My Y-DNA haplogroup is Q2. Does this mean that my paternal ancestor was an Amerindian?

Probably not. Q2 is found at low to moderate frequency among populations of Central Asia and Siberia. Haplogroup Q3 is the most common among the indigenous peoples of the Americas. There are always exceptions and it is possible that your Q2 ancestor traveled with the Q3 populations across the land bridge to North America. ... more