Answer:
<em>Like every other organism the population size of the humans have increased over time.</em>
Explanation:
With the improvements in science and technology, life becomes better and better for human beings. In the past, when there were no discoveries for curing diseases, the human population declined because of the spread of various diseases and famine conditions.
But as the developments in the scientific world are made, it has been easier to cure diseases and other problems. As a result, the population size of the human goes on increasing.
as insects became exposed to pyrethroids, toxicity of pyrethroids weakened over time. which means that Most insects had the allele for pyrethroid resistance, but it remained masked. The allele for said pyrethroid resistance, evidently increased throughout the population.
has this helped?
Valves ensure blood flows toward your heart. Vein valves work to bring the blood that flowed down via arteries back up to your heart.