Because the parental species of S. × gulngai are roughly equally abundant, the hypothesis based on relative abundance makes no prediction for direction of hybridization.
The reduction in fitness of female bagworms near the geographic range limit, which concords with the abundant centre hypothesis from biogeography, provides a concrete, empirical example of how an Allee effect (increased pre-reproductive mortality of females in sparsely populated areas) may interact with other demographic factors to induce a geographic range limit.
In this context, the abundant-center hypothesis posits that species abundance peaks in the center of its distributional range and decline in the edges (Wulff 1950; Whittaker 1975; Hengeveld and Haeck 1982).
For example, these broad-scale physiological inquiries confer the ability to directly assess the abundant-center hypothesis (aka Brown's principle) which proposes that species have decreased performance toward their range edges.
In some cases, researchers question the validity of the abundant-centre hypothesis on the ground that apparent empirical support stems from reduced sampling near the edge of species range [27], [28].
One of the most influential framework on the distribution of genetic variation across species' ranges is the Abundant-Centre Hypothesis (ACH) [ 7].
Consistent with this hypothesis, abundant TG2 activity was detected around a wound in a scratched fibroblast monolayer while almost no TG2 activity was detected in uninjured regions of the monolayer despite the presence of cell surface TG2 on WI-38 fibroblasts [27], [28].
Consistent with this hypothesis, an abundant 31 kDa protein isolated from poplar phloem exudate was subsequently identified as a closely-related TLP.
If non-synonymous substitutions are more abundant than expected, the null hypothesis is rejected, and positive selection is determined to be occurring at that site.
An abundant literature has explored this hypothesis and found mixed results without convincing proof (Ruderman, 1986).
A corollary of our hypothesis is that abundant cellular proteins such as Hsp70 and Hsp90 represent important targets that, when modified, can exert a profound cellular response.
