Intrinsic and measured statistics of discrete stochastic populations

2008 ◽  
Vol 464 (2099) ◽  
pp. 2929-2948 ◽  
Author(s):  
O.E French ◽  
K.I Hopcraft ◽  
E Jakeman ◽  
T.J Shepherd
Keyword(s):  
Measurement Technique ◽  
Statistical Properties ◽  
Single Population ◽  
Quantum Phenomena ◽  
Two Populations

The notion that the nature of a measurement is critical to its outcome is usually associated with quantum phenomena. In this paper, we show that the observed statistical properties are also a function of the measurement technique in the case of simple classical populations. In particular, the measured and intrinsic statistics of a single population may be different, while correlation and transfer of individuals between two populations may be hidden from the observer.

A European warm waters neophyte Shinnersia rivularis — new alien species to the Slovak flora

Biologia ◽  
2009 ◽  
Vol 64 (4) ◽  
Author(s):  
Pavol Eliáš ◽  
Michal Hájek ◽  
Petra Hájková
Keyword(s):  
Alien Species ◽  
Central Europe ◽  
Water Surface ◽  
Thermal Spring ◽  
Warm Water ◽  
Single Population ◽  
A Site ◽  
Two Populations

AbstractShinnersia rivularis is reported as a new alien species of the Slovak flora. The species was found in the catchment water of a thermal spring at a site in Partizánske, part Veľké Bielice (West Slovakia) in 2002. In the year of discovery, plants formed single population of about 30 square metres of water surface of the canal discharging warm water from the spa. Two populations covering the area ca 90 square meters were found in 2007. A brief description of the species is given and its distribution in Central Europe is reviewed. So far, the species has been reported from only three localities in Central Europe, which are distributed in three countries: Austria, Hungary and Germany.

scholarly journals Heteroplasmy variability in individuals with biparentally inherited mitochondrial DNA

2020 ◽  
Author(s):  
Jesse Slone ◽  
Weiwei Zou ◽  
Shiyu Luo ◽  
Eric S Schmitt ◽  
Stella Maris Chen ◽  
...  
Keyword(s):  
Mitochondrial Dna ◽  
Single Cell ◽  
Strong Evidence ◽  
Genetic Factors ◽  
Single Cell Level ◽  
Biparental Inheritance ◽  
Cell Level ◽  
Single Population ◽  
Parent Of Origin ◽  
Two Populations

ABSTRACTWith very few exceptions, mitochondrial DNA (mtDNA) in humans is transmitted exclusively from mothers to their offspring, suggesting the presence of a strong evolutionary pressure favoring the exclusion of paternal mtDNA. We have recently shown strong evidence of paternal mtDNA transmission. In these rare situations, males exhibiting biparental mtDNA appear to be limited to transmitting just one of the mtDNA species to their offspring, while females possessing biparental mtDNA populations consistently transmit both populations to their offspring at a very similar heteroplasmy level. The precise biological and genetic factors underlying this unusual transmission event remain unclear. Here, we have examined heteroplasmy levels in various tissues among individuals with biparental inheritance. Our results indicate that individuals with biparental mtDNA have remarkable inter-tissue variability in heteroplasmy level. At the single-cell level, paternal mtDNA heteroplasmy in sperm varies dramatically, and many sperm possess only one of the two mtDNA populations originally in question. These results show a fundamental, parent-of-origin difference in how mtDNA molecules transmit and propagate. This helps explain how a single population of mtDNAs are transmitted from a father possessing two populations of mtDNA molecules, suggesting that some mtDNA populations may be favored over others when transmitted from the father.

scholarly journals FLOWERING CYCLE OF CHUSQUEA MOLLIS L.G. CLARK (MAGNIFOLIAE, CHUSQUEINAE, BAMBUSAE) IN THE VENEZUELAN ANDES

Ciencia ◽  
2020 ◽  
Vol 22 (1) ◽  
pp. 79
Author(s):  
Francisca Ely
Keyword(s):  
Growth Form ◽  
Herbarium Specimens ◽  
Flowering Pattern ◽  
Single Population ◽  
Vegetative Period ◽  
Age Diversity ◽  
Online Databases ◽  
Woody Bamboos ◽  
Two Populations ◽  
Juvenile Plants

Flowering cycles are poorly understood in the majority of woody bamboos, since their frequency and duration may vary according their growth-form and distribution across latitude and altitude ranges. Tropical Andean bamboos are known for combining gregarious (asynchronic) and asynchronic flowering events; the main objective of this study was to determine the flowering pattern of Chusquea mollis Swallen) L.G. Clark (= Neurolepis mollis Swallen), a monocarpic, native bamboo that grows in the subparamos and paramos of Venezuela and Colombia. The chronology of flowering events of this species was based on the revision of herbarium specimens, online databases and the occurrence of flowering events in two populations of the Cordillera de Mérida, Venezuela. Taking in account that age diversity may also contribute to identify flowering patterns in bamboo populations, we performed a survey of a single population located in the Páramo La Aguada. Our results suggest that C. mollis combines gregarious and asynchronic flowering cycles, after a relatively short vegetative period (5-7 years). The census conducted in a single population of La Aguada revealed the co-existence of plantlets, juvenile plants, vegetative, reproductive and post-reproductive adults, of which the juvenile were the most numerous group.

Psycho-Cognitive Aspects of Dynamic Model-Building in Logo: A Simple Population Evolution and Predator/Prey Program

1988 ◽  
Vol 4 (3) ◽  
pp. 227-252 ◽  
Author(s):  
Bruno Vitale
Keyword(s):  
Dynamical Systems ◽  
Dynamic Model ◽  
Model Building ◽  
Mutual Interaction ◽  
Dynamical Models ◽  
Single Population ◽  
Predator Prey ◽  
Population Evolution ◽  
Programming Skills ◽  
Two Populations

A family of simple models, which can be deployed from the case of the growth of a single population to the mutual interaction of two populations in a predators/prey relation, is programmed in LOGO by using the most elementary programming skills. The deployment is followed step by step, by emphasizing the elements of cognitive novelty and the possible cognitive obstructions, more than the possible programming difficulties. This family of models is used to model a way of introducing, through programming experience, dynamical models of change and a first approach to dynamical systems.

Rediscovery of the restricted endemic Reseda balansae (Resedaceae) in Turkey

Phytotaxa ◽  
2018 ◽  
Vol 362 (1) ◽  
pp. 87 ◽  
Author(s):  
EMRE ÇİLDEN ◽  
ŞİNASİ YILDIRIMLI ◽  
GOLSHAN ZARE ◽  
SANTIAGO MARTÍN-BRAVO
Keyword(s):  
Endemic Species ◽  
Global Scale ◽  
Critically Endangered ◽  
Conservation Assessment ◽  
Single Population ◽  
Iucn Categories ◽  
Type Population ◽  
Distribution And Ecology ◽  
Two Populations

Reseda balansae Müll. Arg. (Resedaceae) is a very restricted and endangered Turkish endemic species known only from Mersin province (South Turkey), in a hotspot of biodiversity. It was first collected in 1855, and subsequently described in 1857. Afterwards, it was only collected once again in 1896. In this study we report the rediscovery of these two populations of R. balansae in Turkey more than 120 years after its last known collection. We provide a detailed revised description of this poorly known species and comments about its taxonomy (including designation of a lectotype), distribution and ecology. We also perform the first conservation assessment of the species at a global scale under IUCN categories and criteria, resulting in the proposal of the critically endangered category for the species, which apparently persists in one single population, since the type population has recently been destroyed.

A new rare species of Acacia from north-east Victoria

2002 ◽  
Vol 15 (4) ◽  
pp. 465 ◽  
Author(s):  
Marisa Bartolome ◽  
Neville G. Walsh ◽  
Elizabeth A. James ◽  
Pauline Y. Ladiges
Keyword(s):  
Morphological Study ◽  
Seed Set ◽  
Herbarium Specimens ◽  
Single Population ◽  
Acacia Species ◽  
North East ◽  
Enzyme Systems ◽  
North Eastern ◽  
Root Suckering ◽  
Two Populations

A new, rare wattle, Acacia daviesii sp. nov., known from only 10 populations discovered in mountainous, subalpine habitat in north-eastern Victoria, is described and illustrated. A comparative morphological study was undertaken, based on phyllode characters measured from all 10 known populations and herbarium specimens of the five most similar Acacia species: A. acinacea, A. aspera, A. glandulicarpa, A. gunnii and A. paradoxa. The new species has a pendulous habit and resinous phyllodes covered by stalked multicellular glands. Acacia daviesii forms clones by root suckering and seed set appears to be rare. Isozyme analysis based on nine enzyme systems showed that plants within any single population are genetically identical. Variation was detected between all but two populations with only nine known genotypes in an area of 12 km2.

scholarly journals FORMATION OF MITOCHONDRIA IN NEUROSPORA CRASSA

1965 ◽  
Vol 24 (3) ◽  
pp. 461-470 ◽  
Author(s):  
David J. L. Luck
Keyword(s):  
Choline Chloride ◽  
Mitochondrial Protein ◽  
Growth Conditions ◽  
Single Population ◽  
Protein Mass ◽  
Minute Period ◽  
Mitochondrial Population ◽  
Time Periods ◽  
Two Populations ◽  
Isopycnic Centrifugation

The choline concentration used in the growth medium influences the density of mitochondria produced by the chol-1 mutant of Neurospora. Isopycnic centrifugation in sucrose gradients can be used to determine the density of mitochondria, and can resolve into two populations, mitochondria derived from a mixture of cells grown at low (1 µg/ml choline chloride) and high (10 µg/ml choline chloride) choline levels. In an experiment in which cells are shifted from low to high choline growth conditions, mitochondria obtained after varying time periods show a gradual decrease in density tending toward the level typical of high choline mitochondria. Over a 90-minute period of observation, during which time there is an increase of mitochondrial protein mass of ∼ 50 per cent over that initially present, the mitochondria change density as a single population. These results are consistent with the view that mitochondria grow by random accretion of new lecithin into existing mitochondrial structures, and also that the mitochondrial population increases by division.

Coevolutionary Computation

1995 ◽  
Vol 2 (4) ◽  
pp. 355-375 ◽  
Author(s):  
Jan Paredis
Keyword(s):  
Neural Net ◽  
Noise Tolerance ◽  
Biologically Inspired ◽  
Single Population ◽  
Genetic Search ◽  
Predator Prey ◽  
Fitness Evaluation ◽  
Different Types ◽  
Coevolutionary Computation ◽  
Two Populations

This article proposes a general framework for the use of coevolution to boost the performance of genetic search. It combines coevolution with yet another biologically inspired technique, called lifetime fitness evaluation (LTFE). Two unrelated problems—neural net learning and constraint satisfaction—are used to illustrate the approach. Both problems use predator-prey interactions to boost the search. In contrast with traditional “single population” genetic algorithms (GAs), two populations constantly interact and coevolve. However, the same algorithm can also be used with different types of coevolutionary interactions. As an example, the symbiotic coevolution of solutions and genetic representations is shown to provide an elegant solution to the problem of finding a suitable genetic representation. The approach presented here greatly profits from the partial and continuous nature of LTFE. Noise tolerance is one advantage. Even more important, LTFE is ideally suited to deal with coupled fitness landscapes typical for coevolution.

scholarly journals PERSISTENCE OF COMMON ALLELES IN TWO RELATED POPULATIONS OR SPECIES

Genetics ◽  
1977 ◽  
Vol 86 (4) ◽  
pp. 901-914
Author(s):  
Wen-Hsiung Li ◽  
Masatoshi Nei
Keyword(s):  
Mutation Rate ◽  
Extinction Time ◽  
Effective Population ◽  
Expected Number ◽  
Single Population ◽  
Molecular Population Genetics ◽  
The Common ◽  
The Mean ◽  
Time Required ◽  
Two Populations

ABSTRACT Mathematical studies are conducted on three problems that arise in molecular population genetics. (1) The time required for a particular allele to become extinct in a population under the effects of mutation, selection, and random genetic drift is studied. In the absence of selection, the mean extinction time of an allele with an initial frequency close to 1 is of the order of the reciprocal of the mutation rate when 4Nv << 1, where N is the effective population size and v is the mutation rate per generation. Advantageous mutations reduce the extinction time considerably, whereas deleterious mutations increase it tremendously even if the effect on fitness is very slight. (2) Mathematical formulae are derived for the distribution and the moments of extinction time of a particular allele from one or both of two related populations or species under the assumption of no selection. When 4Nv << 1, the mean extinction time is about half that for a single population, if the two populations are descended from a common original stock. (3) The expected number as well as the proportion of common neutral alleles shared by two related species at the tth generation after their separation are studied. It is shown that if 4Nv is small, the two species are expected to share a high proportion of common alleles even 4N generations after separation. In addition to the above mathematical studies, the implications of our results for the common alleles at protein loci in related Drosophila species and for the degeneration of unused characters in cave animals are discussed.

scholarly journals A latitudinal cline in P–M gonadal dysgenesis potential in Australian Drosophila melanogaster populations

1987 ◽  
Vol 49 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Ian A. Boussy
Keyword(s):  
Population Dynamics ◽  
Drosophila Melanogaster ◽  
Gonadal Dysgenesis ◽  
East Coast ◽  
Isofemale Lines ◽  
Single Population ◽  
The North ◽  
Different Characteristics ◽  
North And South ◽  
Two Populations

SummaryIsofemale lines of Drosophila melanogaster from six localities along the east coast of Australia, spanning 2900 km and 26 degrees of latitude, were assayed for their gonadal dysgenesis characteristics in the P–M system of hybrid dysgenesis. A strong clinal pattern with latitude was discovered. From north to south, the first two populations were typical strong P populations, and the next population was moderate P. The next population to the south was neutral (Q), with some weak P and weak M characteristics. The two southernmost populations were typical M populations. Much variance in P activity in P populations and in susceptibility to P activity in M populations was detected among isofemale lines. This clinal pattern with latitude of the P–M system is paralleled by similar clinal patterns for frequencies of common cosmopolitan inversions and of certain allozymes in Australia. A model of introductions of flies with different characteristics in the north and south could account for the P–M clinal pattern, but cannot account for an intermediate Q population, nor establish the inversion and isoenzyme dines at the same time. Current models of transposable element population dynamics are limited to single population dynamics, and are therefore inadequate for these clinal data.

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