However, researchers realized it was more common than they had supposed--it's been documented in mammals, insects, spiders, and birds--and some researchers came to see it as a way for parents to invest in future reproduction at the expense of their current offspring.
According to parental investment theory, parents must trade off the benefits of investment into current offspring with possible negative effects on their future inclusive fitness [ 13, 25- 27].
In general, parents are predicted to stop investing in their current offspring when the marginal gain from parental care is less than that of alternative behaviors that enhance the parent's future reproductive opportunities [ 3, 39, 40].
The evolutionary response is symbolized as R, and is calculated as the average trait value in the current generation (offspring) subtracted from the average trait value in the previous generation (parents).
Indeed, in the current study, offspring from obese dams consumed more when they were fed either chow or HFD.
An appreciation of the extent to which hosts invest in immunity is therefore critical to understanding the strategies through which animals maximise fitness, and how trade-offs are mediated between current offspring production, longevity and future reproductive success [3], [4].
There was no difference in response between parents whose infants were no longer dependent and former parents with no current offspring.
Every time you watch Britney Spears or any of her current offspring swing around in skimpy lingerie, draping themselves across sweaty bodies of anonymous men, the message is just this: fuck, fuck, fuck; suck, suck, suck; violence; materialism; drugs, drugs, drugs; live fast, never die because you will live on through Facebook legends; spring break, spring break, spring break foreva!
As egg production and offspring care are costly, females should invest resources adaptively into their eggs to optimize current offspring quality and their own lifetime reproductive success.
