Toxins essays

Toxins essays Toxins are present in plants and foods that we eat. Do toxins have a purpose besides simply making us sick, and if so what is their purpose? In this paper, I will focus on how toxins affect our body and how toxins evolved over the years. Research has shown that toxins are a plants defense against herbivores in their effort to survive (Nesse and Williams, 1995). There are countless toxins present because herbivores quickly adapt to toxins and this requires plants to make different toxins in the race to survive (Nesse and Williams, 1995). Adaptation in toxin production does come at a cost to plants. Sumner states that tannins cost up to 30 percent of the dry weight of a sugar maple leaf. Tannins provide protection for the plant, but at a considerable price. According to Wilson, more research is needed to understand the cost of the evolution of toxins in plants. Nesse and Williams state that plants can generally have high toxin levels or rapid growth. Thus fast growing plants are usually safer for herbivores to devour than slow growing plants. Likewise, the more important a part of a plant is for its reproduction, the more likely it is to be toxic. For example, sweet fruit is not toxic, but the seed that is ne eded to produce another tree is often quite toxic (Nesse and Williams, 1995). Also acorns are very toxic as they are necessary for new tree growth. Trees have also evolved to discourage helpful herbivores from devouring their fruit before the seed is ready for harvest. An example of this is a green apple causing an upset stomach, but when the apple is ripe and the seed is ready for planting, it causes no ill effects (Nesse and Williams, 1995). Some plants do not make toxins until they are damaged. A study by Turlings, Loughrin, McCall, Rose, Lewis, and Tumlinson, shows that some plants emit chemical signals that call natural enemies to their plant to devour the herbivores eating th ...