Ongoing ecological divergence in an emerging genomic model.
Ongoing ecological divergence in an emerging genomic model.
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DOI：
10.1111/j.1365-294x.2009.04249.x
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发表时间：
2009-07
影响因子：
4.9
通讯作者：
Arnegard ME
中科院分区：
文献类型：
--
作者：
Arnegard ME
地球上的大部分生物多样性都是通过适应性辐射产生的。在这一过程中，表型分化的重要途径包括体型和生活史的进化。在非洲的五大湖中，慈鲷鱼发生了广泛的适应性辐射，导致了物种之间非常复杂和多样化的行为。在坦噶尼干产壳的稚鱼族Lamprologini中，伴随着复杂的繁殖系统和使用空螺壳来躲避捕食者和抚养后代的巨大种内体型差异。发表在本期《分子生态学》杂志上的一项研究首次揭示了同一名称lamprologine物种（Telmatochromis temporalis）的侏儒和正常大小变种之间遗传差异的案例。种群结构模式表明，在湖泊的多个地区，矮小的壳栖型可能是由正常的岩栖型独立产生的，不同地点的成对型可能代表了生态物种形成过程的不同早期阶段。Takahashi等人的发现是理解这些有趣的物种进化的重要的第一步，但关于交配系统、基因流动、可塑性和选择，仍有许多问题没有得到解答。尽管存在这些限制，由于比较基因组学的资源即将到来，像他们这样的描述性工作在非洲慈鲷中具有重要意义。
Much of Earth’s biodiversity has arisen through adaptive radiation. Important avenues of phenotypic divergence during this process include the evolution of body size and life history. Extensive adaptive radiations of cichlid fishes have occurred in the Great Lakes of Africa, giving rise to behaviors that are remarkably sophisticated and diverse across species. In Tanganyikan shell-brooding cichlids of the tribe Lamprologini, tremendous intraspecific variation in body size accompanies complex breeding systems and use of empty snail shells to hide from predators and rear offspring. A study by in this issue of Molecular Ecology reveals the first case of genetic divergence between dwarf and normal-sized morphs of the same nominal lamprologine species, Telmatochromis temporalis. Patterns of population structure suggest that the dwarf, shell-dwelling morph of T. temporalis might have arisen from the normal, rock-dwelling morph independently in more than one region of the lake, and that pairs of morphs at different sites may represent different stages early in the process of ecological speciation. The findings of Takahashi et al. are important first steps toward understanding the evolution of these intriguing morphs, yet many questions remain unanswered about the mating system, gene flow, plasticity, and selection. Despite these limitations, descriptive work like theirs takes on much significance in African cichlids due to forthcoming resources for comparative genomics.