Sperm competition intensity shapes divergence in both sperm morphology and reproductive genes across murine rodents.

It remains unclear how variation in the intensity of sperm competition shapes phenotypic and molecular evolution across clades. Mice and rats in the subfamily Murinae are a rapid radiation exhibiting incredible diversity in sperm morphology and production. We combined phenotypic and genomic data to perform phylogenetic comparisons of male reproductive traits and genes across 78 murine species.

Geography and elevation as drivers of cloacal microbiome assemblages of a passerine bird distributed across Sulawesi, Indonesia.

Background: Empirical field studies allow us to view how ecological and environmental processes shape the biodiversity of our planet, but collecting samples in situ creates inherent challenges. The majority of empirical vertebrate gut microbiome research compares multiple host species against abiotic and biotic factors, increasing the potential for confounding environmental variables. To minimize these confounding factors, we focus on a single species of passerine bird found throughout the geologically complex island of Sulawesi, Indonesia.

A set of principles and practical suggestions for equitable fieldwork in biology.

Field biology is an area of research that involves working directly with living organisms in situ through a practice known as "fieldwork." Conducting fieldwork often requires complex logistical planning within multiregional or multinational teams, interacting with local communities at field sites, and collaborative research led by one or a few of the core team members. However, existing power imbalances stemming from geopolitical history, discrimination, and professional position, among other factors, perpetuate inequities when conducting these research endeavors.

Locomotory mode transitions alter phenotypic evolution and lineage diversification in an ecologically rich clade of mammals.

The relationship between organismal function and form is a cornerstone of biology because functional diversity is key to generating and maintaining ecological diversity. Morphological changes often occur in unison with behavioral or ecological transitions, and this process may foster diversification, but alternately could trap a species on an adaptive peak. We estimated the most comprehensive phylogenetic hypothesis of Murinae, a young (∼15 million years) and diverse (∼700 species) clade of mammals.

Native and Introduced Trypanosome Parasites in Endemic and Introduced Murine Rodents of Sulawesi.

The Indonesian island of Sulawesi is a globally significant biodiversity hotspot with substantial undescribed biota, particularly blood-borne parasites of endemic wildlife. Documenting the blood parasites of Sulawesi's murine rodents is the first fundamental step towards the discovery of pathogens likely to be of concern for the health and conservation of Sulawesi's endemic murines. We screened liver samples from 441 specimens belonging to 20 different species of murine rodents from 2 mountain ranges on Sulawesi, using polymerase chin reaction (PCR) primers targeting the conserved 18S rDNA region across the protozoan class Kinetoplastea.

Convergent evolution of olfactory and thermoregulatory capacities in small amphibious mammals.

Olfaction and thermoregulation are key functions for mammals. The former is critical to feeding, mating, and predator avoidance behaviors, while the latter is essential for homeothermy. Aquatic and amphibious mammals face olfactory and thermoregulatory challenges not generally encountered by terrestrial species.

Convergent evolution of an extreme dietary specialisation, the olfactory system of worm-eating rodents.

Turbinal bones are key components of the mammalian rostrum that contribute to three critical functions: (1) homeothermy, (2) water conservation and (3) olfaction. With over 700 extant species, murine rodents (Murinae) are the most species-rich mammalian subfamily, with most of that diversity residing in the Indo-Australian Archipelago. Their evolutionary history includes several cases of putative, but untested ecomorphological convergence, especially with traits related to diet.

Sperm morphology of the Rattini - are the interspecific differences due to variation in intensity of intermale sperm competition?

It is widely accepted that in mammals a causal relationship exists between postcopulatory sexual selection and relative testes mass of the species concerned, but how much it determines sperm size and shape is debatable. Here we detailed for the largest murine rodent tribe, the Rattini, the interspecific differences in relative testes mass and sperm form. We found that residual testes mass correlates with sperm head apical hook length as well as its angle, together with tail length, and that within several lineages a few species have evolved highly divergent sperm morphology with a reduced or absent apical hook and shorter tail.

Repeated evolution of carnivory among Indo-Australian rodents.

Convergent evolution, often observed in island archipelagos, provides compelling evidence for the importance of natural selection as a generator of species and ecological diversity. The Indo-Australian Archipelago (IAA) is the world's largest island system and encompasses distinct biogeographic units, including the Asian (Sunda) and Australian (Sahul) continental shelves, which together bracket the oceanic archipelagos of the Philippines and Wallacea. Each of these biogeographic units houses numerous endemic rodents in the family Muridae.

Convergent evolution of aquatic foraging in a new genus and species (Rodentia: Muridae) from Sulawesi Island, Indonesia.

The island of Sulawesi, in Indonesia, lies at the crossroads of the Indo-Australian Archipelago and has remained isolated from the Asian (Sunda) and Australian (Sahul) continental shelves for at least the last 10 million years. Of the 50 native species of rodents on Sulawesi, all are endemic and represent the evolution of a variety of ecological and morphological forms within the Muridae and Sciuridae. Carnivorous rodents have evolved, perhaps independently, in Muridae from the Philippines, Sulawesi, and Sahul, but semi-aquatic murids are only known from Sahul.

Carving out turf in a biodiversity hotspot: multiple, previously unrecognized shrew species co-occur on Java Island, Indonesia.

In theory, competition among species in a shared habitat results in niche separation. In the case of small recondite mammals such as shrews, little is known about their autecologies, leaving open questions regarding the degree to which closely related species co-occur and how or whether ecological niches are partitioned. The extent to which species are able to coexist may depend on the degree to which they exploit different features of their habitat, which may in turn influence our ability to recognize them as species.

Evolutionary novelty in a rat with no molars.

Rodents are important ecological components of virtually every terrestrial ecosystem. Their success is a result of their gnawing incisors, battery of grinding molars and diastema that spatially and functionally separates the incisors from the molars. Until now these traits defined all rodents.