Environmental Contaminants and Reproductive Abnormalities in Wildlife: Implications for Public Health?

1996 ◽  
Vol 12 (3-4) ◽  
pp. 537-550 ◽  
Author(s):  
Louis J. Guillette ◽  
Elizabeth A. Guillette

At the onset of the industrial age, environmental contaminants began to pose a major threat to the health of wildlife. That threat appears to continue today. In the last three decades, the focus of our concern on the health consequences of environmental pollution has been on lethal, carcinogenic, and/or extreme teratogenic manifestations. Evidence from a number of sources suggests that another mechanism, endocrine-disruption, also must be examined. There is excellent laboratory and field evidence that man-made chemicals (xenochemicals) released into the environment act as hormones or antihormones. They act as endocrine-disrupting contaminants (EDCs). The release of EDCs occurred in the past and continues today. The development of the reproductive system is vulnerable to perturbation by EDCs. Wildlife studies demonstrate that both sexes are affected and experience modifications of gonadal and reproductive tract development or functioning and abnormal synthesis or metabolism of hormones. A number of abnormalities seen in the reproductive system of various wildlife species correlate with similar abnormalities described as rising in human populations. We suggest that wildlife are excellent sentinels of ecosystem health. Data from these wildlife studies present models and methodologies for examining human health.

2013 ◽  
Vol 21 (2) ◽  
pp. T13-T31 ◽  
Author(s):  
Douglas A Gibson ◽  
Philippa T K Saunders

Endocrine disrupting chemicals (EDC) are ubiquitous and persistent compounds that have the capacity to interfere with normal endocrine homoeostasis. The female reproductive tract is exquisitely sensitive to the action of sex steroids, and oestrogens play a key role in normal reproductive function. Malignancies of the female reproductive tract are the fourth most common cancer in women, with endometrial cancer accounting for most cases. Established risk factors for development of endometrial cancer include high BMI and exposure to oestrogens or synthetic compounds such as tamoxifen. Studies on cell and animal models have provided evidence that many EDC can bind oestrogen receptors and highlighted early life exposure as a window of risk for adverse lifelong effects on the reproductive system. The most robust evidence for a link between early life exposure to EDC and adverse reproductive health has come from studies on women who were exposedin uteroto diethylstilbestrol. Demonstration that EDC can alter expression of members of the HOX gene cluster highlights one pathway that might be vulnerable to their actions. In summary, evidence for a direct link between EDC exposure and cancers of the reproductive system is currently incomplete. It will be challenging to attribute causality to any single EDC when exposure and development of malignancy may be separated by many years and influenced by lifestyle factors such as diet (a source of phytoestrogens) and adiposity. This review considers some of the evidence collected to date.


Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2323
Author(s):  
Lloyd A. Courtenay ◽  
Darío Herranz-Rodrigo ◽  
José Yravedra ◽  
José Mª Vázquez-Rodríguez ◽  
Rosa Huguet ◽  
...  

Human populations have been known to develop complex relationships with large carnivore species throughout time, with evidence of both competition and collaboration to obtain resources throughout the Pleistocene. From this perspective, many archaeological and palaeontological sites present evidence of carnivore modifications to bone. In response to this, specialists in the study of microscopic bone surface modifications have resorted to the use of 3D modeling and data science techniques for the inspection of these elements, reaching novel limits for the discerning of carnivore agencies. The present research analyzes the tooth mark variability produced by multiple Iberian wolf individuals, with the aim of studying how captivity may affect the nature of tooth marks left on bone. In addition to this, four different populations of both wild and captive Iberian wolves are also compared for a more in-depth comparison of intra-species variability. This research statistically shows that large canid tooth pits are the least affected by captivity, while tooth scores appear more superficial when produced by captive wolves. The superficial nature of captive wolf tooth scores is additionally seen to correlate with other metric features, thus influencing overall mark morphologies. In light of this, the present study opens a new dialogue on the reasons behind this, advising caution when using tooth scores for carnivore identification and contemplating how elements such as stress may be affecting the wolves under study.


1979 ◽  
Vol 44 (1) ◽  
pp. 155-160 ◽  
Author(s):  
Bruce D. Smith

To determine the pattern of selective utilization of animal species by prehistoric human populations, it is first necessary to quantify the relative importance of species of animals in the diet of prehistoric human groups through analysis of archaeologically recovered faunal samples. These values are then compared with estimates of the relative availability of different species of animals in the environment. Such estimates of the relative availability of animal species in prehistoric habitat situations, usually quantified in terms of biomass, are obtained by projecting data from modern analog situations into the past. When attempting to reconstruct prehistoric biotic communities in this manner, it is important to be aware of a number of possible sources of bias and to evaluate and apply modern wildlife data according to a set of interrelated principles. Sources of bias and criteria for selecting modern wildlife analog data are discussed.


2017 ◽  
Vol 284 (1861) ◽  
pp. 20170706 ◽  
Author(s):  
Valentin Thouzeau ◽  
Philippe Mennecier ◽  
Paul Verdu ◽  
Frédéric Austerlitz

Linguistic and genetic data have been widely compared, but the histories underlying these descriptions are rarely jointly inferred. We developed a unique methodological framework for analysing jointly language diversity and genetic polymorphism data, to infer the past history of separation, exchange and admixture events among human populations. This method relies on approximate Bayesian computations that enable the identification of the most probable historical scenario underlying each type of data, and to infer the parameters of these scenarios. For this purpose, we developed a new computer program PopLingSim that simulates the evolution of linguistic diversity, which we coupled with an existing coalescent-based genetic simulation program, to simulate both linguistic and genetic data within a set of populations. Applying this new program to a wide linguistic and genetic dataset of Central Asia, we found several differences between linguistic and genetic histories. In particular, we showed how genetic and linguistic exchanges differed in the past in this area: some cultural exchanges were maintained without genetic exchanges. The methodological framework and the linguistic simulation tool developed here can be used in future work for disentangling complex linguistic and genetic evolutions underlying human biological and cultural histories.


2021 ◽  
Author(s):  
Moisès Coll Macià ◽  
Laurits Skov ◽  
Benjamin Marco Peter ◽  
Mikkel Heide Schierup

AbstractAfter the main out-of-Africa event, humans interbred with Neanderthals leaving 1-2% of Neanderthal DNA scattered in small fragments in all non-African genomes today1,2. Here we investigate the size distribution of these fragments in non-African genomes3. We find consistent differences in fragment length distributions across Eurasia with 11% longer fragments in East Asians than in West Eurasians. By comparing extant populations and ancient samples, we show that these differences are due to a different rate of decay in length by recombination since the Neanderthal admixture. In line with this, we observe a strong correlation between the average fragment length and the accumulation of derived mutations, similar to what is expected by changing the ages at reproduction as estimated from trio studies4. Altogether, our results suggest consistent differences in the generation interval across Eurasia, by up to 20% (e.g. 25 versus 30 years), over the past 40,000 years. We use sex-specific accumulations of derived alleles to infer how these changes in generation intervals between geographical regions could have been mainly driven by shifts in either male or female age of reproduction, or both. We also find that previously reported variation in the mutational spectrum5 may be largely explained by changes to the generation interval and not by changes to the underlying mutational mechanism. We conclude that Neanderthal fragment lengths provide unique insight into differences of a key demographic parameter among human populations over the recent history.


2021 ◽  
Vol 118 (28) ◽  
pp. e2024150118
Author(s):  
Clarence Lehman ◽  
Shelby Loberg ◽  
Michael Wilson ◽  
Eville Gorham

Human populations have grown to such an extent that our species has become a dominant force on the planet, prompting geologists to begin applying the term Anthropocene to recognize the present moment. Many approaches seek to explain the past and future of human population growth, in the form of narratives and models. Some of the most influential models have parameters that cannot be precisely known but are estimated by expert opinion. Here we apply a unified model of ecology to provide a macroscale summary of the net effects of many microscale processes, using a minimal set of parameters that can be known. Our models match estimates of historic and prehistoric global human population numbers and provide predictions that correspond to some of the more complicated current models. In addition to fitting the data well they reveal that, amidst enormous complexity in our human and prehuman past, three key ecological discontinuities have occurred in turn: 1) becoming dominant competitors of large predators rather than their prey, 2) becoming mutualists with food species rather than acting as predators upon them, and 3) changing from a regime of uncontrolled population growth to one of controlled fertility instead. All three processes have been interlinked with cultural evolution and all three ushered in developments of the Anthropocene. Understanding the trajectories that have delivered us to this stage can help guide prudent paths into the future.


2021 ◽  
Vol 77 (02) ◽  
pp. 6491-2021
Author(s):  
MAGDALENA KULUS ◽  
MARIA WIECZORKIEWICZ ◽  
JAKUB KULUS ◽  
MARIUSZ T. SKOWROŃSKI ◽  
WIESŁAWA KRANC ◽  
...  

The complexity of processes in the female reproductive system of mammals is extremely sophisticated. The overall relationship between the processes during the oestrus cycle in animals is quite well understood, but the molecular background of these processes still requires an in-depth analysis. Bitches are distinguished by a specific course of sexual cycle during which the oocyte matures after ovulation in the oviduct. Other species of mammals are characterized by maturation of the oocyte within the ovary. Acquisition of developmental competence by cumulus – oocyte complexes seems to be a process with a complex molecular background, and the key to understanding it may be the analysis of intercellular channels. Aquaporins and connexins are structural proteins that are built into the cell membrane. Their location is widespread in many body tissues. Recent years have shown that they exhibit significant expression in different parts of the mammalian reproductive system, although the number of studies on dogs is still negligible. This review paper presents the current state of knowledge of water channels and gap junction connections in different animal species, with particular focus on dogs, and also explores the role of aquaporins and connexins in the acquisition of reproductive competences.


Endocrinology ◽  
2020 ◽  
Vol 162 (1) ◽  
Author(s):  
Manasi Das ◽  
Consuelo Sauceda ◽  
Nicholas J G Webster

Abstract Mounting evidence suggests a role for mitochondrial dysfunction in the pathogenesis of many diseases, including type 2 diabetes, aging, and ovarian failure. Because of the central role of mitochondria in energy production, heme biosynthesis, calcium buffering, steroidogenesis, and apoptosis signaling within cells, understanding the molecular mechanisms behind mitochondrial dysregulation and its potential implications in disease is critical. This review will take a journey through the past and summarize what is known about mitochondrial dysfunction in various disorders, focusing on metabolic alterations and reproductive abnormalities. Evidence is presented from studies in different human populations, and rodents with genetic manipulations of pathways known to affect mitochondrial function.


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