Answer: Humans first evolved in Africa, and much of human evolution occurred on that continent. The fossils of early humans who lived between 6 and 2 million years ago come entirely from Africa. Most scientists currently recognize some 15 to 20 different species of early humans.
Explanation:
 
        
             
        
        
        
What is an invasive species? they are plants/fungi/animals that isn't native to a specific area (an introduced species). They have the tendency to spread and cause damage too the environment, human economy, and/or human health. The Answer to your question is No. Not every species that is introduced to a specific area is invasive. The introduced species might have a natural predator that might eat it. The species may even be biologically, chemically, or mechanically controlled. I hope this helps you out:)
        
             
        
        
        
Answer: Genetic Drift
Explanation:
It's all based on sampling errors.
 
        
             
        
        
        
Answer:
May not 
Explanation:
Adaptation is made possible as a result of an organism being exposed to different environmental conditions. These exposure makes it adopt different techniques for its survival which eventually results in it being adapted to the condition and is then passed on as traits to its offsprings. They are then able to survive when met with such environmental condition.
When an organism is exposed to the same conditions all the time then there is lack of genetic variation and adaptation may not occur.