Predator Avoidance

[ATJ]

One of the characteristics we should be looking at is predator avoidance. This got me thinking about organisms where there appears to be no attempt to avoid predators.

From an evolutionary perspective, the most important thing for an organism is to survive long enough to pass on its genes. If it is successful, it will pass on its success. If it is not, the line potentially stops there and the failure does not continue. One alternative strategy to predator avoidance may simply be rapid asexual or sexual reporduction such that the organism reproduces faster than predation occurs.

Does that make sense?

 

[seasailor]

Sure it makes sense. Increasing the both the rate of reproduction and the number of progeny increases the chances for survival. Predation isn't the only concern. Environmental conditions and food supply are two others - perhaps even more important since without food (or appropriate habitate), it really doesn't matter how many or how efficient the predators.

Charles

 

[rshimek]

Charles,

The question of predator avoidance isn't one of priority. Certainly, obtaining of nutrition is the prime directive for animals, without food, all else is moot.

However, virtually every organism has some sort of predator avoidance behavior. If it is adaptive and inhertable, they will have it.

For protozoans - what ever that term may mean - there is often no defined avoidance of larger predators, but there often appears to be avoidance responses for predators of about the same size range.

ATJ-

Yes, your supposition makes good sense, and it is probably part of the adaptive strategy of many of these organisms, particularly if we consider that the major predators may be organisms that they simply can't avoid. However, many protozoans appear to have poisons in their bodies (which are likely anti-predator defenses), and particular behaviors (such as altering swimming patterns when predatory protozoans are around) that indicate that many of them actively do avoid predation.

Possibly the rapid asexual reproduction is more important in those groups (and you get to name them....) in which sexual reproduction is rare or absent.