Significance: Our ability to predict the identity of future invasive alien species is largely based upon knowledge of prior invasion history. Emerging alien species—those never before encountered as aliens—therefore pose a significant challenge to biosecurity interventions worldwide. Using a global database of the first regional records of alien species covering the years 1500–2005 we detected a surprisingly high proportion of species in recent records that have never been recorded as alien before. The high proportion of these emerging alien species mainly resulted from the increased accessibility of new source species pools in the native range. Risk assessment approaches that rely less on invasion history will need to be prioritized.

The rise of informatics has presented new opportunities for analyzing, visualizing, and interacting with data across the sciences, and biodiversity science is no exception. Recently, comprehensive datasets on the geographic distributions of species have been assembled that represent a thorough accounting of a given taxonomic group of species (e.g. birds, mammals, etc.), and which form critical tools for both basic biology and conservation. However, these databases present several challenges for visualization, interaction, and participation for users across a broad range of scientists and the public. In support of the development of a new comprehensive ant biodiversity database containing over 1.7 million records, we developed a new client–server web-mapping application, antmaps.org, to visualize and interact with the geographic distributions of all 15,050 ant species and aggregate patterns of their diversity and biogeography. Our application development approach was based on user-centered design principles of usability engineering, human-computer interaction, and cartography. The resulting application is highly focused on providing efficient and intuitive access to geographic biodiversity data using a client–server interaction that allows users to query and retrieve data on the fly. This is achieved with a backend solution to efficiently work with large volumes of geospatial data. The usability and utility of the final version of the application was measured based on effectiveness, efficiency and user satisfaction, and assessed using questionnaires, usability lab studies and surveys. While the development of antmaps.org was motivated by a particular ant biodiversity dataset, the basic framework, design, and functionality are not specific to ants and could be used to interact with biodiversity data of any taxonomic group

Human-mediated transport beyond biogeographic barriers has led to the introduction and establishment of alien species in new regions worldwide. However, we lack a global picture of established alien species richness for multiple taxonomic groups. Here, we assess global patterns and potential drivers of established alien species richness across eight taxonomic groups (amphibians, ants, birds, freshwater fishes, mammals, vascular plants, reptiles and spiders) for 186 islands and 423 mainland regions. Hotspots of established alien species richness are predominantly island and coastal mainland regions. Regions with greater gross domestic product per capita, human population density, and area have higher established alien richness, with strongest effects emerging for islands. Ants and reptiles, birds and mammals, and vascular plants and spiders form pairs of taxonomic groups with the highest spatial congruence in established alien richness, but drivers explaining richness differ between the taxa in each pair. Across all taxonomic groups, our results highlight the need to prioritize prevention of further alien species introductions to island and coastal mainland regions globally.

The latitudinal diversity gradient—the tendency for more species to occur toward the equator—is the dominant pattern of life on Earth, yet the mechanisms responsible for it remain largely unexplained. Recently, the analysis of global data has led to advances in understanding, but these advances have been mostly limited to vertebrates and trees and have not provided consensus answers. Here we synthesize large-scale geographic, phylogenetic, and fossil data for an exemplar invertebrate group—ants—and investigate whether the latitudinal diversity gradient arose due to higher rates of net diversification in the tropics, or due to a longer time period to accumulate diversity due to Earth’s climatic history. We find that latitudinal affinity is highly conserved, temperate clades are young and clustered within tropical clades, and diversification rate shows no systematic variation with latitude. These results indicate that diversification time—and not rate—is the main driver of the diversity gradient in ants.