Origins of Life and Evolution of Biospheres
March 2018, Volume 48, Issue 1, pp 35–54 | Cite as
Environmental Adaptation from the Origin of Life to the Last Universal Common Ancestor
Authors
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Marjorie D. Cantine1
Gregory P. Fournier1
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1.Department of Earth, Atmospheric and Planetary SciencesMassachusetts Institute of TechnologyCambridgeUSA
Hypothesis
First Online: 06 July 2017
Abstract
Extensive fundamental molecular and biological evolution took place between the prebiotic origins of life and the state of the Last Universal Common Ancestor (LUCA). Considering the evolutionary innovations between these two endpoints from the perspective of environmental adaptation, we explore the hypothesis that LUCA was temporally, spatially, and environmentally distinct from life’s earliest origins in an RNA world. Using this lens, we interpret several molecular biological features as indicating an environmental transition between a cold, radiation-shielded origin of life and a mesophilic, surface-dwelling LUCA. Cellularity provides motility and permits Darwinian evolution by connecting genetic material and its products, and thus establishing heredity and lineage. Considering the importance of compartmentalization and motility, we propose that the early emergence of cellularity is required for environmental dispersal and diversification during these transitions. Early diversification and the emergence of ecology before LUCA could be an important pre-adaptation for life’s persistence on a changing planet.
Keywords
Origin of life Last universal common ancestor (LUCA) Environmental adaptation
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