The Proceedings of the Eighth International Conference on Creationism (2018)

Guliuzza and Gaskill ◀ How organisms continuously track environmental changes ▶ 2018 ICC 177 Table 2 continued. Table 2 continued on next page. Mechanism Action Reference Research Entity Results Descriptive Extract of Function in CET Framework 6. Directed Mutation Regulated genetic changes and histone acetylation directed to particular loci leading to the rapid emergence of adapted clones upon detection of particular environmental conditions. Hull and Houseley. 2017. Environmental change drives accelerated adaptation through stimulated copy number variation. PLoS Biol ( see also: Metzgar and Wills 2000. Evidence for the Adaptive Evolution of Mutation Rates. Cell. Chakrabati. 2008. Mutagenic evidence for the optimal control of evolutionary dynamics. Physical Review Letters) Multiple strains of budding yeast Yeast cells exposed to copper stimulate copy number amplification of the copper resistance gene CUP1 . "Stimulated copy number variation (CNV) provides cells with a remarkable and unexpected ability to alter their own genome in response to the environment...CNV therefore represents an unanticipated and remarkably controllable pathway facilitating organismal adaptation to new environments.” “The assertion that adaptation occurs purely through natural selection of random mutations is deeply embedded in our understanding of evolution. However, we have demonstrated that a controllable mechanism exists in yeast for increasing the mutation rate in response to at least 1 environmental stimulus and that this mechanism shows remarkable allele selectivity ... evolutionary theory asserts that adaptive mutations, which improve cellular fitness in challenging environments, occur at random and cannot be controlled by the cell...evidence for adaptation through genome-wide nonrandom mutation is substantial...regarding the function of particular loci in particular environments that is encapsulated in existing gene regulatory systems” pgs. 16-20. 7. GC-Biased Mutational Hetero- genous Gene Conversion Nonreciprocal genetic exchanges of during meiosis elevate GC biased mutations in specific regions leading to gene conversion and massive stretches of "dark DNA." Hargreaves, et al. 2017. Genome sequence of a diabetes-prone rodent reveals a mutation hotspot around the ParaHox gene cluster. PNAS Insulin-regulating homeobox gene Pdx1 of the sand rat Psammomys obesus An unusual genomic region of biased mutation where 7 of the top 10 highest "protein deviation index" results correspond to genes located within the GC-biased mutational hotspot which contribute to coding sequence divergence across this region. Extremely large diversification parameter, PDI, enable tracking of environmental changes diverging greatly from the norm. “Hotspots of mutation could drive rapid evolutionary change at the molecular level, and it will be important to decipher to what extent such hotspots have constrained and influenced evolutionary adaptation across the animal kingdom” p. 7680.