Publications by authors named "Chris D Thomas"

Biological communities are changing rapidly in response to human activities, with the high rate of vertebrate species extinction leading many to propose that we are in the midst of a sixth mass extinction event. Five past mass extinction events have commonly been identified across the Phanerozoic, with the last occurring at the end of the Cretaceous, 66 million years ago (Ma). However, life on Earth has always changed and evolved, with most species ever to have existed now extinct.

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Species distribution models (SDMs) are widely used to project how species distributions may vary over time, particularly in response climate change. Although the fit of such models to current distributions is regularly enumerated, SDMs are rarely tested across longer time spans to gauge their actual performance under environmental change. Here, we utilise paleozoological presence/absence records to independently assess the predictive accuracy of SDMs through time.

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Article Synopsis
  • Humans have changed ecosystems and biodiversity around the world for a long time, but we don’t fully understand how these changes have happened over time.
  • Researchers studied a lot of pollen samples to see how plant communities have changed for thousands of years, finding that differences in plant types and numbers have varied across the globe.
  • In some areas, as humans impacted the land, biodiversity increased, while in other places, it decreased, showing that humans have both helped and harmed plant diversity over the last 8,000 years.
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Entomology is key to understanding terrestrial and freshwater ecosystems at a time of unprecedented anthropogenic environmental change and offers substantial untapped potential to benefit humanity in a variety of ways, from improving agricultural practices to managing vector-borne diseases and inspiring technological advances.We identified high priority challenges for entomology using an inclusive, open, and democratic four-stage prioritisation approach, conducted among the membership and affiliates (hereafter 'members') of the UK-based Royal Entomological Society (RES).A list of 710 challenges was gathered from 189 RES members.

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  • Scientists studied how climate change and habitat loss affect different plants and animals in Great Britain over 75 years.
  • They found that warmer temperatures and losing grasslands helped some species survive but made it harder for others.
  • Most species reacted differently, so it's important to look at each one when creating plans to protect nature.
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  • Different aspects of biodiversity, like the number of species on islands, change at different rates because of human activity, and this isn't as simple as it seems.
  • Sometimes when humans impact biodiversity, it can either make ecosystems stronger against extinction or cause a lot of species to disappear rapidly.
  • A study found that while islands might get more species from human help, the total number of species worldwide is going down, but those new communities can still be strong and work well together.
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  • Scientists are studying how wildlife and plant life (biodiversity) is changing around the world because of human activities.
  • They look at different measures of biodiversity, like how many species there are, how species change over time, and how similar or different species are in different places.
  • While some areas show both increases and decreases in species, research suggests that overall, the number of extinct species is going up faster than new species are forming globally.
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Compositional change is a ubiquitous response of ecological communities to environmental drivers of global change, but is often regarded as evidence of declining "biotic integrity" relative to historical baselines. Adaptive compositional change, however, is a foundational idea in evolutionary biology, whereby changes in gene frequencies within species boost population-level fitness, allowing populations to persist as the environment changes. Here, we present an analogous idea for ecological communities based on core concepts of fitness and selection.

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  • Land-use change usually makes nature simpler, but studying the last 1,000 years shows that the variety of ecosystems has actually increased.
  • After around 1700, ecosystem diversity grew faster, but later slowed down especially after people started impacting the Earth more in the mid-20th century.
  • While some areas have become more alike globally because of human activities, there has still been an increase in different types of ecosystems overall, even if some natural areas have been harmed.
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Mammals have experienced high levels of human-mediated extirpations but have also been widely introduced to new locations, and some have recovered from historic persecution. Both of these processes-losses and gains-have resulted in concern about functional losses and changes in ecological communities as new ecological states develop. The question of whether species turnover inevitably leads to declines in functional and phylogenetic diversity depends, however, on the traits and phylogenetic distinctiveness of the species that are lost, gained, or regained.

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  • Changes in evolution can affect how insect pests, pollinators, or disease-carrying insects move to new places.
  • It's important to pay attention to these changes because they can have big effects on the environment and the economy, but they often get ignored in managing these issues.
  • To better understand and deal with these changes, scientists need to use smart study designs and new technology, and future plans should take into account how insects adapt to new situations for the benefit of nature and its services.
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  • Some countries are making big promises to protect more land for conservation, but they might not be picking the best places to do that.
  • In the UK, many protected areas are not located in the places that need it the most for saving different plants and animals.
  • A better way to choose conservation sites is to use a method called systematic conservation planning, which helps find the best areas to protect.
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  • The study focuses on how climatic changes during the Pleistocene have influenced the genetic diversity of a montane butterfly species in Europe, analyzing both current genetic patterns and future threats from climate change.
  • Using mitochondrial DNA and species distribution modeling, researchers identified significant genetic diversity concentrated in certain regions and projected potential losses of unique haplotypes due to expected climate changes by 2070.
  • The findings indicate that historical population dynamics led to unique genetic variations, which are now vulnerable; thus, assisted colonization strategies may be necessary to help preserve at-risk populations in suitable habitats.
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Illegal hunting is a persistent problem in many protected areas, but an overview of the extent of this problem and its impact on wildlife is lacking. We reviewed 40 years (1980-2020) of global research to examine the spatial distribution of research and socio-ecological factors influencing population decline within protected areas under illegal hunting pressure. From 81 papers reporting 988 species/site combinations, 294 mammal species were reported to have been illegally hunted from 155 protected areas across 48 countries.

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Trends in insect abundance are well established in some datasets, but far less is known about how abundance measures translate into biomass trends. Moths (Lepidoptera) provide particularly good opportunities to study trends and drivers of biomass change at large spatial and temporal scales, given the existence of long-term abundance datasets. However, data on the body masses of moths are required for these analyses, but such data do not currently exist.

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Suggitt et al. reply to the concerns raised by Le Roux et al. on their original manuscript.

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The development of Anthropocene biotas.

Philos Trans R Soc Lond B Biol Sci

March 2020

Biodiversity has always responded dynamically to environmental perturbations in the geological past, through changes to the abundances and distributions of genes and species, to the composition of biological communities, and to the cover and locations of different ecosystem types. This is how the 'nature' that exists today has survived. The same is true in the Anthropocene.

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Major environmental changes in the history of life on Earth have given rise to novel habitats, which gradually accumulate species. Human-induced change is no exception, yet the rules governing species accumulation in anthropogenic habitats are not fully developed. Here we propose that nonnative plants introduced to Great Britain may function as analogues of novel anthropogenic habitats for insects and mites, analysing a combination of local-scale experimental plot data and geographic-scale data contained within the Great Britain Database of Insects and their Food Plants.

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Steep insect biomass declines ('insectageddon') have been widely reported, despite a lack of continuously collected biomass data from replicated long-term monitoring sites. Such severe declines are not supported by the world's longest running insect population database: annual moth biomass estimates from British fixed monitoring sites revealed increasing biomass between 1967 and 1982, followed by gradual decline from 1982 to 2017, with a 2.2-fold net gain in mean biomass between the first (1967-1976) and last decades (2008-2017) of monitoring.

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Advances in phenology (the annual timing of species' life-cycles) in response to climate change are generally viewed as bioindicators of climate change, but have not been considered as predictors of range expansions. Here, we show that phenology advances combine with the number of reproductive cycles per year (voltinism) to shape abundance and distribution trends in 130 species of British Lepidoptera, in response to ~0.5 °C spring-temperature warming between 1995 and 2014.

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Range shifting is vital for species persistence, but there is little consensus on why individual species vary so greatly in the rates at which their ranges have shifted in response to recent climate warming. Here, using 40 years of distribution data for 291 species from 13 invertebrate taxa in Britain, we show that interactions between habitat availability and exposure to climate change at the range margins explain up to half of the variation in rates of range shift. Habitat generalists expanded faster than more specialised species, but this intrinsic trait explains less of the variation in range shifts than habitat availability, which additionally depends on extrinsic factors that may be rare or widespread at the range margin.

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Both community composition changes due to species redistribution and within-species size shifts may alter body-size structures under climate warming. Here we assess the relative contribution of these processes in community-level body-size changes in tropical moth assemblages that moved uphill during a period of warming. Based on resurvey data for seven assemblages of geometrid moths (>8000 individuals) on Mt.

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