Progress in Biophysics and Molecular Biology ( IF 3.2 ) Pub Date : 2019-10-21 , DOI: 10.1016/j.pbiomolbio.2019.10.002 Saibal Mitra 1
Biomolecules can be synthesized in interstellar ice grains subject to UV radiation and cosmic rays. I show that on time scales of years, these processes lead to the formation of large percolation clusters of organic molecules. Some of these clusters would have ended up on proto-planets where large, loosely bound aggregates of clusters (superclusters) would have formed. The interior regions of such superclusters provided for chemical micro-environments that are filtered versions of the outside environment.
I argue that models for abiogenesis are more likely to work when considered inside such micro-environments. As the supercluster breaks up, biochemical systems in such micro-environments gradually become subject to a less filtered environment, allowing them to get adapted to the more complex outside environment. A particular system originating from a particular location on some supercluster would have been the first to get adapted to the raw outside environment and survive there, thereby becoming the first microbe.
A collision of a microbe-containing proto-planet with the Moon could have led to fragments veering off back into space, microbes in small fragments would have been able to survive a subsequent impact with the Earth.
中文翻译:
星际冰粒中有机物的渗透簇是生命的孵化器。
可以在经受紫外线辐射和宇宙射线的星际冰粒中合成生物分子。我证明了几年来,这些过程导致形成了大的有机分子渗滤簇。其中一些星团最终会落在原行星上,在那里会形成大型的,松散结合的星团(超集群)。这种超团簇的内部区域提供了化学微环境,是外部环境的过滤形式。
我认为,在这样的微环境中考虑生物发生的模型更可能起作用。随着超级集群的破裂,这种微环境中的生化系统逐渐受到过滤程度较低的环境的影响,从而使其能够适应更复杂的外部环境。源自某个超级集群上特定位置的特定系统将是第一个适应原始外部环境并在那里生存的系统,从而成为第一个微生物。
含有微生物的原行星与月球的碰撞可能会导致碎片转向太空,小碎片中的微生物将能够幸免于与地球的后续撞击。