Population bottlenecks. Medical search. Frequent questions

A slightly different form of bottleneck can occur if a small group becomes reproductively (e.g., geographically) separated from the main population, such as through a founder event, e.g., if a few members of a species successfully colonize a new isolated island, or from small captive breeding programs such as animals at a zoo. (wikipedia.org)
Alternatively, invasive species can undergo population bottlenecks through founder events when introduced into their invaded range. (wikipedia.org)
According to a 1999 model, a severe population bottleneck, or more specifically a full-fledged speciation, occurred among a group of Australopithecina as they transitioned into the species known as Homo erectus two million years ago. (wikipedia.org)
Identifying local adaptation in bottlenecked species is essential for effective conservation management. (biorxiv.org)
Selection detection methods are often applied to bottlenecked species and have an important role in species management plans, assessments of the species' adaptive capacity, and looking for responses to major threats like climate change. (biorxiv.org)
Therefore, Pinsky & Palumbi (2013) used a Control-Impact approach to look at 11,000+ microsatellites (rather than 5-10) across 140 species (rather than 1) to determine if there was a relationship between overfishing and genetic diversity, or if overfishing was producing a population bottleneck. (rutgers.edu)
History of our own species provides plenty of examples of sub-populations that went through population bottlenecks followed by re-expansions. (blogspot.com)
Wilson, Pellegrino University Research Professor at Harvard, recited a gloomy litany of impending environmental catastrophes before a crowd of about 350 Wednesday (Jan. 16): Populations are exploding, rainforests are falling, species are dying, and the climate is warming. (harvard.edu)
We genotyped avian β-defensin (AvBD) genes in contemporary (2000-2008) and museum samples (1876-1940) of the Seychelles warbler to investigate whether immunogenetic variation was lost through this bottleneck, and examined AvBD variation across four other Acrocephalus species with varying demographic histories. (uea.ac.uk)
Variation in the Seychelles warbler was significantly lower than in the mainland migratory congeneric species investigated, but it similar to that found in other bottlenecked species. (uea.ac.uk)
Given the limited pathogen fauna, this lack of variation at the AvBD loci may currently not pose a problem for this isolate population of Seychelles warblers, but it may be detrimental to the species' long-term survival if new pathogens reach the population in the future. (uea.ac.uk)
Population bottlenecks have occurred in the evolutionary history of many species, including humans. (jrank.org)
Present-day bottlenecks are seen in endangered species such as the Yangtze River dolphin, whose numbers have dwindled to less than 100. (jrank.org)
Within species, there is variation among populations, groups of animals in a particular area that interbreed. (wur.nl)
This finding among wild mammal populations shows that survival rates among animals with canine distemper (CD) infection can be high, as most clearly evidenced in populations of rare or threatened species that are likely to be closely monitored by field conservation efforts. (cdc.gov)
De Roos and Persson investigate the community consequences of these bottlenecks for trophic configurations that vary in the number and type of interacting species and in the degree of ontogenetic niche shifts exhibited by their individuals. (princeton.edu)
It is even more austere when we analytically examine population declines, rather than the complete loss of species, as 32% of known vertebrate species are showing substantial population deterioration [7]. (scirp.org)
During the spread of livestock species across Europe, Asia, and Africa, numerous geographically separate populations of livestock species emerged, where each of these populations is expected to have adapted to their respective environment. (scirp.org)
Population size is a significant indicator of a species' health. (discovermagazine.com)
For example, if a species' population is small, or it's small and has declined or is projected to in the future, it faces a higher extinction risk. (discovermagazine.com)
First, the wall will divide up natural habitats which can result in a bottleneck population - a sharp decline in the numbers of a species. (earth.com)
This will particularly affect species that end up with a small portion of the population isolated on one side of the wall. (earth.com)
The species historically lived across the Southeastern United States, but due to overhunting and habitat destruction, a small remnant set of populations lives in southern Florida isolated from all other panther populations," said Dr. Egan. (earth.com)
For example, Ernst Mayr suggested that many species had passed through extreme bottlenecks in founder events. (uncommondescent.com)
Take a small, isolated population of 10,000 of the precursor species - let's call it Homo stupidus . (uncommondescent.com)
The conventional wisdom linking high genetic diversity with population viability is increasingly scrutinized, as empirical evidence shows that some species can persist despite low genetic diversity. (lu.se)
Our project seeks to unravel these mysteries by examining how genetic redundancy through duplicated sequences, like orthologs, and the role of non-coding elements such as transposable elements (TEs), contribute to species resilience during and after population bottlenecks. (lu.se)
But most of the infectious diseases that devastate human populations have their roots in wild species, and many pathogens are maintained silently by local wildlife communities before spillover to humans occurs. (cdc.gov)

The current ease in obtaining genome-wide SNP data has driven a renaissance of studies scanning for selection at the genomic level in wild populations (e.g. (biorxiv.org)
The genomic research landscape has transformed dramatically since the completion of the human genome project in 2003, but focus in the field has been constrained, in terms of worldwide populations included in this research. (nature.com)
Using this process to interrogate an individual's entire genome, the proportion of an individual's genomic inheritance from specific ancestral populations can be estimated. (nature.com)
will use genomic data to infer recent inbreeding history of the shark population. (wur.nl)
The aim is to develop a genomic tool to monitor inbreeding in wild populations. (wur.nl)
Genomic regions exhibiting signatures of both balancing and divergent selection were remarkably consistent across multiple, independently derived populations, indicating that replicate parallel phenotypic evolution in stickleback may be occurring through extensive, parallel genetic evolution at a genome-wide scale. (discovermagazine.com)
These data illustrate the complementary nature of laboratory crosses and population genomic scans by confirming the adaptive significance of previously identified genomic regions, elucidating the particular evolutionary and demographic history of such regions in natural populations, and identifying new genomic regions and candidate genes of evolutionary significance. (discovermagazine.com)

No variation was detected at four of the six AvBD loci screened in the post-bottleneck population of Seychelles warbler, but two silent nucleotide polymorphisms were identified at AvBD8 and one potentially functional amino-acid variation was observed at AvBD11. (uea.ac.uk)
The project will explore the hypothesis that duplicated sequences offer genetic redundancy, potentially crucial for survival post-bottleneck, by providing backup gene copies for essential functions or evolving new ones. (lu.se)
Furthermore, the adaptive role of TEs under post-bottleneck selective pressures, facilitating recovery and adaptation, will also be a significant focus. (lu.se)

Marta Lahr has attributed bottlenecks to migrations of small populations across geographic barriers, a phenomenon variously referred to as the founder effect or colonization bottlenecks. (jrank.org)
Both breeds have small populations predominantly found in the Northern part of the country. (scirp.org)
It seems that we must invoke "bottlenecks" since otherwise the percentage of heterozygosity would be very different for large and small populations, and this would debunk neutral theory. (uncommondescent.com)

In the past years, I have been involved in several studies that contrast levels of population differentiation in putatively neutral marker genes with the corresponding data for potentially adaptive phenotypic traits to examine whether past selection pressures have been diversifying, unifying, or too weak to have any influence on the phenotypic variation. (lu.se)
Most of these studies have included analyses of phenotypic characters that are likely to be the targets of selection in natural populations. (lu.se)

Changes of population size expose differences between recessive and additive selection, potentially providing insight into the prevalence of dominance in natural populations. (blogspot.com)
Next-generation sequencing technology provides novel opportunities for gathering genome-scale sequence data in natural populations, laying the empirical foundation for the evolving field of population genomics. (discovermagazine.com)
Here we conducted a genome scan of nucleotide diversity and differentiation in natural populations of threespine stickleback (Gasterosteus aculeatus). (discovermagazine.com)
To provide greater confidence when inferring genetic effects of small population size, we have extended our analyses to experimental systems or natural populations with a known history of fragmentation. (lu.se)

Their study illustrates that large biobank datasets like these, particularly in founder populations, can provide deeper insights into the effects of dosage of Mendelian variants, meaning the number of copies of the variant that are present. (bridgeinformatics.com)
Our results show how biobanks, particularly in founder populations, can broaden our understanding of complex dosage effects of Mendelian variants on disease. (nature.com)

As a little tip, if you ever have a population genetics question you're not sure about, just scour Kimura's papers. (stackexchange.com)
A technical study that however gives an interesting glimpse on the complex but generally reductive genetic effect of bottlenecks such as the Out-of-Africa migration of humankind is out in PLoS Genetics. (blogspot.com)
The response of alleles under selection to such demographic perturbations has been a subject of great interest in population genetics. (blogspot.com)
Marine Animal Ecology contributes to the fields of population genetics and population ecology and studies how population dynamics change over time and space. (wur.nl)
Survival, migration patterns and population genetics will be studied and compared with patterns of large populations. (wur.nl)
Molecular population genetics of the primary neotropical malaria vector Anopheles darlingi using mtDNA. (ajtmh.org)
Molecular population genetics of the malaria vector Anopheles darlingi in Central and South America. (ajtmh.org)
There has recently been dramatic progress in the development of experimental and statistical methods appropriate for gene mapping in admixed populations," said David Goldstein, Wolfson Professor of Genetics, University College London. (mongabay.com)
But the idea of population genetics, as a standard explanation of speciation given common descent, shouldn't be too hard to understand. (uncommondescent.com)
This is originally due to Elliott Sober (1984), who developed a conceptual model of the Hardy-Weinberg equilibrium in population genetics based on an analogy with Newtonian forces. (blogspot.com)
Profile: We are seeking a student with a strong background in bioinformatics, coupled with a keen interest and a solid understanding of population genetics and evolutionary genomics. (lu.se)

Genetic diversity remains lower, increasing only when gene flow from another population occurs or very slowly increasing with time as random mutations occur. (wikipedia.org)
Alternatively, if survivors of the bottleneck are the individuals with the greatest genetic fitness, the frequency of the fitter genes within the gene pool is increased, while the pool itself is reduced. (wikipedia.org)
Analyses of gene sequences provide evidence of a possible second exodus from Africa by a small founding population that traveled overland Figure 2 . (jrank.org)
Gene flow among Anopheles albimanus populations in Central America, South America, and the Caribbean assessed by microsatellites and mitochondrial DNA. (ajtmh.org)
That population has its own mix of gene alleles compared to the world population of H. stupidus , just as Finns or Melanesians have theirs. (uncommondescent.com)

The genetic drift caused by a population bottleneck can change the proportional random distribution of alleles and even lead to loss of alleles. (wikipedia.org)
Pinsky & Palumbi (2013) grouped fish populations by genus or family and into overfished and not overfished categories to conduct the analyses on both heterozygosity and allelic richness (the number of alleles per locus, which is the data included in this investigation). (rutgers.edu)
The number of dominant or additive deleterious alleles per haploid genome is expected to be slightly increased following the bottleneck and re-expansion. (blogspot.com)
However, the effect of dominance introduces substantial technical complications into theoretical models describing dynamics of alleles in populations. (blogspot.com)
Although Europeans are used for reference this bottleneck and the corresponding accumulation of deleterious alleles is the same for all non-Africans. (blogspot.com)
In addition, screening AvBD7 in 15 museum specimens of Seychelles warblers sampled prior to the bottleneck (1877-1905) revealed that this locus possessed two alleles previously, compared to the single allele in the contemporary population. (uea.ac.uk)
By reading thousands of alleles and estimating mutation rates, the duo can work out the separation date for each allele and calculate past population sizes. (newscientist.com)
For instance, evidence that many alleles share the same separation date suggests the population was small and genetically similar at the time. (newscientist.com)

First, I note that both Schaffner and Felsenstein agree with my point that the bottleneck hypothesis has not been directly tested. (uncommondescent.com)
Overall estimates of genetic diversity and differentiation among populations confirm the biogeographic hypothesis that large panmictic oceanic populations have repeatedly given rise to phenotypically divergent freshwater populations. (discovermagazine.com)

Smaller population size can also cause deleterious mutations to accumulate. (wikipedia.org)
where x i represents the derived allele frequency, to compare the number of mutations in different populations, and detail its functional dependence on the strength of selection and the intensity of the population bottleneck. (blogspot.com)
The mutations eventually generate inbreeding depression, which means the overall population becomes less healthy. (earth.com)
This population then, over time, gets its own particular mutations, some of which get spread around. (uncommondescent.com)

The controversial Toba catastrophe theory, presented in the late 1990s to early 2000s, suggested that a bottleneck of the human population occurred approximately 75,000 years ago, proposing that the human population was reduced to perhaps 10,000-30,000 individuals when the Toba supervolcano in Indonesia erupted and triggered a major environmental change. (wikipedia.org)
For example, Cheetahs experienced a large decline in population size due to changing climates ~10,000 years ago initially and then due to over-hunting in Africa over the past few centuries. (rutgers.edu)
And so the whole population (always 10,000, always isolated) gradually changes from Homo stupidus to Homo sapiens , just as there was never a single pair of "Finns" or "Melanesians", even though they differ a lot. (uncommondescent.com)

Populations that have undergone recent bottlenecks are also characterized by an excess of mildly deleterious variants, which are derived from rare variants that stochastically increased in frequency after a bottleneck event 4 . (nature.com)

Some of the most useful resources for identifying clear signals in genome-wide studies are populations with limited genetic diversity. (bridgeinformatics.com)
The Seychelles warbler, Acrocephalus sechellensis, is an endemic passerine that underwent a recent bottleneck in its last remaining population, resulting in a considerable reduction in genome-wide variation. (uea.ac.uk)

Results from field surveys, genetic analyses, stress-manipulation experiments and comparative studies of population structure indicate that several selection pressures, operating at both vegetative and reproductive stages, contribute to the maintenance of these pollen-color dimorphisms. (lu.se)

Even though the Africa coast is only one-twentieth of the distance to Indonesia, it appears that migrations from Africa may have been more limited, as less of the diversity seen in the source population has survived in Madagascar. (mongabay.com)
The population structure in Madagascar is a fascinating snapshot of human history and a testament to the remarkable abilities of early populations to undertake migrations across vast reaches of ocean. (mongabay.com)

This colonization bottleneck occurred during a period of milder climate about 50,000 years ago, and also coincides with the appearance of advanced stone tool technologies. (jrank.org)

Differentiation of human genetic lineages within a population through time, and the effects of environmental and colonization bottlenecks (founder events) on survival of human lineages. (jrank.org)

This can happen in populations with recent bottlenecks, producing a founder effect- where a current population is the result of a small pool of initial "founders" either due to catastrophe (like a significant famine) or geographical isolation. (bridgeinformatics.com)

In conservation biology, minimum viable population (MVP) size helps to determine the effective population size when a population is at risk for extinction. (wikipedia.org)
Nonetheless, a 2023 genetic analysis discerned such a human ancestor population bottleneck of a possible 100,000 to 1000 individuals "around 930,000 and 813,000 years ago [which] lasted for about 117,000 years and brought human ancestors close to extinction. (wikipedia.org)
Since the diffusion rate is larger than the local growth rate (the general condition of spatially unconstrained animal populations, since reproduction is a relatively slow process compared to movement) and the population is now surrounded by unoccupied area, the population is drifting towards extinction! (animalspaceuse.net)
At this low level of population abundance it is important to consider and implement three aspects: First, accelerated extinction at very low abundance levels have to be introduced. (animalspaceuse.net)
Due to a CLM's intrinsic design of Markovian, scale-specific dynamics, it ultimately - in an open environment - makes a population susceptible to extinction. (animalspaceuse.net)
A population bottleneck is a significant reduction in the size of a population that causes the extinction of many genetic lineages within that population, thus decreasing genetic diversity. (jrank.org)
The combined effect of rabies and CDV increases the chance of pack extinction, exacerbating the typically slow recovery of wolf populations, and represents a key extinction threat to populations of this highly endangered carnivore. (cdc.gov)

The speed with which these changes happen can be dramatically increased when a population bottleneck occurs (due to environmental events or human activities). (rutgers.edu)
As highlighted in the previous Cheetah example, human activities can produce a population bottleneck, scientists became interested in looking at whether overfishing was having an impact on the genetic diversity of fish. (rutgers.edu)
Animals like these will be helped by NGOs, Wilson said, which are leading the way in striking the difficult balance between meeting the needs of local human populations and lessening their impact on fragile and increasingly scarce wild areas. (harvard.edu)
These NGOs, Wilson said, are leading the way in striking the difficult balance between meeting the needs of local human populations and lessening their impact on fragile and increasingly scarce wild areas. (harvard.edu)
The genetic structure of human populations suggests four bottlenecks in our lineage. (jrank.org)
survived the human populations bottlenecks 20-60ky ago? (linguistlist.org)
Rapidly expanding human populations increase domestic dog contact with wild canids ( 10 , 11 ), exacerbating the risk for disease transmission ( 12 , 13 ). (cdc.gov)
It seems every one of us carries in our genes a million-year record of past human population size. (newscientist.com)
The idea that each human genome contains information about the history of its ancestors' population size has been known theoretically, but we have never had the data or methods to pull out that information until now," says John Novembre of the University of California, Los Angeles. (newscientist.com)
Domesticates have indeed emerged in the last 12.000 years as results of co-evolutionary interactions between plants and human populations ( Meyer and Purugganan, 2013 ). (frontiersin.org)
As the human population increases rapidly, we modify the landscape to meet our increasing need for the resources to sustain our modern lifestyles. (scirp.org)
The continuous increase in the human population coupled with rising incomes and urbanization necessitates the need to conserve the genetic potential of animals to avoid or lower the consequences of biodiversity loss. (scirp.org)
Its global population is declining, and a variety of factors, many human-caused factors, are responsible for this downward trend. (discovermagazine.com)
And finally, Chicago is an area of recent Lyme disease emergence in the human population. (cdc.gov)

Overfishing and other pressures can lead to severe population bottlenecks. (wur.nl)

Our analysis compares two sub-populations with different demographic histories. (blogspot.com)
Lithuania's population has fallen by nearly 25 per cent since the early 1990s due to high emigration and adverse demographic trends. (ilo.org)

thereafter, a smaller population, with a smaller genetic diversity, remains to pass on genes to future generations of offspring. (wikipedia.org)
The other main issue is that a border wall interferes with the natural exchange of genes within a population. (earth.com)

Stephens (2004) claimed that drift does have direction, since it drives populations toward less and less heterozygosity (or more and more homozygosity). (blogspot.com)
Stephens is redefining "direction" for his own purposes, as heterozygosity does not appear on the adaptive landscape, making Stephens' response entirely artificial and not consonant with accepted population genetic theory. (blogspot.com)

Discovered in 2015 the research suggests that the reason for the bottleneck was not a reduction in the number of males, but a drastic decrease in the percentage of males with reproductive success. (wikipedia.org)
However, unlike the privations suffered by those eastward travellers, the data suggests the early Malagasy population survived the voyage well, because more genetic variation is found in them than is found in the islands of Polynesia. (mongabay.com)

Searching for evidence of adaptation to copper in a population of three-spined stickleback. (exeter.ac.uk)

2015). The long-term success of evolutionary conservation management requires accurate assessments of the evolutionary processes in bottlenecked populations and thus, an understanding of the analytical constraints non-equilibrium populations can face. (biorxiv.org)
Population dynamics focusses on the study of demographics, such as growth and decline, and the environmental processes that driving them. (wur.nl)
H-W is a simple equation that describes the genotypic frequencies in a population where no evolutionary processes are at work: no selection, no mutation, no migration, no assortative (i.e., non random) mating, and infinite population size (which implies no drift). (blogspot.com)

Populations like these are well established in genomics research for GWAS and searching for Mendelian traits. (bridgeinformatics.com)
Representation in genomics studies has been dominated by populations descending from Europe. (nature.com)

A severe bottleneck around 70,000 years ago may have reduced the effective population size in Africa to only 5,000 females. (jrank.org)
Drought and famine during this cataclysmic event undoubtedly decimated populations in most parts of Africa. (jrank.org)
Analysis of Y chromosomes shows that all modern populations in southern Australasia can trace their ancestry to a small founding population from the Horn of northeast Africa (Ethiopia and Somalia) around 60,000 to 70,000 years ago. (jrank.org)
All living humans outside of Africa can thus trace their ancestry to these colonizing populations. (jrank.org)
Population structure of Anopheles gambiae in Africa. (ajtmh.org)
Southern and Eastern Africa are the strongholds of the current cheetah population. (discovermagazine.com)
While protected areas exist within Africa, most of the cheetah population lives outside those areas. (discovermagazine.com)

The result is a population with low genetic variation and often a much higher incidence of variants that may be rarer in the general population. (bridgeinformatics.com)
As a result, the Finnish population is characterized by higher rates of DNA stretches with a common origin 6 , 7 carrying particular sets of genetic variants. (nature.com)
In the context of this paper, ancestry is defined using genetic variants based on the distribution of those variants in worldwide populations. (nature.com)
By comparing segments of DNA with the distribution of genetic variants in worldwide populations, it is possible to determine the likely "parental" or source population for each segment of DNA, indicating a component of the individual's overall ancestry. (nature.com)
Recent investigations in our labs, by analyzing the whole-plant dynamics of a turnip crinkle virus (TCV) population, coupled with cell biological interrogation of individual TCV variants, revealed possible novel mechanisms for cross protection and the closely related process of superinfection exclusion (SIE). (frontiersin.org)

In 2000, a Molecular Biology and Evolution paper suggested a transplanting model or a 'long bottleneck' to account for the limited genetic variation, rather than a catastrophic environmental change. (wikipedia.org)
Bottlenecks' in evolutionary history, where the population is dramatically reduced in number, are a common cause of reduced genetic variation. (mongabay.com)
A bottleneck population has less genetic variation and contains fewer breeding individuals. (earth.com)
Less genetic variation means a population is not as likely to survive changes in the environment such as climate change. (earth.com)
In the past years, I have been involved in several studies on genetic erosion - the loss of genetic variation resulting from genetic drift in small, fragmented populations. (lu.se)
Data from artificially bottlenecked populations of Nigella degenii and wild populations of Brassica cretica show that genetic drift causes idiosyncratic, trait-specific changes in the genetic variation rather than a consistent, proportional decline in all measures of variation. (lu.se)

Analysing the ways that mitochondrial DNA sequences differ across a large number of living people has helped to establish prehistoric population trends, but this record stretches back only 200,000 years to the point where all humans alive today shared a common female ancestor. (newscientist.com)

In addition, we have identified several novel regions showing parallel differentiation across independent populations. (discovermagazine.com)
This study represents the first high-density SNP-based genome scan of genetic diversity and differentiation for populations of threespine stickleback in the wild. (discovermagazine.com)

In other words, in this scenario most local populations have gone extinct as a consequence of the recent crunch event. (animalspaceuse.net)
By contrast, in populations that have encountered a recent reduction in population size, certain founder diseases with recessive inheritance are present at higher frequencies. (nature.com)
We did go through some population bottlenecks in our past, perhaps as recent as about 130,000 years ago. (edge.org)
Minority Populations,'' presented the the three most recent years and by race for each state. (cdc.gov)

Third, at very low population densities random events take its toll. (animalspaceuse.net)
The largest population is in the Bale Mountains National Park (BMNP) in southeastern Ethiopia, where wolf populations reach densities of up to 1.4 adults and subadults/km 2 ( 15 ). (cdc.gov)

In addition, the remaining population has also become spatially fragmented during this catastrophe. (animalspaceuse.net)

The effects of a population bottleneck often depend on the number of individuals remaining after the bottleneck and how that compares to the minimum viable population size. (wikipedia.org)

In this study, we used simulations to explore if signals of selection could be confidently distinguished from genetic drift across 23 bottlenecked and reintroduced populations of Alpine ibex ( Capra ibex ). (biorxiv.org)
And the authors make a compelling case that population models should explore juvenile-adult structure because it can result in qualitatively different outcomes. (princeton.edu)

For the first time, we have been able to assign every genetic lineage in the Malagasy population to a likely geographic origin with a high degree of confidence. (mongabay.com)

Population bottlenecks play an important role in conservation biology (see minimum viable population size) and in the context of agriculture (biological and pest control). (wikipedia.org)
This classic Lenski paper computes the effective population size of an evolving E. coli population subjected to daily population bottlenecks as $N_e = N_0 * g$ , where $N_e$ is the effective population size, $N_0$ is the population size directly after the bottleneck and $g$ is the number of generations between bottlenecks. (stackexchange.com)
Since the population size is cyclical in Lenski's experiments (this procedure is done at regular time intervals, so at approximately consistent generation time), the average over one cycle should be the same effective population size as integrating over all time. (stackexchange.com)
This means we can approximate the inverse effective population size as follows. (stackexchange.com)
We show that historical changes in population size can provide a way to differentiate between recessive and additive selection. (blogspot.com)
Effective population size was calculated based on the increase of classical inbreeding, and based on ancestral inbreeding to obtain what was termed as ancestral effective population size. (scirp.org)
The effective population size estimates ranged from 156 to 170 for the classical inbreeding based method, and as low as from 50 to 54 for the ancestral history coefficient based method. (scirp.org)
They also demonstrate how insights into the effects of maturation and reproduction limitation on community equilibrium carry over to the dynamics of size-structured populations and give rise to different types of cohort-driven cycles. (princeton.edu)
Felsenstein: "Most of the effort in analyzing these data has been to infer the past history of population size, rather than to make statements about A&E. (uncommondescent.com)
The strength of drift is inversely proportional to population size, which also means it has an antagonistic effect to natural selection (whose strength is directly proportional to population size). (blogspot.com)

Starting with the standard condition of scale-specific population dynamics/kinetics (Coupled map lattice model) and setting diffusion rate at unit scale to 5% between cells and net population growth of 2%, the following image to the left the population dispersion after 20 iterations. (animalspaceuse.net)
On the other hand, memory-influenced and scale-free dynamics allows for population-saving intraspecific cohesion under similar environmental conditions and events. (animalspaceuse.net)
In this book, André de Roos and Lennart Persson advance a synthetic and individual-based theory of the effects of this plastic ontogenetic development on the dynamics of populations and communities. (princeton.edu)
Featuring numerous examples and tests of modeling predictions, this book provides a pioneering and extensive theoretical and empirical treatment of the ecology of ontogenetic growth and development in organisms, emphasizing the importance of an individual-based perspective for understanding population and community dynamics. (princeton.edu)
This is probably the most important new book on animal population dynamics to appear in a decade. (princeton.edu)
It provides a lucid exposition of a coherent, individual-based approach to population dynamics based on fundamental bioenergetic principles. (princeton.edu)

Yet, the allele frequency changes driven by selection and exploited in selection detection methods, are similar to those caused by the strong neutral genetic drift expected during a bottleneck. (biorxiv.org)
Evolution is due to changes in the allelic frequency in a population over time. (rutgers.edu)

Within reintroduced populations specifically, the sudden environmental change experienced when founder individuals are released in new locations may fuel rapid adaptive change (e.g. (biorxiv.org)
It is easy to have misleading intuitions about the population genetic effects of a short, sudden bottleneck. (uncommondescent.com)

We used Illumina-sequenced RAD tags to identify and type over 45,000 single nucleotide polymorphisms (SNPs) in each of 100 individuals from two oceanic and three freshwater populations. (discovermagazine.com)

Drift has to do with stochastic events in generation-to-generation population sampling of gametes. (blogspot.com)

Question 2: If overfishing is producing a population bottleneck, what patterns or relationship would you look for in the data? (rutgers.edu)

In New Guinea, cultivated accessions exhibited higher diversity than their direct wild ancestor, the latter recovering from a bottleneck. (frontiersin.org)
Differential susceptibility to copper in wild populations of three-spined stickleback. (exeter.ac.uk)

The concentration of research and resources within one ancestral group has the potential to further perpetuate and even exacerbate known disparities that negatively affect populations with ancestry that is underrepresented in research (see Box 1: "What do we mean by ancestry? (nature.com)
An individual's genome is a mosaic of segments from different ancestral populations. (nature.com)

Presently, the world's population is currently growing at 1.5 percent per annum [3]. (scirp.org)
Although data limitations preclude precise measurement of the number of people with adequate service coverage, it is clear that at least half of the world's population do not have full coverage of essential services. (who.int)

Parallel bottlenecks were proposed to exist among chimpanzees, gorillas, rhesus macaques, orangutans and tigers. (wikipedia.org)

The European bottleneck has estimated intensity I B ~ 𝒪(0.5), an order of magnitude stronger than the simple bottleneck above. (blogspot.com)
Emerging market and developing countries should use available policy space to smooth the adjustment to less favorable external conditions, while pursuing efforts to remove bottlenecks to stronger growth. (imf.org)

Time to simulate a stress-test of the two population-kinetic frameworks, the traditional Coupled map lattice model and the novel Zoomer model! (animalspaceuse.net)
Their approach was based on the best scientific information available at that time (e.g., historical data, vaccine supply, vaccine impact in different scenarios, and different population groups), and directly considered the values of our society and the ethical issues involved in planning a phased approach to pandemic vaccination that, by necessity, means that some people will receive vaccine before others. (cdc.gov)

self-published source] This results in a reduction in the robustness of the population and in its ability to adapt to and survive selecting environmental changes, such as climate change or a shift in available resources. (wikipedia.org)

A major challenge is identifying the exact genetic variant responsible for a given Mendelian disorder, particularly if the variant is rare, found in a highly genetically diverse population, or is only harmful when two copies of the variant are present (called a homozygous recessive inheritance pattern). (bridgeinformatics.com)

A significant heterozygote excesses based on different models, suggested that Caspian horse population has decreased to low numbers in the past, but a bottleneck event is still very striking, and its number has recently increased is not in mutation drift equilibrium. (caspianhorse.org)
Drift has always been an interesting and conceptually confusing issue in evolutionary biology, and of course it plays a crucial role in mathematical population genetic theory. (blogspot.com)
I'm pretty sure this is not what population geneticists mean by drift. (blogspot.com)
This is a way to visualize the relationship between allelic frequencies and selection: the latter will move populations "upwards" (i.e., toward higher fitness) on any slope in the landscape, while drift will tend to shift populations randomly around the landscape. (blogspot.com)

A 2005 study from Rutgers University theorized that the pre-1492 native populations of the Americas are the descendants of only 70 individuals who crossed the land bridge between Asia and North America. (wikipedia.org)

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