INBREEDING IN DARWIN'S MEDIUM GROUND FINCHES (GEOSPIZA FORTIS)

We studied the frequency and causes of inbreeding and its effect on reproductive success in a population of Darwin's Medium Ground Finches (Geospiza fortis) on Isla Daphne Major, Galápagos, during four breeding seasons (1981, 1983, 1984, and 1987). Pedigree analysis showed that levels of inbreeding were low but comparable with those observed in other passerine birds. For pairs with at least half of their grandparents known, approximately 20% of all pairings were between detectably related birds. The frequency of pairings between closely related birds (coefficient of kinship [φ] ≥ 0.250) among all pairs was 0.6%. We detected no effect of inbreeding on reproductive success, although sample sizes were small. The observed reproductive output of related pairs was not significantly different from the output of unrelated pairs, and there was no correlation between a pair's kinship coefficient and an estimate of the potential magnitude of inbreeding depression. Comparisons with a study of Great Tits (Parus major) by van Noordwijk and Scharloo (1981) suggest that, even if present, the fitness costs of inbreeding in this population of G. fortis would be low. Observed levels of inbreeding in each breeding episode were accurately predicted by simulations of random mating in which relatedness had no influence on pairing between individuals. This result suggests that levels of inbreeding in this population are determined more by demographic factors than by behavioral avoidance of mating with kin.     

Diet alters delayed selfing,inbreeding depression,and reproductive senescence in a freshwater snail

Reproductive success is a critical fitness attribute that is directly influenced by resource availability. Here, we investigate the effects of diet‐based resource availability on three interrelated aspects of reproductive success: a change in mating system based on mate availability, consequent inbreeding depression, and the deterioration of reproductive efficiency with age (senescence). We employed a factorial experimental design using 22 full‐sib families of the hermaphroditic freshwater snail Physa acuta to explore these interactions. Individual snails were reared in one of two mate‐availability treatments (isolated [selfing] or occasionally paired [outcrossing]) and one of two diet treatments (boiled lettuce or Spirulina, an algae that is rich in protein, vitamins, and minerals). Spirulina‐fed snails initiated reproduction at a 13% earlier age and 7% larger size than lettuce‐fed snails. Spirulina also resulted in a 30% reduction in the time delay before selfing. Compared to lettuce, a diet of Spirulina increased inbreeding depression by 52% for egg hatching rate and 64% for posthatching juvenile survival. Furthermore, Spirulina led to a 15‐fold increase in the rate of reproductive senescence compared with a diet of lettuce. These transgenerational, interactive effects of diet on inbreeding depression and reproductive senescence are discussed in the context of diet‐induced phenotypic plasticity.     

INBREEDING AND ITS FITNESS EFFECTS IN AN INSULAR POPULATION OF SONG SPARROWS (MELOSPIZA MELODIA)

Inbreeding depression is thought to be a major factor affecting the evolution of mating systems and dispersal. While there is ample evidence for inbreeding depression in captivity, it has rarely been documented in natural populations. In this study, I examine data from a long-term demographic study of an insular population of song sparrows (Melospiza melodia) and present evidence for inbreeding depression. Forty-four percent of all matings on Mandarte Island, British Columbia, were among known relatives. Offspring of a full-sib mating (f = 0.25) experienced a reduction in annual survival rate of 17.5% on average. Over their lifetime, females with f = 0.25 produced 48% fewer young that reached independence from parental care. In contrast, male lifetime reproductive success was not affected by inbreeding. Reduced female lifetime reproductive success was mostly due to reduced hatching rates of the eggs of inbred females. Relatedness among the parents did not affect their reproductive success. Using data on survival from egg stage to breeding age, I estimated the average song sparrow egg on Mandarte Island to carry a minimum of 5.38 lethal equivalents (the number of deleterious genes whose cumulative effect is equivalent to one lethal); 2.88 of these lethal equivalents were expressed from egg stage to independence of parental care. This estimate is higher than most estimates reported for laboratory populations and lower than those reported for zoo populations. Hence, the costs of inbreeding in this population were substantial and slightly above those expected from laboratory studies. Variability in estimates of lethal equivalents among years showed that costs of inbreeding were not constant across years.     

Disentangling the pollination system of the food-deceptive orchid Anacamptis longicornu (Orchidaceae): from breeding system to spatio-temporal variation in reproductive success

Abstract

The deceptive breeding system in the Orchidaceae family has been studied for decades to disentangle how pollination service can occur. Moreover, the interference of introduced herbivores on population development has been reported to affect the reproductive output in different plant species, including orchids. In this study, the breeding system of the food-deceptive species Anacamptis longicornu has been assessed. The spatio-temporal variation in both male and female reproductive fitness and its relationship with plant features were also analyzed. The possible herbivory effects were investigated by an exclusion experiment using two types of cages. The results confirm that this species is pollinator dependent and mostly allogamous but is also self-compatible. This species showed high values of cumulative inbreeding depression index for fruit set and seed viability parameters and was highly pollen-limited. Male fitness was always higher than female fitness between years and locations, and both parameters showed spatio-temporal variation. The use of cages excluded herbivores but, eventually, also excluded pollinators, so that both male and female reproductive success parameters decreased significantly in the complete exclusion treatment. The strong dependence of the species’ fitness on pollinator-mediated pollen transfer must be considered for the long-term conservation of A. longicornu.     

Inbreeding effects on mating system traits for two species of Lupinus (Leguminosae)

The consequences of inbreeding for reproductive traits were investigated for two closely related annual lupines that differ in their mating system. Lupinus bicolor (Leguminosae) is a primarily selling species while Lupinus nanus outcrosses at intermediate rates. A controlled crossing program was used for each species to produce selfed and outcrossed progeny. These progeny were then grown in a greenhouse and scored for the date of first flower, flower morphology, and autofertility. Selfed progeny of L. bicolor produced significantly smaller flowers but did not differ from outcrossed progeny for the remaining traits. Selfed progeny of L. nanus produced flowers that significantly differed in shape and had fewer ovules than the flowers of outcrossed progeny. Selfed progeny of L. nanus also had significantly lower rates of autofertility in comparison to outcrossed progeny. The significant effects of inbreeding on these mating system traits may indicate the presence of directional dominance at the loci underlying these characters. The consequences of these direct effects of inbreeding on reproductive traits for plants growing in natural populations may include nonadaptive changes in the outcrossing rate between generations.     

Age specificity of inbreeding depression during a life cycle ofCallosobruchus chinensis (Coleoptera: Bruchidae)

Age-specific effects of inbreeding on fecundity were assayed for adzuki bean weevil Callosobruchus chinensis by comparing inbred lines and their cross. Four consecutive full-sib matings reduced only 10.3 percent in total fecundity, and did not decrease early fecundity at all until third day from the onset of reproduction. It is suggested that recessive detrimental genes have been eliminated from the early period of adult life span when reproductive value is high. There was a slight tendency that inbreeding depression increased as age proceeded though not statistically significant.     

PEDIGREE ERROR DUE TO EXTRA‐PAIR REPRODUCTION SUBSTANTIALLY BIASES ESTIMATES OF INBREEDING DEPRESSION

Understanding the evolutionary dynamics of inbreeding and inbreeding depression requires unbiased estimation of inbreeding depression across diverse mating systems. However, studies estimating inbreeding depression often measure inbreeding with error, for example, based on pedigree data derived from observed parental behavior that ignore paternity error stemming from multiple mating. Such paternity error causes error in estimated coefficients of inbreeding (f) and reproductive success and could bias estimates of inbreeding depression. We used complete “apparent” pedigree data compiled from observed parental behavior and analogous “actual” pedigree data comprising genetic parentage to quantify effects of paternity error stemming from extra‐pair reproduction on estimates of f, reproductive success, and inbreeding depression in free‐living song sparrows (Melospiza melodia). Paternity error caused widespread error in estimates of f and male reproductive success, causing inbreeding depression in male and female annual and lifetime reproductive success and juvenile male survival to be substantially underestimated. Conversely, inbreeding depression in adult male survival tended to be overestimated when paternity error was ignored. Pedigree error stemming from extra‐pair reproduction therefore caused substantial and divergent bias in estimates of inbreeding depression that could bias tests of evolutionary theories regarding inbreeding and inbreeding depression and their links to variation in mating system.     

Variation in self-fertility,inbreeding depression and levels of inbreeding in four Cyclamen species

The ability to self in the absence of pollinators, i.e. reproductive assurance, and the detrimental consequences of inbreeding, i.e. inbreeding depression, are central factors influencing plant mating system evolution. The purpose of this study was to quantify whether self-fertility and inbreeding depression are related to levels of inbreeding in four Cyclamen species, namely C. balearicum (mean F_is = 0.930), C. creticum (mean F_is = 0.748), C. repandum (mean F_is = 0.658) and C. hederifolium (mean F_is = 0.329). C. balearicum showed a markedly greater capacity to autonomously self-fertilize than the three other species, which may have favoured inbreeding in this species. Levels of inbreeding depression were highest in C. creticum and C. hederifolium at the fruit maturation (δ = 0.18 and 0.20, respectively) and seed number (δ = 0.32 and 0.30, respectively) stages, and for C. repandum at the seed weight stage (δ = 0.23). Although C. balearicum showed inbreeding depression on seed germination (δ = 0.45), this may be an artefact of the generally low levels of seed germination in the experiment. Overall, we observed only limited evidence for the predicted negative relation between inbreeding coefficients and levels of inbreeding since C. creticum had high levels of inbreeding and inbreeding depression. Other factors may thus influence the relationship between inbreeding and inbreeding depression in these species.     

The interaction between follicular fluid total antioxidant capacity,infertility and early reproductive outcomes during in vitro fertilization

Abstract

Introduction: The objective of this study was to determine whether the relationship between antioxidant capacity of follicular fluid and early reproductive outcomes is influenced by the cause of infertility, polycystic ovarian morphology, age and smoking.

Patients and methods: This was a prospective, cross-sectional study performed in an assisted conception unit and a teaching hospital. The study cohort was 34 women undergoing IVF treatment. Interventions included total antioxidant capacity (TAC) measured using ferric reducing/antioxidant power assay in 303 follicular fluid samples. The main outcome measures were follicular fluid TAC, percentage TAC loss after 72 h and early reproductive outcomes.

Results: Follicular TAC was elevated in women with infertility of 'unexplained' (UE) or tubal factor (TF) aetiology, relative to those with male factor (MF) infertility, when reproductive outcomes were positive but not when they were negative. In the TF and UE groups, low TAC was associated with ovum fertilization incompetence, whereas TAC was comparable irrespective of embryo viability. Unexplained infertility was associated with significantly elevated follicular TAC. Among women with polycystic ovaries, fertilization incompetence was associated with elevated TAC; the opposite was true in women with normal ovaries. Follicular fluid 72-h TAC consumption > 20% was associated with poorer reproductive performance.

Conclusions: The follicular fluid pro-oxidant-antioxidant balance required for conception in women undergoing IVF is related to the aetiology of infertility, age, the presence of polycystic ovary morphology and smoking.     

Alcohol Consumption Practices among Married Women of Reproductive Age in Nepal: A Population Based Household Survey

BackgroundAlcohol chemically known as ethanol, causes several health, economic and social consequences across the world. Literatures suggest potential harm of alcohol drinking by pregnant women especially to the fetus and the mother. Despite anumber of significant public health problems related to alcohol consumption, this area has been ignored in Nepal and information at the national level is limited. Thus this study aimed at finding the prevalence of alcohol consumption among married women of reproductive age.MethodsA nationally representative household survey was carried out from April to August 2013 by taking 16 districts across all 15 eco administrative regions. From the selected districts, 86 village development committees and 14 municipalities were selected as primary sampling units using probability proportionate to size, followed by random selection of 3 wards from each primary sampling unit. Finally, 30 households within each ward were selected using systematic random sampling, and one married women of reproductive age from each household. A total of 9000 married women of reproductive age were interviewed using a semi-structured questionnaire, on alcohol consumption practices including environmental factors and socio demographic characteristics and were included in the analysis.ResultsNational prevalence of alcohol consumption ever among married women of reproductive age was 24.7% (95% CI:21.7–28.0), last 12 months 17.9% (95% CI:15.3–20.7) and last 30 days (current drinking) 11.8% (95% CI:9.8–14.1). There was substantial variation among the districts ranging from 2% to 60%. Multivariable analysis suggests women with no education or within formal education, dalit and janajatis ethnicity, whose husbands drink alcohol, who brew alcohol at home and women from mountains were significantly at higher risk of consuming alcohol. Among the women who drank alcohol in last 12 months, a substantial proportion of them drank home brewed alcoholic beverages (95.9%, 95% CI:94.3–97.4).ConclusionAlcohol consumption was common practice among married women of reproductive age in Nepal with variation among the subgroups of population. Thus, further investigation and behavior change communication interventions to reduce alcohol consumption especially among the women with higher risk of drinking is essential.     

Reproductive and external hormonal factors and the risk of renal cell cancer in the Netherlands Cohort Study

BackgroundSeveral reproductive and hormonal factors, like age at menarche, parity, age at menopause, use of oral contraceptives and postmenopausal treatment, have been associated with the risk of renal cell cancer (RCC) in women, but results have not always been consistent. We therefore investigated the association between these factors and the risk of RCC in postmenopausal women participating in the Netherlands Cohort Study on Diet and Cancer.MethodsInformation on reproductive history, exogenous hormone use and gynecological surgery was obtained through a self-administered questionnaire at baseline in 1986. After 20.3 years of follow-up, 204 cases and 2280 subcohort members were available for case-cohort analysis. Multivariable hazard ratios (HR) were calculated using Cox Proportional Hazard analysis.ResultsWomen who reported a hysterectomy had an increased RCC risk compared to women who did not (HR, 1.42, 95%CI, 1.01–2.00). Women with a natural age at menopause between 45 and 49 years compared to 50–54 years had an increased RCC risk (HR, 1.61; 95%CI, 1.10–2.35). RCC risk was slightly and not statistically significant increased among parous women with three or more children and age at first birth before 25 years compared to nulliparous women (HR, 1.36; 95% confidence interval (CI), 0.84–2.20). No associations were observed with RCC risk for age at menarche, use of oral contraceptives and use of hormonal replacement therapy.ConclusionHysterectomy and age at natural menopause were associated with an increased RCC risk. Other hormonal and reproductive factors and RCC risk were not increased. Further studies are required to establish the mechanism(s) that explain the observed association.     

Reproductive factors,exogenous hormone use,and risk of pancreatic cancer in postmenopausal women

IntroductionThe epidemiologic literature on menstrual and reproductive factors associated with pancreatic cancer has yielded weak and inconsistent evidence of an association. Furthermore, few cohort studies have examined the association of exogenous hormone use, including type and duration, with this disease. The aim of this study was to assess the association of these exposures with risk of pancreatic cancer in a large cohort of postmenopausal women.MethodsWe used data from the Women’s Health Initiative on 1003 cases of pancreatic cancer diagnosed among 158,298 participants over 14.3 years of follow-up. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (95% CI) for the associations of interest.ResultsBeing parous vs. nulliparous was associated with reduced risk (HR = 0.84, 95% CI 0.70–1.00), and women who had 1–2 and 3–4 births were at decreased risk compared to nulliparous women, whereas women who had >5 births showed no decrease in risk. Compared to women who gave birth between the ages of 20–29, women who gave birth at age 30 or above were at increased risk (HR 1.23, 95% CI 1.00–1.53, p for trend 0.003). Other reproductive factors and exogenous hormone use were not associated with risk.ConclusionsTogether with the existing literature on this topic, our results suggest that reproductive and hormonal exposures are unlikely to play an important role in the etiology of pancreatic cancer.     

Duration of ovarian hormone exposure and gynecological cancer risk in Korean women: the Korean Heart Study

BackgroundAlthough reproductive and hormonal factors – such as early menarche and late menopause – have been reported as independent risk factors for cancer, few studies have examined these factors in East Asian populations.MethodsWe performed a large prospective cohort study of 66,466 women. Ovarian hormone exposure was defined as length of time between menarche and menopause. Incidence rates for breast, ovarian, endometrial and cervical cancers were examined separately in relation to reproductive lifespan defined as age at menopause minus age at menarche. Multivariable adjusted hazard ratios (HRs) with 95% confidence intervals (95% CIs) were calculated using the Cox proportional hazards model.ResultsWomen with early menarche were at increased risk for developing breast cancer (HR, 1.57, 95% CI, 1.17–2.10) for age at menarche ≤12 years compared to women with age at menarche ≥17 years. Women with late age at menopause (≥52 years) had increased risks for cancers of the breast (HR, 1.59, 95%CI, 1.11–2.28) and ovary (HR, 3.22, 95% CI, 1.09–9.55) compared to women with early menopause (≤45 years of age). Women with longer duration of ovarian hormone exposure (≥40 years) were at increased risk for developing breast cancer (HR, 2.23, 95% CI, 1.35–3.68) as well as endometrial cancer (p for trend, 0.0209).ConclusionsWe showed that longer reproductive spans are associated with an increased risk of breast and endometrial cancer in Korean women.     

Religion and intensity of inbreeding in Tamil Nadu,South India

Abstract

A representative random sample of 11,628 rural couples and 8,998 urban couples from North Arcot District of Tamil Nadu in South India are under follow up since 1969 in a study of inbreeding eflFects. This paper describes the level of inbreeding and its relationship to religion of the couples. Wright's F for autosomal genes in the rural and urban areas were 0.0371 and 0.0205, respectively. The F for sex‐linked genes was significantly higher than that for autosomal and was 0.0411 in the rural areas and 0.0228 in the urban. Hindus had the highest inbreeding coefficients as compared to Muslims or Christians for both autosomal and sex‐linked genes, but there were significant variations among the different castes. The level of inbreeding among Muslims and Christians was similar and fairly high. Significant rural‐urban differentials persist in all religions. There is no appreciable change in the level of inbreeding over the past few decades in any religion, although minor declines are observed in certain castes in the urban areas.     

Do gravidity and age affect pregnancy outcome?

Abstract

Fetal loss has generally been found to vary with gravidity, previous experience of fetal loss, and maternal age, but the literature is divided on the reasons for these associations. In this paper we examine pregnancy histories obtained retrospectively from a nationally representative one‐in‐one‐thousand sample of women in Australia aged 20 to 59 years. The relations of fetal loss ratios with both gravidity and previous outcome are consistent with heterogeneity of risk over the study population and a stopping rule, whereby high‐risk women undertake more pregnancies than low‐risk women to achieve the same number of live births. Evidence is presented that elevated loss ratios in the teens indicate not higher risk but a selection for short gestation intervals, while loss ratios beyond the mid‐thirties do not point unequivocally to a substantial increase in risk at the older reproductive ages.     

RELATIONSHIP BETWEEN SELF-FERTILITY,ALLOCATION OF GROWTH,AND INBREEDING DEPRESSION IN THREE CONIFEROUS SPECIES

Mortality and growth of self and outcross families of three wind-pollinated, mixed-mating, long-lived conifers, Douglas-fir (Pseudotsuga menziesii), ponderosa pine (Pinus ponderosa), and noble fir (Abies procera) were followed from outplanting to age 26 (25 for noble fir) in spaced plantings at a common test site. Response to inbreeding differed greatly among species over time and in all regards. Only Douglas-fir and noble fir will be contrasted here, because ponderosa pine usually was intermediate to the other two in its response to inbreeding. In earlier reports, compared to noble fir Douglas-fir had a higher rate of primary selfing and larger inbreeding depression in seed set. Douglas-fir continued to have higher inbreeding depression in nursery and early field survival. The species differed in time courses of inbreeding depression in height and in allocation of growth due to crowding. Between ages 6 and 12, the relative elongation rate (dm · dm^?1 · yr^?1) of Douglas-fir was significantly greater in the selfs than in the outcrosses. The response was not observed in noble fir. At final measurement, inbreeding depression in diameter relative to inbreeding depression in height was greater in Douglas-fir than in noble fir. At final measurement inbreeding depression in height was inversely related to inbreeding depression in survival. Cumulative inbreeding depressions from time of fertilization to final measurement were 0.98, 0.94, and 0.83 for Douglas-fir, ponderosa pine, and noble fir, respectively, which indicates that selfs will not contribute to the mature, reproductive populations.     

Effects of Inbreeding on Skeletal Size and Fluctuating Asymmetry of Peromyscus polionotus Mice

Measurements of size and asymmetry in morphology might provide early indications of damaging effects of inbreeding or other genetic changes in conservation breeding programs. We examined the effects of inbreeding on size and fluctuating asymmetry (FA) in skull and limb bone measurements in experimental populations of three subspecies of Peromyscus polionotus mice that had previously been shown to suffer significant reductions in reproductive success when inbred. Inbreeding caused significant depression in mean size in two of the subspecies (P. p. rhoadsi and P. p. subgriseus), but the effects were smaller in the third (P. p. leucocephalus). Inbreeding caused an increase in FA of just one of eight bilateral traits in one subspecies (P. p. rhoadsi). Inbreeding depression in size was more easily detected than the effects of inbreeding on FA. FA may be much less sensitive to inbreeding and other stresses than are more direct measures of fitness such as reproductive output and body mass growth rate. Given the large sample sizes and statistical complexity required to assess changes to typically very small levels of FA in captive populations, FA will not likely provide a useful measure of inbreeding depression in captive populations. Zoo Biol. 32:125‐133, 2013. © 2012 Wiley Periodicals, Inc.     

Polymorphic microsatellite loci in the ponerine ant,Hypoponera opacior (Hymenoptera,Formicidae)

The ant genus Hypoponera, with its high diversity of alternative reproductive tactics, is of particular interest in studies on sexual selection. In the species Hypoponera opacior, winged and wingless males and queens co‐occur and molecular markers are essential to study the reproductive success of these sexual tactics. Primers were developed for five polymorphic microsatellite loci isolated from H. opacior. Their variability was tested on 34 colonies from a population in the United States. Nine to 21 alleles per locus were found with observed heterozygosities between 0.1 and 0.7. A significantly positive F_IS value suggests inbreeding in this ant with predominant intracolonial matings.     

Reproductive factors and serum uric acid levels in females from the general population: the KORA F4 study

Objective

Hyperuricemia is associated with an increased risk of metabolic and cardiovascular diseases. There are pronounced sex differences in the levels of uric acid. It is largely unknown whether or not reproductive parameters which induce hormonal changes are responsible for this. We examined if there are associations between reproductive parameters and uric acid levels in a female population-based sample.

Methods

In this cross-sectional analysis, data of 1530 women aged 32 to 81 years participating in the KORA F4 study, conducted between 2006 and 2008 in Southern Germany were used. Reproductive parameters were obtained by standardized interviews. Uric acid levels were tested by the uricase method. The whole study sample and stratified in pre- and postmenopausal women was analyzed.

Results

Menopausal status and earlier age at menarche were associated with higher serum uric acid levels (age-adjusted: p-values 0.003, <0.001 respectively; after multivariable adjustment, including BMI: p-values 0.002, 0.036). A history of oral contraceptive use showed an association with uric acid levels only after multivariable adjustment (p-value 0.009). Hot flushes showed an association with uric acid levels only after age-adjustment (p-value 0.038), but lost significance after adding other confounders. Other reproductive factors, including parity, current or ever use of hormone replacement therapy, current use of oral contraceptives, hysterectomy, bilateral oophorectomy, or depressive mood related to menopausal transition were not associated with uric acid levels.

Conclusions

Postmenopausal status, earlier age at menarche and a history of oral contraceptive use were independently associated with higher serum uric acid concentrations in women from the general population. Further studies, especially longitudinal population-based studies investigating the relationship of female reproductive parameters with uric acid levels are necessary to confirm our findings.     

Monitoring age‐related trends in genomic diversity of Australian lungfish

An important challenge for conservation science is to detect declines in intraspecific diversity so that management action can be guided towards populations or species at risk. The lifespan of Australian lungfish (Neoceratodus forsteri) exceeds 80 years, and human impacts on breeding habitat over the last half century may have impeded recruitment, leaving populations dominated by old postreproductive individuals, potentially resulting in a small and declining breeding population. Here, we conduct a “single‐sample” evaluation of genetic erosion within contemporary populations of the Australian lungfish. Genetic erosion is a temporal decline in intraspecific diversity due to factors such as reduced population size and inbreeding. We examined whether young individuals showed signs of reduced genetic diversity and/or inbreeding using a novel bomb radiocarbon dating method to age lungfish nonlethally, based on ¹⁴C ratios of scales. A total of 15,201 single nucleotide polymorphic (SNP) loci were genotyped in 92 individuals ranging in age from 2 to 77 years old. Standardized individual heterozygosity and individual inbreeding coefficients varied widely within and between riverine populations, but neither was associated with age, so perceived problems with recruitment have not translated into genetic erosion that could be considered a proximate threat to lungfish populations. Conservation concern has surrounded Australian lungfish for over a century. However, our results suggest that long‐lived threatened species can maintain stable levels of intraspecific variability when sufficient reproductive opportunities exist over the course of a long lifespan.