论文标题
标点平衡是大量人群在适应性景观上以鞍点为主导的默认人群进化模式
Punctuated equilibrium as the default mode of evolution of large populations on fitness landscapes dominated by saddle points in the weak-mutation limit
论文作者
论文摘要
标点平衡是一种进化模式，在快速爆发中发生候位变化，而瞬间的暂停间隔较长，在此过程中突变积累，但没有发生重大的表型变化。最初在古生物学框架内提出了标点平衡，以解释化石记录典型的过渡形式。从理论上讲，标点的平衡与自组织的临界（SOC）有关，该模型在该模型中，不断发展的系统中的雪崩大小是幂律分布的，从而增加了重大事件的罕见性。我们在这里表明，在弱势限制下，大部分时间将在健身景观中的马鞍点附近花费大部分时间。在LNNE时间（NE，有效的人口大小）中，当新的有益突变固定在不断发展的种群中，从鞍座转变为不同的鞍座，或者在较少的情况下，从鞍座到局部峰。因此，标点平衡是在不涉及SOC或其他特殊条件的简单模型下的默认进化模式。
Punctuated equilibrium is a mode of evolution in which phenetic change occurs in rapid bursts that are separated by much longer intervals of stasis during which mutations accumulate but no major phenotypic change occurs. Punctuated equilibrium has been originally proposed within the framework of paleobiology, to explain the lack of transitional forms that is typical of the fossil record. Theoretically, punctuated equilibrium has been linked to self-organized criticality (SOC), a model in which the size of avalanches in an evolving system is power-law distributed, resulting in increasing rarity of major events. We show here that, under the weak-mutation limit, a large population would spend most of the time in stasis in the vicinity of saddle points in the fitness landscape. The periods of stasis are punctuated by fast transitions, in lnNe time (Ne, effective population size), when a new beneficial mutation is fixed in the evolving population, which moves to a different saddle, or on much rarer occasions, from a saddle to a local peak. Thus, punctuated equilibrium is the default mode of evolution under a simple model that does not involve SOC or other special conditions.
