Alternatively, species-level shifts could result from extinction of certain populations and therefore loss of a unique portion of the species' evolutionary legacy coupled with local growth and spatial expansion in previously marginal populations.
The long branches leading to these microendemic taxa might have resulted from extinction of sister lineages [ 82], a plausible scenario if rocky habitats were eroded and became scarce in the intervening regions [ 20], given the site specificity of T. semitaeniatus group to saxicolous environments.
Finally, we evaluated whether the observed differences in network topology and/or quantitative concordance translated into changes in their robustness, in terms of sensitivity to secondary extinctions of epiphytes (resulting from simulated extinctions of host trees).
This not only can halt trends that had been proceeding before the event, it also can generate trends of its own (Fig. 13e)—in fact, it is possible that trends generated during normal times can be reversed by those resulting from a mass extinction.
In our study, incorporating immigration from downstream of the study area was observed to rescue the tributary/mainstem population from extinction resulting from fragmentation under most scenarios.
Barnosky cautioned that the current study captures only the grossest environmental changes resulting from large-mammal extinctions, since not all ecosystem changes leave traces in the fossil record.
The amount of superoxide anion produced was calculated and resulted from the extinction coefficient of cytochrome C according to the Lambert Beer law.
Critical biodiversity has been defined as the level of species richness at which communities are most susceptible to disturbance, where even small perturbations resulting from the introduction or extinction of a single species may trigger a mass extinction event.
At the same time, it is also a sort of unity with distinctions resulting from the division and extinction of those ethnicities.
Competition between native and invading species may result in local extirpations of native species, but no compelling cases of global extinction resulting from competition with introduced species exist (Lockwood et al. 2007).
