Adaptive radiation is the likely source of much of the ecological and morphological diversity of life 1 – 4 . How adaptive radiations proceed and what determines their extent remains unclear in most cases 1 , 4 . Here we report the in-depth examination of the spectacular adaptive radiation of cichlid fishes in Lake Tanganyika. On the basis of whole-genome phylogenetic analyses, multivariate morphological measurements of three ecologically relevant trait complexes (body shape, upper oral jaw morphology and lower pharyngeal jaw shape), scoring of pigmentation patterns and approximations of the ecology of nearly all of the approximately 240 cichlid species endemic to Lake Tanganyika, we show that the radiation occurred within the confines of the lake and that morphological diversification proceeded in consecutive trait-specific pulses of rapid morphospace expansion. We provide empirical support for two theoretical predictions of how adaptive radiations proceed, the ‘early-burst’ scenario 1 , 5 (for body shape) and the stages model 1 , 6 , 7 (for all traits investigated). Through the analysis of two genomes per species and by taking advantage of the uneven distribution of species in subclades of the radiation, we further show that species richness scales positively with per-individual heterozygosity, but is not correlated with transposable element content, number of gene duplications or genome-wide levels of selection in coding sequences. Analyses of molecular, anatomical, pigmentation and ecological characteristics of nearly all of the approximately 240 species of cichlid fishes in Lake Tanganyika show that the massive adaptive radiation occurred within the confines of the lake through trait-specific pulses of accelerated evolution.

中文翻译：

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慈鲷鱼类大规模适应性辐射的驱动因素和动力学

适应性辐射可能是生命的大部分生态和形态多样性的来源 1 - 4 。在大多数情况下，适应性辐射如何进行以及决定其范围的因素仍不清楚 1, 4 。在这里，我们报告了对坦噶尼喀湖慈鲷壮观的适应性辐射的深入研究。在全基因组系统发育分析的基础上，对三个生态相关性状复合体（体型、上口腔颌形态和下咽颌形状）进行多变量形态测量，对几乎所有大约 240 个物种的色素沉着模式和生态学进行评分坦噶尼喀湖特有的慈鲷物种，我们表明，辐射发生在湖的范围内，并且形态多样化是在连续的特征特异性脉冲快速形态空间扩张中进行的。我们为自适应辐射如何进行的两个理论预测提供经验支持，即“早期爆发”情景 1、5（针对体型）和阶段模型 1、6、7（针对所有研究的特征）。通过对每个物种的两个基因组进行分析，并利用辐射亚群中物种分布不均匀的优势，我们进一步表明物种丰富度与每个个体的杂合度呈正相关，但与转座因子含量、基因数量无关编码序列中的重复或全基因组水平的选择。分子分析、解剖学、