A population bottleneck or genetic bottleneck is a sharp reduction in the size of a population due to environmental events (such as earthquakes, floods, fires, disease, or droughts) or human activities (such as genocide).
 Such events can reduce the variation in the gene pool of a population; thereafter, a smaller population, with a correspondingly smaller genetic diversity, remains to pass on genes to future generations of offspring through sexual reproduction.
 Genetic diversity remains lower, increasing only when gene flow with another population occurs or very slowly increasing with time as random mutations occur.
 As a consequence of such population size reductions and the loss of genetic variation, the robustness of the population is reduced and its ability to adapt to and survive selecting environmental changes, like climate change or a shift in available resources, is reduced.
 Alternatively, if by chance 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.
Sample size determination is the act of choosing the number of observations or replicates to include in a statistical sample.
 The sample size is an important feature of any empirical study in which the goal is to make inferences about a population from a sample.
 In practice, the sample size used in a study is determined based on the expense of data collection, and the need to have sufficient statistical power.
 In complicated studies there may be several different sample sizes involved in the study: for example, in a stratified survey there would be different sample sizes for each stratum.
 In a census, data are collected on the entire population, hence the sample size is equal to the population size.
 In experimental design, where a study may be divided into different treatment groups, this may be different sample sizes for each group.
The stepwise mutation model (SMM) is a mathematical theory, developed by Motoo Kimura and Tomoko Ohta, that allows for investigation of the equilibrium distribution of allelic frequencies in a finite population where neutral alleles are produced in step-wise fashion.
 The original model assumes that if an allele has a mutation that causes it to change in state, mutations that occur in repetitive regions of the genome will increase or decrease by a single repeat unit at a fixed rate (i.e. by the addition or subtraction of one repeat unit per generation) and these changes in allele states are expressed by an integer (. . . A-1, A, A1, .
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 The model also assumes random mating and that all alleles are selectively equivalent for each locus.
 The SMM is distinguished from the Kimura-Crow model, also known as the infinite alleles model (IAM), in that as the population size increases to infinity, while the product of the N (effective population size) and the mutation rate is fixed, the mean number of different alleles in the population rapidly reaches a peak and plateaus, at which time that value is almost the same as the effective number of alleles.
Shane O'Neill (Irish: "Seán Mac Cuinn Ó Néill" ; c. 1530 – 2 June 1567), was an Irish king of the O'Neill dynasty of Ulster in the mid 16th century.
 Shane O'Neill's career was marked by his ambition to be The O'Neill – sovereign of the dominant O'Neill family of Tír Eoghain—and thus overking of the entire province.
 This brought him into conflict with competing branches of the O'Neill family and with the English government in Ireland, who recognised a rival claim.
 Shanes's support was considered worth gaining by the English even during the lifetime of his father Conn O'Neill, 1st Earl of Tyrone (died 1559).
 But rejecting overtures from Thomas Radclyffe, 3rd Earl of Sussex, the lord deputy from 1556, Shane refused to help the English against the Scottish settlers on the coast of Antrim, allying himself instead with the MacDonnells, the most powerful of these immigrants.
Genetic monitoring is the use of molecular markers to (i) identify individuals, species or populations, or (ii) to quantify changes in population genetic metrics (such as effective population size, genetic diversity and population size) over time.
 Genetic monitoring can thus be used to detect changes in species abundance and/or diversity, and has become an important tool in both conservation and livestock management.
 The types of molecular markers used to monitor populations are most commonly mitochondrial, microsatellites or single-nucleotide polymorphisms (SNPs), while earlier studies also used allozyme data.
 Species gene diversity is also recognized as an important biodiversity metric for implementation of the Convention on Biological Diversity.
In population genetics, the Watterson estimator is a method for describing the genetic diversity in a population.
 It is estimated by counting the number of polymorphic sites.
 It is a measure of the "population mutation rate" (the product of the effective population size and the neutral mutation rate) from the observed nucleotide diversity of a population.
 formula_1, where formula_2 is the effective population size and formula_3 is the per-generation mutation rate of the population of interest ( ).
 The assumptions made are that there is a sample of formula_4 haploid individuals from the population of interest, that there are infinitely many sites capable of varying (so that mutations never overlay or reverse one another), and that formula_5.
The flat-headed cat ("Prionailurus planiceps") is a small wild cat patchily distributed in the Thai-Malay Peninsula, Borneo and Sumatra.
 Since 2008, it has been listed as Endangered on the IUCN Red List due to destruction of wetlands in its habitat.
 It is suspected that the effective population size could be fewer than 2,500 mature individuals, with no subpopulation having an effective population size larger than 250 adult individuals.
The effective population size is the number of individuals that an idealised population would need to have, in order for some specified quantity of interest to be the same in the idealised population as in the real population.
 Idealised populations are based on unrealistic but convenient simplifications such as random mating, simultaneous birth of each new generation, constant population size, and equal numbers of children per parent.
 While in some simple scenarios, the effective population size can be equal to the number of breeding individuals in the population, for most quantities of interest and most real populations, the census population size "N" of a real population is usually larger than the effective population size "N".
 The same population may have multiple effective population sizes, for different properties of interest, including for different genetic loci.
Rural Canada has many faces and many dimensions (social, cultural, economic, etc.) but the common element of most conceptualizations of "rural" is the spatial dimension.
 Rural is primarily low population density, small population size, and distance from high population density and big size.
 Not surprisingly, the prevailing definitions of “rural” (in Canada as in most countries) emphasize this spatial dimension.
 Rural Canada is usually defined by measures of population density, population size and distance from major agglomerations.
County Antrim (named after the town of Antrim, from Irish: "Aontroim" , meaning "lone ridge" , )) is one of six counties that form Northern Ireland.
 Adjoined to the north-east shore of Lough Neagh, the county covers an area of 3046 km2 and has a population of about 618,000.
 County Antrim has a population density of 203 people per square kilometer / 526 people per square mile.
 It is also one of the thirty-two traditional counties of Ireland, as well as part of the historic province of Ulster.

Question: What is the population size of the place where Shane O'Neill refused to help the English against the Scottish settlers?
Answer: 618,000