Darwin went to the continents of Africa and South America, wherein both of them have a tropical grassland/Savanna biome. The grasslands in these continents gave him a chance to notice that species do vary globally. He observed the similarities between the different large, flightless birds species–rheas, ostriches, and emu.
Hypomagnesemia is a condition of low magnesium levels in the body and because magnesium acts as an active cardiovascular electrolyte, its deficiency leads to cardiac complications such as dysrhythmias.
People who suffer from myocardial infarction are often treated for hypomagnesemia to improve their cardiac conduction, however, hypomagnesemia can also develop in chronic alcoholics.
The other reasons that could lead to the condition faced by Robert Stevens can be hypokalaemia however, as he is also chronic alcoholic hypomagnesemia is the main cause.
