“Jack‐of‐all‐trades” is parthenogenetic

Abstract

Sex is evolutionarily more costly than parthenogenesis, evolutionary ecologists therefore wonder why sex is much more frequent than parthenogenesis in the majority of animal lineages. Intriguingly, parthenogenetic individuals and species are as common as or even more common than sexuals in some major and putative ancient animal lineages such as oribatid mites and rotifers. Here, we analyzed oribatid mites (Acari: Oribatida) as a model group because these mites are ancient (early Paleozoic), widely distributed around the globe, and include a high number of parthenogenetic species, which often co‐exist with sexual oribatid mite species. There is evidence that the reproductive mode is phylogenetically conserved in oribatid mites, which makes them an ideal model to test hypotheses on the relationship between reproductive mode and species' ecological strategies. We used oribatid mites to test the frozen niche variation hypothesis; we hypothesized that parthenogenetic oribatid mites occupy narrow specialized ecological niches. We used the geographic range of species as a proxy for specialization as specialized species typically do have narrower geographic ranges than generalistic species. After correcting for phylogenetic signal in reproductive mode and demonstrating that geographic range size has no phylogenetic signal, we found that parthenogenetic lineages have a higher probability to have broader geographic ranges than sexual species arguing against the frozen niche variation hypothesis. Rather, the results suggest that parthenogenetic oribatid mite species are more generalistic than sexual species supporting the general‐purpose genotype hypothesis. The reason why parthenogenetic oribatid mite species are generalists with wide geographic range sizes might be that they are of ancient origin reflecting that they adapted to varying environmental conditions during evolutionary history. Overall, our findings indicate that parthenogenetic oribatid mite species possess a widely adapted general‐purpose genotype and therefore might be viewed as “Jack‐of‐all‐trades.”

On the role of niche specialization in the geographic distribution of aphid asexual lineages: a case study using the leaf‐curl plum aphid superclones

“…But in many species that encompass asexual lineages, when these lineages expand over large geographic areas, they are often assumed to be generalists without further analyses of environmental variables behind their distribution. This is the case in orabid mites (Maraun et al 2022) where geographic range sizes have been explicitly used as a proxy for specialisation. In this system, conclusions regarding asexual lineages' generalist ecological strategy have been drawn from their large range sizes but this was solely based on range size comparison of sexual and asexual populations.…”

Hunger for sex: Abundant, heterogeneous resources select for sexual reproduction in the field

“…More generally, there is no evidence that sexual oribatid mite species tend to be ecologically more variable than asexual species, at least in terms of number of occupied habitats (Cianciolo & Norton, 2006; Norton & Palmer, 1991). Indeed, asexual oribatid mite species tend to have larger geographic ranges, although widespread species might encompass many cryptic species with smaller ranges (Maraun et al, 2022).…”

“…More generally, there is no evidence that sexual oribatid mite species tend to be ecologically more variable than asexual species, at least in terms of number of occupied habitats (Cianciolo & Norton, 2006;Norton & Palmer, 1991). Indeed, asexual oribatid mite species tend to have larger geographic ranges, although widespread species might encompass many cryptic species with smaller ranges (Maraun et al, 2022). It has been suggested that an inverse relationship between the proportion of sexual species and individuals and the density of individual mites across oribatid mite communities would support the structured resource hypothesis, assuming higher mite density implies higher resource abundance (Maraun et al, 2012(Maraun et al, , 2013(Maraun et al, , 2019.…”

How mites surprise us

“…Explanations relate to what might be considered their 'permissive' cytogenetics, as first posited by Wrensch et al 1993 (recently put in modern context by Archetti 2021): they are meiotic, and in a way that permits extended existence and, ultimately, speciation. In the past two-three decades dozens of research papers have examined many aspects of oribatid mite asexuality, including cytology, genetics, selective forces, phylogeny, and ecological ramifications, many from the laboratories of Michael Heethoff, Mark Maraun, andtheir students (e.g., Heethoff et al 2009, 2013;Maraun et al 2019Maraun et al , 2022 and most recently by Pequeno et al (2022).…”