DS3618: “Have you ever considered that naturalistic explanations cannot explain DNA, or the Cambrian explosion… I challenge you to explain how through naturalistic processes you can form even the simplest bacteria (which by the way has ~160 kilobases)”
My formula for the origin of life is “RNA world plus micelles”.
A micelle is a self-organized sphere of hydrophobic molecules. “RNA world” refers to a stage when you don’t have the division of labor between DNA (information) and protein (structure), with RNA instead doing double duty (information from sequence, structure from conformation). Lipids and RNA polymers are capable of forming spontaneously in abiotic circumstances. So the idea is that the lipids mechanically self-organized into populations of micelles, which in turn contained different populations of RNA polymers. RNAs can both reproduce (in that one RNA strand can serve as a template for the formation of a second) and catalytically interact with each other (thus increasing or decreasing the reproduction rate of the other RNA species in a population). Finally one supposes a physical process, such as turbulence, which keeps breaking up these RNA-loaded micelles. Voila, you have a population of protocells subject to natural selection.
This is just a sketch of how biological evolution might get underway, by someone who is not even a biologist. But I don’t think it’s that hard to understand.
And as for the Cambrian explosion, if you know anything about how tissue differentiation and embyronic development work, I don’t see how you could regard it as fundamentally mysterious. Sponges are the primordial multicellular lifeform and they already have the relevant genetic regulatory networks. Once that level of genetic complexity exists, it’s not that amazing to see how it could lead to the diversity of multicellular life that we have now. So in a way the question is just, how did we get sponges. I am fond of the theory (promoted by John Mattick and others) that the essential new step involved in the transition to complex multicellularity is the development of a new level of genetic regulation involving transcribed intronic RNAs which never become protein but which do play a regulatory role controlling other genes. The idea is that this extra level of regulatory complexity permitted the transition from homogeneous colonies of single-celled organisms to multicellular organisms with differentiated tissues. But again, the bottom line is that this stuff does not look fundamentally mysterious. There’s plenty to discover about how it might have happened and how it did happen, but it’s not baffling, let alone naturalistically impossible.
DS3618: “Have you ever considered that naturalistic explanations cannot explain DNA, or the Cambrian explosion… I challenge you to explain how through naturalistic processes you can form even the simplest bacteria (which by the way has ~160 kilobases)”
My formula for the origin of life is “RNA world plus micelles”.
A micelle is a self-organized sphere of hydrophobic molecules. “RNA world” refers to a stage when you don’t have the division of labor between DNA (information) and protein (structure), with RNA instead doing double duty (information from sequence, structure from conformation). Lipids and RNA polymers are capable of forming spontaneously in abiotic circumstances. So the idea is that the lipids mechanically self-organized into populations of micelles, which in turn contained different populations of RNA polymers. RNAs can both reproduce (in that one RNA strand can serve as a template for the formation of a second) and catalytically interact with each other (thus increasing or decreasing the reproduction rate of the other RNA species in a population). Finally one supposes a physical process, such as turbulence, which keeps breaking up these RNA-loaded micelles. Voila, you have a population of protocells subject to natural selection.
This is just a sketch of how biological evolution might get underway, by someone who is not even a biologist. But I don’t think it’s that hard to understand.
And as for the Cambrian explosion, if you know anything about how tissue differentiation and embyronic development work, I don’t see how you could regard it as fundamentally mysterious. Sponges are the primordial multicellular lifeform and they already have the relevant genetic regulatory networks. Once that level of genetic complexity exists, it’s not that amazing to see how it could lead to the diversity of multicellular life that we have now. So in a way the question is just, how did we get sponges. I am fond of the theory (promoted by John Mattick and others) that the essential new step involved in the transition to complex multicellularity is the development of a new level of genetic regulation involving transcribed intronic RNAs which never become protein but which do play a regulatory role controlling other genes. The idea is that this extra level of regulatory complexity permitted the transition from homogeneous colonies of single-celled organisms to multicellular organisms with differentiated tissues. But again, the bottom line is that this stuff does not look fundamentally mysterious. There’s plenty to discover about how it might have happened and how it did happen, but it’s not baffling, let alone naturalistically impossible.