Allopatric speciation is just a fancy name for speciation by geographic isolation, discussed earlier. In this mode of speciation, something extrinsic to the organisms prevents two or more groups from mating with each other regularly, eventually causing that lineage to speciate.
The downside of this is that it can only tell if youâve engaged in drug use in that window. For example, if you smoke marijuana on a daily basis but stop 2-3 days prior to your mouth swab test, the results will probably come back negative. It canât detect prolonged use or the remaining presence of a trace amounts like a urine test can.
Blood tests are more sophisticated than we think. While THC can be detectable in the blood of non-regular marijuana smokers up to 27 hours after consuming, regular smokers can be caught within up to nearly 90 days. Furthermore, it is not for sure: in some cases, the detection period turns out to be even longer.