Therefore, an adaptive advantage exists if an animal can control its deployment in regard to actuary-like evaluations of future benefits and costs as to its biological fitness.
Fever has the future benefit of clearing infections since it reduces the replication of bacteria[13] and viruses.
[17][18] Circumstances in which fever deployment is not selected or is reduced include: Antioxidants such as carotenoids, vitamin C, Vitamin E, and enzymes such as superoxide dismutase (SOD) and glutathione peroxidase (GPx) can protect against reactive oxygen species that damage DNA, proteins and lipids, and result in cell senescence and death.
This creates a conflict between the biological fitness benefits of future survival compared with the use of these antioxidants to advantage present reproductive success.
In some birds, antioxidants are diverted from maintaining the body to reproduction for this reason with the result that they have accelerated senescence[22] Related to this, birds can show their biological capacity to afford the cost of diverting antioxidants (such as carotenoids) in the form of pigments into plumage as a costly signal.