scholarly journals The impact of parental investment on lifetime reproductive success in Iceland

PeerJ ◽  
2017 ◽  
Vol 5 ◽  
pp. e2904 ◽  
Author(s):  
Robert F. Lynch ◽  
Emily C. Lynch
Keyword(s):  
Reproductive Success ◽  
Parental Investment ◽  
Genetic Data ◽  
Lifetime Reproductive Success ◽  
Narrow Sense ◽  
Narrow Sense Heritability ◽  
Full Sibling ◽  
Close Relatives ◽  
The Impact ◽  
The Relationship

BackgroundDemonstrating the impact that parents have on the fitness of their children is a crucial step towards understanding how parental investment has affected human evolution. Parents not only transfer genes to their children, they also influence their environments. By analyzing reproductive patterns within and between different categories of close relatives, this study provides insight into the genetic and environmental effects that parents have on the fitness of their offspring.MethodsWe use data spanning over two centuries from an exceptionally accurate Icelandic genealogy, Íslendingabók, to analyze the relationship between the fertility rates of close relatives. Also, using genetic data, we determine narrow sense heritability estimates (h2) to further explore the genetic impact on lifetime reproductive success. Finally, we construct four simulations to model the expected contribution of genes and resources on reproductive success.ResultsThe relationship between the reproduction of all full sibling pairs was significant and positive across all birth decades (r = 0.19) while the reproductive relationship between parents and offspring was often negative across many decades and undetectable overall (r = 0.00) (Fig. 1 and Table 1). Meanwhile, genetic data among 8,456 pairs of full siblings revealed a narrow sense heritability estimate (h2) of 0.00 for lifetime reproductive success. A resources model (following the rule that resources are transmitted from parents to children, distributed equally among siblings, and are the only factor affecting reproductive success) revealed a similar trend: a negative relationship between parent and offspring reproduction (r =  − 0.35) but a positive relationship among full siblings (r = 0.28). The relationship between parent and offspring lifetime reproductive success (LRS) and full sibling LRS was strongly and positively correlated across time (r = 0.799,p < 0.001). Similarly, the LRS among full siblings was positively correlated with both the LRS among half siblings (r = 0.532,p = 0.011) and the relationship between the LRS of aunts and uncles with their nieces and nephews (r = 0.438,p = 0.042).DiscussionWe show that an individual’s lifetime reproductive success is best predicted by the reproduction of their full and half siblings, but not their parents, grandparents or aunts and uncles. Because all siblings share at least one parent, we believe parental investment has had an important impact on fitness. Overall, these results indicate that direct parental investment, but not genes, is likely to have had an important and persistent impact on lifetime reproductive success across more than two centuries of Icelandic history.

Haemoproteusinfected birds have increased lifetime reproductive success

Parasitology ◽  
2015 ◽  
Vol 142 (8) ◽  
pp. 1033-1043 ◽  
Author(s):  
M. ZYLBERBERG ◽  
E. P. DERRYBERRY ◽  
C. W. BREUNER ◽  
E. A. MACDOUGALL-SHACKLETON ◽  
J. M. CORNELIUS ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Lifetime Reproductive Success ◽  
Parasitic Infections ◽  
Host Fitness ◽  
Return Rates ◽  
Long Term Study ◽  
In The Wild ◽  
The Impact ◽  
The Relationship

SUMMARYThe impact of haematozoan infection on host fitness has received substantial attention since Hamilton and Zuk posited that parasites are important drivers of sexual selection. However, short-term studies testing the assumption that these parasites consistently reduce host fitness in the wild have produced contradictory results. To address this complex issue, we conducted a long-term study examining the relationship between naturally occurring infection withHaemoproteusandPlasmodium, and lifetime reproductive success and survival of Mountain White-crowned Sparrows. Specifically, we tested the hypothesis that birds infected with haematozoan parasites have reduced survival (as determined by overwinter return rates) and reproductive success. Contrary to expectation, there was no relationship betweenHaemoproteusandPlasmodiuminfection and reproduction or survival in males, nor was there a relationship betweenPlasmodiuminfection and reproduction in females. Interestingly,Haemoproteus-infected females had significantly higher overwinter return rates and these females fledged more than twice as many chicks during their lifetimes as did uninfected females. We discuss the impact of parasitic infections on host fitness in light of these findings and suggest that, in the case of less virulent pathogens, investment in excessive immune defence may decrease lifetime reproduction.

scholarly journals Associations of autozygosity with a broad range of human phenotypes

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
David W Clark ◽  
Yukinori Okada ◽  
Kristjan H S Moore ◽  
Dan Mason ◽  
Nicola Pirastu ◽  
...  
Keyword(s):  
Reproductive Success ◽  
Inbreeding Depression ◽  
Social Factors ◽  
Genetic Variants ◽  
Runs Of Homozygosity ◽  
Sibling Pairs ◽  
Full Sibling ◽  
Inbreeding Coefficients ◽  
Genomic Inbreeding ◽  
Close Relatives

Abstract In many species, the offspring of related parents suffer reduced reproductive success, a phenomenon known as inbreeding depression. In humans, the importance of this effect has remained unclear, partly because reproduction between close relatives is both rare and frequently associated with confounding social factors. Here, using genomic inbreeding coefficients (FROH) for >1.4 million individuals, we show that FROH is significantly associated (p < 0.0005) with apparently deleterious changes in 32 out of 100 traits analysed. These changes are associated with runs of homozygosity (ROH), but not with common variant homozygosity, suggesting that genetic variants associated with inbreeding depression are predominantly rare. The effect on fertility is striking: FROH equivalent to the offspring of first cousins is associated with a 55% decrease [95% CI 44–66%] in the odds of having children. Finally, the effects of FROH are confirmed within full-sibling pairs, where the variation in FROH is independent of all environmental confounding.

Comparative effects of mites and lice on the reproductive success of rock doves (Columba livia)

Parasitology ◽  
1995 ◽  
Vol 110 (2) ◽  
pp. 195-206 ◽  
Author(s):  
D. H. Clayton ◽  
D. M. Tompkins
Keyword(s):  
Reproductive Success ◽  
Body Mass ◽  
Growth Rates ◽  
Columba Livia ◽  
Nestling Growth ◽  
Adult Body Mass ◽  
Evolution Of Virulence ◽  
Relationship Of ◽  
The Impact ◽  
The Relationship

SUMMARYWe report experimental data comparing the effects of Mesostigmatid mites and Ischnoceran lice on the reproductive performance of a single group of captive rock doves (Columba livia). Several components of host reproductive success were compared for the two groups, including number of eggs laid, hatching success, nestling growth rates, fledging success, post-fledging body mass and survival. Adult body mass and survival were also compared. There was a dramatic difference in the effects of the mites and lice. The former drove host reproductive success to zero, mainly by agitating adults and causing them to incubate eggs less faithfully. Nestling growth rates and post-fledging survival were also significantly reduced by mites. Lice showed no effect on reproductive success whatsoever, even though the feather damage they cause is known to have energetic consequences (Booth, Clayton & Block, 1993). Neither parasite had a significant effect on adult birds. Although Ischnocera are found on most species of birds, our results for lice constitute the first experimental test of the impact of Ischnocera on avian reproductive success (preliminary report by Clayton & Tompkins, 1994). We discuss reasons for the different effects of mites and lice, including the relationship of horizontal (mites) and vertical (lice) transmission to the evolution of virulence.

An experimental test of the effect of male attractiveness on maternal investment in Dark-eyed Juncos

The Auk ◽  
2019 ◽  
Vol 136 (1) ◽  
Author(s):  
Elise D Ferree
Keyword(s):  
Maternal Investment ◽  
Lifetime Reproductive Success ◽  
Differential Allocation ◽  
Reproductive Behaviors ◽  
Extrapair Paternity ◽  
Female Investment ◽  
Correlated Factors ◽  
The Impact ◽  
The Relationship

AbstractWhile social mate choice is an obvious point where sexual selection acts on males, cryptic selection can occur based on how much females invest in a male’s offspring. I tested 4 hypotheses about the relationship between female investment and social mate attractiveness by manipulating a sexually selected trait, white tail feathers (“tail white”), in male Dark-eyed Juncos (Junco hyemalis thurberi): (1) the differential allocation hypothesis predicts that females optimize lifetime reproductive success by maximizing parental investment in the offspring of ornamented mates and minimizing investment when mated to less attractive males; (2) instead of positive differential allocation, females could show negative differential allocation by investing more in less attractive males to compensate for their lower quality; (3) female care could also be influenced directly by paternal investment, in particular what appears to be positive differential allocation could be compensation for reduced care by attractive males; or (4) females could reduce care when paired with socially attractive males that are “good parents”. To evaluate these hypotheses, I examined the impact of tail white manipulation on clutch size, female incubation and brooding, and female and male provisioning. Females did not differentially allocate in relation to social mate attractiveness, nor were females responsive to patterns of male investment, even although artificially attractive males provisioned offspring significantly more than did controls. Naturally bright males, who were also the largest males, did not provision at higher rates, highlighting the need to experimentally separate the role of specific traits from other correlated factors. Tail white-manipulated males were involved in rare cases of polygyny and at times were actively guarded by their mates. Together, these results suggest that tail white influences reproductive behaviors in this junco population, but because of the potential for extrapair paternity, additional data are needed to accurately investigate the trait’s role in female investment.

Forest management effects on survival of a long-lived bird

2019 ◽  
Author(s):  
Paul James Haverkamp ◽  
Julian Klein ◽  
Michael Griesser
Keyword(s):  
Life History ◽  
Forest Management ◽  
Reproductive Success ◽  
Boreal Forests ◽  
Late Onset ◽  
Life History Evolution ◽  
Lifetime Reproductive Success ◽  
High Exposure ◽  
Natural Landscapes ◽  
The Impact

1.A high number of reproductive events is a critical fitness correlate for long-lived species. Thus, individuals of these species should be sensitive to factors that increase their mortality. Living in habitats with high exposure to predators can decrease lifespan, but the ecological drivers of longevity within populations remain poorly studied. Forest management in boreal forests can increase the predation risk by creating edges and open forests, which facilitate prey detection for visual hunters.2.We assessed the impact of forest structure on breeding lifespan and lifetime reproductive success on a population of Siberian jays (Perisoreus infaustus) in northern Sweden located in managed and natural landscapes. 3.We used survival analyses to assess the influence of life history and ecological correlates on lifespan after attaining breeder status. The analyses included N=133 individuals within 38 territories in the managed landscape, and N=74 individuals within 25 territories in the natural landscape. The same correlates were used to investigate influences on the number of surviving offspring, as a measure of lifetime reproductive success.4.Breeder lifespan was longest when individuals attained breeder status at an older age, in territories with dense understory, and few linear edges and natural openings, which reduce the risk of detection by primary predators (accipiter hawks). Moreover, a late onset of reproduction was associated with a higher lifetime reproductive success. Remarkably, these effects were only found in the managed landscape. 5.These results suggest that forestry shapes risk gradients in landscapes that particularly affect individuals that begin to breed at an earlier age. Thus, experience may be more critical to survive in managed than natural landscapes, making populations less resilient to disturbance and affecting life history evolution.

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