After the 1986 nuclear disaster in Chernobyl, the regional domestic dog population suffered from environmental pollution originating from the radiation. This disaster made the environment highly mutagenic, leading to various evolutionary processes including, but not limited to, bottlenecks, directional selection, and higher rates of mutation resulting in evolutionary trajectories that differ from unexposed animals. [1]
The exact origin of the populations of dogs living in the Chernobyl Nuclear Power Plant (CNPP) and the surrounding areas of the Chernobyl Exclusion Zone is unknown. [1] However, it is hypothesized that these animals are the descendants of pets left behind during the original evacuation of Pripyat. While many of these original pets population were killed by the Ukrainian Ministry of Internal Affairs to prevent the further spread of radiation, [2] the remainder survived to reproduce. There are currently two geographically and genetically distinct populations of dogs in the area, one in the CNPP and one in Chernobyl City. [1]
At least 302 feral dogs live around the Chernobyl Exclusion Zone (CEZ). However, there are projections of up to a thousand individuals due to the present differences with the nearby populations (10 miles away). [1] They differentiate from populations only 16 km away. At least 15 families are living inside the area mostly related to shepherd breeds such as the German shepherds, characteristics shared by other feral dogs living in Eastern Europe. [3]
The dogs suffer from radiation that may differentiate them genetically from the population of CEZ with their surroundings. Nevertheless, processes such as the high likelihood of inbreeding can lead to difficulties at the moment of analyzing their genome. In addition, the conditions of their habitat, human control in the access to the CEZ, may simulate an island habitat in terms of evolutionary processes such as isolation. [1]
Despite the evidence of genetic differentiation mainly due to the radioactive environment, there is no support for pinpoint radiation as the primary driver of genetic differentiation; the evidence serves as insight for further research in these populations. Some regions of the genome indicate that they can be driven by directional selection. 391 outlier loci are influenced by directional selection, with at least 52 candidate genes [4]
Genetic signatures of the Chernobyl dog populations have been compared to both pure-bred and free-breeding dog population genetic structures. The Chernobyl populations did not share increased similarity to pure-bred dogs, indicating that the populations of dogs of Chernobyl have not been inundated with individuals that are modern pets. Instead, this population is similar to free-breeding populations, indicating that the population has been established at least since the disaster in 1986. However, the Chernobyl dogs show enough differentiation from these populations that they can be used as a unique entity for further genomic study. [1]
Since 2017, the Clean Futures Fund has implemented annual clinics in the Chernobyl exclusion zone to vaccinate, spay, and neuter the dogs of Chernobyl. This effort is made to reduce the risk of rabies passing to workers and tourists, to decrease the population size of the dogs, and to minimize the suffering that the dogs experience. [5] The dogs in the zone are able to recognize the uniforms of CFF personnel, and often avoid capture. For this reason, the CFF changes the color of their uniforms every year in order to vaccinate, spay, and neuter the dogs. [6]
Neutering, from the Latin neuter, is the removal of a non-human animal's reproductive organ, either all of it or a considerably large part. The male-specific term is castration, while spaying is usually reserved for female animals. Colloquially, both terms are often referred to as fixing. In male horses, castrating is referred to as gelding. An animal that has not been neutered is sometimes referred to as entire or intact.
In population genetics, directional selection is a type of natural selection in which one extreme phenotype is favored over both the other extreme and moderate phenotypes. This genetic selection causes the allele frequency to shift toward the chosen extreme over time as allele ratios change from generation to generation. The advantageous extreme allele will increase in frequency among the population as a consequence of survival and reproduction differences among the different present phenotypes in the population. The allele fluctuations as a result of directional selection can be independent of the dominance of the allele, and in some cases if the allele is recessive, it can eventually become fixed in the population.
Trap–neuter–return (TNR), also known as trap–neuter–release, is a controversial method that attempts to manage populations of feral cats. The process involves live-trapping the cats, having them neutered, ear-tipped for identification, and, if possible, vaccinated, then releasing them back into the outdoors. If the location is deemed unsafe or otherwise inappropriate, the cats may be relocated to other appropriate areas. Often, friendly adults and kittens young enough to be easily socialized are retained and placed for adoption. Feral cats cannot be socialized, shun most human interaction and do not fare well in confinement, so they are not retained. Cats suffering from severe medical problems such as terminal, contagious, or untreatable illnesses or injuries are often euthanized.
The Chernobyl Nuclear Power Plant Zone of Alienation, also called the 30-Kilometre Zone or simply The Zone, was established shortly after the 1986 Chernobyl disaster in the Ukrainian SSR of the Soviet Union.
The Chernobyl disaster began on 26 April 1986 with the explosion of the No. 4 reactor of the Chernobyl Nuclear Power Plant near the city of Pripyat in northern Ukraine, near the Belarus border in the Soviet Union. It is one of only two nuclear energy accidents rated at the maximum severity on the International Nuclear Event Scale, the other being the 2011 Fukushima nuclear accident. The response involved more than 500,000 personnel and cost an estimated 18 billion rubles. It remains the worst nuclear disaster in history, and the costliest disaster in human history, with an estimated cost of $700 billion USD.
The Chernobyl disaster of 26 April 1986 triggered the release of radioactive contamination into the atmosphere in the form of both particulate and gaseous radioisotopes. As of 2024, it remains the world's largest known release of radioactivity into the natural environment.
The dog is a domesticated descendant of the wolf. Also called the domestic dog, it was selectively bred from an extinct population of wolves during the Late Pleistocene by hunter-gatherers. The dog was the first species to be domesticated by humans, over 14,000 years ago and before the development of agriculture. Experts estimate that due to their long association with humans, dogs have gained the ability to thrive on a starch-rich diet that would be inadequate for other canids.
A no-kill shelter is an animal shelter that does not kill healthy or treatable animals based on time limits or capacity, reserving euthanasia for terminally ill animals, animals suffering poor quality of life, or those considered dangerous to public safety. Some no-kill shelters will commit to not killing any animals at all, under any circumstance, except as required by law. A no-kill shelter uses many strategies to promote shelter animals; to expanding its resources using volunteers, housing and medical protocols; and to work actively to lower the number of homeless animals entering the shelter system. Up to ten percent of animals could be killed in a no-kill shelter and still be considered a no-kill shelter.
Canine reproduction is the process of sexual reproduction in domestic dogs, wolves, coyotes and other canine species.
In biology, a cline is a measurable gradient in a single characteristic of a species across its geographical range. Clines usually have a genetic, or phenotypic character. They can show either smooth, continuous gradation in a character, or more abrupt changes in the trait from one geographic region to the next.
The Red Forest is the ten-square-kilometre (4 sq mi) area surrounding the Chernobyl Nuclear Power Plant within the Exclusion Zone, located in Polesia. The name "Red Forest" comes from the ginger-brown colour of the pine trees after they died following the absorption of high levels of ionizing radiation as a consequence of the Chernobyl nuclear disaster on 26 April 1986. The site remains one of the most contaminated areas in the world today.
Cancer in cats is the leading cause of death among cats. It is caused by uncontrolled cell growth, and affects a wide range of cell types and organs in the body. Feline cancer initially manifests as a lump or bump on any part of the body. It rapidly grows in the affected cell, attaches itself to the tissue under the skin in that area, and, depending on the tumour, it can spread to other parts of the body. Although cancer accounts for approximately 32% of deaths in cats over ten years old, it can be successfully treated if diagnosed early.
Cancer is the leading cause of death in dogs. It is estimated that 1 in 3 domestic dogs will develop cancer, which is the same incidence of cancer among humans. Dogs can develop a variety of cancers and most are very similar to those found in humans. Dogs can develop carcinomas of epithelial cells and organs, sarcomas of connective tissues and bones, and lymphomas or leukemias of the circulatory system. Selective breeding of dogs has led certain pure-bred breeds to be at high-risk for specific kinds of cancer.
The health of domestic cats is a well studied area in veterinary medicine.
A genetic isolate is a population of organisms that has little to no genetic mixing with other organisms of the same species due to geographic isolation or other factors that prevent reproduction. Genetic isolates form new species through an evolutionary process known as speciation. All modern species diversity is a product of genetic isolates and evolution.
Population control is the practice of artificially maintaining the size of any population. It simply refers to the act of limiting the size of an animal population so that it remains manageable, as opposed to the act of protecting a species from excessive rates of extinction, which is referred to as conservation biology.
A free-ranging dog is a dog that is not confined to a yard or house. Free-ranging dogs include street dogs, village dogs, stray dogs, feral dogs, etc., and may be owned or unowned. The global dog population is estimated to be 900 million, of which around 20% are regarded as owned pets and therefore restrained.
The Polesie State Radioecological Reserve is a radioecological nature reserve in the Polesie region of Belarus, which was created to enclose the territory of Belarus most affected by radioactive fallout from the Chernobyl disaster. The reserve adjoins the Chernobyl Exclusion Zone in Ukraine. The environmental monitoring and countermeasure agency, Bellesrad, oversees the agriculture and forestry in the area.
This glossary of genetics and evolutionary biology is a list of definitions of terms and concepts used in the study of genetics and evolutionary biology, as well as sub-disciplines and related fields, with an emphasis on classical genetics, quantitative genetics, population biology, phylogenetics, speciation, and systematics. It has been designed as a companion to Glossary of cellular and molecular biology, which contains many overlapping and related terms; other related glossaries include Glossary of biology and Glossary of ecology.
This article uses Chernobyl as a case study of nuclear fallout effects on an ecosystem.
What the dogs have learned surviving in the zone all this time is actually one of the biggest problems for the Clean Futures Fund. Many dogs have memorized the uniforms of those trying to capture them for neutering and/or vaccination, and scatter at the sight of personnel. They are so good at memorizing humans, in fact, that every year the CFF has to change the colors of all of their uniforms.
| Effects | |
|---|---|
| Individuals | |
| Locations | |
| Organisations | |
| Related topics | |
