Where Do Complex Organisms Come From?
Where Do Complex Organisms Come From?
Meyer, Darwins doubt, page 212:
According to neo-Darwinism, new information, form, and structure arise from natural selection acting on random mutations arising at a very low level within the biological hierarchy—within the genetic text. Yet both body-plan formation during embryological development and major morphological innovation during the history of life depend upon a specificity of arrangement at a much higher level of the organizational hierarchy, a level that DNA alone does not determine. If DNA isn’t wholly responsible for the way an embryo develops— for body-plan morphogenesis—then DNA sequences can mutate indefinitely and still not produce a new body plan, regardless of the amount of time and the number of mutational trials available to the evolutionary process. Genetic mutations are simply the wrong tool for the job at hand.
Even in a best-case scenario—one that ignores the immense improbability of generating new genes by mutation and selection—mutations in DNA sequence would merely produce new genetic information. But building a new body plan requires more than just genetic information. It requires both genetic and epigenetic information—information by definition that is not stored in DNA and thus cannot be generated by mutations to the DNA. It follows that the mechanism of natural selection acting on random mutations in DNA cannot by itself generate novel body plans, such as those that first arose in the Cambrian explosion.
Cell and body shape, and organism development depends on following :
Membrane targets and patterns
Cytoskeletal arrays
Centrosomes
Ion channels, and
Sugar molecules on the exterior of cells (the sugar code)
Gene regulatory networks
Various codes and the encoded epigenetic information is required:
The Genetic Code
The Splicing Codes
The Metabolic Code
The Signal Transduction Codes
The Signal Integration Codes
The Histone Code
The Tubulin Code
The Sugar Code
The Glycomic Code
" Junk DNA "
MicroRNAs--"Once Dismissed as Junk"--Confirmed To Have Important Gene Regulatory Function
In 2008 Scientific American noted that microRNAs were "once dismissed as junk" and said the following:
Tiny snippets of the genome known as microRNA were long thought to be genomic refuse because they were transcribed from so-called "junk DNA," sections of the genome that do not carry information for making proteins responsible for various cellular functions. Evidence has been building since 1993, however, that microRNA is anything but genetic bric-a-brac. Quite the contrary, scientists say that it actually plays a crucial role in switching protein-coding genes on or off and regulating the amount of protein those genes produce.
Where Do Complex Organisms Come From?
Meyer, Darwins doubt, page 212:
According to neo-Darwinism, new information, form, and structure arise from natural selection acting on random mutations arising at a very low level within the biological hierarchy—within the genetic text. Yet both body-plan formation during embryological development and major morphological innovation during the history of life depend upon a specificity of arrangement at a much higher level of the organizational hierarchy, a level that DNA alone does not determine. If DNA isn’t wholly responsible for the way an embryo develops— for body-plan morphogenesis—then DNA sequences can mutate indefinitely and still not produce a new body plan, regardless of the amount of time and the number of mutational trials available to the evolutionary process. Genetic mutations are simply the wrong tool for the job at hand.
Even in a best-case scenario—one that ignores the immense improbability of generating new genes by mutation and selection—mutations in DNA sequence would merely produce new genetic information. But building a new body plan requires more than just genetic information. It requires both genetic and epigenetic information—information by definition that is not stored in DNA and thus cannot be generated by mutations to the DNA. It follows that the mechanism of natural selection acting on random mutations in DNA cannot by itself generate novel body plans, such as those that first arose in the Cambrian explosion.
Cell and body shape, and organism development depends on following :
Membrane targets and patterns
Cytoskeletal arrays
Centrosomes
Ion channels, and
Sugar molecules on the exterior of cells (the sugar code)
Gene regulatory networks
Various codes and the encoded epigenetic information is required:
The Genetic Code
The Splicing Codes
The Metabolic Code
The Signal Transduction Codes
The Signal Integration Codes
The Histone Code
The Tubulin Code
The Sugar Code
The Glycomic Code
" Junk DNA "
MicroRNAs--"Once Dismissed as Junk"--Confirmed To Have Important Gene Regulatory Function
In 2008 Scientific American noted that microRNAs were "once dismissed as junk" and said the following:
Tiny snippets of the genome known as microRNA were long thought to be genomic refuse because they were transcribed from so-called "junk DNA," sections of the genome that do not carry information for making proteins responsible for various cellular functions. Evidence has been building since 1993, however, that microRNA is anything but genetic bric-a-brac. Quite the contrary, scientists say that it actually plays a crucial role in switching protein-coding genes on or off and regulating the amount of protein those genes produce.
