The Afrikaner population of South Africa is mainly descended from one shipload of
immigrants which landed in 1652. The early colonists included individuals with a
number of rare genes. The ship of 1652 contained a Dutch man carrying the gene for
Huntington's disease, an autosomal dominant disease which does not appear until the
sufferer is over 40 years old and leads to certain death within five to 10 years. Today,
the Afrikaner population has an unusually high frequency of the gene that causes
Huntington's disease, because those original Dutch colonists just happened to carry
that gene with unusually high frequency.
anism of evolution is this?
Reproductive isolation
Founders effect
Co evolution
Bottle neck

hypoxemia refers to a below usual concentration of oxygen in the blood, mainly in the arteries. hypoxemia is an indication of an issue associated with circulation or breathing and may lead to various symptoms like shortness of breath.  

the condition is identified by determining the level of oxygen in the blood sample obtained from an artery. it can also be predicted by determining the oxygen saturation of the blood with the application of a pulse oximeter.  

the normal arterial oxygen is about 75 to 100 mm hg. the values underneath 60 mm hg is generally considered with the requirement for supplemental oxygen. the normal pulse oximeter readings generally range between 95 to 100 percent. the values under 90 percent are regarded as low.  

in the given case, the oxygen saturation is measured at 93 percent, hence, there is no need to administer oxygen, that is, one should withhold oxygen.