The diversification of lineages is facilitated or constrained by the simultaneous evolution of multiple components of the phenotype that interact with each other during the course of speciation. When evolutionary radiations are adaptive, lineages proliferate via the emergence of multiple phenotypic optima that underlie diversification of species across multiple ecological niches. When radiations are non-adaptive, lineage proliferation unfolds constrained by similar (or nearly identical) correlations among traits that keep phenotypic and ecological diversity across newly emerging species within a single optimum. Nature offers very few opportunities where both types of diversification occur between closely related and highly diverse lineages. The Liolaemidae family of South American lizards offers unique such opportunities given two speciose lineages that have rapidly proliferated via adaptive (Liolaemus) and non-adaptive (Phymaturus) radiations. We analyze body shape in lizards in association with type of diet (herbivory, omnivory or carnivory). In these lizards, diet types have been suggested to be linked to body size. Our results confirm this hypothesis, with three body size optima tightly linked to all three diet types when radiation is both adaptive and non-adaptive. Diet reconstruction along their evolutionary history showed that the common ancestor of Liolaemidae was likely omnivorous, which is matched by ancestral reconstruction of body size. Phylogenetic PCA revealed that herbivorous species generally have more differentiated body shape than insectivores and omnivores. Herbivorous species have evolved larger heads, shorter hindlimbs and a small difference between forelimb and hindlimb length. In contrast, omnivores and insectivores have smaller heads and longer hindlimbs. Collectively, trophic niche plays an important role in defining body shape and size across species within lineages, and the patterns of trait–ecology correlations remain consistent when lineages have diversified via adaptive and non-adaptive radiation.

中文翻译：

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物种丰富的辐射蜥蜴的形态多样化模式受到饮食进化的影响

在物种形成过程中相互作用的多个表型成分的同时进化促进或限制了谱系的多样化。当进化辐射具有适应性时，谱系会通过多种表型最佳值的出现而增殖，这是跨多个生态位的物种多样化的基础。当辐射不具有适应性时，谱系增殖的展开受到性状之间相似（或几乎相同）相关性的限制，这些性状将新出现的物种的表型和生态多样性保持在一个最佳值内。在密切相关和高度多样化的谱系之间发生两种类型的多样化的情况下，大自然提供的机会很少。南美蜥蜴的 Liolaemidae 家族提供了独特的此类机会，因为它们的两个物种谱系通过适应性迅速繁殖（利奥莱穆斯) 和非自适应 (长毛藻属）辐射。我们分析蜥蜴的体形与饮食类型（草食性、杂食性或肉食性）的关系。在这些蜥蜴中，饮食类型被认为与体型有关。我们的结果证实了这一假设，当辐射具有适应性和非适应性时，三种最佳体型与所有三种饮食类型紧密相关。沿着进化史进行的饮食重建表明，Liolaemidae 的共同祖先可能是杂食性的，这与体型的祖先重建相匹配。系统发育主成分分析显示，食草动物通常比食虫动物和杂食动物具有更多分化的体型。草食性物种进化出了更大的头部、更短的后肢以及前肢和后肢长度之间的微小差异。相比之下，杂食动物和食虫动物的头部较小，后肢较长。总的来说，营养生态位在定义谱系内物种的体型和大小方面发挥着重要作用，并且当谱系通过适应性和非适应性辐射实现多样化时，性状-生态相关性的模式保持一致。