Changes in the timing of development within a lineage (heterochrony) have an enormous impact on floral diversification. However, comparative quantitative studies in a broad range of ontogenetic stages are still needed to identify the role of different heterochronic processes shaping diversification patterns. In this study, changes in petal development were compared across species in the genus Schizanthus showing floral diversification mediated by pollinators. In this genus, transitions from bee- to hummingbird- and moth- pollination are associated with lower lip diversification. Variation in size and shape of petals was quantified at key ontogenetic stages by using a traditional and a geometric morphometric approach. Buds from petal initiation until shortly before anthesis were considered. Lower lip reduction can arise by different combinations of ontogenetic processes such as a delay in organ initiation, a decrease in growth rate, and/or by terminal deletion of the final shape. These processes may interact having an additive effect along ontogeny. Compensatory effects can also occur, as an increase in growth rates can offset the effect of a delay in organ initiation. Heterochronic changes underlying independent reductions of the lower lip varied between lower lip structures: the wing and the keel. While wing reduction was achieved by similar ontogenetic process in both clades, keel reduction was achieved mostly by terminal deletion of the final shape in the moth-pollinated clade and by a decrease in growth rates in the hummingbird-pollinated clade. Therefore, the lower lip structures (keel and wings) originating from the same primordia are governed by different processes indicating that they are discrete developmental units. In conclusion, comparative quantitative studies along a broad range of ontogenetic stages are key to understand how different combinations of ontogenetic processes shape morphological variation and promote adaptive evolution.

谱系内发育时间的变化（异时）对花卉的多样性产生巨大影响。然而，仍然需要在广泛的个体发育阶段进行比较定量研究，以识别不同的异时过程对多样化模式的影响。在这项研究中，比较了五味子属物种之间花瓣发育的变化显示出授粉媒介介导的花卉多样化。在这个属中，从蜜蜂授粉到蜂鸟授粉和蛾授粉的过渡与下唇的多样化有关。花瓣的大小和形状的变化在关键的个体发育阶段通过使用传统的和几何形态计量学方法进行了量化。从花瓣开始直到花期不久前的芽被考虑。由于个体发育过程的不同组合，例如器官启动的延迟，生长速度的降低和/或最终形状的末端缺失，可能导致下唇减少。这些过程可能相互作用，并在个体发育中产生累加效应。由于增长率的增加可以抵消器官启动延迟的影响，因此也会产生补偿作用。下唇独立还原的异时变化在下唇结构（机翼和龙骨）之间变化。虽然在两个进化支中通过相似的个体发育过程实现了机翼的减少，但是龙骨的减少主要是通过在蛾授粉的进化支中最终形状的末端缺失和在蜂鸟授粉的进化率的降低中实现的。因此，源自相同原基的下唇结构（龙骨和翼）受不同过程控制，表明它们是离散的发育单位。总之，在广泛的个体发育阶段进行比较定量研究对于了解个体发育过程的不同组合如何塑造形态变异并促进适应性进化至关重要。虽然在两个进化支中通过相似的个体发育过程实现了机翼的减少，但龙骨的减少主要是通过在蛾授粉的进化支中最终形状的末端缺失和在蜂鸟授粉的进化率的降低中实现的。因此，源自相同原基的下唇结构（龙骨和翼）受不同过程控制，表明它们是离散的发育单位。总之，在广泛的个体发育阶段进行比较定量研究对于了解个体发育过程的不同组合如何塑造形态变异并促进适应性进化至关重要。虽然在两个进化支中通过相似的个体发育过程实现了机翼的减少，但是龙骨的减少主要是通过在蛾授粉的进化支中最终形状的末端缺失和在蜂鸟授粉的进化率的降低中实现的。因此，源自相同原基的下唇结构（龙骨和翼）受不同过程控制，表明它们是离散的发育单位。总之，在广泛的个体发育阶段进行比较定量研究对于了解个体发育过程的不同组合如何塑造形态变异并促进适应性进化至关重要。龙骨减少主要是通过在飞蛾授粉的进化枝中最终形状的末端缺失和在蜂鸟授粉的进化枝的生长速度的降低中实现的。因此，源自相同原基的下唇结构（龙骨和翼）受不同过程控制，表明它们是离散的发育单位。总之，在广泛的个体发育阶段进行比较定量研究对于了解个体发育过程的不同组合如何塑造形态变异并促进适应性进化至关重要。龙骨减少主要是通过在飞蛾授粉的进化枝中最终形状的末端缺失和在蜂鸟授粉的进化枝的生长速度的降低中实现的。因此，源自相同原基的下唇结构（龙骨和翼）受不同过程控制，表明它们是离散的发育单位。总之，在广泛的个体发育阶段进行比较定量研究对于了解个体发育过程的不同组合如何塑造形态变异并促进适应性进化至关重要。