The identification of cellular life in the rock record is problematic, since microbial life forms, and particularly bacteria, lack sufficient morphologic complexity to be effectively distinguished from certain abiogenic features in rocks. Examples include organic pore‐fillings, hydrocarbon‐containing fluid inclusions, organic coatings on exfoliated crystals and biomimetic mineral aggregates (biomorphs). This has led to the interpretation and re‐interpretation of individual microstructures in the rock record. The morphologic description of entire populations of microstructures, however, may provide support for distinguishing between preserved micro‐organisms and abiogenic objects. Here, we present a statistical approach based on quantitative morphological description of populations of microstructures. Images of modern microbial populations were compared to images of two relevant types of abiogenic microstructures: interstitial spaces and silica–carbonate biomorphs. For the populations of these three systems, the size, circularity, and solidity of individual particles were calculated. Subsequently, the mean/SD, skewness, and kurtosis of the statistical distributions of these parameters were established. This allowed the qualitative and quantitative comparison of distributions in these three systems. In addition, the fractal dimension and lacunarity of the populations were determined. In total, 11 parameters, independent of absolute size or shape, were used to characterize each population of microstructures. Using discriminant analysis with parameter subsets, it was found that size and shape distributions are typically sufficient to discriminate populations of biologic and abiogenic microstructures. Analysis of ancient, yet unambiguously biologic, samples (1.0 Ga Angmaat Formation, Baffin Island, Canada) suggests that taphonomic effects can alter morphometric characteristics and complicate image analysis; therefore, a wider range of microfossil assemblages should be studied in the future before automated analyses can be developed. In general, however, it is clear from our results that there is great potential for morphometric descriptions of populations in the context of life recognition in rocks, either on Earth or on extraterrestrial bodies.

中文翻译：

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鉴定岩石中的微生物生命：种群形态学的见解。

由于微生物的生命形式，尤其是细菌，缺乏足够的形态复杂性，无法有效地与岩石中的某些生物成因特征区分开来，因此在岩石记录中确定细胞生命是有问题的。例如，有机孔隙填充物，含烃流体包裹体，脱落晶体上的有机涂层以及仿生矿物聚集体（生物形态）。这导致对岩石记录中单个微结构的解释和重新解释。但是，对整个微观结构种群的形态学描述可能会为区分保存的微生物和非生物物体提供支持。在这里，我们提出了一种基于定量的微观结构种群形态描述的统计方法。将现代微生物种群的图像与两种相关类型的生物成因的微结构图像进行了比较：间质空间和硅碳酸盐生物形态。对于这三个系统的总体，计算了单个粒子的大小，圆形度和固体度。随后，均值/标清确定了这些参数的统计分布的偏度，偏度和峰度。这样就可以对这三个系统中的分布进行定性和定量比较。另外，确定了种群的分形维数和隐隐性。总共有11个参数，与绝对尺寸或形状无关，用于表征每个微观结构。使用带有参数子集的判别分析，发现大小和形状分布通常足以区分生物和非生物微观结构的种群。对古老而明确的生物样本（加拿大加芬岛1.0 Ga Angmaat岩层）的分析表明，透声效应会改变形态特征并使图像分析复杂化。所以，在开发自动化分析之前，应在将来研究更广泛的微化石组合。但是，从总体上看，从我们的结果来看，很明显，在岩石或地球上或地球外生物的生命识别中，有可能对种群进行形态计量学描述。