Understanding of diachroneity: Palaeoenvironmental controls on dispersal of planktic foraminifera in the Plio-Pleistocene oceans

对历时性的理解：古环境对上里奥-更新世海洋中浮游有孔虫扩散的控制

• 批准号: NE/T012382/1
• 负责人: Paul Wilson
• 金额: $ 6.43万
• 依托单位: University of Southampton
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2019
• 资助国家: 英国
• 起止时间: 2019 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FT012382%2F1
• 关键词: Understanding; diachroneity; Palaeoenvironmental; controls; dispersal

Macroevolution is the generation, proliferation and removal of species. The lack of physical barriers and large population size of most marine species should allow for rapid dispersal and colonization of new habitats following speciation. However, gene flow appears more limited than we would predict based on this analysis: diachronous first occurrence dates among and within ocean basins of many species of planktonic foraminifera suggest that population establishment is often temporarily restricted immediately after speciation. Recent work shows that even in a cosmopolitan marine diatom species, gene flow is restricted at an ocean basin scale. These observations indicate that (i) physical barriers to dispersion in the open ocean are stronger than commonly invoked and (ii) the identity of these barriers and their working mechanisms are poorly understood. The proposed research will study environmental drivers of dispersal dynamics in the open ocean of the circum- Antarctic using planktonic foraminifera of Plio-Pleistocene age in deep sea sediments recovered during International Ocean Discovery Program (IODP) Expedition 383 in May-July 2019. The named researcher, Dr Anieke Brombacher, participated in Expedition 383 shipboard as a planktonic foraminifer biostratigrapher as a UK-IODP sponsored scientist.Planktonic foraminifera are ideally suited for in-depth analysis of temporal dispersal dynamics because their high-resolution fossil record in marine sediments allows for reconstructions of population dynamics across space and through time. Using sediments recovered by IODP Expedition 383, we will study species dispersal and migration in the sub-polar Southern Pacific Ocean, a region that, via the Drake Passage, connects the Pacific and Atlantic Oceans but lies at the edge of many species' geographical ranges. Expedition 383 drilled six South Pacific sites well north of the Antarctic front, that are well-suited to producing extremely high-resolution sediment records undisturbed by major ice rafting. We will document foraminifera evolution at three of these sites and compare those records to geochemical reconstructions of variability in the Antarctic Circumpolar Current (ACC). Specifically, high-resolution Pliocene-Pleistocene sediment archives recovered from IODP Sites U1539, U1540 and U1541 will be used to study edge population dispersal through Drake Passage, a key high latitude ocean gateway connecting the Pacific and Atlantic Oceans in response to 40-kyr glacial cycles.The Neogene planktonic foraminifera species Truncorotalia truncatulinoides, Globoconella puncticulata puncticuloides and Globoconella inflata all originated in the Southwest Pacific Ocean. However, G. puncticulata puncticuloides has not been recorded in any other ocean basin, and T. truncatulinoides and G. inflata do not appear in the Atlantic Ocean until 0.5-1.0 Myr after their first appearance in the tropical to mid-latitude Pacific despite the Drake Passage forming an obvious potential migration route. This observation suggests that the high latitudes presented an environmental barrier to the dispersal of temperate-water species early in their evolutionary history. Initial shipboard results from IODP 383 Sites U1539 - U1541, all located around 55 degrees S in the SW Pacific, show varying assemblage compositions across glacial-interglacial cycles. Glacial assemblages are dominated by the polar species Neogloboquadrina pachyderma but interglacial assemblages contain more temperate species including various Truncorotalia and Globoconella taxa. These initial findings suggest that interglacials potentially act to weaken barriers to dispersal to higher latitudes and facilitate adaptation there, a mechanism akin to 'island hoping'. To test this working hypothesis, high-resolution species counts, morphometric and stable isotope data are required to determine whether adaptation improves with exposure to ocean conditions in successive interglacials.

宏观进化是物种的产生，增殖和去除。物理障碍缺乏物理障碍和大多数海洋物种的人口大小应允许种种物种后的新栖息地快速分散和定植。但是，基因流程似乎比我们根据此分析所预测的要有限：直觉上首次发生的日期和内部的许多浮游有孔虫物种的海盆之间和内部发生的日期表明，物种物种物种后通常立即暂时限制种群的建立。最近的工作表明，即使在国际化海洋硅藻物种中，基因流也受到海盆量表的限制。这些观察结果表明，（i）在开阔的海洋中分散的物理障碍比通常所调用的要强，并且（ii）这些障碍及其工作机制的身份知之甚少。拟议的研究将研究在2019年5月至7月在国际海洋发现计划（IODP）探险计划（IODP）探险期间，使用Plio-Ple-peple-ecepeen恢复的Plio-peple-epenepene时代的浮游生物有孔虫在2019年5月至7月在国际海洋发现计划（IODP）探险期间恢复的Plio-peple-egise Age的环境驱动力。 BioStratigrapher作为英国IODP赞助的科学家。浮游有孔虫非常适合对时间分散动力学的深入分析，因为它们的高分辨率化石记录可以使海洋沉积物中的高分辨率化石记录可以重建整个空间和时间的人口动态。使用IODP Expedition 383回收的沉积物，我们将研究Suplar Southern Pacific的物种分散和迁移，该地区通过Drake Passage连接了太平洋和大西洋，但位于许多物种地理范围的边缘。 Expedition 383钻了南太平洋六个地点，在南极阵线以北，它们非常适合生产出极高的高分辨率沉积物记录，这不受重大冰冻的影响。我们将记录其中三个地点的有孔虫进化，并将这些记录与南极圆极电流（ACC）中变异性的地球化学重建进行比较。具体而言，将使用从IODP站点恢复U1539，U1540和U1541的高分辨率上新世宁静的沉积物档案，将用于通过Drake Passage（Drake Passage）来研究边缘种群分散，这是一个关键的高纬度海洋网关，这是一个连接了太平洋和大西洋型海洋杂志的太平洋和大西洋大西洋杂种。 Truncatulinoides，Globoconella Puncticulata Puncticuloides和Globoconella inflata均起源于西南太平洋。然而，在任何其他海洋盆地都没有记录过点状的点核苷，直到在0.5-1.0 Myr中首次出现在热带到中年的太平洋中，尽管Drake传递形成了明显的潜在迁移，truncatulinoides和G. inforta才出现在大西洋中。该观察结果表明，高纬度在其进化史上早期给温带物种扩散带来了环境障碍。最初的船舶从IODP 383个地点U1539 -U1541产生，它们位于SW太平洋的55度左右，显示了跨冰川间冰期循环的不同组合组成。冰川组合以极地物种Neogloboquadrina Pachyderma为主，但冰川间组合包含更多的温带物种，包括各种trunco​​rotalia和Globoconella taxa。这些最初的发现表明，冰川间有可能作用于削弱扩散到更高纬度的障碍并促进在那里的适应，这是一种类似于“岛屿希望”的机制。为了检验这一工作假设，需要高分辨率物种计数，形态计量和稳定的同位素数据，以确定适应性是否会随着连续的冰川间暴露于海洋状况而改善。

项目成果

Morphological variation across space does not predict phenotypic change through time in two Neogene planktonic foraminifera species

空间形态变化并不能预测两种新近纪浮游有孔虫物种随时间的表型变化

• DOI: 10.3389/fevo.2023.1165174
• 发表时间: 2023
• 期刊: Frontiers in Ecology and Evolution
• 影响因子: 3
• 作者: Brombacher A

A new sea-level record for the Neogene/Quaternary boundary reveals transition to a more stable East Antarctic Ice Sheet

新近纪/第四纪边界的新海平面记录揭示了向更稳定的东南南极冰盖的过渡

• DOI: 10.1073/pnas.2004209117
• 发表时间: 2020
• 期刊: Proceedings of the National Academy of Sciences
• 作者: Wilson;Fiebig;Repschläger;Friedrich
• 通讯作者: Friedrich