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POPSChemists edge closer to recreating early life Joyce's experiment was designed to test the 'RNA World' theory, which proposes that DNA-based life evolved from a stage whereby RNA acted as both an information-storage molecule, like DNA, and as a catalyst, like enzymes, and was also capable of self-replication. This work is the biggest injection of support for the RNA world hypothesis in a long time,' says Donna Blackmond, Chair in Catalysis at Imperial College London, UK. 'It's a demonstration of principle that indefinite replication, coupled with selection via mutation, is quite plausible for RNA. The fact that it goes on indefinitely is a big thing for showing that this really could have been how life started,' she adds.
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POPSMapping the Bio Cosmos Microbes are responsible for many biogeochemical cycles and are crucial to the continued function of the , Woese's efforts to clarify the evolution and diversity of microbes provided an invaluable service to ecologists and conservationists. Woese’s big idea is that primitive life existed as a community of cells that freely exchanged genes. They shared a basic translation system for making proteins, but had little else in common. These cells evolved as a community and not as distinct lineages. Before Woese, the tree of life had two main branches called prokaryotes and eukaryotes, the prokaryotes composed of cells without nuclei and the eukaryotes composed of cells with nuclei.
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POPSBiologists on the Verge of Creating New Form of Life "We've made more progress on how the membrane of a protocell could grow and divide," Szostak said in a phone interview. "What we can do now is copy a limited set of simple sequences, but we need to be able to copy arbitrary sequences so that sequences could evolve that do something useful." By doing "something useful" for the cell, these genes would launch the new form of life down the Darwinian evolutionary path similar to the one that our oldest living ancestors must have traveled. Though where selective pressure will lead the new form of life is impossible to know.
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POPSIs our universe fine-tuned for life? Claims of fine-tuning have generally been based on what happens when you vary a single characteristic of the universe, say the strength of gravity, while holding all others constant. That, says Adams, is too artificial a scenario to tell you anything about whether there are other universes that can support life. "The right way to do the problem is to start from scratch," he says. "You have to turn all the knobs and find out what happens."
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POPSHuge hidden biomass lives deep beneath the oceans They found simple organisms known as prokaryotes in every sample. Prokaryotes are organisms that often have just one cell. Their peculiarity is that, unlike any other form of life, their DNA is not neatly packed into a nucleus.
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