Fire is the primary agent responsible for natural disturbances in the taiga.
The importation of plants is the primary agent in the modern spread of species, for animals have almost invariably gone along with the plants — quarantine being a comparatively recent and never completely effective innovation.
On the other hand, sulfur trioxide (SO3) in the gaseous form is a vital pollutant, which is the primary agent in acid rain.
Natural selection is always most powerful mechanism of evolution, and it is the primary agent of evolutionary change 9, 12, 17, 20 Confusing genetic drift with evolutionary processes other than natural selection 8.
Because metastable argon is thought to be the primary agent in the formation of molecular ions through Penning ionization of the neutral molecular precursor there is no benefit to be expected from an increase of the interelectrode distance.
High magnitude storm events are the primary agent responsible for gully incision, but neither such events nor cooler/wetter climatic episodes appear to have produced gully systems in the region before 3000 cal.
Geological phenomena, such as tectonic changes, and phenomena related to changing climates on a local or regional scale, drive these episodes, which seem to have been the primary agent of evolutionary radiations and production of regional biotas (Brooks and Hoberg 2006, 2007a, b; Erwin 1979, 1981; Lieberman and Eldredge 1996; Lieberman 2000, 2003; Halas et al. 2005).
Among paramagnetic compounds, Gd is the primary agent used for MRI due to high relaxation efficiency and magnetic moments.
Dipterocarp seed dispersal is known to occur over short distances [43], [44], [45], [46], [47], which suggests that long distance pollen flow is likely to be the primary agent undermining SGS.
