According to life-history theory, adaptation under our experimental evolution conditions of 4-day discrete and non-overlapping generations is expected to shift reproduction schedules towards earlier ages [ 47, 48].
Basic knowledge concerning aging patterns by means of physiological aging markers in eggs or somatic tissues has, however, not previously been investigated in cod, but if fisheries may shift reproduction to younger ages and smaller sizes also accelerate female aging, this could have additional and so far overlooked negative consequences for stock restoration and survival.
When workers shift to reproduction as a gamergate, they also change the regulation of stress resistance, which may be causally linked to increased lifespan.
Since most stress signalling has been shown to involve ROS in some way, one speculative possibility is that the changes we have observed could correspond to a more basal metabolic shift from reproduction and/or growth towards defence that increases the plant's ability to respond competently to stimuli elicited by specific stresses.
Regular shifts between reproduction and diapauses has been documented in F. polyctena queens.
Once growth is nearly complete, the primary trade-off then shifts between reproduction and maintenance (Hill 1993; Kaplan et al. 2000).
By generating flies lacking these proteins, it is possible to demonstrate benefits to males producing them (e.g., increased probability of paternity), and costs to females receiving them (e.g., shifts in reproduction and/or reduced female life span; [ 1, 2, 8]).
In addition to resource-dependent trade-offs, life-history theory predicts that in iteroparous organisms an increase in extrinsic mortality selects for optimal life history that shifts towards earlier reproduction, and higher reproductive effort [8].
Instead, as the optimal temperature zones for development and reproduction shift, fish in the north part of the sea are probably doing better than those in the south, the team reports online today in Science.
In a simple verbal model, based on present-day data from Germany, we show that amphibian populations which have undergone phenological shift towards earlier reproduction potentially suffer less from applications of glyphosate-based herbicides compared to those which (yet) show no such reproductive shift.
Such a shift to earlier reproduction has been observed, for example, in some intensively harvested fish species [9] and in natural populations of guppies (Poecilia reticulata) [10] [11].
