A population is a group of individuals of the same species that live in a particular geographical area and are able to interbreed. A population is described with respect to several features such as death and birth rates, age structure, density, dispersion, change in the population size due to density-dependent and density-independent factors and the survivorship curve.

These features are not exhibited by a particular individual. Natural selection also works at populations. The evolutionary forces act upon populations to change their allele and genotype frequencies. Therefore, populations are the unit of evolution and change genetically over time, not the individuals. Population ecology studies the size of a populations and the trends and causes of changes in the populations over time.

5 0

3 years ago

If a person experiences rapid breathing, muscle twitches, and perspiration when trying to quit using illegal opiates, he or she

Nuetrik [128]

<span>This person is experiencing common physical symptoms of what is called "withdrawals". Opiates, when used illegally, can be highly addictive. This drug targets the central nervous system (the brain, cardiovascular and respiratory systems) and contains opioid receptors that receive opiate drugs. Abusing this drug can disrupt a person's brain chemistry, leading to severe physical withdrawal symptoms as listed in the question.</span>

3 0

2 years ago