulls for breeding is increasing. The Colombian Normande breed is at an acceptable level of genetic variability, although some losses of founder alleles have occurred. As the level of inbreeding has been increasing, inbreeding and mating strategies should be monitored in order to maintain the genetic diversity of the breed.

scholarly journals Genetic and phenotypic changes in an Atlantic salmon population supplemented with non-local individuals: a longitudinal study over 21 years

2015 ◽  
Vol 282 (1802) ◽  
pp. 20142765 ◽  
Author(s):  
Sabrina Le Cam ◽  
Charles Perrier ◽  
Anne-Laure Besnard ◽  
Louis Bernatchez ◽  
Guillaume Evanno
Keyword(s):  
Genetic Diversity ◽  
Life History ◽  
Atlantic Salmon ◽  
Life History Traits ◽  
Genetic Admixture ◽  
Phenotypic Traits ◽  
Source Population ◽  
Wild Populations ◽  
Non Local ◽  
Source Populations

While introductions and supplementations using non-native and potentially domesticated individuals may have dramatic evolutionary effects on wild populations, few studies documented the evolution of genetic diversity and life-history traits in supplemented populations. Here, we investigated year-to-year changes from 1989 to 2009 in genetic admixture at 15 microsatellite loci and in phenotypic traits in an Atlantic salmon ( Salmo salar ) population stocked during the first decade of this period with two genetically and phenotypically distinct source populations. We detected a pattern of temporally increasing introgressive hybridization between the stocked population and both source populations. The proportion of fish returning to the river after a single winter at sea ( versus several ones) was higher in fish assigned to the main source population than in local individuals. Moreover, during the first decade of the study, both single-sea-winter and multi-sea-winter (MSW) fish assigned to the main source population were smaller than local fish. During the second decade of the study, MSW fish defined as hybrids were lighter and smaller than fish from parental populations, suggesting outbreeding depression. Overall, this study suggests that supplementation with non-local individuals may alter not only the genetic diversity of wild populations but also life-history traits of adaptive significance.

scholarly journals Selection is stronger in early-versus-late stages of divergence in a Neotropical livebearing fish

2016 ◽  
Vol 12 (3) ◽  
pp. 20151022 ◽  
Author(s):  
Spencer J. Ingley ◽  
Jerald B. Johnson
Keyword(s):  
Life History ◽  
Life History Traits ◽  
Single Point ◽  
Evolutionary Trajectory ◽  
Trait Evolution ◽  
The Difference ◽  
Livebearing Fish ◽  
Late Stages ◽  
Over Time

How selection acts to drive trait evolution at different stages of divergence is of fundamental importance in our understanding of the origins of biodiversity. Yet, most studies have focused on a single point along an evolutionary trajectory. Here, we provide a case study evaluating the strength of divergent selection acting on life-history traits at early-versus-late stages of divergence in Brachyrhaphis fishes. We find that the difference in selection is stronger in the early-diverged population than the late-diverged population, and that trait differences acquired early are maintained over time.

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