墨尔本，今天，我们的星球充满了生命，但它并非一直如此。早在森林冲向天空、动物在陆地上行走、恐龙兴衰之前，我们的星球是由一种更小、更不起眼的生命形式塑造的。如今，我们仍能发现它的痕迹。这些古老的化石是地球上生命最早的可见证据，被称为微生物岩。西澳大利亚拥有微生物岩的非凡记录：从已知最古老的例子——保存在皮尔巴拉地区近35亿年岩石中的微生物岩，到鲨鱼湾联合国教科文组织世界遗产区的现存例子。
Melbourne, Today, our planet is teeming with life, but it has not always looked the same. Long before forests reached skyward, animals walked on land, and the rise and fall of dinosaurs, our planet was shaped by a much smaller, more unassuming form of life. And we can still find traces of it today. These ancient fossils, the earliest visible evidence of life on Earth, are known as microbialites. Western Australia contains an extraordinary record of microbialites: from the oldest known examples, preserved in rocks almost 3.5 billion years old in the Pilbara, to living examples in the UNESCO World Heritage area of Shark Bay.
我们今天在《Alcheringa》期刊上发表的对西澳大利亚50年微生物岩研究的综述，总结了这一档案能告诉我们关于地球生命演化和韧性的信息。尽管微生物岩的化石记录跨越数十亿年，但它们出人意料地脆弱。化石遗址仍面临过度采集和退化的威胁，而现存的微生物岩则承受着日益增长的压力。在克利夫顿湖和鲨鱼湾等地，一些事件可能已经造成了不可逆转的损害。
Our review of 50 years of microbialite research in Western Australia, published today in the journal Alcheringa, summarises what this archive can tell us about the evolution and resilience of life on Earth. Despite a fossil record that spans billions of years, microbialites are surprisingly fragile. Fossil sites remain vulnerable to over-collection and degradation, while living microbialites are facing growing pressures. At sites such as Lake Clifton and Shark Bay, some events may have already caused irreparable damage.
例如，2024年5月，数十名追逐极光的人在克利夫顿湖的禁区内践踏了2000年历史的栓状菌岩。地球上最古老的生命证据微生物岩是呈 mound 状的结构，形状和大小各不相同。它们形成于微生物群落要么沉淀矿物质，要么捕获并粘合沉积物的过程。微生物岩的类型可通过其内部结构来描述。层状菌岩是最著名的一种，具有明显的层理。
One such example was in May 2024, when dozens of aurora chasers trampled 2,000-year-old thrombolites in a restricted area at Lake Clifton. Earth's oldest evidence of lifeMicrobialites are mounded structures that come in many shapes and sizes. They form when communities of microbes either precipitate minerals, or trap and bind sediment. Types of microbialites can be characterised by their internal structure. Stromatolites are the best known, and have distinctive layers.
相比之下，栓状菌岩则具有凝块状的质地。微生物岩的记录可以告诉我们关于地球生命的许多信息。
Thrombolites, by contrast, have a clotted texture. The microbialite record can tell us a great deal about life on Earth.
它为我们提供了线索，说明最早的一些生命存在于何处，我们可能在何处寻找地球以外的生命，以及我们的大气层是如何变得富含氧气的，为更复杂生命的出现铺平了道路。现代地点尤为重要，因为它们帮助我们更好地理解形成古老岩石记录中微生物岩的过程。来自鲨鱼湾的活体微生物岩甚至被描述为理解其化石对应物的“罗塞塔石碑”。
It gives us clues about where some of the earliest life lived, where we might look for life beyond Earth, and how our atmosphere became oxygen rich, paving the way for more complex life to follow. Modern sites are particularly important because they help us better understand processes that formed microbialites in the ancient rock record. Living microbialites from Shark Bay have even been described as a "Rosetta Stone" for understanding their fossil counterparts.
微生物岩还保存了生命在过去如何应对环境剧变的证据。西澳大利亚的微生物岩记录至少跨越了地球五次大规模灭绝事件中的一次，甚至可能有两次。这一深时记录表明，微生物岩可能作为生态压力的早期指标发挥作用。证据表明，微生物岩的突然增加往往在过去的重大生态破坏和大规模灭绝之前出现或同时发生。然而，我们的综述也凸显出若干重要的知识空白。
Microbialites also preserve evidence of how life responded to environmental upheaval in the past. Western Australia's microbialite record spans at least one, and potentially two, of Earth's five major mass extinctions. This deep-time record suggests microbialites may act as early indicators of ecological stress. Evidence suggests that the sudden increase of microbialites often preceded or coincided with major ecological disruption and mass extinction in the past. Yet our review highlights several significant knowledge gaps.
科学家们仍在争论如何区分由生命构建的结构和由非生物过程产生的结构。我们也不能总是确定地说出古代微生物岩形成的环境。此外，对控制微生物岩形状和结构的因素仍存在不确定性。我们也不完全清楚现代例子在多大程度上反映了化石形态。为何凝结藻岩的内部结构是絮状的，而不是像层状藻岩那样分层的，仍然是一个谜题。
Scientists are still debating how to distinguish structures built by life from those produced by non-biological processes. We also cannot always say with certainty what environments ancient microbialites formed in. There is further uncertainty about what controls the shape and structure of microbialites. We also don't fully know how closely modern examples reflect fossil forms. Why the internal structure of thrombolites is clotted rather than layered, as in stromatolites, remains a conundrum.
它们在地质记录中能追溯到何时也是未知之谜。西澳大利亚可能包含一些已知最古老的凝结藻岩，但这些例子尚未被详细记录。简而言之，地球上最古老的生物记录尚未完结，尽管这些空白正在慢慢被填补。
So does how far back they extend in the geological record. Western Australia may contain some of the oldest known thrombolites, but these examples have not yet been documented in detail. In short, Earth's oldest biological record is not a finished story, although the gaps are slowly being filled.
保存证据，无论是活的还是化石的，对未来科学家回答我们目前尚无答案的问题至关重要，甚至可能提出我们尚未想到的问题。面临风险的古代档案尽管微生物岩具有地质学上的长寿和看似不变的特性，但它们出人意料地脆弱。岩石般的外观使得这一点难以被认识到。活的微生物岩对环境干扰极其敏感。它们极其缓慢的生长速度意味着物理损害可能需要数十年甚至数百年才能修复，甚至可能永远无法修复。
Preserving the evidence, both living and fossil, is essential if future scientists are to answer questions we don't have answers for yet, or perhaps even to ask questions we have not yet thought to ask. An ancient archive at riskDespite their geological longevity and seemingly unchanging nature, microbialites are surprisingly fragile. Their rock-like appearance can make this difficult to appreciate. Living microbialites can be highly sensitive to environmental disturbance. Their extremely slow growth rates mean physical damage can take decades or centuries to repair, if at all.
许多现代微生物岩遗址正面临着水质变化、气候变化和游客增加带来的日益增长的压力。化石微生物岩同样脆弱。在西澳大利亚，旅游业、不当采集甚至科学采样都可能损害或削减这些不可替代的遗址。作为地质特征，它们的保护属于地质遗产范畴。然而，在地质遗产方面，澳大利亚在联邦和州两级仍然认知不足、资源匮乏。
Many modern microbialite sites face growing pressures from changes in water quality, climate change and increasing visitation. Fossil microbialites are also vulnerable. Across Western Australia, tourism, inappropriate collecting and even scientific sampling can damage or diminish these irreplaceable sites. As geological features, their protection falls under geoheritage. Yet geoheritage remains poorly recognised and under resourced in Australia at both the federal and state levels.
2021年澳大利亚环境状况报告得出结论：“由于缺乏国家框架、关注和资源，地质遗产的总体前景令人担忧。”不幸的是，情况几乎没有改善。如今，我们正面临前所未有且加速的生物多样性丧失。微生物岩档案提供了深时间视角，以了解生态系统如何响应环境变化、生态破坏和条件变化。这些见解能在多大程度上帮助我们理解当今生命面临的挑战，仍然是一个悬而未决的问题。
The 2021 Australian State of the Environment report concluded that "the overall outlook for geoheritage is poor" due to the lack of national frameworks, focus and resourcing for this area of heritage. Unfortunately, little has changed. Today, we face an unprecedented and accelerating loss of biodiversity. The microbialite archive offers a deep-time perspective on how ecosystems respond to environmental change, ecological disruption and changing conditions. How far these insights can inform our understanding of the challenges facing life today remains an open question.
同样重要的是，这些档案——无论是活的还是化石的——是否能够保持完整并为后代所访问，以便他们不仅能研究我们今天提出的问题，还能探索我们尚未构想的问题。AMS
Just as important is whether the archives themselves, both living and fossil, will remain intact and accessible for future generations to investigate not only the questions we are asking today, but those we have yet to conceive. AMS