School of Chemistry, University of Glasgow, Glasgow, UK.
Astrobiology Analytical Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD, USA.
Nat Commun. 2021 May 24;12(1):3033. doi: 10.1038/s41467-021-23258-x.
The search for alien life is hard because we do not know what signatures are unique to life. We show why complex molecules found in high abundance are universal biosignatures and demonstrate the first intrinsic experimentally tractable measure of molecular complexity, called the molecular assembly index (MA). To do this we calculate the complexity of several million molecules and validate that their complexity can be experimentally determined by mass spectrometry. This approach allows us to identify molecular biosignatures from a set of diverse samples from around the world, outer space, and the laboratory, demonstrating it is possible to build a life detection experiment based on MA that could be deployed to extraterrestrial locations, and used as a complexity scale to quantify constraints needed to direct prebiotically plausible processes in the laboratory. Such an approach is vital for finding life elsewhere in the universe or creating de-novo life in the lab.
寻找外星生命是困难的，因为我们不知道哪些特征是生命独有的。我们展示了为什么在高丰度下发现的复杂分子是普遍的生物特征，并首次提出了一种可实验测量的分子复杂性内在指标，称为分子组装指数（MA）。为此，我们计算了数百万种分子的复杂性，并验证了其复杂性可以通过质谱法实验确定。这种方法使我们能够从来自世界各地、外太空和实验室的一组多样化样本中识别出分子生物特征，证明基于 MA 构建生命探测实验是可行的，该实验可以部署到外星地点，并用作复杂性尺度来量化在实验室中进行前生物似然过程所需的约束条件。这种方法对于在宇宙中寻找其他生命或在实验室中创造新生命至关重要。
