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.
Punctuated equilibrium can be accommodated within the classical neo-Darwinian synthesis as an end-member of the spectrum of possible evolutionary events that lead to the appearance of new species. But it's not the only possible mode of speciation: it is one possible mode. There's no intrinsic reason that evolutionary change should occur only in small populations, and there's no evidence that populations that have undergone marked evolutionary change are any smaller than those that are stable.