A Natural History of Amphibians

Oliveira

et al. 2022

PeerJ

Quantifying variability is important for understanding how evolution operates in polymorphic species such as those of the genus Proceratophrys Miranda-Ribeiro, 1920, which is widely distributed in South America. P. cristiceps distribution is limited to the Caatinga biome in Brazil. We examined its chromatic variation from a populational perspective, looking at different phenetic polymorphism levels and probable chromotypic association by applying statistical and GIS tools that could facilitate future taxonomic research regarding this and other species. We characterized P. cristiceps colour patterns and re-evaluated its geographic variation, highlighting potential consequences for the taxonomy of the genus. Our results revealed six principle chromotypes whose frequencies varied among sex and ontogenetic classes. Phenotypic expression appeared to respect defined proportions and evidenced selective value for the species. We conclude that individual variation, together with typological traditionalism may overestimate the polymorphic magnitude at the population level and cause taxonomic inflation. Our data support the usefulness of P. cristiceps as a model for microevolutionary studies.

Section: Discussionmentioning

confidence: 99%

Polymorphism in a Neotropical toad species: ontogenetic, populational and geographic approaches to chromatic variation inProceratophrys cristiceps(Müller, 1883) (Amphibia, Anura, Odontophrynidae)

Oliveira

et al. 2022

PeerJ

“…Such communication can facilitate the sharing of information about predation risk, such as demonstrated in yellow‐legged gull Larus michahellis embryos (Noguera & Velando, 2019), or optimal hatching conditions, as is the case in pig‐nosed turtles Carettochelys insculpta (Doody et al ., 2012). In taxa where parents brood or incubate the eggs [chiefly birds, but also pythons (Aubret et al ., 2005), monotreme mammals (Beard & Grigg, 2000), and several amphibian species (Stebbins & Cohen, 1995)], embryos may also gain considerable information from parental behaviours. For example, parental vocalisations produced while on the nest have been suggested to influence nestling phenotype in zebra finches Taeniopygia guttata (Mariette & Buchanan, 2016), although whether or not such vocalisations are indeed adaptive is still debated (McDiarmid, Naguib & Griffith, 2018, 2019; Mariette & Buchanan, 2019).…”

Section: Adaptive Plasticity In Response To Maternal Hormone Signalsmentioning

confidence: 99%

Who listens to mother? A whole‐family perspective on the evolution of maternal hormone allocation

Bebbington

Groothuis

2021

Biological Reviews

Maternal effects, or the influence of maternal environment and phenotype on offspring phenotype, may allow mothers to fine-tune their offspring's developmental trajectory and resulting phenotype sometimes long after the offspring has reached independence. However, maternal effects on offspring phenotype do not evolve in isolation, but rather within the context of a family unit, where the separate and often conflicting evolutionary interests of mothers, fathers and offspring are all at play. While intrafamilial conflicts are routinely invoked to explain other components of reproductive strategy, remarkably little is known about how intrafamilial conflicts influence maternal effects. We argue that much of the considerable variation in the relationship between maternally derived hormones, nutrients and other compounds and the resulting offspring phenotype might be explained by the presence of conflicting selection pressures on different family members. In this review, we examine the existing literature on maternal hormone allocation as a case study for maternal effects more broadly, and explore new hypotheses that arise when we consider current findings within a framework that explicitly incorporates the different evolutionary interests of the mother, her offspring and other family members. Specifically, we hypothesise that the relationship between maternal hormone allocation and offspring phenotype depends on a mother's ability to manipulate the signals she sends to offspring, the ability of family members to be plastic in their response to those signals and the capacity for the phenotypes and strategies of various family members to interact and influence one another on both behavioural and evolutionary timescales. We also provide suggestions for experimental, comparative and theoretical work that may be instrumental in testing these hypotheses. In particular, we highlight that manipulating the level of information available to different family members may reveal important insights into when and to what extent maternal hormones influence offspring development. We conclude that the evolution of maternal hormone allocation is likely to be shaped by the conflicting fitness optima of mothers, fathers and offspring, and that the outcome of this conflict depends on the relative balance of power between family members. Extending our hypotheses to incorporate interactions between family members, as well as more complex social groups and a wider range of taxa, may provide exciting new developments in the fields of endocrinology and maternal effects.

“…The mountain yellow‐legged frog ( Rana muscosa ; Figure 1) is a highly threatened anuran endemic to California. Once widely distributed in high‐altitude streams and lakes across mountain ranges of southern California and the southern Sierra Nevada, R. muscosa populations have been declining since the late 1960's (Bradford et al, 1994; Jennings & Hayes, 1994; Stebbins & Cohen, 1997; Knapp & Matthews, 2000). The southern California distinct population segment (DPS) of the mountain yellow‐legged frog has since been extirpated from all its range except at a few sites in three mountain ranges (Figure 2): the San Gabriel, San Bernardino and San Jacinto mountains (Backlin et al, 2015; Schoville et al, 2011; Stebbins, 2003).…”

Section: Introductionmentioning

confidence: 99%

Defining relevant conservation targets for the endangered Southern California distinct population segment of the mountain yellow‐legged frog (Rana muscosa)

Chambert¹,

Backlin

Gallegos

et al. 2022

Conservat Sci and Prac

The endangered mountain yellow-legged frog (Rana muscosa) has been reduced to <10 isolated populations in the wild. Due to frequent catastrophic events (floods, droughts, wildfires), the recent dynamics of these populations have been erratic, making the future of the species highly uncertain. In 2018, a recovery plan was developed to improve the species status by reducing the impacts of various threats (predation, disease, habitat destruction), as well as reinforcing wild populations through the reintroduction of captive-bred frogs.The short-term goal stated in this plan was to reach a minimum of 20 populations of 50 adults each (hereafter, the 20/50 target), before the species can be considered for downlisting from the U.S. Endangered Species Act. However, there is no guarantee that this 20/50 target will be sufficient to ensure the species persistence in the long run. Using 19 years of mark-recapture data, we estimated populations' demographic trends and assessed the viability of R. muscosa from a starting state of 20 populations of 50 adults each (i.e., the downlisting criteria). Our results reveal that, from this 20/50 state, the species has high chances of persistence only at a short time horizon (50 years). Moreover, >80% of populations would be extinct 50 years later. Therefore, the species will not be able to persist without implementation of the reintroduction program. We found that it is more important to increase the number of suitable sites occupied by R. muscosa than to simply reinforce or augment existing populations. Expanding the current distribution by establishing new populations at suitable sites, even after the "20 populations" mark has been reached, would increase the likelihood of the species' persistence in the longer term.