Research Hub for Coral Reef Ecosystem Functions, College of Science and Engineering, James Cook University, Townsville, QLD, 4811, Australia.
ARC Centre of Excellence for Coral Reef Studies, James Cook University, Townsville, QLD, 4811, Australia.
Nat Commun. 2022 May 3;13(1):2426. doi: 10.1038/s41467-022-30234-6.
Ecological interactions are ubiquitous on tropical coral reefs, where sessile organisms coexist in limited space. Within these high-diversity systems, reef-building scleractinian corals form an intricate interaction network. The role of biotic interactions among reef corals is well established on ecological timescales. However, its potential effect on macroevolutionary patterns remains unclear. By analysing the rich fossil record of Scleractinia, we show that reef coral biodiversity experienced marked evolutionary rate shifts in the last 3 million years, possibly driven by biotic interactions. Our models suggest that there was an overwhelming effect of staghorn corals (family Acroporidae) on the fossil diversity trajectories of other coral groups. Staghorn corals showed an unparalleled spike in diversification during the Pleistocene. But surprisingly, their expansion was linked with increases in both extinction and speciation rates in other coral families, driving a nine-fold increase in lineage turnover. These results reveal a double-edged effect of diversity dependency on reef evolution. Given their fast growth, staghorn corals may have increased extinction rates via competitive interactions, while promoting speciation through their role as ecosystem engineers. This suggests that recent widespread human-mediated reductions in staghorn coral cover, may be disrupting the key macroevolutionary processes that established modern coral reef ecosystems.
热带珊瑚礁上存在着广泛的生态相互作用，固着生物在有限的空间中共存。在这些高多样性的系统中，造礁珊瑚形成了一个复杂的相互作用网络。生物相互作用在生态时间尺度上对珊瑚礁的作用已经得到充分证实。然而，其对宏观进化模式的潜在影响尚不清楚。通过分析石珊瑚丰富的化石记录，我们表明，在过去的 300 万年里，珊瑚礁生物多样性经历了显著的进化率变化，这可能是由生物相互作用驱动的。我们的模型表明，鹿角珊瑚（鹿角珊瑚科）对其他珊瑚类群的化石多样性轨迹有压倒性的影响。鹿角珊瑚在更新世的多样化过程中出现了无与伦比的激增。但令人惊讶的是，它们的扩张与其他珊瑚科的灭绝和物种形成率的增加有关，从而导致谱系更替增加了九倍。这些结果揭示了多样性依赖性对珊瑚礁进化的双重影响。鉴于鹿角珊瑚生长迅速，它们可能通过竞争相互作用增加了灭绝率，同时通过其作为生态系统工程师的作用促进了物种形成。这表明，最近人类介导的鹿角珊瑚覆盖率的广泛减少，可能正在破坏建立现代珊瑚礁生态系统的关键宏观进化过程。
