The hardy-weinberg equation is an expression showing the frequencies of 100 percent of the alleles for a specific gene in a population. if biologists can show that either p or q is changing over a period of time, what is occurring in the population?

In the Hardy-Weinberg equation, which is:
p² + 2pq + q² = 1
The letter p represents the homozygous dominant genotype and the letter q represents the homozygous recessive genotype.
If the value of either p and q decrease, this means that there is more mixing and interbreeding between the population of species, resulting in deviation from homozygous genotypes. 
This mixing may arise from removed barriers or from selection pressures causing the organisms to move from their original habitats.

I’m not exactly sure what your trying to ask, but if it’s how an organelle is similar to a body system or a part a nucleus is like a in function. but i don’t fully understand what you’re trying to ask