The high genetic diversity sampled from Hawaii suggests that the Hawaiian Islands could be the origin of Caenorhabditis elegans.
Recent efforts to understand the natural niche of the keystone model organism Caenorhabditis elegans have suggested that this species is cosmopolitan and associated with rotting vegetation and fruits. However, most of the strains isolated from nature have low genetic diversity likely because recent chromosome-scale selective sweeps contain alleles that increase fitness in human-associated habitats.
Strains from the Hawaiian Islands are highly divergent from non-Hawaiian strains. This result suggests that Hawaiian strains might contain ancestral genetic diversity that was purged from most non-Hawaiian strains by the selective sweeps. The higher genetic diversity in the Hawaii population might indicate that it represents an ancient population, similar to African populations in humans. The possibility that the C. elegans species might have originated from the Hawaiian Islands, or migrated there from adjacent landmasses shortly after speciation, requires that the Hawaiian Islands predate the split between C. elegans and its closest known relative C. inopinata, which is estimated to be 10.5 million years. [Crombie et al. eLife 2019].
WMicrotracker Smart is our new technology with which you can get detailed information about behaviour of small animals populations in function of time and space. Including Multiworm path tracking. The plot shows the single worms trails on the plate, and its reduction with age. 20 adult C.elegans were cultured at 25°C in a 35mm Petri Dish with NGM+FuDR. Data acquisition has been performed once a day, using 5 minute acquisition lapse. Plates were subjected to “tap” stimulation before each measure.