The phrase "a lack of isolation" is correct and usable in written English.
It can be used to describe a situation or condition where there is insufficient separation or solitude, often in contexts related to social interactions, mental health, or environmental factors.
Example: "The study revealed that a lack of isolation can lead to increased feelings of anxiety and depression among individuals."
Alternatives: "insufficient isolation" or "absence of isolation".
These include excesses of rare alleles and low-frequency mutations, reduced genetic diversity (homozygosity, shorter demographic histories) resulting in negative latitudinal clines, and a lack of isolation-by-distance (reviewed in [ 4, 9, 69, 70]).
Baer [ 42] also hypothesized an important role for population expansion and cross-peninsula gene flow in influencing current levels of genetic variation including recent founding of ACP populations after Early Pleistocene high seas (≤1.5 Ma; 'northeast colonization' hypothesis), supported by lower genetic diversity and a lack of isolation-by-distance only among ACP populations.
A second explanation is that these discordances arise from the contrasting modes of transmission, evolution, and resolution of these marker-types; this could plausibly explain a lack of isolation-by-distance in the mtDNA, but isolation-by-distance in the allozymes.
However, a lack of reproductive isolation, coupled with evidence of continuous variation, substantiates the view that these annual and perennial forms are more accurately viewed as distinct ecotypes of O. rufipogon (Barbier et al. 1991; Lu et al. 2002; Oka 1988; Zhu and Ge 2005; Zhu et al. 2007).
In this analysis, Europe and Siberia were combined because F ST = 0, indicating a lack of genetic isolation between them (24 ).
We identified a single population with secondary contact between the Chefu and Limpopo groups, where mtDNA haplotypes from both haplogroups were unambiguously identified, while nuclear markers revealed no intrapopulation genetic structure (Additional file 3), suggesting a lack of reproductive isolation between the two mtDNA clades.
This is consistent with Baer's 'northeast colonization' hypothesis (ACP populations colonized following an Early Pleistocene high-sea stand following 1.5 Ma), which he argued was also supported by lower allozyme diversity and a lack of ACP isolation-by-distance [ 42] (see below).
However, contrasting these patterns, we find: a lack of mtDNA isolation-by-distance across the range; Ne m suggesting zero on-going mtDNA gene flow (see Supplement S1); and ACP populations as indistinct from other regions (i.e. nonmonophyletic; Figures 2, 6 and 7).
