Evolutionary Proliferation: Diversification and its Contex in Neogastropod Molluscs

[9706749 . Vermeij]进化扩张时期的特征是什么？在这样的时期，进化支的增殖有什么特征？这些基本问题激发了对新生代新腹足类软体动物的选择分支的多样化研究。巨大的形态和生态多样性，以及这一大群软体动物的优秀化石记录，使新腹足类动物成为研究进化增殖的理想选择，这是一种在生命史上尚不为人所知但至关重要的现象。分类，系统发育，分布，和生态的进化历史明显不同的分支将被研究。在早期研究rapanine muricides和pseudoolivids的基础上，将对杀戮亚科ocenbrinae和Muricinae， buccineae亚科Pisaniinae， Photinae和Siphonaliinae以及片形虫科进行祖先-后代和姐妹群关系的分析。这些所谓的进化分支之间的比较将集中在化石和现存物种的外壳特征上，这些特征将在世界上主要的博物馆收藏中进行检验，并将从活着的代表身上获得DNA序列。将在巴拿马的两个海岸进行有关贝壳形态与生活方面的观察，包括进食、运动和防御。有待验证的假设包括：1)关键创新和反掠食性特征减少了物种形成的障碍，增加了进化支系中潜在表型的范围；2)气候变暖时期（中至晚始新世、晚渐新世至早中新世、上新世早期）有利于全球多样性；3)晚中新世开始的中美洲海道收缩刺激了热带美洲的物种形成，但其他地方没有；4)冰川引起的气候波动刺激了中新世晚期开始的高纬度进化枝的物种形成。姐妹群体之间的多重比较，孟时间间隔，以及具有不同历史的区域之间的多重比较将用于评估这些内在和外在触发物种形成和适应性多样化的作用。对多样化的研究之所以重要，不仅是因为人们对进化扩散知之甚少，还因为它与经济增长有着密切的相似之处。以经验为基础的生命史经济学观点可能会揭示人类经济的重要控制因素，并使进化科学与经济学的社会科学学科之间的知识联系成为可能。

9706749 Vermeij Which circumstances characterize times of evolutionary expansion? What attributes characterize clades that proliferate at such times? These fundamental questions motivate the proposed study of diversification in selected clades of Cenozoic neogastropod molluscs. The great morphological and ecological diversity, as well as the excellent fossil record of this large group of molluscs make the Neogastropoda ideal for the study of evolutionary proliferation, an as yet poorly understood but crucially important phenomenon in the history of life. The taxonomy, phylogeny, distribution, and ecology of clades with apparently contrasting evolutionary histories will be studied. Building on earlier work with rapanine muricids and pseudolivids, analyses of ancestor-descendant and sister-group relationships will be conducted in the muricid subfamilies Ocenebrinae and Muricinae, the buccinid subfamilies Pisaniinae, Photinae, and Siphonaliinae, and the family Fasciolariidae. Comparisons within and between these purported clades will focus on shell characters of fossil and living species, to be examined in the major museum collections of the world, and on DNA sequences to be obtained from living representatives. Observations relating shell morphology to aspects of life including feeding, locomotion, and defense will be conducted on the two coasts of Panama. Hypotheses to be tested include the following: 1) key innovations as well as antipredatory traits reduce barriers to speciation and increase the range of potential phenotypes in a clade; 2) times of climatic warming (Middle to Late Eocene, Late Oligocene to Early Miocene, Early Pliocene) favor worldwide diversification; 3) constriction of the Central American seaway beginning in the Late Miocene stimulated speciation in tropical America but not elsewhere; 4) glacially induced climatic fluctuations stimulated speciation among high-latitude clades beginning in the latest Miocene. Multiple comparisons among sister-groups, a mong time intervals, and among regions with contrasting histories will be used to evaluate the roles of these intrinsic and extrinsic triggers of speciation and adaptive diversification. The study of diversification is important not only because evolutionary proliferation remains little understood, but also because of close parallels with economic growth. An empirically based economic perspective on the history of life may shed light on important controls of the human economy, and make possible intellectual links between evolutionary science and the social science discipline of economics.