In recent years, the rate of species extinction has become a focal point for scientists and conservationists alike, drawing comparisons to Earth’s historical mass extinction events. Despite the global concern, a groundbreaking study published in the open-access journal PLOS Biology provides a crucial new perspective on the severity of these modern biodiversity losses. Led by John Wiens of the University of Arizona and Kristen Saban of Harvard University, the research carefully assessed over 22,000 plant and animal genera to evaluate the true scope of higher-level extinctions since the year 1500. Their findings challenge prevailing narratives that portray a rapidly accelerating crisis similar to past mass extinctions, suggesting instead that extinctions at the genus level remain rare, localized, and have actually decelerated in recent times.
To understand how current extinction rates compare with Earth’s historical background, it is essential to distinguish between species-level and higher taxonomic extinctions. While hundreds of species have undoubtedly vanished in recent centuries, mass extinction events in geological history have been synonymous with the loss of entire genera, families, or even broader taxonomic groups. These losses represent a more profound disruption of ecological complexity and functionality than species extinction alone, highlighting the need to focus not just on species counts but on the fate of larger biological groupings. By leveraging data curated by the International Union for Conservation of Nature (IUCN), the researchers targeted genus-level extinctions, thereby gaining a more integrated view of biodiversity changes over the last 500 years.
The meticulous analysis revealed that only 102 genera have gone extinct since 1500, a figure that constitutes less than 0.5% of the genera assessed by the IUCN. Significantly, these extinctions are geographically and taxonomically clustered, with nearly half concentrated within birds and mammals. The study highlights that more than three-quarters of extinct genera were endemic to islands, a factor that underscores how isolated ecosystems remain particularly vulnerable to ecological disturbances such as invasive species introduction and habitat degradation. Temporally, extinction rates peaked during the late 19th and early 20th centuries but have not continued to increase since, countering claims that modern extinction crises reflect an ongoing, escalating rate of higher-level biological loss.
The nuanced spatial and temporal distribution of extinctions calls into question the extent to which modern biodiversity losses equate to classical mass extinction events. Historically, mass extinctions led to widespread collapses of ecological networks and massive taxonomic turnovers, profoundly reshaping Earth’s biosphere. However, the recent data indicate that such extensive breakdowns have not yet occurred in the present day at the genus level. This divergence suggests that although the loss of species and ecological functions associated with them are undoubtedly severe, the current biodiversity crisis may not yet mirror the catastrophic levels previously documented in paleontological records.
Importantly, the authors emphasize that their findings do not minimize the ongoing threats to global biodiversity, which remain significant and demand concerted conservation efforts. Rather, the study advocates for precision in how extinction data are interpreted and communicated. By distinguishing between species and higher taxonomic extinctions, conservation biologists can more accurately gauge the magnitude of biodiversity loss and better inform policy and management strategies. Such clarity is especially critical in an era marked by misinformation and widespread skepticism toward scientific evidence.
John Wiens is unequivocal in his assessment, stating that previous research overstated the frequency and consequences of genus-level extinctions. Contrary to assertions of rapid acceleration in animal genus extinctions that endanger human survival, Wiens explains that such extinctions have been notably infrequent across both plant and animal kingdoms and predominantly associated with island endemics. The past century, in fact, has seen a deceleration in the rate of genus extinctions. This fresh understanding reframes the narrative around biodiversity declines to be more precise and grounded in observed data rather than extrapolation.
Wiens further clarifies the ethical dimension underlying conservation priorities. He argues that the imperative to prevent future extinctions should not rest solely on anthropocentric concerns — the idea that biodiversity loss threatens human existence — but instead on moral grounds. The extinction of species is an irreversible act carried out by human activities, and thereby a violation of humanity’s responsibility toward other life forms sharing our planet. This philosophical standpoint re-centers conservation discussions around intrinsic ecological value rather than utilitarian benefit.
Kristen Saban adds to the conversation by highlighting the broader need for scientific accountability and rigor within conservation research. In a socio-political climate where science is often contested, presenting accurate and carefully analyzed findings is imperative to sustaining public trust and driving meaningful environmental action. The study exemplifies this approach by combining comprehensive data analysis with cautious interpretation, avoiding alarmism while calling attention to real but contextually nuanced biodiversity issues.
The implications of this research extend into how conservation priorities are set at international and national levels. Recognizing that most genus extinctions are island-specific underlines the critical importance of protecting insular ecosystems, which are frequently hotspots for endemism as well as vulnerability. Island conservation initiatives might therefore represent some of the most effective strategies to mitigate higher-level biological losses. Additionally, ongoing monitoring of taxa beyond species-level data could enhance our predictive capability regarding future extinction trajectories.
Technically, this study employed an observational methodology using a vast dataset from the IUCN’s Red List, the most comprehensive global inventory of the conservation status of species and genera. By focusing on validated genus extinctions—rather than tentative or speculative losses—the research ensured robustness and minimized the influence of reporting biases or incomplete data. This approach sets a valuable standard for future assessments aiming to quantify biodiversity change on large taxonomic scales.
It is also noteworthy that the paper’s authors declared no competing interests, underscoring the independent nature of their findings. Supported in part by a National Science Foundation Graduate Research Fellowship, the research team’s conclusions are rooted in objective analysis absent external financial or corporate pressures. As such, the study stands as a credible and important contribution to the discourse on biodiversity and extinction dynamics during the Anthropocene.
In conclusion, while the current extinction crisis undeniably reflects severe species losses and habitat degradation, the level of genus extinction remains comparatively low, localized, and has slowed in pace. This revelation calls for a recalibration of how extinction data inform public perception and policy, highlighting the value of a taxonomically nuanced approach to biodiversity conservation. The moral imperative to protect Earth’s diversity remains paramount, yet the narrative should align with scientific evidence to foster effective and transparent environmental stewardship.
Subject of Research: Animals
Article Title: Recent extinctions of plant and animal genera are rare, localized, and decelerated
News Publication Date: September 4, 2025
Web References: http://dx.doi.org/10.1371/journal.pbio.3003356
References: Wiens JJ, Saban KE (2025) Recent extinctions of plant and animal genera are rare, localized, and decelerated. PLoS Biol 23(9): e3003356.
Image Credits: John J. Wiens (CC-BY 4.0)
Keywords: biodiversity crisis, genus extinction, mass extinction, conservation biology, island endemics, IUCN Red List, ecological function, Anthropocene extinction, species loss, taxonomic extinction, conservation ethics, observational study
