I think that habitat loss and destruction is probably responsible for the highest number of extinctions.
Other major causes can include pollution, overhunting/poaching, and global warming.
The primary factor that determines which substance is most responsible for chemical reactions is the reactivity of the substances involved.
The Sun
The factor most responsible for the growth in the colonial population between 1700 and 1770 was the natural reproduction of colonial families.
it is used in the binomial nomencleature
Physical isolation of population
Erosion
Lack of physical activity
The climate in the region
a postzygotic barrier
vital natural resources in a strategic location
plentiful natural resources
the increasing use of technology