SOLVING THE PARADOX OF STASIS: SQUASHED STABILIZING SELECTION AND THE LIMITS OF DETECTION

• DOI: 10.1111/evo.12275
• Publication Date: 2013-10-08T15:11:05Z
• Authors: Benjamin C. Haller; Andrew P. Hendry
• Keywords: Stabilizing selection; Trait; Directional selection; Fitness landscape

Despite the potential for rapid evolution, stasis is commonly observed over geological timescales—the so-called "paradox of stasis." This paradox would be resolved if stabilizing selection were common, but infrequently detected in natural populations. We hypothesize a simple solution to this apparent disconnect: hard detect empirically once populations have adapted fitness peak. To test hypothesis, we developed an individual-based model population evolving under invariant function. Stabilizing on was "empirical" sampling protocol, because (1) trait variation low relative peak breadth; (2) nonselective deaths masked selection; (3) wandered around peak; and (4) sample sizes typically too small. Moreover, addition negative frequency-dependent further hindered detection by flattening or even dimpling peak, phenomenon term "squashed selection." Our demonstrates that provides plausible resolution despite its infrequent nature. The key reason "erases traces": they are no longer expected exhibit detectable selection.