Earth and Planetary Sciences, University of California, Davis, CA, USA
Proc Biol Sci. 2018 Nov 14;285(1891):20182027. doi: 10.1098/rspb.2018.2027.
The North Pacific is the largest cold-water source of lineages spreading to other modern marine temperate biotas. How this status was achieved remains unclear. One hypothesis is that functional innovations of large effect, defined as departures from the norm in temperate clades and which confer competitive or defensive benefits, increase resource availability, and raise performance standards in the biota as a whole, evolved earlier and more frequently in the North Pacific than elsewhere in the temperate zone. In support of this hypothesis, phylogenetic and fossil evidence reveals 47 temperate marine innovations beginning in the latest Eocene, of which half arose in the North Pacific. Of the 22 innovations of large effect, 13 (39%) evolved in the North Pacific, including basal growth in kelps and bottom-feeding herbivory and durophagy in mammals. Temperate innovations in the Southern Hemisphere and the North Atlantic appeared later and were less consequential. Most other innovations arose in refuges where the risks of predation and competition are low. Among temperate marine biotas, the North Pacific has the highest incidence of unique innovations and the earliest origins of major breakthroughs, five of which spread elsewhere.
北太平洋是向其他现代海洋温带生物群传播的谱系的最大冷水源。这种地位是如何形成的尚不清楚。一种假设是，功能创新的大效应，定义为温带进化枝中的常态偏离，赋予竞争或防御优势，增加资源可用性，并提高整个生物群的性能标准，在北太平洋比在温带地区的其他地方更早、更频繁地进化。支持这一假设的是，系统发育和化石证据揭示了 47 种始于晚始新世的温带海洋创新，其中一半发生在北太平洋。在 22 种大效应的创新中，有 13 种（39%）发生在北太平洋，包括大型褐藻的基础生长以及哺乳动物的底栖食草和硬骨食性。南半球和北大西洋的温带创新出现得更晚，影响也更小。大多数其他创新出现在捕食和竞争风险较低的避难所。在温带海洋生物群中，北太平洋独特创新的发生率最高，重大突破的起源最早，其中五个突破传播到其他地方。
