Final answer:
The census population (N) size is always larger than the effective population size (Ne) due to sampling errors and the inclusion of individuals not actively reproducing. The difference between N and Ne is important for understanding genetic diversity and population dynamics.
Step-by-step explanation:
The census population size (N) is always larger than the effective population size (Ne) for natural populations due to various factors. One of the main factors is the sampling error that occurs during the census. The census relies on counting individuals in a specific area or volume, but it is difficult to accurately count every single individual. Some individuals may be missed or double-counted, leading to an overestimate of the population size.
Additionally, the census population size includes all individuals, including those that may not be actively reproducing or contributing to the gene pool. On the other hand, the effective population size (Ne) takes into account only the individuals that are capable of reproducing and passing their genes to the next generation.
For example, if a population census counts 500 individuals, the effective population size (Ne) may be lower if only a fraction of those individuals are actively reproducing. This difference between the census population size (N) and the effective population size (Ne) is important in understanding the genetic diversity, adaptation, and population dynamics of natural populations.