Department of Philosophy and History of Science, Charles University, Vinicná 7, CZ-128 44 Praha 2, Czech Republic.
Biol Direct. 2010 Jan 13;5:2. doi: 10.1186/1745-6150-5-2.
Darwin's evolutionary theory could easily explain the evolution of adaptive traits (organs and behavioral patterns) in asexual but not in sexual organisms. Two models, the selfish gene theory and frozen plasticity theory were suggested to explain evolution of adaptive traits in sexual organisms in past 30 years.
The frozen plasticity theory suggests that sexual species can evolve new adaptations only when their members are genetically uniform, i.e. only after a portion of the population of the original species had split off, balanced on the edge of extinction for several generations, and then undergone rapid expansion. After a short period of time, estimated on the basis of paleontological data to correspond to 1-2% of the duration of the species, polymorphism accumulates in the gene pool due to frequency-dependent selection; and thus, in each generation, new mutations occur in the presence of different alleles and therefore change their selection coefficients from generation to generation. The species ceases to behave in an evolutionarily plastic manner and becomes evolutionarily elastic on a microevolutionary time-scale and evolutionarily frozen on a macroevolutionary time-scale. It then exists in this state until such changes accumulate in the environment that the species becomes extinct.
Frozen plasticity theory, which includes the Darwinian model of evolution as a special case--the evolution of species in a plastic state, not only offers plenty of new predictions to be tested, but also provides explanations for a much broader spectrum of known biological phenomena than classic evolutionary theories.
This article was reviewed by Rob Knight, Fyodor Kondrashov and Massimo Di Giulio (nominated by David H. Ardell).
达尔文的进化理论可以很容易地解释无性生物适应性特征（器官和行为模式）的进化，但不能解释有性生物适应性特征的进化。在过去的 30 年里，有两个模型，自私基因理论和冻结可塑性理论，被用来解释有性生物适应性特征的进化。
冻结可塑性理论表明，有性物种只有在其成员具有遗传同质性时才能进化出新的适应性，也就是说，只有在原始物种的一部分已经分裂出来、在灭绝的边缘平衡了几代之后，然后经历快速扩张。在很短的时间内，根据古生物学数据估计，这相当于物种持续时间的 1-2%，由于频率依赖选择，基因库中的多态性积累；因此，在每一代中，新的突变都会在不同等位基因的存在下发生，从而使它们的选择系数一代一代地发生变化。该物种不再表现出进化可塑性，而是在微观进化时间尺度上具有进化弹性，在宏观进化时间尺度上具有进化冻结性。然后，它以这种状态存在，直到环境发生变化，导致物种灭绝。
冻结可塑性理论，包括达尔文进化模型作为一个特例——在可塑性状态下的物种进化，不仅提供了大量可供测试的新预测，而且与经典进化理论相比，它还为更广泛的已知生物学现象提供了解释。
这篇文章由 Rob Knight、Fyodor Kondrashov 和 Massimo Di Giulio（由 David H. Ardell 提名）进行了评审。
