DNA repair efficiency and thermotolerance in Drosophila melanogaster from 'Evolution Canyon'

When various wild strains of Penicillium lanosum and Aspergillus niger were placed in the same mild laboratory environment, their frequencies of new spontaneous mutations were clearly related to whether they had been isolated from a region of high or low microclimatic stress. In the mild environment, the total frequencies of conidial color and morphological mutations in P. lanosum, summed over all relevant loci, ranged from 0.29% to 2.4% for six strains from the north-facing, less stressful ''European'' slope (ES/NFS) of ''Evolution Canyon'' I, compared with 6.5-11.6% for five strains from the south-facing ''African'' slope (AS/SFS), which is a much more stressful environment, being harsher, drier, more fluctuating in temperature, and receiving up to eight times more UV radiation than the opposite slope. The corresponding figures for A. niger were 0.42-1.50% for three strains from the ES/NFS and 2.3-4.9% for six strains from the AS/SFS. The more mutagenic environment of the AS/SFS than of the ES/NFS means that, in Evolution Canyon, the mutation frequency differences between the very stressful environment and the less stressful environment are probably even larger than the 4-and 6-fold differences found here in a mild laboratory environment. The evidence from these two filamentous fungi, which have no sexual cycle, is that there are inherited differences in spontaneous mutation rates according to the levels of stress in the environment, and this feature may well be adaptive. Evolution Canyon I is at Nahal Oren, Mount Carmel, Israel.adaptation ͉ Aspergillus niger ͉ mutation rates ͉ Penicillium lanosum

Section: Discussionsupporting

confidence: 89%

Differences in spontaneous mutation frequencies as a function of environmental stress in soil fungi at “Evolution Canyon,” Israel

Lamb

Mandaokar

Bahsoun

et al. 2008

“…The findings of this study of the microevolution of soil bacteria in EC concur well with other prokaryotic and eukaryotic model organisms of EC, including the cyanobacterium N. linckia, the fungus S. fimicola, the spiny mouse Acomys cahirinus, the fruit f ly D. melanogaster, and the wild barley Hordeum spontaneum (19,20,(23)(24)(25)(26)(27)(28)(29)(30)(31)(32)61). Most of the macrobiotic model organisms (11 of 14) express higher genetic diversity on the generally more stressful African-like slope (21).…”

Section: Conclusion and Prospectssupporting

confidence: 78%

Adaptation and incipient sympatric speciation of Bacillus simplex under microclimatic contrast at “Evolution Canyons” I and II, Israel

Sikorski

Nevo

2005

114

The microevolutionary dynamics of prokaryotes in natural habitats, such as soil, is poorly understood in contrast to our increasing knowledge on their immense diversity. We performed microevolutionary analyses on 945 soil isolates of Bacillus simplex from ''Evolution Canyons'' I (Carmel, Israel) and II (Galilee, Israel). These canyons represent similar ecological replicates, separated by 40 km, with highly contrasting interslope abiotic and biotic conditions in each (within a distance of only 100 -400 m). Strains representing genetic groups were identical in their 16S sequences, suggesting high genetic similarity and monophyletic origin. Parallel and nested phylogenetic structures correlated with ecological contrasts rather than geographical distance. Additionally, slope-specific populations differed substantially in their diversity. The levels of DNA repair (determined by UV sensitivity) and spontaneous mutation rate (resistance to rifampicin) relate to ecological stress and phylogeny. Altogether, the results suggest adaptive radiation at a microscale. We discuss the observed adaptive population structures in the context of incipient sympatric speciation in soil bacteria. We conclude that, despite different biology, prokaryotes, like sexually reproducing eukaryotes, may consist of true species and parallel ecological speciation in eukaryotes.adaptive radiation ͉ Bacillus soil isolates ͉ environmental stress ͉ microbial population genetics ͉ natural selection

“…DNA repair efficiency as an adaptive trait against solar radiation has been also demonstrated locally at EC I in D. melanogaster (36), and regionally across Israel in wild barley, Hordeum spontaneum (37). The repair efficiency of four thermotolerant and four thermosensitive isofemales lines of D. melanogaster from EC I in Mount Carmel was tested using 2-acetylaminofluorene as the mutagen (36).…”

Section: Resultsmentioning

confidence: 99%

“…The repair efficiency of four thermotolerant and four thermosensitive isofemales lines of D. melanogaster from EC I in Mount Carmel was tested using 2-acetylaminofluorene as the mutagen (36). Thermotolerant isofemale lines showed high DNA repair efficiency at both high and room temperatures.…”

Section: Resultsmentioning

confidence: 99%

“Evolution Canyon,” a potential microscale monitor of global warming across life

Nevo

2012

Climatic change and stress is a major driving force of evolution. The effects of climate change on living organisms have been shown primarily on regional and global scales. Here I propose the "Evolution Canyon" (EC) microscale model as a potential life monitor of global warming in Israel and the rest of the world. The EC model reveals evolution in action at a microscale involving biodiversity divergence, adaptation, and incipient sympatric speciation across life from viruses and bacteria through fungi, plants, and animals. The EC consists of two abutting slopes separated, on average, by 200 m. The tropical, xeric, savannoid, "African" south-facing slope (AS = SFS) abuts the forested "European" north-facing slope (ES = NFS). The AS receives 200-800% higher solar radiation than the ES. The ES represents the south European forested maquis. The AS and ES exhibit drought and shade stress, respectively. Major adaptations on the AS are because of solar radiation, heat, and drought, whereas those on the ES relate to light stress and photosynthesis. Preliminary evidence suggests the extinction of some European species on the ES and AS. In Drosophila, a 10-fold higher migration was recorded in 2003 from the AS to ES. I advance some predictions that could be followed in diverse species in EC. The EC microclimatic model is optimal to track global warming at a microscale across life from viruses and bacteria to mammals in Israel, and in additional ECs across the planet.climate and evolution | species extinction | climate impact | adaptive response | natural selection C limate variation and change are major abiotic stresses driving life's evolution (1-22). Parmesan and Yohe (9), analyzing results for 1,700 species, showed that recent biological trends match climate-change predictions. Global meta-analyses documented significant range shifts averaging 6.1 km per decade northward (or 6.1 m per decade upward) and significant mean advancement of spring events by 2.3 d per decade. A significant globally coherent fingerprint of climate change across natural systems was identified for 289 species (9). Parmesan (7) reviewed evidence of climate change indicating that climate change is already affecting living systems in diverse perspectives, including phenological changes, species interactions, range shifts, contractions and abundance, elevation shifts, marine communities' shifts, pest and disease shifts, tree-line patterns, extinctions, and evolutionary genetic and plasticity changes. New concerns have been raised about the ability of the earth's biodiversity of plants and animals to maintain a viable foothold on the planet if temperatures continue to rise. (See ref. 21 for an alternative point of view). In a recent review on global warming, during the last three decades in wild cereals, the progenitors of cultivated wheat and barley showed earliness in flowering time and in genetic changes (22) and global decline in cultivars' crops (19). Rapid range shifts of species are associated with high levels of climate warming, shifting to ...