Step 1: Understanding population characteristics.
A population refers to a group of individuals of the same species living in a particular area.
Step 2: Distinctive properties.
Two distinctive properties of a population are:
1. Population Density: The number of individuals per unit area or volume.
2. Population Growth: The increase or decrease in the number of individuals in a population over time.
Step 3: Conclusion.
Thus, the two distinctive properties of any population are population density and population growth.
Final Answer:
\[
\boxed{\text{Population Density, Population Growth}}
\]