Julian G. de Aledo is a PhD candidate at the Universidad Autónoma de Madrid, Spain. She is a ecologist with special focus on biodiversity of tropical plants. Here, Julia shares her recent work on plant diversity and distribution in the western Amazonia.

PhD candidate Julia G. de Aledo

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Institute. Universidad Autónoma de Madrid and Universidad Rey Juan Carlos, Spain

Academic life stage. PhD candidate

Major research themes. My major research interests revolve around plant diversity, distribution, and uses in western Amazonia, particularly focusing on how plants and people interact in tropical ecosystems across gradients.

Current study system. I am currently studying the woody plants of western Amazonia, which include approximately 110 different families with distinct growth forms, from large trees, to palms, ferns, small bushes, lianas and hemiepiphytes. Despite an estimated 50,000 plant species in the Amazon basin, only 14,000 tree species have been described, which highlights the vast amount of work still to be done.

Recent JBI paper. de Aledo, J. G., Paneghel, M., Cayuela, L., Matas-Granados, L., Ben Saadi, C., Salinas, N., La Torre-Cuadros, M. d. l. Á., García-Villacorta, R., & Macía, M. J. (2023). Floristic diversity, composition and dominance across Amazonian forest types respond differently to latitude. Journal of Biogeography, 50, 673–698. https://doi.org/10.1111/jbi.14561

Motivation behind this paper. During fieldwork, we have observed distinct variations in species diversity and composition across different forest types. We noticed that floodplain forests appeared to have a lower diversity of species compared to the well-drained forests yet filled with species with different physiological adaptations to the seasonal flood pulse. On the other hand, in submontane forests, diversity seemed to peak at higher elevations (500 m). These observations led us to question whether there was a discernible pattern in how plant species respond to latitude in each forest type to ultimately understand the causes of the vast diversity of the Amazonian ecosystem.

Drawing of the diversity of species and life forms in western Amazon.

Key methodologies. In the fieldwork, we gathered information from unexplored areas using 10 temporary plots per region located 300 meters apart. This approach allowed us to obtain maximum floristic variability within an area, which is crucial when studying diverse ecosystems. Moreover, all data were gathered by the authors themselves, and no data from existing databases were used.

In terms of the analysis, we made a plot called non-metric multidimensional scaling (NMDS) and used a smooth line to show how latitude affects the changes in species composition across plots . This helped us see if there was a trend or pattern in how each forest type responds to latitude. Additionally, we explored dominant species through their changes in abundance, which helped us understand how these species adapt and dominate over large areas. We used a novel stream graph approach to better illustrate these changes, providing new insights into their distribution and dispersion peaks.

Forest vertical structure of woody plants in Reserva Yanesha, Peru.

Unexpected challenges. In this type of field campaign, nothing can be predicted in advance. Nonetheless, we encountered some outcomes and challenges even beyond our imagination. For example, we ended up collecting more species than we had expected. This led to difficulties in transporting the collected material, as well as troubles in the final identification of some of the specimens, mostly the ones without fertile material. Another important challenge was reaching high trees (over 20 meters) for collection, which required specialized equipment and climbing expertise. Finally, the flooding of the rivers due to heavy rains made the fieldwork complicated, leaving us confined to the campsite for several days. Despite this, the team was able to ultimately export 5000 vouchers and identifying 1300 species for future research.

Major results. Our recent work confirms the latitudinal diversity gradient towards the equator both for alpha and beta diversity. This provides further evidence for the importance of tropical forests in maintaining global biodiversity. However, the finding that floodplain forests did not increase their diversity towards the equator as much as other forest types did, highlights the need for further research on these forests and their species performance. Despite this, the number of species found was still very high, with 100 species per 0.1 ha.

Concerning species dominance, this study also reveals different responses to latitude. Floodplain forests harbored more homogenous dominant species abundances, while well-drained forests had dominant species that peaked heterogeneously along the gradient, giving insights of differences in dispersion strategies.

An additional important contribution is that the field team have generated a comprehensive database of almost 30,000 individuals that is available for use by other researchers in the field of tropical community ecology of tropical forests (https://datadryad.org/stash/dataset/doi:10.5061/dryad.jm63xsjcc). Botanical vouchers obtained in this research were deposited in different herbariums in Ecuador (QCA, QCNE), Bolivia (LPB), Peru (USM, MOL) and Spain (MA).

Left: aerial image of Amazonian forest surrounding the Tambopata River in the Tambopata National Reserve (Madre de Dios, Peru). Right: photo of Coussapoa ovalifolia tree with aerial roots in Amazonian flooded forest.

Next steps for this research. Further investigation can be done to understand the underlying mechanisms driving the observed latitudinal diversity gradient in our study. This can involve exploring in depth floodplain forests to highlight its importance, promote their conservation and to understand its species adaptations. Also, including in situ mechanistic factors as temperature, precipitation, and soil nutrients in the analysis could improve the latitudinal model. Incorporating phylogenetic information can also provide insights into the evolutionary history of tropical plant communities and their responses to environmental change. By studying functional attributes of the species, we can understand the adaptation of species to seasonally harsh conditions. Finally, efforts can be made to expand this investigation to other regions and biomes to compare the latitudinal patterns observed in our study in other environments.

If you could study any organism on Earth, what would it be? Tropical woody plants are fascinating. In particular, I like lianas, which are a unique group of plants with unique growth form which allows them to climb up trees and compete for resources, affecting the structure and dynamics of the forest community. The Lecythidaceae family is also an interesting group to study because of their large flowers and fruits, which are important food sources for many animals and humans.

Drawing of Couratari guianensis (Lecythidaceae) fruit by Julia G. de Aledo

Anything else to add? In addition to my work on tropical woody plants, I also conduct research on ethnobotany, ecosystem services, and the cultural diversity of indigenous communities in tropical forests in western Amazonia. I believe that including people in ecology research is essential for understanding how species respond to changes in their environment, and for developing effective conservation and management strategies. Additionally, I am interested in using visual data analysis techniques, including bioinformatics, modelling, statistics, and data visualization, to better understand complex ecological systems.

Changes in the abundance of each dominant species by forest type in western Amazonia.

Yago Barros-Souza is a PhD candidate at the the Universidade de São Paulo, Brazil. He is a evolutionary biologist with special focus on biogeography and diversification of neotropical plants. Here, Yago shares his recent work on spatial and evolutionary processes that drive plant community assembly.

The PhD candidate Yago Barros-Souza

Personal links. Twitter

Institute. Universidade de São Paulo, Brazil

Academic life stage. PhD candidate

Major research themes. My main research interest is the biogeography of neotropical plants and the role of morphological traits in plant evolution.

Current study system. The ancient eastern South American mountains (campos rupestres) harbor high levels of plant diversity and endemism. In an area smaller than Ireland, the campos rupestres contain more than 5000 plant species, most of them narrowly distributed. Therefore, the campos rupestres are considered one of the richest and most endemic floras in the tropics. This astonishingplant diversity brought forth a number of questions about the underlying cause of diversity patterns in this vegetation and other similar systems (e.g., fynbos). However, these questions remain largely unanswered, thus posing an exciting opportunity for research in this field.

Recent JBI paper. Barros-Souza, Y., & Borges, L. M. (2022). Spatial-and lineage-dependent processes underpin floristic assembly in the megadiverse Eastern South American mountains. Journal of Biogeography, 50, 302–315. https://doi.org/10.1111/jbi.14527

Motivation behind this paper. The campos rupestres have a very complex evolutionary history that fuels an interesting ongoing debate. For example, there are multiple lines of evidence suggesting that recent and fast diversification likely shaped the vegetation, leading to a flora mainly composed by young lineages. On the other hand, the long-term climatic and topographic stability of the campos rupestres could have facilitated the persistence of old lineages. Therefore, multiple, and sometimes competing hypotheses have been proposed to describe the evolutionary processes that shaped this vegetation diversity. Nonetheless, the spatial component of the campos rupestres history is often neglected. In our study, we wanted to investigate the evolutionary history of the campos rupestres from an innovative angle, by explicitly placing evolution into a spatial perspective.

Key methodologies. We used metrics of biodiversity to assess phylogenetic diversity, phylogenetic endemism, and beta phylogenetic and taxonomic diversity. As we were particularly interested in identifying general and lineage-specific patterns, we inferred spatial diversity and endemism for all model groups combined, but also for each model group individually. We consider this our most insightful approach, as we found results that wielded interesting conclusions about the idiosyncratic nature of the flora assemblage process.

Campos rupestres at the Serra da Canastra, Minas Gerais, Brazil. (Author: Yago Barros-Souza)

Unexpected challenges. The greatest challenge was to select groups that would function as models for the entire flora. We tried to select both monocots and eudicots that are well represented in the campos rupestres and occur in multiple life forms so we could assess both general and lineage-dependent processes. Initially, we were not focused on lineage-specific patterns, but those turned out to be a central character of the story we told in this recent paper.

Major results. This recent paper conciliates competing hypotheses, showing that multiple processes, such as the persistence of old lineages and recent and fast diversification, have shaped the astonishing diversity of the campos rupestres in different ways. We also show that those processes are both space- and lineage-dependent. Thus, we highlight the importance of considering not only the spatial component of evolutionary processes, but also the unique evolutionary history of each lineage.

Campos rupestres at the Serra do Cipó, Minas Gerais, Brazil. (Author: Leonardo Borges)

Next steps for this research. We are currently work on a project that integrates multiple data types to assess lineage and morphological composition of the campos rupestres and the surrounding vegetation, as well as identifywhich factor(s) mostly influenced shifts in diversification rates in the campos rupestres. Also, we want to understand the role those morphological traits and the surrounding vegetation played on the processes that shaped the campos rupestres astonishing diversity.

If you could study any organism on Earth, what would it be? I’ve never thought of studying any organism in particular. My main interest is to investigate the history of neotropical plants in general,especially those that dwell in mountainous habitats, like the campos rupestres. The campos rupestres is only recently receiving global attention. Considering that, I’m happy with my choice of studying one of the most diverse tropical floras and contribute towards the understanding of the fundamental evolutionary processes that shaped the campos rupestres and other similar systems.

Marco is a PhD student at the Monash University, Australia. He is a evolutionary biologist with special focus on biogeography and ecomorphological evolution of lizards. Here, Marco shares his recent work on biogeographic patterns of limb reduction in skinks.

The evolutionary biologist Marco Camaiti

Personal links. Twitter

Institute. Monash University

Academic life stage. PhD student

Major research themes. Evolution, ecomorphology, biogeography, lizards, osteology

Current study system. Currently, I am studying skinks (a group of lizards), specifically forms with reduced or absent legs. These animals are fascinating because of their incredible variety of body shapes, which include a series of intermediates between lizard-like and long-limbed, and snake-like and limbless. Limb reduction also tends to be coupled with the elongation of the trunk and an increase in the number of presacral vertebrae. Skinks also make a great model system to study phenotypic evolution and adaptations because they independently evolved these body shapes multiple times (more than fifty, in fact) and are widespread on almost all continents and through a variety of environments.

Recent JBI paper. Camaiti, M., Evans, A. R., Hipsley, C. A., Hutchinson, M. N., Meiri, S., Anderson, R. O., Slavenk, A., & Chapple, D. G. (2023). Macroecological and biogeographical patterns of limb reduction in the world’s skinks. Journal of Biogeography, 50(2), 428-440. https://doi.org/10.1111/jbi.14547

Motivation behind this paper. The evolution of limb-reduced forms in squamates has been variously investigated; however, the environmental drivers that gave rise to the existing variability of limb-reduced shapes have so far remained unexplored beyond the simple distinction between fossorial and above-ground ecomorphs. For example, different groups of skinks have reduced or lost their legs in different ways, some reducing their forelimbs faster, others their hindlimbs, and in some groups, both are reduced at the same rate. Moreover, skinks have evolved limb reduction and loss in different continents and environmental contexts, ranging from arid desert sands to humid forest floors. In our recent paper, we aimed to investigate the link between these morphologies and their environments and whether similar, if independently evolved morphologies correspond to similar environmental conditions.

Fitzroy Sandslider (Lerista simillima), a limb-reduced skink without forelimbs.

Key methodologies. We first quantified morphological variation in skinks by regressing measurements of body proportions to identify divergent evolutionary trajectories of limb reduction across subfamilies and focal clades. One of the innovative aspects of this approach was to use limb disparity as a new metric to quantify variations in limb proportions, which tends to 1 for species with longer hindlimbs than forelimbs and to -1 for species with longer forelimbs than hindlimbs. Secondly, we investigated whether aspects of the skink’s morphologies (i.e., limb proportions and elongation of the body) were associated with specific substrate categories for our global dataset of limb-reduced skinks. To investigate ecomorphological associations beyond simple categories, we conducted a parallel analysis using ecological data extracted from the distributions of a large subclade of limb-reduced skinks, the Australian sphenomorphines.

North-western Sandslider (Lerista bipes), a limb-reduced skink without forelimbs. Detail of the foot.

Unexpected challenges. It was certainly challenging to conduct comparative analyses of the relations between all possible combinations of body measurements across clades for almost 300 species. One unexpected result from these analyses was that some clades really have unique ways of becoming limb-reduced and elongating their bodies. In particular, we were surprised to find that one clade, the skink genus Glaphyromorphus, had evolved elongated bodies by increasing the length of its vertebrae instead of their number. Another significant hurdle we encountered was obtaining precise microhabitat data across the distribution of Australian species for our downscaled analyses, given that each had to be extracted and averaged across thousands of data points. Surprisingly, ecomorphological analyses conducted on these data found that more dramatically limb-reduced forms associate with humid, cool, and carbon-rich microhabitats as opposed to dry, arid environments, challenging the assumption that limb reduction is necessarily an adaptation to desert conditions.

Major results. Different clades of skinks evolved limb reduction following different trajectories. Contrary to what previously thought, we found that the shortening of limbs does not correspond to the elongation of the trunk in all clades, and that trunk elongation is not always achieved via an increase in the number of presacral vertebrae. Beyond that, our global ecomorphological investigation found that skinks with longer hindlimbs than forelimbs (positive limb disparity) associate with poor, sandy substrates, as opposed to skinks with equal or shorter hindlimbs, which associate with richer substrates. In other words, more penetrable substrates like humus and sand are generally associated with smaller body sizes. The smaller-scale investigation of the Australian sphenomorphines found a similar result, showing that positive limb disparity is associated with drier, poorer substrates with higher sand percentages. Contrary to previous assumptions, both limb reduction and body elongation are associated with rich, more humid substrates instead.

Dampier Land Limbless Slider (Lerista apoda), a limbless skink.

Next steps for this research. We are interested in investigating other aspects of the morphology of skinks with limb-reduced forms, specifically the internal changes that accompany the evolutionary transitions to limb reduction. We also would like to investigate aspects sensorial adaptations that make fossorial forms so efficient at navigating subterranean environments. Currently, we are working on examining the morphology of the internal bone structures of these animals using computerized tomography (CT) scanning techniques.

If you could study any organism on Earth, what would it be? A squamate, no doubt. They are critically understudied, but they deserve way more attention than they’re currently getting! The extent to which they can change according to different environments is almost unparalleled among tetrapods, making them a unique model system to study evolution.

Anything else to add? I find that the most impressive forms are the ones where a pair of legs is completely gone or vestigial, while the other pair still remains and can actually be quite well-developed. Interestingly, hindlimb-only forms seem to have independently evolved across continents and islands, being found in different lineages across Australia, Madagascar, Africa and Asia, always in association with sand and sandy soil. While forelimb-only forms are rarer, they do exist, and appear to associate with rich substrates like humus.

Jackson’s Three-toed Slider (Lerista jacksoni), a limb-reduced skink with three fingers and toes.

Kyle is a PhD candidate at the Arizona State University, U.S.A. He is a evolutionary biologist with special focus on natural history, biogeography and evolution of ants. Here, Kyle shares his recent work on global biogeography of ant social parasites.

Kyle enjoys collecting ants in beautiful places such as Bishop, California, U.S.A.

Personal links. Website

Institute. Arizona State University, U.S.A. & University of Hohenheim, Germany.

Academic life stage. PhD candidate

Major research themes. Biodiversity, biogeography, and evolution of ants.

Current study system. My doctoral dissertation focuses on the biodiversity, biogeography and evolution of socially parasitic ants and ants in the South Pacific. Ant social parasites are a diverse set of species that exploit the parental caring behaviour of other ant species and do so in a variety of ways. Ants in the South Pacific are equally interesting to me because there have been numerous radiations of endemic species across different archipelagos that exhibit a fascinating diversity of morphologies, and there are still under-sampled archipelagos that offer much room for novel discoveries.

Recent JBI paper. Gray, K. W., & Rabeling, C. (2022). Global biogeography of ant social parasites: Exploring patterns and mechanisms of an inverse latitudinal diversity gradient. Journal of Biogeography, 50(2), 316-329. https://doi.org/10.1111/jbi.14528

Motivation behind this paper. The motivation for this paper was to use distribution data and our current understanding of the ant tree of life to test the historical biogeographic hypothesis that ant social parasites are most species-rich in the northern hemisphere where the fewest free-living ant species exist, i.e., that ant social parasites are distributed along an inverse latitudinal diversity gradient. Although previous works have discussed this pattern, these were either qualitative or focused on a few species. Given the significant increase in our understanding of ant biodiversity around the globe, especially in tropical regions, the time was ripe to look closely at the current global biogeography of ant social parasites. Furthermore, we hoped our research would serve as a basis for future works that aim to answer how abiotic and biotic factors possibly shape the geographic distribution of socially parasitic Hymenoptera.

Key methodologies. We assembled a comprehensive biogeographic and life history dataset of all 371 described socially parasitic ant species using published data sources. We then used phylogenetic and taxonomic studies to estimate independent evolutionary origins of ant social parasitism to compare species richness with the number of species representing independent evolutionary origins of social parasitism across a latitudinal gradient. This corrects for phylogenetic non-independence caused by species radiations in some clades of ant social parasites. In addition, we compared ant social parasite diversity across biogeographic regions using rarefaction to account for different sampling efforts and data availability – which is important given the historic sampling bias for ant social parasites in the northern hemisphere. Finally, we tested for a correlation between latitude and the proportion of ant social parasite species within regional ant faunae.

Workers of the dulotic ant social parasite species Polyergus mexicanus taking a stolen pupa back to its nest. Bishop, California, U.S.A.

Unexpected challenges. I think the primary challenge was the breadth of the study both in terms of the history of ant social parasite research (at least since the days of Darwin) and that these species span numerous genera and subfamilies. I ended up reading over seven hundred papers to extract all the data used in this study, which included a significant portion of papers written in 19^th or early 20^th century German, French, and Italian. Reading through these historic papers was a struggle sometimes, but I began to enjoy the historical aspect of this. I was not only learning about the biology of these fascinating ants, but also learning about ant biology history. In addition, given that the study was on a global scale, I learned about different places across the globe. Overall, this project ended up being a scientific, historical, linguistic, and geographical endeavour.

Major results. Ant social parasites peak in both species richness and in the number of evolutionary origins of parasitism in the northern hemisphere where the least free-living ant diversity exists. Thus, ant social parasites exhibit an inverse latitudinal diversity gradient by peaking in diversity outside the equatorial tropics. The dulotic social parasites, which refers to species that perform interspecific brood raids to capture workers for colony maintenance tasks, contribute significantly to the pattern because they are still only found in the northern hemisphere mostly within temperate regions. It also appears that this inverse latitudinal diversity gradient is driven by large species radiations in the northern hemisphere. Additionally, the proportion of ant parasite species increases significantly with latitude only in the northern hemisphere, which resembles a pattern reported in parasitic bees. Overall, the biogeography of ant social parasites provides another interesting example of how specialized life histories shape global biodiversity patterns.

Exploring a vast landscape in southern Arizona, U.S.A. for the ant social parasite species Pogonomyrmex anergismus.

Next steps for this research. We hope this work reinforces the need for continued sampling and in-depth natural history studies for ant social parasites, especially in under-sampled tropical regions of Africa and Asia where exciting discoveries undoubtedly wait to be revealed. For example, one of the most puzzling observations in ant social parasite research is that dulotic species are still only found in the northern hemisphere. Is this due to some special aspect of the northern hemispheric ant fauna facilitating the evolution of dulosis? Possibly. Or do dulotics occur in the southern hemisphere but we just have not found them yet? One can only speculate. The answer will come with more field work!

If you could study any organism on Earth, what would it be? I am happy to say that I would keep studying ants! There are enough interesting phenomena in the ants to keep me busy for multiple lifetimes. Plus, I just love the way ants look. I can watch ant colonies do their thing for hours or look at images and illustrations of ants all day. They are beautiful, savage little beasts.

Anything else to add? This study would not have been possible without the efforts of other ant biologists as well as AntMaps (antmaps.org), AntWeb (antweb.org) and AntWiki (antwiki.org). The fact that we have these wonderful resources is truly a blessing and I cannot express my gratitude enough for the people that made these resources happen.

Two males of the ant social parasite species Pogonomyrmex anergismus at the nest of its host species Pogonomyrmex rugosus in southern Arizona, U.S.A.

André is a PhD student at the Research Centre in Biodiversity and Genetic Resources, Portugal. He is an ecologist with special focus on biogeography, for which he combines historical and conservation perspectives. Here, André shares his recent work on the evolution of lizards inhabiting the most arid habitats of the Sahara Desert.

André during his Ph.D. sampling in the ergs (sand dune fields) of Ouarane, Mauritania.

Personal links. Researchgate | GoogleScholar | Institution | Facebook

Institute. CIBIO/InBIO, ​Research Centre in Biodiversity and Genetic Resources, University of Porto.

Academic life stage. PhD student.

Major research themes. Biogeography and phylogeography interface between comparative and conservation approaches. During my Ph.D. (ongoing), I investigate spatial biodiversity patterns in the Sahara Desert, aiming at (1) understanding the origin of the desert’s unique fauna and (2) synthesizing knowledge that can be used to minimize the impacts of the unprecedented climatic emergency on species’ persistence.

Current study system. Because they are intensely arid and bare, Saharan hyper-arid habitats (like the dune “erg” fields) appear to be virtually devoid of life, but such empty-desert rule is to some extent misleading given that some organisms successfully persist within these habitats. Beyond desert-flagship invertebrates (such as scorpions and beetles), the best example are spiny-footed lizards, Acanthodactylus scutellatus complex. These are conspicuous and widespread dwellers of sandy fields, wherein they have thrived for millions of years under extreme dryness thanks to their remarkable tolerance towards aridity constraints. These singularities make spiny-footed lizards unique pieces to understand the Sahara puzzle.

Vegetated patches and rocky outcrops contrast with the endless desert sand. Photo Credits: José Carlos Brito.

Recent JBI paper. Liz, A. V., Rödder, D., Gonçalves, D. V., Velo‐Antón, G., Tarroso, P., Geniez, P., Crochet, P.-A., Carvalho, S. B., & Brito, J. C. (2022). Overlooked species diversity in the hyper‐arid Sahara Desert unveiled by dryland‐adapted lizards. Journal of Biogeography 23(1), 101–115. https://doi.org/10.1111/jbi.14510

Motivation behind this paper. We know very little about hyper-arid habitats in the Sahara Desert, despite the area’s vastness (it is larger than the whole Australian continent!) and key role in global dynamics (like dust exportation to feed the Amazon rainforest). Indeed, filling existing knowledge gaps is important from both a natural-history and conservation perspective; first, because the paleoclimatic cycles that affected the desert’s extent make it a unique natural system to understand biodiversity responses to steep environmental shifts; and second, because the expected drastic impact of global warming in the region urges efficient measures to protect its unique wildlife. These reasons led us to study the biogeography of spiny-footed lizards, bearing in mind that, through the analysis of present-day species’ distribution and evolutionary patterns, we could infer historical landscape dynamics (such as shifts in sandy habitats and surface humidity) and verify the magnitude of regional biodiversity shortfalls (how many species have not been properly described?).

Key methodologies. One strength of this paper was the integration of different methodologies, namely ecological modelling, phylogeography and population genetics, to obtain a rather complete picture of the evolutionary history of spiny-footed lizards across the Sahara, and partially overcome sampling biases towards the more accessible areas. For instance, through ecological modelling and spatial interpolations of genetic data, we were able to obtain information from unexplored areas – which species are likely to occur therein? where should we expect higher diversity?

Specimen of Long Fringe-fingered Lizard, Acanthodactylus longipes, a conspicuous dweller of Saharan ergs. Photo Credits: José Carlos Brito.

Unexpected challenges. Certainly, the main challenge was to compile a representative set of samples that were relatively well distributed across the Sahara, considering that it would take us ages to survey the whole region or reach remote areas far from the main human settlements. The Sahara spans over 10 countries, some of them affected by long-lasting armed conflicts and political instability, which adds another layer of difficulty to field campaigns. To solve these issues, we focused sampling on the most accessible hyper-arid habitats, which could be reached in “only” a few days of driving, and by complementing it with natural-history collection samples. Finally, after over a decade of intermittent fieldwork and countless car breakdowns, we were able to build a rich dataset of ~700 samples to start the analyses.

Major results. The most exciting result was the amount of diversity still to be described from the group, which we had far underestimated. Even for taxa that are linked to habitats that are super common in the Sahara, most widespread “species” are in fact a collection of range-restricted species. You take sand specialists, there is sand everywhere and they are present everywhere, yet they have diverged (mostly until speciation) to a level totally crazy! And yet some candidate species are going from the Red Sea to nearly the Atlantic coast… This is very interesting both in terms of natural history (which environmental/geological mechanisms are responsible for such great diversity and connectivity?) and conservation (because the hyper-arid Sahara harbours many more species than what is often realised).

Next steps for this research. I would like to dig more into the biogeographic role of hyper-arid habitats in shaping local species structure, especially during “Green Sahara” phases – did sandy/gravel lowlands become the single pockets of suitable habitats for dryland specialists? were mountains more efficient shelters instead? or was it a mix between these two scenarios, where species persisted in the edge of hyper-arid habitats? are there differences according to functional groups (for instance, would reptiles and arthropods show the same trend)? Understanding these issues would help clarify the ecological value of these historically neglected habitats in the origin of the desert’s unique diversity.

An old truck near Bir Moghrein, which could not make it through the harsh desert conditions. Photo Credits: José Carlos Brito.

If you could study any organism on Earth, what would it be? I am fascinated by tropical habitats and the explosion of life present therein. Prior to my Ph.D., I spent two years in southern Brazil; this experience really marked me both at the professional and personal level. There, I learned to appreciate the symphonic communities of the Atlantic Forest, but also became aware of the conflicting context of dramatic environmental destruction that imperils their perpetuation. I would love to move back there one day and contribute to the conservation of these habitats.