Hypotheses For The Evolution of Schreckstoff
A number of different hypotheses have been proposed for the evolution of schreckstoff (see Smith 1992 for a review). The first hypothesis is that the evolution of schreckstoff has been driven by kin selection (Smith 1992). Support for this hypothesis would include evidence that individuals live in groups of closely related kin and that the release of chemical alarm signals increases the likelihood that related individuals will avoid predation. The second hypothesis, predator attraction, suggests that the release of schreckstoff may attract additional predators which will interfere with the predation event, increasing the likelihood that the prey will escape and survive the attack. This hypothesis assumes that predators will be attracted to schreckstoff and will interfere with one another either through competition for the captured prey or through predation of one another. It additionally assumes that, despite the fact that the prey has already incurred mechanical damage, it is possible for the prey to escape and recover from the attack. Testing and validating these assumptions would provide support for the predator attraction hypothesis. The third hypothesis proposes that schreckstoff has an immune function, providing protection against pathogens, parasites and/or UVB radiation. For this hypothesis to be supported, a correlation between alarm substance cell production and the presence of pathogens and parasites would need to be observed. Direct evidence that schreckstoff inhibits the growth of aquatic pathogens and parasites would provide additional support for the immunity hypothesis. Another hypothesis is that schreckstoff is a breakdown product of mucus and club cells, induced by injury. Selection for the alarm response is primarily at the level of the receiver.
Read more about this topic: Schreckstoff
Famous quotes containing the words hypotheses and/or evolution:
“We shall do better to abandon the whole attempt to learn the truth ... unless we can trust to the human minds having such a power of guessing right that before very many hypotheses shall have been tried, intelligent guessing may be expected to lead us to one which will support all tests, leaving the vast majority of possible hypotheses unexamined.”
—Charles S. Pierce (18391914)
“The evolution of humans can not only be seen as the grand total of their wars, it is also defined by the evolution of the human mind and the development of the human consciousness.”
—Friedrich Dürrenmatt (19211990)