We live amid a global wave of anthropogenically driven biodiversity loss: species and population extirpations and, critically, declines in local species abundance. Particularly, human impacts on animal biodiversity are an under-recognized form of global environmental change. Among terrestrial vertebrates, 322 species have become extinct since 1500, and populations of the remaining species show 25% average decline in abundance. Invertebrate patterns are equally dire: 67% of monitored populations show 45% mean abundance decline. Such animal declines will cascade onto ecosystem functioning and human well-being. Much remains unknown about this “Anthropocene defaunation”; these knowledge gaps hinder our capacity to predict and limit defaunation impacts. Clearly, however, defaunation is both a pervasive component of the planet’s sixth mass extinction and also a major driver of global ecological change.

/pdf/defaunation-in-the-anthropocene-46k054u5cx.pdf

Defaunation in the Anthropocene

Humans have brought about unprecedented changes to environments worldwide. For many species, behavioral adjustments represent the first response to altered conditions. In this review, we consider the pivotal role that behavior plays in determining the fate of species under human-induced environmental change and highlight key research priorities. In particular, we discuss the importance of behavioral plasticity and whether adaptive plastic responses are sufficient in keeping pace with changing conditions. We then examine the interplay between individual behavioral responses and population processes and consider the many ways in which changes in behavior can affect ecosystem function and stability. Lastly, we turn to the evolutionary consequences of anthropogenic change and consider the impact of altered behaviors on the evolutionary process and whether behavior can facilitate or hinder adaptation to environmental change.

/pdf/behavioral-responses-to-changing-environments-3g36mlmtr8.pdf

Behavioral responses to changing environments

Phenotype-based selective harvests, including trophy hunting, can have important implications for sustainable wildlife management if they target heritable traits. Here we show that in an evolutionary response to sport hunting of bighorn trophy rams (Ovis canadensis) body weight and horn size have declined significantly over time. We used quantitative genetic analyses, based on a partly genetically reconstructed pedigree from a 30-year study of a wild population in which trophy hunting targeted rams with rapidly growing horns, to explore the evolutionary response to hunter selection on ram weight and horn size. Both traits were highly heritable, and trophy-harvested rams were of significantly higher genetic 'breeding value' for weight and horn size than rams that were not harvested. Rams of high breeding value were also shot at an early age, and thus did not achieve high reproductive success. Declines in mean breeding values for weight and horn size therefore occurred in response to unrestricted trophy hunting, resulting in the production of smaller-horned, lighter rams, and fewer trophies.

Undesirable evolutionary consequences of trophy hunting

Species conservation practice, as opposed to principle, generally emphasizes species at risk of imminent extinction. This results in priority lists principally of those with small populations and/or geographical ranges. However, recent work emphasizes the importance of common species to ecosystems. Even relatively small proportional declines in their abundance can result in large absolute losses of individuals and biomass, occurrences significantly disrupting ecosystem structure, function and services. Here, we argue that combined with evidence of dramatic declines in once common species, this suggests the need to pay more attention to such depletions. Complementing the focus on extinction risk, we highlight important implications for conservation, including the need to identify, monitor and alleviate significant depletion events.

Commonness, population depletion and conservation biology

It is unclear when, where and how novel pathogens such as human immunodeficiency virus (HIV), monkeypox and severe acute respiratory syndrome (SARS) will cross the barriers that separate their natural reservoirs from human populations and ignite the epidemic spread of novel infectious diseases. New pathogens are believed to emerge from animal reservoirs when ecological changes increase the pathogen's opportunities to enter the human population1 and to generate subsequent human-to-human transmission2. Effective human-to-human transmission requires that the pathogen's basic reproductive number, R0, should exceed one, where R0 is the average number of secondary infections arising from one infected individual in a completely susceptible population3. However, an increase in R0, even when insufficient to generate an epidemic, nonetheless increases the number of subsequently infected individuals. Here we show that, as a consequence of this, the probability of pathogen evolution to R0 > 1 and subsequent disease emergence can increase markedly.

/pdf/the-role-of-evolution-in-the-emergence-of-infectious-1p8g1x9zs5.pdf

The role of evolution in the emergence of infectious diseases

A common assumption is that breeding in polygnous systems is not limited by the number of males because one male can inseminate many females1,2. But here we show that reproductive collapse in the critically endangered saiga antelope (Saiga tatarica tatarica) is likely to have been caused by a catastrophic drop in the number of adult males in this harem-breeding ungulate, probably due to selective poaching for their horns. Fecundity and calf survival are known to be affected by markedly skewed sex ratios3, but in the saiga antelope the sex ratio has become so distorted as to lead to a drastic decline in the number of pregnancies — a finding that has implications both for the conservation of the species and for understanding the reproductive ecology of polygynous ungulates.

Conservation: Reproductive collapse in saiga antelope harems.

We analysed the mtDNA control region (HV1) of 93 tissue samples from all five populations of the saiga antelope Saiga tatarica. The results show a slight but clear distinction between S. t. mongolica and S. t. tatarica, supporting the current designation of S. t. mongolica as a subspecies rather than a separate species. Levels of genetic diversity were low in S. t. mongolica, consistent with the small size of its population and long isolation. Although populations of S. t. tatarica have reasonable levels of genetic diversity, their conservation status is perilous. The Kalmykian and Kazakhstan samples each contained unique haplotypes, although the species as a whole appears polyphyletic, consistent with recent fragmentation and rapid population decline. An understanding of the population genetics of this species is an essential prerequisite for conservation action.

/pdf/mitochondrial-dna-variation-and-population-structure-of-the-3oy1fq74sc.pdf

Mitochondrial DNA variation and population structure of the Critically Endangered saiga antelope Saiga tatarica

In the bovid family (Bovidae), the taxonomy of a subfamily Antilopinae is the most complex and contradictory by now. In particular, the ambiguity originates from the fact that the term antelopes is too widely used. Some researchers [1, 2] even propose dividing the bovid into only two families, Bovinae and Antilopinae, of which the former should remain about the same, whereas the latter should encompass all subfamilies of the rank of tribe. Because of the complexity and heterogeneity of the group, the conclusions that different taxonomists make from their studies are contradictory. For example, V. E. Sokolov [3] accepted Halthenorth’s [4] almost ungrounded subdivision of bovids into subfamilies according to which the Tragelaphini (African kudu) are included into the Antilopinae subfamily, whereas the Neotragini (dwarf antelopes) are considered a separate subfamily Neotraginae. Nevertheless, in the previous reports, G.G. Simpson [5] and I.I. Sokolov [6] clearly demonstrated the closeness of Tragelaphini to Bovini, which allowed them to combine these tribes into a single subfamily Bovinae.

https://link.springer.com/content/pdf/10.1023/A:1025102617714.pdf

Revision of Phylogenetic Relationships in the Antilopinae Subfamily on the Basis of the Mitochondrial rRNA and β-Spectrin Nuclear Gene Sequences

Genetic diversity is one of the main characteristics of populations, largely determining their adaptability and the prospect of long survival [1–4]. The loss of genetic diversity is now an urgent problem not only for rare animals, but also for the species that were numerous until recently, such as the saiga ( Saiga tatarica ). The total size of all populations of the nominative subspecies ( S. t. tatarica ), namely, one European and three Kazakhstan populations, was more than 10 6 until the mid-1990s; however, excessive hunting and unfavorable environment has already caused its decrease to 5–10% of that value [5]. We studied the effect of a catastrophic decrease in population size on genetic diversity using the European saiga population as an example. The left domain of the control region (D loop) of mitochondrial DNA (mtDNA), which is its most variable region, was used as a molecular marker. Variation in this mtDNA region reflect changes in the effective population, including bottlenecking [6–10].

Changes in the Genetic Diversity of European Saiga tatarica during a Drastic Population Depression

Geographic distribution and molecular genetic identification of the parasite of the genus Ichthyodinium causing mass mortality of fish eggs and larvae in coastal waters of Vietnam.

Handle everyday research tasks with reliable, citation-backed results

Your personal Research Agent to handle research tasks with citation-backed results

Popular Tasks used by Researchers

How can I help with your research?

Meet SciSpace

Get more enhanced response by uploading the PDFs you want me to reference.

No relevant PDFs in your library

SciSpace is the AI research assistant for academics. Run systematic literature reviews on 280M+ papers, and write papers with cited sources. Trusted by 1M+ students, PhDs & researchers.

SciSpace | AI for Research

Analyze PDFs

Code & Manuscripts

Funding & Grants

Literature & Patents

Medical & Clinical Data

Systematic Review

Visualize & Present

Web & Data

Build a Google Scholar-like website for your research.

Build a website

Create charts and images for your research

Create a Chart

Write a paper for submission to a journal

Draft a manuscript

Patent Search

Design eye-catching scientific posters in minutes.

Scientific Poster Generation

Systematic Literature Review

One task is running at the moment. Your messages will be shown right after.

Drag and drop or click here to browse

Loved by <highlight>1 million+</highlight> researchers

Extract a list of specific topics and their sources from unstructured text

Topics

Compare and analyze relevant papers that matches with your search

Papers

Get insights from PDFs and bookmarked papers from your library

My library

Recent searches

Try searching for:

Catch AI-generated content in scholarly and non-scholarly content

{ai} Detector

Ai Writer

Get PDF Summaries, highlighted text explanations 

Chat with PDF

Effortlessly create in-text citations and bibliographies in APA and 2,500 other formats

Citation generator

Get explanations, summaries, and answers on academic papers

Ease up your research workflow with {scispace}'s cohort of exciting AI tools

Elevate your academic writing skills and convey your ideas the way you want

Paraphraser

Explore our range of reading and writing tools

Your file is being prepared and should be ready in a few minutes. If it's a large file, it might take a bit longer. You can close this window, and we'll email you the file when it's done.

You have reached a maximum limit of <strong>{limit}</strong> columns in the table. Remove at least <strong>1</strong> column to add or create another one.

M. V. Kholodova

Author Tools

Chat about Author