|
parasites
Why is it rare that an individual parasite kills its host?
[ ]
Want to answer more questions in the Miscellaneous category?
Maybe give some free advice about: Random Weirdos?
Probably because, from an evolutionary standpoint, that would be bad for a parasite.
To a parasite, killing a host would be like our, well, destroying the earth. Kill your host, and where do you live? Sure with parasites you could possibly find another host, though that often isn't possible for the initial parasite - nevermind that for every host you kill, the harder it would be to find new additional hosts. Many need another body to live in while they undergo changes in their life cycle. As such, the form that a parasite enters your body with often isn't the form they leave in, and they then need another host or enviroment to continue their life cycle in. For example, some parasites start off in dirt/fecal matter, get into one form of animal and change physically, perhaps eventually being excreted and then finishing off their lives back in the dirt.
Another problem could very well be in the evolution and viability of hosts. If a parasite killed off large numbers of its hosts, eventually you *might* get the only survivors from the host species being ones who might have defenses or mutations that prohibit the parasite. If a parasite kills off all its 'good' hosts and forces a species to a point where the only survivors are those that the parasite cannot survive in, potentially the parasite would just have (potentially) made themselves extinct. Whereas as it happens today, parasites usually don't kill those it can easily survive in, therefore allowing 'good' host reproduction and not forcing a host species to evolve along a path that would hurt the parasite.
]
Forgive me for being blunt, but this is a personal advice website, not an Ask Doctor Science website. Try an encyclopedia.
]
I am not 100% sure this is the right answer, but it makes sense to me. Actually, I have two ideas about it, and both are probably at least somewhat right:
1. One parasite is too small to fully drain the host of blood, especially since the host body will continue to produce blood, most likely faster than the parasite is draining it.
2. If the host dies, the parasite can't eat. It is not the goal of the parasite to kill the host, since that could mean its own death.
There are cases where parasites on small animals make the host ill or weak enough that a larger animal can easily catch and eat it, thus providing a larger host for the parasite to feed on. So, in those cases, the host does die, but not as a direct result of the parasite.
]
More Questions: |