Calling Biology Buffs!

[Tequila Sunrise]

I'm trying to remember two terms that define sexually reproducing species: one term is for species that breed continually until their environment can't sustain them, then a bunch die off, then the process starts all over again. The other term is for species that only breed continually until their population reaches a healthy level, then breeding slows down so that their population plateaus out. Does that sound familiar?

[CrazySopher]

Well, I'm no scientist, but it sounds like you're talking about Population Cycles, though I could be missing a much more sciency sounding term.

[The Rose Dragon]

I think the first one is irruptive growth. The second one should be logistic growth.

The species themselves can be r-selected or K-selected, respectively.

I think I should have paid more attention to my ecology classes, since I'm most probably wrong.

[Tequila Sunrise]

I think the first one is irruptive growth. The second one should be logistic growth.
Yeah that's it, except there are two similar terms used specifically by biologists to classify sexual species.

[Serpentine]

Just sounds like r-selected and K-selected to me, though there could be another set of terms I forgot... To wikipedia! "Opportunistic" and "equalibrium"?

Fun fact: humans have the traits of K-selected creatures (large size, long lifespan, few slow-growing high-survival offspring), but our population follows the r-selection pattern.

[daggaz]

I'm trying to remember two terms that define sexually reproducing species: one term is for species that breed continually until their environment can't sustain them, then a bunch die off, then the process starts all over again. The other term is for species that only breed continually until their population reaches a healthy level, then breeding slows down so that their population plateaus out. Does that sound familiar?

Thats not entirely accurate. A solid K species, for example the grizzly bear, does not raise up to a max healthy level then slow its breeding down. It breeds right past the healthy max, and the lack of resources (food) which results (after spreading the population to acquire all the available food sources) then impinges on their reproductive rate due to malnutrition. A bear's reproductive system is highly keyed to this stimuli, more so than in a human, but all species respond negatively to malnutrition. As well, the slow rate of reproduction in the first place means this process is very slow and finds a "stable" equilibrium, but in all reality it is swinging and bears are not reproducing for much the same reasons as happens in a swarm of locusts or arctic voles, just in far less numbers.

Its a tricky point, but its important to realize that ALL species will reproduce as much as they can, whenever they can. Just some are "better" at it short term vs long term, it all comes down to how much resources are invested in the offspring.