Micro‐organisms have long been implicated in the construction of stromatolites. Yet, establishing a microbial role in modern stromatolite growth via molecular analysis is not always straightforward because DNA in stromatolites can have multiple origins. For example, the genomic material could represent the microbes responsible for the construction of the stromatolite (i.e., “builders”), microbes that inhabited the structure after it was built (i.e., “tenants”), or microbes/organic matter that were passively incorporated after construction from the water column or later diagenetic fluids (i.e., “squatters”). Disentangling the role of micro‐organisms in stromatolite construction, already difficult in modern systems, becomes more difficult as organic signatures degrade, and their context is obscured. To evaluate our ability to accurately decipher the role of micro‐organisms in stromatolite formation in geologically recent settings, 16/18S SSU rRNA gene sequences were analyzed from three systems where the context of growth was well understood: (a) an actively growing stromatolite from a silicic hot spring in Yellowstone National Park, Wyoming, where the construction of the structure is controlled by cyanobacteria; (b) a mixed carbonate and silica precipitate from Little Hot Creek, a hot spring in the Long Valley Caldera of California that has both abiogenic and biogenic components to accretion; and (c) a near‐modern lacustrine carbonate stromatolite from Walker Lake, Nevada that is likely abiogenic. In all cases, the largest percentage of recovered DNA sequences, especially when focused on the deeper portions of the structures, belonged to either the tenant or squatter communities, not the actual builders. Once removed from their environmental context, correct interpretation of biology's role in stromatolite morphogenesis was difficult. Because high‐throughput genomic analysis may easily lead to incorrect assumptions even in these modern and near‐modern structures, caution must be exercised when interpreting micro‐organismal involvement in the construction of accretionary structures throughout the rock record.

中文翻译：

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建筑商，租户和擅自占地者：现代叠层岩中遗传物质的起源

微生物早已牵涉到叠层石的构造中。但是，通过分子分析确定微生物在现代叠层石生长中的作用并不总是那么容易，因为叠层石中的DNA可能有多种来源。例如，基因组材料可以代表负责叠层石构造的微生物（即“建筑者”），构造后居住在结构中的微生物（即“租户”）或被动地形成的微生物/有机物。在从水柱或以后的成岩流体（即“ qua屋”）中建造后掺入。在有机体系降解中，要弄清微生物在叠层石构造中的作用，在现代系统中本来就很困难，但随着有机特征的降解和掩盖它们的背景，微生物变得更加困难。为了评估我们在最近的地质环境中准确破译微生物在叠层石形成中的作用的能力，我们从三个易于理解生长背景的系统中分析了16 / 18S SSU rRNA基因序列：怀俄明州黄石国家公园的硅质温泉，其结构由蓝细菌控制；（b）来自Little Hot Creek的碳酸盐和二氧化硅的混合沉淀物，Little Hot Creek是加利福尼亚州长谷火山口的温泉，同时具有生源和生物成因成分；（c）来自内华达州沃克湖的近现代湖相碳酸盐岩叠层岩，可能是生物成因的。在所有情况下，回收的DNA序列所占的百分比最高，尤其是当关注结构的较深部分时，属于租户或屋者，而不是实际的建设者。一旦脱离环境，就很难正确解释生物学在叠层石形态发生中的作用。因为即使在这些现代和近现代的结构中，高通量基因组分析也很容易导致错误的假设，所以在解释整个岩石记录中微生物对增生结构的构造时，必须谨慎行事。