Viewing a single comment thread. View all comments

PlaidBastard t1_iw7lzj1 wrote

Reply to comment by penis_in_my_hand in Are there any K-Strategists insects? by [deleted]

Evolutionarily, investing the time and resources while the offspring are gestating, after birth, or before fertilization is probably as good as the same thing. At least as far as K-strategy etc terminology is concerned, right? One new tarantula hawk per tarantula is a strategy based on it working most of the time, vs sea turtle hatchling death gauntlets for a vertebrate opposite example.

143

UDPviper t1_iw8q8al wrote

I saw a vid of sea horses where it stated only 1-2% of around 1000 or so births per father survive to adulthood. Brutal odds.

51

mabolle t1_iwhzend wrote

You can actually do this math for any species at all, without knowing anything about its biology except how many offspring they tend to have.

Think of it this way: animal and plant populations may fluctuate wildly from year to year, but in the medium-term, we can assume that the per-year average total population of a species is more or less stable — neither increasing or decreasing. This necessarily means that (assuming equal sex ratios, which most species have) each female is having, on average, two offspring per year that survive long enough to have their own offspring. That's one offspring per female to replace herself, and one to replace her male partner. Some females will have much more than two offspring survive to adulthood, and some will have none, but the per-female average is approximately two.

So if you find out that a species tends to have approximately 1000 offspring, you can divide 2 by 1000 to get the survival rate. If the typical litter size is four, you know that only half of them on average will make it. If a species tends to have a million offspring, it's two in a million.

5

SunburntWombat t1_iwa95m4 wrote

Does that mean that social insects are k-strategist? Think about it. For one queen bee to beget the next queen bee, she produces an entire colony of workers and drones, which in turn put in an enormous amount of work to build and maintain a hive. That’s a lot of work just for the genes to be passed down to the next colony.

12

KingoPants t1_iwahnfk wrote

I think its better to think of the colony as a single reproductive evolutionary unit, not as a collection of individuals. Ant colonies produce a large number of new queen's and drones for nuptial flights. Unless they are very lucky to find a good unoccupied spot most of the next generation perish.

In that sense ants don't put too much investment into reproduction.

13

Cephandrius17 t1_iwadoo6 wrote

Maybe. They probably have fairly low infant mortality, since the babies are all being fed/cared for until they are mostly grown up.

6