The evolution of plant development can be studied in many different ways, each of which provides new insights into how plants have been modified over evolutionary time. DNA sequencing shows that most developmental genes are under purifying selection and that obvious adaptive change in proteins is rare. This may indicate that most change occurs in cis-regulatory sequences, that tests for detecting selection lack power, or both. Gene duplications are common and often correlate with divergence of function, as predicted by theory. Studies of gene expression illuminate similarities among structures in disparate plant groups and indicate that the same genes have been deployed repeatedly for similar developmental ends. Comparative functional studies remain uncommon, but promise to illuminate how changing proteins lead to changes in development. Precise characterization of phenotypes by studies of developmental morphology is beginning to occur in some taxonomic groups. The genetic variation necessary for morphological change must originate as allelic polymorphism within populations; such polymorphism has been identified in grasses and in sunflowers, although it is often cryptic.

中文翻译：

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发展特征的演变。

可以用许多不同的方法来研究植物发育的进化，每种方法都为植物在进化过程中如何被修饰提供了新的见解。DNA测序表明，大多数发育基因都处于纯化选择之下，而蛋白质中明显的适应性变化却很少。这可能表明大多数变化发生在顺式调控序列中，检测选择的检测缺乏功效或两者兼有。正如理论所预测的，基因重复很常见，并且通常与功能的差异相关。基因表达的研究阐明了不同植物群中结构之间的相似性，并表明相同的基因已被重复用于相似的发育目的。比较功能研究仍然不常见，但有望阐明不断变化的蛋白质如何导致发育变化。通过发展形态学研究对表型进行精确表征已开始在某些分类学组中发生。形态变化所必需的遗传变异必须起源于种群内的等位基因多态性。尽管这种多态性通常是神秘的，但已在草和向日葵中鉴定出。