In humans gene flow usually comes about through the actual migration of human populations, either voluntary or forced. Although gene flow does not change allele frequencies for a species as a whole, it can alter allele frequencies in local populations.
Hopefully this helps.
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Threatened is the definition used when describing a species at risk of extinction
C. Less than 5% because technology had been formed and better perfomances to treated the infectious diaeas
I believe the answer is restriction organism.