An error sometimes made by beginning biology students is called the "Adaptationist Fallacy" wherin a trait observed in a population is automatically presumed to be the most beneficial phenotype for that species/population. Why is this presumption not always correct? Describe a scenario where the adaptationist fallacy is incorrect.

The Adaptationist Fallacy can prove very costly to biologist who are assuming it wrong according to the function in the environment. Let us have an example of the phenotype of wheat diploid breed that produces non-bearded grains variety, but we cannot assume it as a beneficial phenotype without further extensive research. After research, we came to know that there is also a major hexaploid bearded variety, that produces more number of grains. That's how, the Adaptationist Fallacy may prove fatal if we have assumed diploid as a major beneficial phenotype.

americans began to notice growing differences between the northern and southern sections of the country. there were more people living in cities in the north, which made it more urban. more people lived on farms in the south, which made it more rural. while many people were farmers in the northern states, there were now other ways to make a living, such as working in mechanical cotton gins factories manufacturing cloth, tools and other goods. people in the north supported high tariffs on goods imported from europe because the extra cost encouraged people to “buy american” instead. in the southern states, planters did not like tariffs because they sold most of their production to europe and bought their tools from there as well. southerners believed the protective tariff was something that only northern factory owners keep their profits high. so the southern politicians came up with an idea. they would opt out. they would simply ignore the protective tariff. it was ‘null and void’ in south carolina. the state would not collect the taxes on goods imported into south carolina, no matter what the president said they had to do. this decision led to the nullification crisis.

as the gila monster consumes the eggs or young of the desert cottontail and gambel's quail, thus its main food supply is only accessible for a restricted time duration every year. however, for this, the gila monsters exhibit three adaptations, which elevate their survival rate in the desert condition.  

first, is that they possess huge bodies, and can consume greater concentrations of food during a small period. secondly, they require to feed infrequently as they can accumulate fat in their tails. ultimately, their rate of metabolism is very low, so that they can burn their reservoirs of fat gradually.