Inbreeding negatively affects various life-history traits, with inbred individuals typically having lower fit- ness than outbred individuals （=inbreeding depression）. Inbreeding depression is often emphasized under ...Inbreeding negatively affects various life-history traits, with inbred individuals typically having lower fit- ness than outbred individuals （=inbreeding depression）. Inbreeding depression is often emphasized under environmental stress, but the underlying mechanisms and potential long-lasting consequences of such inbreeding-environment interactions remain poorly understood. Here, we hypothesize that inbreeding-environment interactions that occur early in life have long-term physiological effects, in partic- ular on the adult oxidative balance. We applied a unique experimental design to manipulate early life conditions of inbred and outbred songbirds （Serinus canaria） that allowed us to separate prenatal and postnatal components of early life conditions and their respective importance in inbreeding-environment interactions. We measured a wide variety of markers of oxidative status in adulthood, resulting in a com- prehensive account for oxidative balance. Using a Bayesian approach with Markov chain Monte Carlo, we found clear sex-specific effects and we also found only in females small yet significant long-term effects of inbreeding-environment interactions on adult oxidative balance. Postnatal components of early life conditions were most persuasively reflected on adult oxidative balance, with inbred females that experienced disadvantageous postnatal conditions upregulating enzymatic antioxidants in adulthood. Our study provides some evidence that adult oxidative balance can reflect inbreeding-environment inter- actions early in life, but given the rather small effects that were limited to females, we conclude that oxida- tive stress miaht have a limited role as mechanism underlvina inhre.e.dina-envirnnme.nt inte.raetinn.q_展开更多
Sibling cannibalism is relatively common in nature,but its evolution in birds and certain other vertebrates with extended parental care had been discarded.Here,however,we demonstrate its regular occurrence in two Euro...Sibling cannibalism is relatively common in nature,but its evolution in birds and certain other vertebrates with extended parental care had been discarded.Here,however,we demonstrate its regular occurrence in two European populations of the Eurasian hoopoe(Upupa epops)and explore possible adaptive and non-adaptive explanations.Results showed that sibling cannibalism was more frequently detected in Spain(51.7%)than in Austria(5.9%).In these two populations,the hoopoes laid similar clutch sizes,resulting in similar fledging production,but hatching failures were more frequent in the northern population.Consequently,having more nestlings condemned to die in the southern population may explain the higher incidence of sibling cannibalism.In accordance with this interpretation,hatching span and failure,but not breeding date,explained the probability of sibling cannibalism in the Spanish hoopoes,while all three variables predicted brood reduction intensity.Furthermore,experimental food supply reduced the probability of sibling cannibalism,but not the intensity of brood reduction.Finally,females allocated fewer resources to the smallest nestlings when they were going to starve,but not necessarily when they were going to be used as food for their siblings.These results suggest that hoopoes produce extra eggs that,in the case of reduced hatching failure and food scarcity,produce nestlings that are used to feed older siblings.These findings provide the first evidence that sibling cannibalism occurs regularly in a bird species,thus expanding our evolutionary understanding of clutch size,hatching asynchrony,parent-offspring conflict,infanticide,and sibling cannibalism in the animal kingdom.展开更多
文摘Inbreeding negatively affects various life-history traits, with inbred individuals typically having lower fit- ness than outbred individuals （=inbreeding depression）. Inbreeding depression is often emphasized under environmental stress, but the underlying mechanisms and potential long-lasting consequences of such inbreeding-environment interactions remain poorly understood. Here, we hypothesize that inbreeding-environment interactions that occur early in life have long-term physiological effects, in partic- ular on the adult oxidative balance. We applied a unique experimental design to manipulate early life conditions of inbred and outbred songbirds （Serinus canaria） that allowed us to separate prenatal and postnatal components of early life conditions and their respective importance in inbreeding-environment interactions. We measured a wide variety of markers of oxidative status in adulthood, resulting in a com- prehensive account for oxidative balance. Using a Bayesian approach with Markov chain Monte Carlo, we found clear sex-specific effects and we also found only in females small yet significant long-term effects of inbreeding-environment interactions on adult oxidative balance. Postnatal components of early life conditions were most persuasively reflected on adult oxidative balance, with inbred females that experienced disadvantageous postnatal conditions upregulating enzymatic antioxidants in adulthood. Our study provides some evidence that adult oxidative balance can reflect inbreeding-environment inter- actions early in life, but given the rather small effects that were limited to females, we conclude that oxida- tive stress miaht have a limited role as mechanism underlvina inhre.e.dina-envirnnme.nt inte.raetinn.q_
基金supported by the Spanish Ministerio de CienciaInnovación y Universidades and European(FEDER)Funds(CGL2017-83103-P)。
文摘Sibling cannibalism is relatively common in nature,but its evolution in birds and certain other vertebrates with extended parental care had been discarded.Here,however,we demonstrate its regular occurrence in two European populations of the Eurasian hoopoe(Upupa epops)and explore possible adaptive and non-adaptive explanations.Results showed that sibling cannibalism was more frequently detected in Spain(51.7%)than in Austria(5.9%).In these two populations,the hoopoes laid similar clutch sizes,resulting in similar fledging production,but hatching failures were more frequent in the northern population.Consequently,having more nestlings condemned to die in the southern population may explain the higher incidence of sibling cannibalism.In accordance with this interpretation,hatching span and failure,but not breeding date,explained the probability of sibling cannibalism in the Spanish hoopoes,while all three variables predicted brood reduction intensity.Furthermore,experimental food supply reduced the probability of sibling cannibalism,but not the intensity of brood reduction.Finally,females allocated fewer resources to the smallest nestlings when they were going to starve,but not necessarily when they were going to be used as food for their siblings.These results suggest that hoopoes produce extra eggs that,in the case of reduced hatching failure and food scarcity,produce nestlings that are used to feed older siblings.These findings provide the first evidence that sibling cannibalism occurs regularly in a bird species,thus expanding our evolutionary understanding of clutch size,hatching asynchrony,parent-offspring conflict,infanticide,and sibling cannibalism in the animal kingdom.
