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

Guliuzza and Gaskill ◀ How organisms continuously track environmental changes ▶ 2018 ICC 182 Table 2 continued. Table 2 continued on next page. Mechanism Action Reference Research Entity Results Descriptive Extract of Function in CET Framework 17. Unreduced Gam- etes Unreduced gametes are now considered the primary mechanism for polyploidization following detec- tion of specific stressful condi- tions. Mason and Pires. 2015. Unreduced gametes: meiotic mishap or evolu- tionary mecha- nism? Trends in Genetics Review article Indications for unreduced gametes in speciation are: 1) they are often observed to be stimulated by stressful environments, 2) they are thought to be the primary mechanism for polyploidization, 3) their prevalence in diverse plant and animal species which occur via wide ranging molecular and cytogenetic causes across divergent lineages of life, 4) heritable genetic variation for production exists within and between species. "Polyploidy is prevalent across eukaryotic life, particularly in the plant, animal, and fungal lineages. It has been suggested that the rationale for this prevalence of polyploids is that it provides novel genetic and genomic variation that can allow polyploid individuals to exploit new environmental niches and outcompete their diploid progenitors... we propose that unreduced gametes are maintained across widely disparate lineages because the ability to produce unreduced gametes facilitates lineage survival by allowing polyploid speciation, particularly in response to stress” pgs. 1, 5. Mable. 2013. Polyploids and hybrids in changing environments: winners or losers in the struggle for adaptation? Heredity “Nevertheless, there has also been much emphasis on the alternative view that polyploidisation and hybridisation can promote diversification and speciation, by creating new combinations of genotypes that could increase the adaptive potential compared to the progenitor species..." p. 95. 18. Regulated Mul- tiple Single Copy Gene Usage Multiple usage of single copy genes by regulat- ed "co-option" to take on new functions while continuing in their previous function. Martinson et al. 2017. The Evolu- tion of Venom by Co-option of Sin- gle-Copy Genes. Current Biology Parasitic Jewel Wasp venom of Urolepis rufipes, Trichomalopsis sarcophagae, Nasonia vitripennis , and N. giraulti Regulatory regions adjacent to venom genes initiates rapid turnover leading to more than half of the venom components coming from single copy genes that had been "co-opted" without being duplicated. There were both gains and losses in each species. Venom composition rapidly changes allowing wasps to adapt to different hosts. Closely related species can differ by up to 40 percent of their venom repertoire. “In contrast, the mechanism of expression specialization by co-option of existing genes allows for a much faster mechanism for adaptation to novel or changing environments…[and could represent] a more general but underappreciated mechanism for rapid adaptation and gene neofunctionalization" p. 2010.