Where does pool collide?

The whole collection of genes and their alleles carried by an interbreeding population at a given time: the shared store of heritable variation that each new generation is drawn from, and on which mutation, migration, drift, and selection act. Dobzhansky's 1950 Mendelian Populations and Their Evolution defined a Mendelian population as a reproductive community sharing a common gene pool, and framed evolution as change in the composition of that pool across generations. The referent is the heritable variation of a living population, tracked as allele frequencies, and it is not a bundle of combined risks, a stock of a substance in an ecosystem, or a cache of ready worker threads.[1]

Unit

The full set of alleles in an interbreeding population, scaled by allele frequency

Recovery means

New variation enters by mutation and by migration from other populations, and the pool is reconstituted each generation

Measured by

Estimated by sampling individuals and computing allele and genotype frequencies, and by diversity measures such as heterozygosity

The gathering of many independent or weakly related risks into one holding, so that their variability relative to the total shrinks: this averaging is what lets an insurer or a centralized inventory absorb uncertainty that no single holder could carry. Eppen's 1979 note on the multi-location newsboy problem showed formally that consolidating variable demand across locations lowers expected holding and shortage costs, putting a number on the gain from pooling. The referent is a portfolio of combined risks whose average steadies as more are added, tracked in variance and cost, and it has nothing to do with a population's genes, a reservoir of carbon, or a set of reusable threads.[2]

Unit

A set of pooled independent risks, scaled by their combined variance relative to the total

Recovery means

Not applicable

Measured by

Quantified by the fall in variance or coefficient of variation of the aggregate, and by expected cost saved versus holding the risks apart

A reservoir or stock of a substance held in one compartment of a biogeochemical cycle, such as the carbon stored in soil organic matter, in living vegetation, or in the ocean: it is defined by contrast with the fluxes that move the substance between compartments. Post, Emanuel, Zinke, and Stangenberger's 1982 Soil carbon pools and world life zones estimated the size of the world soil carbon pool by life zone, treating soil as a measurable stock in the global carbon cycle. The referent is a quantity of matter resident in an environmental compartment, tracked in mass per area or total gigatonnes, and it is not a population's shared genes, an aggregation of financial risks, or a cache of computing resources.[3]

Unit

A stock of a substance in one compartment of a cycle, in mass such as gigatonnes of carbon

Recovery means

The pool turns over as inputs and outputs, the fluxes, exchange matter with the compartments connected to it

Measured by

Estimated by sampling concentration and bulk density over area and depth, then scaling to the compartment's extent

A set of pre-created, interchangeable resources, such as worker threads, database connections, or memory blocks, kept ready so a program can borrow one on demand and return it, instead of paying to create and destroy it each time. Ling, Mullen, and Lin's 2000 Analysis of optimal thread pool size modelled a server's thread pool and derived the size that balances the cost of holding threads against responsiveness under load. The referent is a managed cache of reusable software resources, sized by a count and a lending policy, and it bears no relation to a population's genes, a bundle of risks, or a reservoir of carbon.[4]

Unit

A fixed or bounded set of reusable resources such as threads or connections, scaled by pool size

Recovery means

Borrowed resources are returned to the pool after use and lent out again rather than destroyed

Measured by

Characterised by pool size, utilisation, the wait time for a free resource, and throughput under load