Genetic noise
Environmental factors can lead to genetic mutation by generating new gene alleles (either of a pair of genes). The new allele may improve its suitability (of propagation in subsequent generations) within the organism and increases its frequency, or decrease its suitability and finally disappear. Such interactions of genes with environment are another component of the nature-nurture debate.
But many mutations do not show immediate effects and such gene alleles are termed "genetic noise'. This genetic noise may produce extreme phenotypes known as outliers; in case of humans there are almost 17 outliers that are responsible for evolution of brain size and behaviour. If environmental changes improve an outlier's suitability, the entire population rapidly adopts the corresponding gene alleles. Thus, genetic noise makes the genome more suitable and stable.
"The mental picture many biologists have of a healthy cell at the genetic level is of a smoothly running Swiss watch,' says Jeff Hasty of University of California at San Diego. But now research is proving otherwise, he adds, referring to a study conducted under his guidance. Cell biologists have described genetic noise while recording large phenotypic differences between supposedly identical cells in a single growth medium. Even a slight change or genetic mutation may lead to variability at the level of the whole organism. "The phenotype of an organism is largely determined at the genetic level, so it is important to zoom in on the noisy details of gene expression to explain the variability that we couldn't otherwise account for,' adds Hasty. Environmental factors can lead to genetic mutation by generating new gene alleles (either of a pair of genes). The new allele may improve its suitability (of propagation in subsequent generations) within the organism and increases its frequency, or decrease its suitability and finally disappear. Such interactions of genes with environment are another component of the nature-nurture debate.
But many mutations do not show immediate effects and such gene alleles are termed "genetic noise'. This genetic noise may produce extreme phenotypes known as outliers; in case of humans there are almost 17 outliers that are responsible for evolution of brain size and behaviour. If environmental changes improve an outlier's suitability, the entire population rapidly adopts the corresponding gene alleles. Thus, genetic noise makes the genome more suitable and stable.
"The mental picture many biologists have of a healthy cell at the genetic level is of a smoothly running Swiss watch,' says Jeff Hasty of University of California at San Diego. But now research is proving otherwise, he adds, referring to a study conducted under his guidance. Cell biologists have described genetic noise while recording large phenotypic differences between supposedly identical cells in a single growth medium. Even a slight change or genetic mutation may lead to variability at the level of the whole organism. "The phenotype of an organism is largely determined at the genetic level, so it is important to zoom in on the noisy details of gene expression to explain the variability that we couldn't otherwise account for,' adds Hasty.