A tracheotomy is performed if enough air is not getting to the lungs, if the person cannot breathe without help, or is having problems with mucus and other secretions getting into the windpipe because of difficulty swallowing. There are many reasons why air cannot get to the lungs.
Trending Now. Answers. Best Answer: Yes, the smallest unit of evolution is the population. The reason is, the techical definition of evolution is change in allele frequency. You have to have a population in order to run the statistics to measure if there has been a change. Remember, a population does not necessarily mean all animals of one species.
Evolution is the change in frequency of the alleles in a gene pool over time; evolution is when a population of species gets more suited to its environment over time. Evolutioâ¦n occurs with mutations and natural selection. What happens is that in a population of species, not all of them are the same.