Dmitrieva NI, Ferraris JD, Norenburg JL, Burg MB.

Cell Cycle. 2006 Jun;5(12):1320-3. doi:10.4161/cc.5.12.2867

The saltiness of the sea breaks DNA in marine invertebrates: possible implications for animal evolution.

Proposes that increased salinity in evaporating seas during the Cambrian caused elevated numbers of DNA breaks and accelerated evolution, leading to the Cambrian explosion. Vertebrates maintain constant interstitial osmolarity at ~300 mosmol/kg. Invertebrates show increased levels of DNA breaks (measured by TUNEL assay) at 1000 mosmol/kg compared to 300 mosmol/kg.