Endless forms most stupid, icky, and small: The preponderance of noncharismatic invertebrates as integral to a biologically sound view of life.

Big, beautiful organisms are useful for biological education, increasing evolution literacy, and biodiversity conservation. But if educators gloss over the ubiquity of streamlined and miniaturized organisms, they unwittingly leave students and the public vulnerable to the idea that the primary evolutionary plot of every metazoan lineage is "progressive" and "favors" complexity. We show that simple, small, and intriguingly repulsive invertebrate animals provide a counterpoint to misconceptions about evolution. Our examples can be immediately deployed in biology courses and outreach. This context emphasizes that chordates are not the pinnacle of evolution. Rather, in the evolution of animals, miniaturization, trait loss, and lack of perfection are at least as frequent as their opposites. Teaching about invertebrate animals in a "tree thinking" context uproots evolution misconceptions (for students and the public alike), provides a mental scaffold for understanding all animals, and helps to cultivate future ambassadors and experts on these little-known, weird, and fascinating taxa.

The Ecology of Nonecological Speciation and Nonadaptive Radiations.

Growing evidence for lineage diversification that occurs without strong ecological divergence (i.e., nonadaptive radiation) challenges assumptions about the buildup and maintenance of species in evolutionary radiations, particularly when ecologically similar and thus potentially competing species co-occur. Understanding nonadaptive radiations involves identifying conditions conducive to both the nonecological generation of species and the maintenance of co-occurring ecologically similar species. To borrow MacArthur's [1] (Challenging Biological Problems 1972;253-259) form of inquiry, the ecology of nonadaptive radiations can be understood as follows: for species of type A, in environments of type B, nonadaptive radiations may emerge. We review purported cases of nonadaptive radiation and suggest properties of organisms, resources, and landscapes that might be conducive to their origin and maintenance. These properties include poor dispersal ability and the ephemerality and patchiness of resources.

Multiple large-scale gene and genome duplications during the evolution of hexapods.

Polyploidy or whole genome duplication (WGD) is a major contributor to genome evolution and diversity. Although polyploidy is recognized as an important component of plant evolution, it is generally considered to play a relatively minor role in animal evolution. Ancient polyploidy is found in the ancestry of some animals, especially fishes, but there is little evidence for ancient WGDs in other metazoan lineages. Here we use recently published transcriptomes and genomes from more than 150 species across the insect phylogeny to investigate whether ancient WGDs occurred during the evolution of Hexapoda, the most diverse clade of animals. Using gene age distributions and phylogenomics, we found evidence for 18 ancient WGDs and six other large-scale bursts of gene duplication during insect evolution. These bursts of gene duplication occurred in the history of lineages such as the Lepidoptera, Trichoptera, and Odonata. To further corroborate the nature of these duplications, we evaluated the pattern of gene retention from putative WGDs observed in the gene age distributions. We found a relatively strong signal of convergent gene retention across many of the putative insect WGDs. Considering the phylogenetic breadth and depth of the insect phylogeny, this observation is consistent with polyploidy as we expect dosage balance to drive the parallel retention of genes. Together with recent research on plant evolution, our hexapod results suggest that genome duplications contributed to the evolution of two of the most diverse lineages of eukaryotes on Earth.

Systematic review of diplommatinid land snails (Caenogastropoda, Diplommatinidae) endemic to the Palau Islands. (3) Description of eight new species and two new subspecies of Hungerfordia.

Hungerfordia Beddome, 1889 is a land snail genus of the family Diplommatinidae, which shows extensive endemic radiation in the Palau (Belau) islands. Although 42 species or subspecies of the genus have been named to date, many species remain to be described. In this article, we describe ten new taxa of the genus: H. goniobasis exserta subsp. nov., H. ngereamensis sp. nov., H. spiroperculata sp. nov., H. fragilipennis sp. nov., H. brachyptera sp. nov., H. elegantissima anomphala subsp. nov., H. nodulosa sp. nov., H. irregularis sp. nov., H. chilorhytis sp. nov., H. globosa sp. nov.

Masters of miniaturization: convergent evolution among interstitial eukaryotes.

Marine interstitial environments are teeming with an extraordinary diversity of coexisting microeukaryotic lineages collectively called "meiofauna." Interstitial habitats are broadly distributed across the planet, and the complex physical features of these environments have persisted, much like they exist today, throughout the history of eukaryotes, if not longer. Although our general understanding of the biological diversity in these environments is relatively poor, compelling examples of developmental heterochrony (e.g., pedomorphosis) and convergent evolution appear to be widespread among meiofauna. Therefore, an improved understanding of meiofaunal biodiversity is expected to provide some of the deepest insights into the following themes in evolutionary biology: (i) the origins of novel body plans, (ii) macroevolutionary patterns of miniaturization, and (iii) the intersection of evolution and community assembly - e.g., "community convergence" involving distantly related lineages that span the tree of eukaryotes.

Adaptive radiation, nonadaptive radiation, ecological speciation and nonecological speciation.

Radiations of ecologically and morphologically differentiated sympatric species can exhibit the pattern of a burst of diversification, which might be produced by ecological divergence between populations, together with the acquisition of reproductive isolation ('ecological speciation'). Here we suggest that this pattern could also arise if speciation precedes significant ecological differentiation (i.e. through geographical isolation and nonadaptive radiation). Subsequently, species ecologically differentiate and spread into sympatry. Alternative routes to producing ecologically differentiated sympatric species are difficult to detect in old radiations. However, nonadaptive radiations are common and might therefore regularly be responsible for currently ecologically differentiated sympatric species (e.g. among groups that are not susceptible to ecological speciation). Species evolving nonadaptively over long periods might eventually replace young, ecologically produced species.

Cryptic diversity, molecular phylogeny and biogeography of the rock- and leaf litter-dwelling land snails of Belau (Republic of Palau, Oceania).

The endemic diplommatinid land snails (Caenogastropoda: Mollusca) of Belau (Republic of Palau, Micronesia) are an exceptionally diverse group of largely undescribed species distributed among rock and leaf litter habitats on most of Belau's 586 islands. Diplommatinid shell morphology (e.g. shell sculpture) reflects habitat type. In this study, I analysed a subset of the 90 diplommatinid species representing a broad geographical spread of islands in order to reveal the species' phylogenetic relationships and biogeography within the Belau archipelago. Diplommatinid species from the islands of Yap, Pohnpei, Kosrae and Guam are also included in the analysis. One nuclear (28S rRNA) and two mitochondrial (16S rRNA, COI) gene regions comprising 1906bp were used for phylogenetic reconstruction. Results show that (i) the Belau Diplommatinidae are not monophyletic, as Guam and Yap species should be included as part of the radiation, (ii) Pohnpei and Kosrae species are highly divergent from Belau diplommatinids, (iii) there is little evidence for in situ radiation within individual Belau islands, (iv) spined and heavily calcified rock-dwelling species form a well-supported clade, and (v) Belau diplommatinid genera are in need of revision.

Molecular phylogeny and biogeography of the endemic Hawaiian Succineidae (Gastropoda: Pulmonata).

The endemic Hawaiian Succineidae represent an important component of the exceptionally diverse land snail fauna of the Hawaiian Islands, yet they remain largely unstudied. We employed 663-bp fragments of the cytochrome oxidase I (COI) mitochondrial gene to investigate the evolution and biogeography of 13 Hawaiian succineid land snail species, six succineid species from other Pacific islands and Japan, and various outgroup taxa. Results suggest that: (1) species from the island of Hawaii are paraphyletic with species from Tahiti, and this clade may have had a Japanese (or eastern Asian) origin; (2) species from five of the remaining main Hawaiian islands form a monophyletic group, and the progression rule, which states that species from older islands are basal to those from younger islands, is partially supported; no geographic origin could be inferred for this clade; (3) succineids from Samoa are basal to all other succineids sampled (maximum likelihood) or unresolved with respect to the other succineid clades (maximum parsimony); (4) the genera Succinea and Catinella are polyphyletic. These results, while preliminary, represent the first attempt to reconstruct the phylogenetic pattern for this important component of the endemic Hawaiian fauna.