Strathmann Richard R, Fenaux Lucienne, Strathmann Megumi F
Friday Harbor Laboratories and Department of Zoology, University of Washington, 620 University Road, Friday Harbor, WA, 98250, USA.
CNRS Station Zoologique, B.P. 28, 06230, Villefranche-sur-Mer, FRANCE.
Evolution. 1992 Aug;46(4):972-986. doi: 10.1111/j.1558-5646.1992.tb00613.x.
Preexisting developmental plasticity in feeding larvae may contribute to the evolutionary transition from development with a feeding larva to nonfeeding larval development. Differences in timing of development of larval and juvenile structures (heterochronic shifts) and differences in the size of the larval body (shifts in allocation) were produced in sea urchin larvae exposed to different amounts of food in the laboratory and in the field. The changes in larval form in response to food appear to be adaptive, with increased allocation of growth to the larval apparatus for catching food when food is scarce and earlier allocation to juvenile structures when food is abundant. This phenotypic plasticity among full siblings is similar in direction to the heterochronic evolutionary changes in species that have greater nutrient reserves within the ova and do not depend on particulate planktonic food. This similarity suggests that developmental plasticity that is adaptive for feeding larvae also contributes to correlated and adaptive evolutionary changes in the transition to nonfeeding larval development. If endogenous food supplies have the same effect on morphogenesis as exogenous food supplies, then changes in genes that act during oogenesis to affect nutrient stores may be sufficient to produce correlated adaptive changes in larval development.
摄食幼虫预先存在的发育可塑性可能有助于从有摄食幼虫的发育向非摄食幼虫发育的进化转变。在实验室和野外，将海胆幼虫暴露于不同量的食物中，会导致幼虫和幼体结构发育时间的差异（异时性变化）以及幼虫身体大小的差异（分配变化）。幼虫形态对食物的变化似乎具有适应性，当食物稀缺时，更多的生长分配到用于捕获食物的幼虫器官；当食物丰富时，则更早地分配到幼体结构。全同胞之间的这种表型可塑性在方向上与卵内营养储备更多且不依赖颗粒浮游食物的物种的异时进化变化相似。这种相似性表明，对摄食幼虫具有适应性的发育可塑性也有助于向非摄食幼虫发育转变过程中的相关适应性进化变化。如果内源性食物供应对形态发生的影响与外源性食物供应相同，那么在卵子发生过程中起作用以影响营养储存的基因变化可能足以在幼虫发育中产生相关的适应性变化。
