Charles Morphy D. Santos

On Reciprocal Illumination and Consilience in Biogeography

Biogeography deals with the combined analysis of the spatial and temporal components of the evolutionary process. To this purpose, biogeographical analysis should consider two extra steps: a reciprocal illumination step, and a consilience step. Even if the traditional challenges of biogeography were successfully handled, the obtained hypothesis is not necessarily meaningful in biogeographical terms––it needs continuous test in the light of external hypotheses. For this reason, a concept analogous to Hennig’s reciprocal illumination is valuable, as well as a sort of biogeographical consilience in Whewell’s sense. Firstly, through the search for different classes of evidence, information useful to improve the hypothesis can be accessed via reciprocal illumination. Following, a more general hypothesis would arise through a consilience process, when the hypothesis explains phenomena not contemplated during its construction, as the distribution of other taxa or the existence (or absence) of fossils. This procedure aims to evaluate the robustness of biogeographical hypotheses as scientific theories. Such theories are reliable descriptions of how life changes its form both in space and time, putting historical biogeography close to Croizat’s statement of evolution as a three dimensional phenomenon.

Timeless standards for species delimitation

Recently a new species of bombyliid fly, Marleyimyia xylocopae, was described by Marshall & Evenhuis (2015) based on two photographs taken during fieldwork in the Republic of South Africa. This species has no preserved holotype. The paper generated some buzz, especially among dipterists, because in most cases photographs taken in the field provide insufficient information for properly diagnosing and documenting species of Diptera.

On typeless species and the perils of fast taxonomy

C H A R L E S M O R P H Y D . S A N T O S 1, D A L T O N S . A M O R I M 2, B R U N A K L A S S A 1, D I E G O A . F A C H I N 2, S I L V I O S . N I H E I 3, C L A U D I O J . B . D E C A R VA L H O 4, R A F A E L A L . F A L A S C H I 5, C Á T I A A . M E L L O P A T I U 6, M Á R C I A S . C O U R I 6, S A R A H S . O L I V E I R A 7, V E R A C . S I L VA 8, G U I L H E R M E C . R I B E I R O 1, R E N A T O S . C A P E L L A R I 9 and C A R L O S J O S É E . L A M A S 5

The world's biogeographical regions revisited: global patterns of endemism in Tipulidae (Diptera)

This paper explores the distributional data of 4,224 Tipulidae (Insecta: Diptera) species to search for endemism patterns in a worldwide scale and to test the extent to which the global patterns of endemism of the group fit into previously proposed regionalization schemes, particularly Wallaces system and recent revisions of it. Large scale areas of endemism are assessed using the grid-based method implemented in VNDM. VNDM depends on the prior definition of the grid size for analysis, but a criterion for choosing beforehand a particular grid size is not clear. The same holds for the choice of the level of similarity in species composition selected for the calculation of consensus areas. In our study, we developed a methodological approach that helped defining objective criteria for choosing suitable values for these critical variables. Large-scale areas of endemism around the globe are identified and ranked according to endemicity levels: 1--West Palaearctic, 2--Nearctic, 3--East Palaearctic-Oriental, 4--West North America, 5--Australia, 6--Neotropical, 7--Sub-Saharan Africa, 8--Palaearctic, and 9--Middle East. Our main conclusion is that there are still some limitations in applying biogeographical classifications proposed mostly on the basis of vertebrate distribution to other taxonomic groups, such as the Tipulidae. While there is a general congruence of the broad-scale areas of endemism of tipulids with previously proposed regionalization schemes, for some areas, the sharpness of boundaries between traditional regions is not so acute, due to a great level of overlap of part of its biotic elements.

Teaching the role of mutation in evolution by means of a board game

BackgroundThe board game ACAGATATA simulates how randomness originates biodiversity. An individual (genotype ACAGATATA) produces offspring with a chance of error during DNA replication (mutation) at each generation, showing that random changes in ancestral genotypes may reflect on descendant phenotypes.MethodsThe game has three steps: (1) construction of a dichotomous diagram by submission of the parental DNA to successive copies in which the chance of mutation is dictated by special roulettes. After three generations, up to eight different DNA sequences could appear; (2) attribution of amino acids series to the eight nucleotide sequences in the third generation, following the genetic code; and (3) analysis of traits in these individuals and scoring of outcomes. To measure ACAGATATA’s effect on learning, undergraduate students answered true-or-false questions before and after the game.ResultsIn the tests, global scores after ACAGATATA were higher than before. Performance increased significantly in ten questions. Questions without direct connection to the game exhibited no significant change in performance. Satisfaction with the game was confirmed by high values in two questions asking the students about the contribution of ACAGATATA to their knowledge on the role of mutation in evolution.ConclusionsACAGATATA is suitable for biology courses concerning genetic information, its expression and molecular evolution, allowing an increase in student performance on these issues. Low cost justifies the adoption of ACAGATATA even by teachers with restricted resources.

Flies, endemicity, and the Atlantic Forest: a biogeographical study using topographic units of analysis

Abstract. We present a study of the endemicity patterns in the Brazilian Atlantic Forest on the basis of the distribution of 107 fly species belonging to 24 genera of 15 families. This is the first picture of endemism for Diptera in the Atlantic Forest. Instead of the traditional grid of geographical coordinates, we used a system of topographic units (TUs) for the analysis, delimited after gathering information on rivers and altitude for each state and country. A parsimony analysis of the data matrix with the species records for the TUs was performed, named topographic-unit parsimony analysis (TUPA). The same distributional data was used in a NDM/VNDM analysis. The combination of the resulting patterns from both analyses indicated the existence of the following three major areas of endemism for flies in the Atlantic Forest: a Northern Atlantic Forest, north of Rio Doce; a Southern Atlantic Forest, south of Rio Doce along the coast, extending to the west and to the south at the level of the state of Paraná; and a Semideciduous Seasonal Forest, west to the ombrophilous forest along the coast. None of these areas seems to be shaped solely by vicariance events. They can possibly be the result of biotic fusion of ancestral areas of endemism as a result of barrier collapse and secondary overlap of sister biotas, a hypothesis yet to be tested. The recognition of a separate area of endemism for flies in the Semideciduous Forest agrees with phytogeographical reconstructions and raises an important alert for the scarcity of biological reserves for this vegetation.

Areas of endemism in the Neotropical region based on the geographical distribution of Tabanomorpha (Diptera: Brachycera).

We aim to investigate the geographical distribution patterns of the infraorder Tabanomorpha and to delimit primary hypotheses of areas of endemism for the group in the Neotropical region. The results were compared to areas of endemism proposed in previous works for other taxa and particularly with the recent Morrones regionalisation proposal. An endemicity analysis was performed with the ndm/vndm algorithm using 3826 occurrence records for 1361 species of Tabanomorpha. Areas of endemism were established based on a grid size of 6º and consensus cut-off of 42%. We identified 13 areas of endemism comprising five main components: Northern South America (NSA), Southeastern South America (SESA), Central America (CA), Brazilian Savannah (BS), Central Andes (CAn). In a broad sense, the main areas of endemism recovered for Tabanomorpha are congruent with the recent proposals of regionalisation for the Neotropical region.

Realism in systematics through biogeographical consilience

There is an overlooked gap between any phylogenetic hypothesis and the natural world shaped by historical evolutionary processes, since the main concern during phylogenetic analyses is solely the search for congruence among characters under a defined criterion. Given a scientific realistic view, however, phylogenetic hypotheses are scientific theories that try to depict the historical series of cladogenetic events among biological entities. In this sense, the challenge is to establish a form of measuring the degree of truthfulness of our phylogenetic hypotheses. Here, we advocate the use of consilient biogeographical hypotheses to recognize the biological meaning of a phylogenetic inference apart from its instrumentalist value. Our proposal is based on the assumption that robust biogeographical hypotheses allows us to be close to the real evolutionary history of taxa.

On the role of assumptions in cladistic biogeographical analyses

As premissas biogeograficas 0, 1 e 2 (respectivamente A0, A1 e A2) sao termos teoricos usados para interpretar e resolver incongruencias com o objetivo de se encontrar areagramas gerais. O objetivo desse trabalho e sugerir o uso de A2 ao inves de A0 e A1 para a solucao de incertezas durante analises biogeograficas cladisticas. Em um exemplo teorico, usando Analise de Componentes e Analise de Parcimonia de Brooks Primaria (BPA primario), A2 permitiu a reconstrucao da sequencia verdadeira de eventos de disjuncao em um cenario hipotetico, enquanto A0 adicionou relacoes de areas espurias. A0, A1 e A2 sao interpretacoes das relacoes entre as areas, nao entre taxons. Uma vez que as relacoes entre areas nao sao equivalentes as relacoes cladisticas, e inapropriado usar informacao de distribuicao dos taxons para resolver padroes ambiguos em areagramas, como faz A0. Apesar da ambiguidade em areagramas ser virtualmente impossivel de se explicar, A2 e melhor e mais neutra que qualquer outra premissa biogeografica.

Primary hypotheses of global areas of endemism based on the distribution of Tabanomorpha (Diptera, Brachycera)

Areas of endemism, or worthy for conservation, are mainly determined based on large data sets of vertebrates and plants. Herein, we investigated the global distribution at the species-level of the infraorder Tabanomorpha (Diptera, Brachycera), identifying areas of endemism for the group. We performed an endemicity analysis through a grid-based method-NDM/VNDM-using 1,385 species (6,392 geographical records) of Tabanomorpha. The grid size of the analysis was 7º and we applied the loose consensus rule (31%) in the recovered areas. Our results revealed 479 total areas of endemism and 18 consensus areas: the whole Neotropical region, six areas in the Nearctic region, two in the Palearctic region, and three areas in each the Oriental, Australian, and African regions. There are parallels among our results and previously proposed bioregionalisation schemes established by other taxa, showing a way forward for using insects to determine global patterns of endemism.