Memory erasure

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Memory_erasure

Memory erasure is the selective artificial removal of memories or associations from the mind.

Overview

Memory erasure has been shown to be possible in some experimental conditions; some of the techniques currently being investigated are: drug-induced amnesia, selective memory suppression, destruction of neurons, interruption of memory, reconsolidation, and the disruption of specific molecular mechanisms.

There are many reasons that research is being done on the selective removal of memories. Potential patients for this research include patients with psychiatric disorders such as post traumatic stress disorder, or substance use disorder, among others.

Memory erasure is also featured in numerous works of fiction, with fictional methods and properties that do not necessarily correspond with scientific reality.

Recent history

Research focused on gaining a better understanding of what memories are has been going on for many years, in this way so has research in memory erasure. The basis for the recent history for memory erasure has been focused on determining how the brain actively keeps memories stored and retrieves them. There have been several instances where researchers found drugs that when applied to certain areas of the brain, usually the amygdala, have relative success in being able to erase some memories. As early as 2009 researchers were able to trace and destroy neurons involved in supporting the specific type of memory that they were trying to erase. These neurons were targeted by using replication-defective herpes simplex virus (HSV) to increase cyclic adenosine monophosphate response element-binding protein (CREB) in them. As a result, the neurons were activated in fear memory or testing far more often in both wild-type and CREB-deficient mice. For the study, transgenic mice were used that allowed use of diphtheria toxin to preferentially target cells that were overexpressing CREB, since these were the cells more likely involved with fear memories. This caused the erasure of the target memory but allowed the mice to still form new fear memories which confirmed the cells were involved only in storing fear memories and not forming them.

Aside from the biotechnology approach to studying memory, research in psychiatry on how memories work has also been going on for several years. There have been some studies that show that some behavioral therapy can erase bad memories. There has been some evidence that psychodynamic therapy and other energy techniques can help with forgetting memories among other psychiatric issues there is no proven therapeutic approach for trying to erase bad memories.

Potential patients

There are several different types of possible patients that have the potential to draw great benefit from the selective memory erasure; these include people with drug addiction, or posttraumatic stress disorder (PTSD). PTSD patients may include war veterans, people who witnessed horrific events, victims of violent crimes and many other possibly traumatic events. These potential patients have unwanted memories that can be absolutely devastating to their daily lives and cause them to not be able to function properly.

Research continues, and in 2020, researchers were looking at potential new approaches to PTSD treatment.

Different types of memories

There are three main types of memories: sensory memory, short-term memory, and long-term memory. Sensory memory, in short, is the ability to hold sensory information for a short period of time, for example, looking at an object and being able to remember what it looked like moments after. Short-term memory is memory that allows a person to recall a short period of time; this can be a few seconds to a minute. Short-term memory allows people to remember what happened during that short time span without actually practicing the memory. Long-term memory has a much larger capacity than the prior two and actually stores information from both these types of memories to create a long lasting and large memory. Long-term memory is the largest target for research involving selective memory erasure.

Within long-term memory there are several types of retention. Implicit memory (or 'muscle memory') is generally described as the ability to remember how to use objects or specific movements of the body (e.g. using a hammer). Explicit memory, (or 'declarative memory') is that which can be consciously drawn upon by a person to remember.

Explicit memory can be split into further subcategories; episodic memory, which is the memory of specific events and the information surrounding it, and semantic memory, which is the ability to remember factual information (e.g. what numbers mean).

A type of memory of main concern for memory erasure are emotional memories. These memories often involve several different aspects of information in them that can come from a variety of the different categories of memories mentioned above. These emotional memories are powerful memories that can illicit strong physiological effects on a person. An example of an emotional memory can be found in patients with PTSD, for these patients a traumatic event has left a lasting emotional memory that can have powerful effects on a person even without them consciously retrieving the memory.

Current research

Drug-induced amnesia

Drug-induced amnesia is the idea of selectively losing or inhibiting the creation of memories using drugs. Amnesia can be used as a treatment for patients who have experienced psychological trauma or for medical procedures where full anesthesia is not an option. Drug-induced amnesia is also a side-effect of other drugs like alcohol and rohypnol.

There are other drugs that also can cause their users to be put in an amnesic state, where they experience some type of amnesia because of their use. Examples of these drugs include Triazolam, Midazolam and Diazepam.

Disruption of molecular mechanisms

There is a growing amount of information that has shown that memory depends largely on the brain's synaptic plasticity, with a large part of this being dependent on its ability to maintain long-term potentiation (LTP). Studies on LTP have also started to indicate that there are several molecular mechanisms that may be at the basis of memory storage. A more recent approach to erasing memories and the associations the brain makes with objects is disrupting specific molecular mechanisms in the brain that are actively keeping memories active.

Recovering methamphetamine (METH) addicts have reported that the sight of certain objects such as a lighter, gum or drug paraphernalia can cause massive cravings that can sometimes lead to a break in their mental strength and cause them to relapse. This indicates that long-term memories can be called upon by various different associations that were made with the memory without the conscious effort of the person. With an increasing belief that memories are largely supported by functional and structural plasticity deriving from F-actin polymerization in postsynaptic dendritic spines at excitatory synapses. Recent research has been done to target this F-actin polymerization by using direct actin depolymerization or a myosin II inhibitor to disrupt the polymerized F-actin associated with METH memory associations. The study indicated types of associations can be disrupted days to weeks after consolidation. Although the depolymerization techniques had no effect on food reward based associations or shock based associations the results demonstrate the idea that meth associated memories' actin cytoskeleton is constantly changing making it uniquely sensitive to depolymerization during the maintenance phase. This is some of the first evidence showing that memories made with different associations are actively maintained using different molecular substrates. These results also show that the actin cytoskeleton may be a promising target for selective disruption of unwanted long-term memories.

Selective memory suppression

Selective memory suppression is the idea that someone can consciously block an unwanted memory. Several different therapeutic techniques or training have been attempted to test this idea with varied success. Many of these techniques focus on blocking the retrieval of a memory using suppression techniques to slowly teach the brain to suppress the memory. Although some of these techniques have been useful for some people it has not been shown to be a clear cut solution to forgetting memories. Because these memories are not truly erased but merely suppressed the question of how permanent the solution is and what actually happens to the memories can be troubling for some.

Selective memory suppression is also something that can occur without a person being consciously aware of suppressing the creation and retrieval of unwanted memories. When this occurs without the person knowing it is usually referred to as memory inhibition; the memory itself is called a repressed memory.

Interruption of memory reconsolidation

One of the ways scientists have attempted to erase these memories through suppression is by interrupting the reconsolidation of a memory. Memory consolidation of a memory is when a person recalls a memory, usually a fearful one, it becomes susceptible to alteration, and then gets stored again. This has led many researchers to believe that this time period is the best time for memories to be altered or erased. Studies have shown that through behavioral training results showed that they were able to erase memories by tampering with memories during the reconsolidation phase.

Destruction of neurons

With evidence showing that different memories excite different neurons or system of neurons in the brain^[23] the technique of destroying select neurons in the brain to erase specific memories is also being researched. Studies have started to investigate the possibility of using distinct toxins along with biotechnology that allows the researchers to see which areas of the brain are being used during the reward learning process of making a memory to destroy target neurons. In a paper published in 2009, authors showed that neurons in the lateral amygdala that had a higher level of cyclic adenosine monophosphate response element-binding protein (CREB) were activated primarily over other neurons by fear memory expression. This indicated to them that these neurons were directly involved in the making of the memory trace for that fear memory. They then proceeded to train mice using auditory fear training to produce a fear memory. They proceeded to check which of the neurons were overexpressing CREB and then, using an inducible diphtheria-toxin strategy, they destroyed those neurons, resulting in persistent and strong memory erasure of the fear memory.

Researchers have also found that the levels of the neurotransmitter, acetylcholine, can also effect which memories are most prominent in our minds.

Due to the lack of understanding of the brain this technique of destroying neurons may have a much larger effect on the patient than just the removal of the intended memories. Due to this complex nature of the brain treatment that would stun the neurons instead of destroying them could be another approach that could be taken.

Optogenetics

A way of selectively erasing memories may be possible through optogenetics, a type of gene therapy that targets specific neurons. In 2017, researchers at Stanford demonstrated a technique for observing hundreds of neurons firing in the brain of a live mouse, in real time, and have linked that activity to long-term information storage. By using a virus to trigger production of a light-sensitive protein in neurons linked to a fear, they could erase the memory by weakening the pathways using light.

Measurement issues

Further information: Mass action principle (neuroscience) and Memory consolidation § Multiple trace theory

There is an epistemological issue in determining whether the absence of evidence (i.e., memory trace) is evidence of absence. In experimental studies, the absence of behavior indicative of memory is sometimes interpreted as the absence of the memory trace; however, the memory impairment may be temporary due to deficits in recall. Alternatively, the memory trace be latent and demonstrable via its indirect effects on new learning^. The measurement issue is compounded by the fact that memory processes are dynamic and may not always manifest in single locations or in static and easily identifiable changes detectable by current technologies.

Michael Davis, researcher at Emory University, argues that complete erasure can only be confidently concluded if all of the biological events that occurred when the memory was formed revert to their original status. The current state of technology and methodology may not be sensitive enough to detect all types of memory traces. Davis contends that because making these measurements in a complex organism is implausible, the concept of complete memory erasure (what he deems "strong form of forgetting") is not useful scientifically.

Ethics

As with most new technologies the idea of being able to erase memories comes with many ethical questions. One ethical question that arises is the idea that although there are some extremely painful memories that some people (for example PTSD patients) would like to be rid of, not all unpleasant memories are bad. The ability to soften or erase memories could have drastic effects on how society functions. The ability to remember unpleasant effects from one's past has a huge impact on the future actions they may take. Remembering and learning from past mistakes is crucial in the emotional development of a person and helps to ensure they do not repeat previous errors. The ability to erase memory could also have a massive impact on the law. When it comes to determining the outcome of a trial, the ability to modify memory could have a massive impact on the judicial system. Another ethical question that arises is to how the government will use this technology and what restrictions would need to be put in place. Some worry that if soldiers can go into battle knowing that the memories created during that time period can simply be erased they may not uphold military morale and standards. Many are also skeptical with who should be able to have procedures done on them, so they are urging for a set of laws to determine this.

In fiction

Memory erasure has also been a common topic of interest in science fiction and other fiction. Several notable comics, TV shows and movies feature mindwipes, including Telefon, Total Recall, Men in Black, Eternal Sunshine of the Spotless Mind, Black Mirror, The Bourne Identity, NBC's Heroes and Dollhouse. Novels that feature memory erasure include The Invincible by Stanisław Lem, some of the Harry Potter novels (including Harry Potter and the Chamber of Secrets) by J. K. Rowling, and The Giver by Lois Lowry. Several works by Philip K. Dick are about mindwipes, including "Paycheck", "We Can Remember It for You Wholesale" (which served as the inspiration for Total Recall).

Robotic pet

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Robotic_pet

Robotic pets are artificially intelligent machines that are made to resemble actual pets. While the first robotic pets produced in the late 1990s, were not too advanced, they have since grown technologically. Many now use machine learning (algorithms that allow machines to adapt to experiences independent of humans), making them much more realistic. Most consumers buy robotic pets with the aim of getting similar companionship that real pets offer, without some of the drawbacks that come with caring for live animals. The pets on the market currently have a wide price range, from the low hundreds into the several thousands of dollars. Multiple studies have been done to show that we treat robotic pets in a similar way as actual pets, despite their obvious differences. However, there is some controversy regarding how ethical using robotic pets is, and whether or not they should be widely adopted in elderly care.

History

The first known robotic pet was a robot dog called Sparko, built by the American company Westinghouse in 1940. It never got sold due to poor public interest.

The first robotic pets to be put on the market were Hasbro's Furby in 1998 and Sony's AIBO in 1999. Since then, robotic pets have grown increasingly advanced.

The shapes of the robotic pet includes:

• familiar animals
• nonfamiliar animals
• imaginary animals or characters

Some popular robotic pets today are:

• Joy for All (by Hasbro) Companion Pets
• Zoomer Interactive Animals (Usually Kittens and Puppies)
• PARO Robot Seals by Intelligent Systems Co.
• AIBO (upgraded) by Sony
• FurReal Friends by Hasbro
• Little Live Pets by Moose Toys
• EMO Pet by Living AI
• Hatchimals
• Pets Alive by the Hong Kong-based company ZURU
• Present Pets by Spin Master

Common Uses

The primary consumer group is elderly people that live alone or in nursing homes, who often suffer from loneliness and social isolation. For this group, robotic pets can be helpful because they often are unable to consistently walk, feed, or otherwise take care of an actual pet. Robotic pets are also marketed towards dementia patients, who are people that suffer from loss of memory and thinking skills. These people often suffer extreme loneliness due to not remembering their loved ones, but having physical contact and constant reminders of a robotic pet can lessen that feeling. For example, a study done in Texas and Kansas found that dementia residents who had group sessions with a PARO (brand of robotic pet) for three months showed decreased anxiety and less behavioral problems, when compared to a control group that experienced activities in a traditional nursing home, such as music and physical activity.

Robotic Pets can be helpful when it comes to patients unable to perform consistent physical action because AIBO performs slower than a live animal. In addition, patients unable to contact their loved ones due to infectious diseases can be eased the loneliness feeling when interacting with AIBO. The new AIBO ERS-1000 AIBO model can be used in household use or therapy. Furthermore, a Qualitative study associated with National Centre for Child Health and Development (NCCHD) has shown the bright future of robot-assisted therapy during special medical care. The experiment was conducted with children who were hospitalised in NCCHD; two physicians observed the participants throughout the experiment and rendered a qualitative analysis to evaluate the possibility of applying robotic Pet in medical. The result of the experiments in National Centre for Child Health and Development (NCCHD) was given out a dominant positive result when the children interact with AIBO (ERS-1000); the research has proved that robot-assisted therapy effectively in medical purposed, especially in this case is a paediatric ward.

Affordability

When robotic pets were first introduced into the market, they were not very financially feasible for most people. Even now, there remains a large price gap between different types of robotic pets. For example, PAROs robotic pet seals cost $6,120, making them unaffordable to most individual consumers. They are therefore bought more by nursing homes, hospitals, or other institutions. On the other end of the price spectrum are Joy For All's Companion Pets. These only cost about $120, which makes it more realistic for individual consumers, such as elderly adults who live alone.

Currently, there is very little insurance coverage available for robotic pet owners. Medicare only covers the costs of certain robotic pets (PARO) for use by therapists, not by any individuals. However, Medicaid and some private insurers are exploring the idea of including robotic pets in their healthcare. If this were to happen, it would significantly boost the sales of the pets.

In 2018, Sony relaunched their discontinued AIBO with a friendly puppy appearance; the new model was released with various significant upgrades compared to the ERS-7 model. The price for a 2018 AIBO (ERS-1000) falls around US$3.000; the price has gone up due to a new design with state of the art sensors integrated into the ERS-1000 model.

Effectiveness

Since the effectiveness of a robotic pet depends heavily on how much consumers see it as a real animal, multiple studies have been done comparing robotic pets to other things, such as live animals and inanimate objects (toys). The studies often focus on whether the robot / animal / toy is seen to have the following characteristics:

Characteristic	Definition	Example Question
Biological / Physical Essence	Whether or not something is alive	Can it eat?
Mental State	Whether or not something can have feelings	Can it be happy?
Sociability	Whether or not something is capable of being a companion	Can you be friends with it?
Moral Standing	Whether or not something is responsible for their actions	Can you justify physically punishing it if it does something wrong?

Robotic Pet vs Stuffed Animal

One study in 2004 compared how children interacted with Sony's AIBO versus with a stuffed dog. The researchers did this by letting the children play with either the stuffed toy or the AIBO for three minutes, and then asking the children a series of questions to determine how they viewed each one. The study found that, when the children were asked questions about the characteristics of either AIBO or the stuffed animal, they responded in similar ways. This held true when they were asked questions concerning biological essence, mental states, sociability, and moral standing. However, there were differences in how the children behaved with AIBO versus the stuffed animal. For example, in the questionnaire the children responded that both the AIBO and the stuffed dog could hear verbal commands. But when the researchers observed how the children interacted with the AIBO or stuffed dog, they found that more children gave verbal commands to the AIBO.

Robotic Pet vs Live Animal

Another study in 2005 compared children's interactions with the AIBO and with a live dog. The researchers did this by letting the children play freely with either the AIBO or the real dog for five minutes, and then asking the children a series of questions to determine how they viewed each one. The study found that more children preferred to play with the live dog over the AIBO, and more children affirmed that the live dog had a physical essence, a mental state, sociability, and moral standing. However, the researchers found that the AIBO was given some dog-like attributes, even if not treated entirely like the dog. For example, many of the children thought the AIBO could have feelings, such as happiness or sadness. Some also thought that the AIBO could be their friend, and that it wasn't okay to kick the AIBO if it did something bad.

Both these studies concluded that robotic pets such as AIBO often aren't categorized as either alive or inanimate, but rather in a new category in between the other two. For example, children in the first study treated the AIBO differently than they treated the stuffed toy, even though they stated that the two were very similar. In contrast, the children in the second study stated that the live dog was different from the AIBO, but ended up treating the two similarly. These findings show that we consciously identify robotic pets as inanimate objects, but we behave as if they are closer to real pets than they are to toys.

Animal Assisted Therapy vs Robot-Assisted Therapy

A study in the United States was conducted on animal-assisted therapy (AAT); the study was carried out to evaluate the effectiveness of the therapy pet method. Participants interact with animals as a pet owner plays with their Pet; the experiment's outcomes were reported with many physical and mental improvements for the participants. However, the concern of transmitted diseases from animals posed a reconsideration from institutions when they consider animal-assisted therapy. In addition, A qualified therapy animal requires a well-trained session and a licensed caregiver, which randomly escalate the operating fees to the service. Opposite to animal-assisted therapy, robot-assisted therapy overcomes the draws back of animal-assisted therapy, and there are studies conducted to justify the possibility of robotic Pet in the medical field. In the study, AIBO is the selected subject for the research. AIBO was used to companion Elderly and hospitalised children. The robot-assisted method has already been applied to many cases, namely aged care, workplace, vulnerable social groups. Robot-assisted therapy comes at a lower cost than animal-assisted therapy. The robot does not need to feed or a licensed professional trainer; ultimately, the robotic Pet hygienic standard is higher than live animals. AIBO-assisted therapy has given positive results, such as stimulating social-emotional function for vulnerable social groups and mental health well-being with elders in the aged-care facility.

The conclusion from the above studies, animal-assisted therapy (AAT) or robot-assisted therapy (RAT) has shown positive results from patients. Robot-assisted therapy can replace animal-assisted therapy in the particular unavoidable situation as social activity support for infectious illness patients, restricted movement patients, elderly whose vulnerable to animal transmitted diseases. In contrast, the animal-assisted therapy study's result shows the positive level of participants higher than robot-assisted therapy; this method was still limited by the cultural beliefs about the cleanliness of the animals; notably, the budget for this method is more pricey than the alternative therapy. Ultimately, with the advancement in robotic technology, robot-assisted therapy gradually can replace live animal therapy because of the safeness of the vulnerable target patient. also, the robot-assisted therapy had proved delightful positive results when it was conducted in a large scale study.

Controversy

While robotic pets have proven to be beneficial to many consumers, especially those who are elderly, there remains some controversy about certain ethical issues. One study from 2016 attempted to discuss two main ethical considerations: elderly consumers may not be able to recognize that the robots aren't actual pets, and that the robot pets will come to replace human interaction. Those who participated in the study came to the conclusion that for most consumers, neither issue is major concern. They found that most robotic pet owners understood that the robot pet was animated, even if they formed a pet-like relationship with it. Additionally, the study participants argued that the robotic pets would more likely be used in a way that facilitated more social interactions in a group setting, such as at a dog park. However, these issues continue to cause debate because there is a minority of consumers, including many dementia patients, who may fail to recognize that the robot is animated.

A robotic pet can mimic animal gestures, and the pet robot's design can look close to a natural pet. In this situation, AIBO ERS-1000 inherited an appearance close to a puppy, and the behaviour can be developed based on the owner interactions. The new AIBO was integrated with cloud memory. The data will be sent online to process and keep AIBO updated; with this function, AIBO behaviours can develop from a new puppy to a mature dog. A financial statistical about own a robot dog to compare with a domestic pet has visualised a financial picture that owns a robotic pet will save the owner from many unexpected issues as veterinary cost when a domestic pet need medical care, food and vaccination, adopt fee, training fee.

Captivity (animal)

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Captivity_(animal)

Monkey in a Cage

Animal captivity is the confinement of domestic and wild animals. More specifically, animals that are held by humans and prevented from escaping are said to be in captivity. The term animal captivity is usually applied to wild animals that are held in confinement, but this term may also be used generally to describe the keeping of domesticated animals such as livestock or pets. This may include, for example, animals in farms, private homes, zoos, and laboratories. Animal captivity may be categorized according to the particular motives, objectives, and conditions of the confinement.

History

Animal husbandry

All throughout history, domestic animals like pets and livestock were kept in captivity and tended by humans. However, pets and livestock were not the only animals to be put in captivity and receive human care because wild animals had this as well. Despite the fact that wild animals have been harbored by humans for thousands of years, this captivity has not always come close to present zoos. Some were failed domestication attempts. Furthermore, the wealthy, predominantly the aristocrats and kings, collected wild animals for various reasons. The affluent built the first zoos as personal collections to demonstrate their dominance and wealth. These private collections of animals were known as menageries. Contrary to domestication, the ferociousness and natural behaviour of the wild animals were preserved and exhibited. Today, zoos claim to have other reasons for keeping animals under human care: conservation, education and science.

Behavior of animals in captivity

Captive animals, especially those not domesticated, sometimes can develop abnormal behaviours.

One type of abnormal behaviour is stereotypical behaviors, i.e. repetitive and apparently purposeless motor behaviors. Examples of stereotypical behaviours include pacing, self-injury, route tracing and excessive self-grooming. These behaviors are associated with stress and lack of stimulation. Animals that exhibit this tend to suffer from zoochosis, as it is manifested in stereotypical behaviors.

Many who keep animals in captivity attempt to prevent or decrease stereotypical behavior by introducing stimuli, a process known as environmental enrichment. The goals of environmental enrichment are to make environments more complex and fluid, offer more engaging and complex processes, and give animals more chances to make decisions. Techniques that are commonly used to provide environmental enrichment include social, occupation, physical, sensory, and nutritional.

Another type of abnormal behavior shown in captive animals is self-injurious behavior (SIB). Self-injurious behavior indicates any activity that involves biting, scratching, hitting, hair plucking, or eye poke that may result in injuring oneself. Although its reported incidence is low, self-injurious behavior is observed across a range of primate species, especially when they experience social isolation in infancy. Self-bite involves biting one's own body—typically the arms, legs, shoulders, or genitals. Threat bite involves biting one's own body—typically the hand, wrist, or forearm—while staring at the observer, conspecific, or mirror in a threatening manner. Self-hit involves striking oneself on any part of the body. Eye poking is a behavior (widely observed in primates) that presses the knuckle or finger into the orbital space above the eye socket. Hair plucking is a jerking motion applied to one's own hair with hands or teeth, thus resulting in its excessive removal.

The proximal causes of self-injurious behavior have been widely studied in captive primates; either social or nonsocial factors can trigger this type of behavior. Social factors include changes in group composition, stress, separation from the group, approaches by or aggression from members of other groups, conspecific male individuals nearby, separation from females, and removal from the group. Social isolation, particularly disruptions of early mother-rearing experiences, is an important risk factor. Studies have suggested that, although mother-reared rhesus macaques still exhibit some self-injurious behaviors, nursery-reared rhesus macaques are much more likely to self-abuse than mother-reared ones.

Nonsocial factors include the presence of a small cut, a wound or irritant, cold weather, human contact, and frequent zoo visitors. For example, a study has shown that zoo visitors density positively correlates with the number of gorillas banging on the barrier, and that low zoo visitors density caused gorillas to behave in a more relaxed way. Captive animals often cannot escape the attention and disruption caused by the general public, and the stress resulting from this lack of environmental control may lead to an increased rate of self-injurious behaviors.

There are studies that suggest the many abnormal captive behaviors, including self-injurious behavior, can be successfully treated by pair housing. Pair housing provides a previously single-housed animal with a same-sex social partner. This method is especially effective with primates, which are widely known to be social animals. Social companionship provided by pair housing encourages social interaction, thus reducing abnormal and anxiety-related behavior in captive animals as well as increasing their locomotion.

Why animals are placed in captivity

Wild animals may be placed in captivity for conservation, studies, exotic pet trade, and farming. Places of captivity that are connected with the AZA, (Association of Zoos and Aquariums), may hold animals’ captive as a means to save them from extinction. For example, the AZA SAFE, (Save Animals From Extinction), promotes well-being and care of animals, conservation, and additional disciplines in order to protect and aid the wildlife. The organization focuses on creating recovery plans, cooperation between AZA workers, and advancement of conservation. Furthermore, the AZA and the zoos and aquariums accredited with the AZA use the help of educators, veterinarians, and people doing research. With their assistance, zoos and aquariums are able to have the proper necessities needed in recovery programs to prevent animals from going extinct.

Kiger wild horse auction.

Annually, it is subjected that thousands of wild animals end up in captivity due to the wild animal trade. These animals can be held in captivity because of the overabundance of their population in roadside zoos. Additional reasons as to why animals may end up in captivity is because animals are captured from their original habitat, come from animal breeders, or come from the black market. When wild animals are captured and held in captivity, then they may be sold in pet stores, auction sales, or the World Wide Web.

Zoos' impact on animal captivity

Photo of a lion at a captive breeding center.

Zoos are known as a place where visitors come in to see wild animals. This means zoos may keep animals in confinement. For example, zoos may keep animals captive as a means to save them from going extinct. More specifically, in 2020 the Science Advances published a study where they concluded that the work and population of human beings has affected the growth of animals going extinct around the world. The uproar of animals going extinct has caused zoos to use their captive breeding programs on endangered animals in an effort to create a stronger population. It is said that zoos are responsible for reducing the number of animals on the endangered species list and from extinction.

Zoos could also be known as a place where animals are put into after they are taken out of their natural habitat. When animals are pulled out from their native habitat and taken to a location they are unfamiliar with, then it is said that animals may experience shock and poor mental health. Furthermore, some wild animals have died inside zoos due to the shock of being placed in an unknown setting. To be more specific, this can also mean that taking animals away from their native habitat can possibly disrupt their way of living.

Before Present

From Wikipedia, the free encyclopedia

https://en.wikipedia.org/wiki/Before_Present

Before Present (BP) years, also known as "time before present" or "years before present (YBP)", is a time scale used mainly in archaeology, geology, and other scientific disciplines to specify when events occurred relative to the origin of practical radiocarbon dating in the 1950s. Because the "present" time changes, standard practice is to use 1 January 1950 as the commencement date (epoch) of the age scale. The abbreviation "BP" has been interpreted retrospectively as "Before Physics", which refers to the time before nuclear weapons testing artificially altered the proportion of the carbon isotopes in the atmosphere, which scientists must now account for.

In a convention that is not always observed, many sources restrict the use of BP dates to those produced with radiocarbon dating; the alternative notation RCYBP stands for the explicit "radio carbon years before present".

Usage

The BP scale is sometimes used for dates established by means other than radiocarbon dating, such as stratigraphy. This usage differs from the recommendation by van der Plicht & Hogg, followed by the Quaternary Science Review, both of which requested that publications should use the unit "a" (for "annum", Latin for "year") and reserve the term "BP" for radiocarbon estimations.

Some archaeologists use the lowercase letters bp, bc and ad as terminology for uncalibrated dates for these eras.

The Centre for Ice and Climate at the University of Copenhagen instead uses the unambiguous "b2k", for "years before 2000 AD", not necessarily, however, often in combination with the Greenland Ice Core Chronology 2005 (GICC05) time scale.

Some authors who use the YBP dating format also use YAP (years after present) to denote years after 1950.

SI prefixes

SI prefix multipliers may be used to express larger periods of time, e.g. ka BP (thousand years BP), Ma BP (million years BP) and many others.

Radiocarbon dating

Radiocarbon dating was first used in 1949. Beginning in 1954, metrologists established 1950 as the origin year for the BP scale for use with radiocarbon dating, using a 1950-based reference sample of oxalic acid. According to scientist A. Currie Lloyd:

The problem was tackled by the international radiocarbon community in the late 1950s, in cooperation with the U.S. National Bureau of Standards. A large quantity of contemporary oxalic acid dihydrate was prepared as NBS Standard Reference Material (SRM) 4990B. Its ¹⁴C concentration was about 5% above what was believed to be the natural level, so the standard for radiocarbon dating was defined as 0.95 times the ¹⁴C concentration of this material, adjusted to a ¹³C reference value of −19 per mil (PDB). This value is defined as "modern carbon" referenced to AD 1950. Radiocarbon measurements are compared to this modern carbon value, and expressed as "fraction of modern" (fM). "Radiocarbon ages" are calculated from fM using the exponential decay relation and the "Libby half-life" 5568 a. The ages are expressed in years before present (BP) where "present" is defined as AD 1950.

The year 1950 was chosen because it was the standard astronomical epoch at that time. It also marked the publication of the first radiocarbon dates in December 1949, and 1950 also antedates large-scale atmospheric testing of nuclear weapons, which altered the global ratio of carbon-14 to carbon-12.

Radiocarbon calibration

Main article: Radiocarbon dating § Calibration

Dates determined using radiocarbon dating come as two kinds: uncalibrated (also called Libby or raw) and calibrated (also called Cambridge) dates. Uncalibrated radiocarbon dates should be clearly noted as such by "uncalibrated years BP", because they are not identical to calendar dates. This has to do with the fact that the level of atmospheric radiocarbon (carbon-14 or ¹⁴C) has not been strictly constant during the span of time that can be radiocarbon-dated. Uncalibrated radiocarbon ages can be converted to calendar dates by calibration curves based on comparison of raw radiocarbon dates of samples independently dated by other methods, such as dendrochronology (dating based on tree growth-rings) and stratigraphy (dating based on sediment layers in mud or sedimentary rock). Such calibrated dates are expressed as cal BP, where "cal" indicates "calibrated years", or "calendar years", before 1950.

Many scholarly and scientific journals require that published calibrated results be accompanied by the name (standard codes are used) of the laboratory concerned, and other information such as confidence levels, because of differences between the methods used by different laboratories and changes in calibrating methods.

Conversion

Conversion from Gregorian calendar years to Before Present years is by starting with the 1950-01-01 epoch of the Gregorian calendar and increasing the BP year count with each year into the past from that Gregorian date.

For example, 1000 BP corresponds to 950 AD, 1949 BP corresponds to 1 AD, 1950 BP corresponds to 1 BC, 2000 BP corresponds to 51 BC.

Example milestone years in the BP time scale

Gregorian year	BP year	Event
9701 BC	11650 BP	End of the Pleistocene and beginning of the Holocene epoch
4714 BC	6663 BP	Epoch of the Julian day system: Julian day 0 starts at Greenwich noon on January 1, 4713 BC of the proleptic Julian calendar, which is November 24, 4714 BC in the proleptic Gregorian calendar
2251 BC	4200 BP	Beginning of the Meghalayan age, the current and latest of the three stages in the Holocene era.
45 BC	1994 BP	Introduction of the Julian calendar
1 BC	1950 BP	Year zero at ISO 8601
AD 1	1949 BP	Beginning of the Common Era and Anno Domini, from the estimate by Dionysius of the Incarnation of Jesus
1582	368 BP	Introduction of the Gregorian calendar
1950	–	Epoch of the Before Present dating scheme
2024	74 YAP	Current year

Pet

From Wikipedia, the free encyclopedia
https://en.wikipedia.org/wiki/Pet

A tabby cat and a mixed mastiff-type dog

A Netherland Dwarf rabbit on a swing

A young black cat resting at home

A pet, or companion animal, is an animal kept primarily for a person's company or entertainment rather than as a working animal, livestock, or a laboratory animal. Popular pets are often considered to have attractive/cute appearances, intelligence, and relatable personalities, but some pets may be taken in on an altruistic basis (such as a stray animal) and accepted by the owner regardless of these characteristics.

Two of the most popular pets are dogs and cats. Other animals commonly kept include rabbits; ferrets; pigs; rodents such as gerbils, hamsters, chinchillas, rats, mice, and guinea pigs; birds such as parrots, passerines, and fowls; reptiles such as turtles, lizards, snakes, and iguanas; aquatic pets such as fish, freshwater snails, and saltwater snails; amphibians such as frogs and salamanders; and arthropod pets such as tarantulas and hermit crabs. Smaller pets include rodents, while the equine and bovine group include the largest companion animals.

Pets provide their owners, or guardians, both physical and emotional benefits. Walking a dog can provide both the human and the dog with exercise, fresh air, and social interaction. Pets can give companionship to people who are living alone or elderly adults who do not have adequate social interaction with other people. There is a medically approved class of therapy animals that are brought to visit confined humans, such as children in hospitals or elders in nursing homes. Pet therapy utilizes trained animals and handlers to achieve specific physical, social, cognitive, or emotional goals with patients.

People most commonly get pets for companionship, to protect a home or property, or because of the perceived beauty or attractiveness of the animals. A 1994 Canadian study found that the most common reasons for not owning a pet were lack of ability to care for the pet when traveling (34.6%), lack of time (28.6%), and lack of suitable housing (28.3%), with dislike of pets being less common (19.6%). Some scholars, ethicists, and animal rights organizations have raised concerns over keeping pets because of the lack of autonomy and the objectification of non-human animals.

Pet popularity

In China, spending on domestic animals has grown from an estimated $3.12 billion in 2010 to $25 billion in 2018. The Chinese people own 51 million dogs and 41 million cats, with pet owners often preferring to source pet food internationally. There are a total of 755 million pets, increased from 389 million in 2013.

According to a survey promoted by Italian family associations in 2009, it is estimated that there are approximately 45 million pets in Italy. This includes 7 million dogs, 7.5 million cats, 16 million fish, 12 million birds, and 10 million snakes.

A 2007 survey by the University of Bristol found that 26% of UK households owned cats and 31% owned dogs, estimating total domestic populations of approximately 10.3 million cats and 10.5 million dogs in 2006. The survey also found that 47.2% of households with a cat had at least one person educated to degree level, compared with 38.4% of homes with dogs.

Sixty-eight percent of U.S. households, or about 85 million families, own a pet, according to the 2017-2018 National Pet Owners Survey conducted by the American Pet Products Association (APPA). This is up from 56 percent of U.S. households in 1988, the first year the survey was conducted. There are approximately 86.4 million pet cats and approximately 78.2 million pet dogs in the United States, and a United States 2007–2008 survey showed that dog-owning households outnumbered those owning cats, but that the total number of pet cats was higher than that of dogs. The same was true for 2011. In 2013, pets outnumbered children four to one in the United States.

Most popular pets in the U.S. (millions)

Pet	Global population	U.S. population	U.S. inhabited households	U.S. average per inhabited household
Cat	202	93.6	38.2	2.45
Dog	171	77.5	45.6	1.70
Fish	N/A	171.7	13.3	12.86
Small mammals	N/A	15.9	5.3	3.00
Birds	N/A	15.0	6.0	2.50
Reptiles & amphibians	N/A	13.6	4.7	2.89
Equine	N/A	13.3	3.9	3.41

Effects on pets' health

Keeping animals as pets may be detrimental to their health if certain requirements are not met. An important issue is inappropriate feeding, which may produce clinical effects. The consumption of chocolate or grapes by dogs, for example, may prove fatal. Certain species of houseplants can also prove toxic if consumed by pets. Examples include philodendrons and Easter lilies, which can cause severe kidney damage to cats, and poinsettias, begonia, and aloe vera, which are mildly toxic to dogs. For birds, chocolate can be deadly, and foods intended for human consumption, such as bread, crackers, and dairy items, can potentially cause health problems.

Housepets, particularly dogs and cats in industrialized societies, are highly susceptible to obesity. Overweight pets have been shown to be at a higher risk of developing diabetes, liver problems, joint pain, kidney failure, and cancer. Lack of exercise and high-caloric diets are considered to be the primary contributors to pet obesity.

Effects of pets on their caregivers' health

A couple with their pet dog

Woman jogging with a dog at Carcavelos beach, Portugal

Health benefits

It is widely believed among the public, and among many scientists, that pets probably bring mental and physical health benefits to their owners; a 1987 NIH statement cautiously argued that existing data was "suggestive" of a significant benefit. A recent dissent comes from a 2017 RAND study, which found that at least in the case of children, having a pet per se failed to improve physical or mental health by a statistically significant amount; instead, the study found children who were already prone to being healthy were more likely to get pets in the first place. Conducting long-term randomized trials to settle the issue would be costly or infeasible.

Observed correlations

Pets might have the ability to stimulate their caregivers, in particular the elderly, giving people someone to take care of, someone to exercise with, and someone to help them heal from a physically or psychologically troubled past. Animal company can also help people to preserve acceptable levels of happiness despite the presence of mood symptoms like anxiety or depression. Having a pet may also help people achieve health goals, such as lowered blood pressure, or mental goals, such as decreased stress. There is evidence that having a pet can help a person lead a longer, healthier life. In a 1986 study of 92 people hospitalized for coronary ailments, within a year, 11 of the 29 patients without pets had died, compared to only 3 of the 52 patients who had pets. Having pet(s) was shown to significantly reduce triglycerides, and thus heart disease risk, in the elderly. A study by the National Institute of Health found that people who owned dogs were less likely to die as a result of a heart attack than those who did not own one. There is some evidence that pets may have a therapeutic effect in dementia cases. Other studies have shown that for the elderly, good health may be a requirement for having a pet, and not a result. Dogs trained to be guide dogs can help people with vision impairment. Dogs trained in the field of Animal-Assisted Therapy (AAT) can also benefit people with other disabilities.

Pets in long-term care institutions

People residing in a long-term care facility, such as a hospice or nursing home, may experience health benefits from pets. Pets help them to cope with the emotional issues related to their illness. They also offer physical contact with another living creature, something that is often missing in an elder's life. Pets for nursing homes are chosen based on the size of the pet, the amount of care that the breed needs, and the population and size of the care institution. Appropriate pets go through a screening process and, if it is a dog, additional training programs to become a therapy dog. There are three types of therapy dogs: facility therapy dogs, animal-assisted therapy dogs, and therapeutic visitation dogs. The most common therapy dogs are therapeutic visitation dogs. These dogs are household pets whose handlers take time to visit hospitals, nursing homes, detention facilities, and rehabilitation facilities. Different pets require varying amounts of attention and care; for example, cats may have lower maintenance requirements than dogs.

Connection with community

In addition to providing health benefits for their owners, pets also impact the social lives of their owners and their connection to their community. There is some evidence that pets can facilitate social interaction. Assistant Professor of Sociology at the University of Colorado at Boulder, Leslie Irvine has focused her attention on pets of the homeless population. Her studies of pet ownership among the homeless found that many modify their life activities for fear of losing their pets. Pet ownership prompts them to act responsibly, with many making a deliberate choice not to drink or use drugs, and to avoid contact with substance abusers or those involved in any criminal activity for fear of being separated from their pet. Additionally, many refuse to house in shelters if their pet is not allowed to stay with them.

Health risks

Health risks that are associated with pets include:

• Aggravation of allergies and asthma caused by dander and fur or feathers
• Falling injuries. Tripping over pets, especially dogs causes more than 86,000 falls serious enough to prompt a trip to the emergency room each year in the United States. Among elderly and disabled people, these falls have resulted in life-threatening injuries and broken bones.
• Injury, mauling, and sometimes death caused by pet bites and attacks
• Disease or parasites due to animal hygiene problems, lack of appropriate treatment, and undisciplined behavior (feces and urine)
• Stress caused by the behavior of animals
• Anxiety over who will care for the animal should the owner no longer be able to do so

Legislation

Treaties

European Convention for the Protection of Pet Animals

	Signed and ratified		Acceded or succeeded
	Only signed		Not signed (CoE member states)
	Not signed (non-CoE member states)

The European Convention for the Protection of Pet Animals is a 1987 treaty of the Council of Europe – but accession to the treaty is open to all states in the world – to promote the welfare of pet animals and ensure minimum standards for their treatment and protection. It went into effect on 1 May 1992, and as of June 2020, it has been ratified by 24 states.

National and local laws

Ownership or guardianship

Pets have commonly been considered private property, owned by individual persons. Many legal protections have existed (historically and today) with the intention of safeguarding pets' and other animals' well-being. Since the year 2000, a small but increasing number of jurisdictions in North America have enacted laws redefining pet's owners as guardians. Intentions have been characterized as simply changing attitudes and perceptions but not legal consequences to working toward legal personhood for pets themselves. Some veterinarians and breeders have opposed these moves. The question of pets' legal status can arise with concern to purchase or adoption, custody, divorce, estate and inheritance, injury, damage, and veterinary malpractice.

Limitations on species

Further information: Exotic pet § Legality

States, cities, and towns in Western countries commonly enact local ordinances to limit the number or kind of pets a person may keep personally or for business purposes. Prohibited pets may be specific to certain breeds such as pit bulls or Rottweilers, they may apply to general categories of animals (such as livestock, exotic animals, wild animals, and canid or felid hybrids), or they may simply be based on the animal's size. Additional or different maintenance rules and regulations may also apply. Condominium associations and owners of rental properties also commonly limit or forbid tenants' keeping of pets.

In Belgium and the Netherlands, the government publishes white lists and black lists (called 'positive' and 'negative lists') with animal species that are designated to be appropriate to be kept as pets (positive) or not (negative). The Dutch Ministry of Economic Affairs and Climate Policy originally established its first positive list (positieflijst) per 1 February 2015 for a set of 100 mammals (including cats, dogs and production animals) deemed appropriate as pets on the recommendations of Wageningen University. Parliamentary debates about such a pet list date back to the 1980s, with continuous disagreements about which species should be included and how the law should be enforced. In January 2017, the white list was expanded to 123 species, while the black list that had been set up was expanded (with animals like the brown bear and two great kangaroo species) to contain 153 species unfit for petting, such as the armadillo, the sloth, the European hare, and the wild boar.

Killing and eating pets

See also: Cat meat and Dog meat

In January 2011, the Belgian Federal Agency for the Safety of the Food Chain stated that people are not allowed to kill random cats walking in their garden, but "nowhere in the law does it say that you can't eat your cat, dog, rabbit, fish or whatever. You just have to kill them in an animal-friendly way." Since 1 July 2014, it is illegal in the Netherlands for owners to kill their own cats and dogs kept as pets. Parakeets, guinea pigs, hamsters and other animals may still be killed by their owners, but nonetheless when owners mistreat their companion animals (for example, in the process of killing them), the owners can still be prosecuted under Dutch law.

Environmental impact

Pets have a considerable environmental impact, especially in countries where they are common or held in high densities. For instance, the 163 million dogs and cats kept in the United States consume about 20% of the amount of dietary energy that humans do and an estimated 33% of the animal-derived energy. They produce about 30% ± 13%, by mass, as much feces as Americans, and through their diet, constitute about 25–30% of the environmental impacts from animal production in terms of the use of land, water, fossil fuel, phosphate, and biocides. Dog and cat animal product consumption is responsible for the release of up to 64 ± 16 million tons CO₂-equivalent methane and nitrous oxide, two powerful greenhouse gasses. Americans are the largest pet owners in the world, but pet ownership in the US has considerable environmental costs.

Types

While many people have kept many different species of animals in captivity over the course of human history, only a relative few have been kept long enough to be considered domesticated. Other types of animal, notably monkeys, have never been domesticated but are still sold and kept as pets. Some wild animals are kept as pets, such as tigers, even though this is illegal. There is a market for illegal pets.

Domesticated

Domesticated pets are most common. A domesticated animal is a species that has been made fit for a human environment, by being consistently kept in captivity and selectively bred over a long enough period of time that it exhibits marked differences in behavior and appearance from its wild relatives. Domestication contrasts with taming, which is simply when an un-domesticated, wild animal has become tolerant of human presence, and perhaps even enjoys it.

Large mammals that might be kept as pets include: alpaca, camel, cattle, donkey, goat, horse, llama, pig, and sheep. Small mammals that might be kept as pets include: ferret, hedgehog, rabbit, sugar glider, and rodents, including rat, mouse, hamster, guinea pig, gerbil, and chinchilla. Other mammals include cat, dog, monkey, and domesticated silver fox.

Birds kept as pets include companion parrots like the budgie and cockatiel, fowl such as chickens, turkeys, ducks, geese, and quail, columbines, and passerines, namely finches and canaries.

Fish kept as pets include: goldfish, koi, Siamese fighting fish (Betta), barb, guppy, molly, Japanese rice fish (Medaka), and oscar.

Arthropods kept as pets include bees, such as honey bees and stingless bees, Silk moth, and ant farms.

Reptiles and amphibians kept as pets include snakes, turtles, axolotl, frogs and salamanders.

Wild animals

Male Tiger, Thailand

Main article: Exotic pet

Wild animals are kept as pets. The term wild in this context specifically applies to any species of animal which has not undergone a fundamental change in behavior to facilitate a close co-existence with humans. Some species may have been bred in captivity for a considerable length of time, but are still not recognized as domesticated.

Generally, wild animals are recognized as not suitable to keep as pets, and this practice is completely banned in many places. In other areas, certain species are allowed to be kept, and it is usually required for the owner to obtain a permit. It is considered animal cruelty by some, as most often, wild animals require precise and constant care that is very difficult to meet in captive conditions. Many large and instinctively aggressive animals are extremely dangerous, and numerous times have they killed their handlers.

History

Prehistory

Archaeology suggests that human ownership of dogs as pets may date back to at least 12,000 years ago.

Ancient history

Ancient Greeks and Romans would openly grieve for the loss of a dog, evidenced by inscriptions left on tombstones commemorating their loss. The surviving epitaphs dedicated to horses are more likely to reference a gratitude for the companionship that had come from war horses rather than race horses. The latter may have chiefly been commemorated as a way to further the owner's fame and glory. In Ancient Egypt, dogs and baboons were kept as pets and buried with their owners. Dogs were given names, which is significant as Egyptians considered names to have magical properties.

Victorian era: the rise of modern pet keeping

Throughout the 17th and 18th-century pet keeping in the modern sense gradually became accepted throughout Britain. Initially, aristocrats kept dogs for both companionship and hunting. Thus, pet keeping was a sign of elitism within society. By the 19th century, the rise of the middle class stimulated the development of pet keeping and it became inscribed within the bourgeois culture.

Economy

As the popularity of pet-keeping in the modern sense rose during the Victorian era, animals became a fixture within urban culture as commodities and decorative objects. Pet keeping generated a commercial opportunity for entrepreneurs. By the mid-19th century, nearly twenty thousand street vendors in London dealt with live animals. The popularity of animals also developed a demand for animal goods such as accessories and guides for pet keeping. Pet care developed into a big business by the end of the nineteenth century.

Profiteers also sought out pet stealing as a means for economic gain. Utilizing the affection that owners had for their pets, professional dog stealers would capture animals and hold them for ransom. The development of dog stealing reflects the increased value of pets. Pets gradually became defined as the property of their owners. Laws were created that punished offenders for their burglary.

Social

Pets and animals also had social and cultural implications throughout the nineteenth century. The categorization of dogs by their breeds reflected the hierarchical, social order of the Victorian era. The pedigree of a dog represented the high status and lineage of their owners and reinforced social stratification. Middle-class owners valued the ability to associate with the upper-class through ownership of their pets. The ability to care for a pet signified respectability and the capability to be self-sufficient. According to Harriet Ritvo, the identification of "elite animal and elite owner was not a confirmation of the owner's status but a way of redefining it."

Entertainment

The popularity of dog and pet keeping generated animal fancy. Dog fanciers showed enthusiasm for owning pets, breeding dogs, and showing dogs in various shows. The first dog show took place on 28 June 1859 in Newcastle and focused mostly on sporting and hunting dogs. However, pet owners produced an eagerness to demonstrate their pets as well as have an outlet to compete. Thus, pet animals gradually were included within dog shows. The first large show, which would host one thousand entries, took place in Chelsea in 1863. The Kennel Club was created in 1873 to ensure fairness and organization within dog shows. The development of the Stud Book by the Kennel Club defined policies, presented a national registry system of purebred dogs, and essentially institutionalized dog shows.

Pet ownership by non-humans

Pet ownership by animals in the wild, as an analogue to the human phenomenon, has not been observed and is likely non-existent in nature. One group of capuchin monkeys was observed appearing to care for a marmoset, a fellow New World monkey species, however observations of chimpanzees apparently "playing" with small animals like hyraxes have ended with the chimpanzees killing the animals and tossing the corpses around.

A 2010 study states that human relationships with animals have an exclusive human cognitive component and that pet-keeping is a fundamental and ancient attribute of the human species. Anthropomorphism, or the projection of human feelings, thoughts and attributes on to animals, is a defining feature of human pet-keeping. The study identifies it as the same trait in evolution responsible for domestication and concern for animal welfare. It is estimated to have arisen at least 100,000 years before present (ybp) in Homo sapiens.

It is debated whether this redirection of human nurturing behaviour towards non-human animals, in the form of pet-keeping, was maladaptive, due to being biologically costly, or whether it was positively selected for. Two studies suggest that the human ability to domesticate and keep pets came from the same fundamental evolutionary trait and that this trait provided a material benefit in the form of domestication that was sufficiently adaptive to be positively selected for. A 2011 study suggests that the practical functions that some pets provide, such as assisting hunting or removing pests, could have resulted in enough evolutionary advantage to allow for the persistence of this behaviour in humans and outweigh the economic burden held by pets kept as playthings for immediate emotional rewards. Two other studies suggest that the behaviour constitutes an error, side effect or misapplication of the evolved mechanisms responsible for human empathy and theory of mind to cover non-human animals which has not sufficiently impacted its evolutionary advantage in the long run.

Animals in captivity, with the help of caretakers, have been considered to have owned "pets". Examples of this include Koko the gorilla who had several pet cats, Tonda the orangutan and a pet cat and Tarra the elephant and a dog named Bella.