Selective breeding

From Wikipedia, the free encyclopedia

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

Mutation and selection

A Belgian Blue cow. The defect in the breed's myostatin gene is maintained through linebreeding and is responsible for its accelerated lean muscle growth.

This Chihuahua mix and Great Dane shows the wide range of dog breed sizes created using selective breeding.

Selective breeding transformed teosinte's few fruitcases (left) into modern maize's rows of exposed kernels (right).

Selective breeding (also called artificial selection) is the process by which humans use animal breeding and plant breeding to selectively develop particular phenotypic traits (characteristics) by choosing which typically animal or plant males and females will sexually reproduce and have offspring together. Domesticated animals are known as breeds, normally bred by a professional breeder, while domesticated plants are known as varieties, cultigens, cultivars, or breeds. Two purebred animals of different breeds produce a crossbreed, and crossbred plants are called hybrids. Flowers, vegetables and fruit-trees may be bred by amateurs and commercial or non-commercial professionals: major crops are usually the provenance of the professionals.

In animal breeding artificial selection is often combined with techniques such as inbreeding, linebreeding, and outcrossing. In plant breeding, similar methods are used. Charles Darwin discussed how selective breeding had been successful in producing change over time in his 1859 book, On the Origin of Species. Its first chapter discusses selective breeding and domestication of such animals as pigeons, cats, cattle, and dogs. Darwin used artificial selection as an analogy to propose and explain the theory of natural selection but distinguished the latter from the former as a separate process that is non-directed.

The deliberate exploitation of selective breeding to produce desired results has become very common in agriculture and experimental biology.

Selective breeding can be unintentional, for example, resulting from the process of human cultivation; and it may also produce unintended – desirable or undesirable – results. For example, in some grains, an increase in seed size may have resulted from certain ploughing practices rather than from the intentional selection of larger seeds. Most likely, there has been an interdependence between natural and artificial factors that have resulted in plant domestication.

History

Selective breeding of both plants and animals has been practiced since prehistory; key species such as wheat, rice, and dogs have been significantly different from their wild ancestors for millennia, and maize, which required especially large changes from teosinte, its wild form, was selectively bred in Mesoamerica. Selective breeding was practiced by the Romans. Treatises as much as 2,000 years old give advice on selecting animals for different purposes, and these ancient works cite still older authorities, such as Mago the Carthaginian. The notion of selective breeding was later expressed by the polymath Abu Rayhan Biruni in the 11th century. He noted the idea in his book titled India, which included various examples.

The agriculturist selects his corn, letting grow as much as he requires, and tearing out the remainder. The forester leaves those branches which he perceives to be excellent, whilst he cuts away all others. The bees kill those of their kind who only eat, but do not work in their beehive.

— Abu Rayhan Biruni, India

Selective breeding was established as a scientific practice by Robert Bakewell during the British Agricultural Revolution in the 18th century. Arguably, his most important breeding program was with sheep. Using native stock, he was able to quickly select for large, yet fine-boned sheep, with long, lustrous wool. The Lincoln Longwool was improved by Bakewell, and in turn the Lincoln was used to develop the subsequent breed, named the New (or Dishley) Leicester. It was hornless and had a square, meaty body with straight top lines.

These sheep were exported widely, including to Australia and North America, and have contributed to numerous modern breeds, despite the fact that they fell quickly out of favor as market preferences in meat and textiles changed. Bloodlines of these original New Leicesters survive today as the English Leicester (or Leicester Longwool), which is primarily kept for wool production.

Bakewell was also the first to breed cattle to be used primarily for beef. Previously, cattle were first and foremost kept for pulling ploughs as oxen, but he crossed long-horned heifers and a Westmoreland bull to eventually create the Dishley Longhorn. As more and more farmers followed his lead, farm animals increased dramatically in size and quality. In 1700, the average weight of a bull sold for slaughter was 370 pounds (168 kg). By 1786, that weight had more than doubled to 840 pounds (381 kg). However, after his death, the Dishley Longhorn was replaced with short-horn versions.

He also bred the Improved Black Cart horse, which later became the Shire horse.

Charles Darwin coined the term 'selective breeding'; he was interested in the process as an illustration of his proposed wider process of natural selection. Darwin noted that many domesticated animals and plants had special properties that were developed by intentional animal and plant breeding from individuals that showed desirable characteristics, and discouraging the breeding of individuals with less desirable characteristics.

Darwin used the term "artificial selection" twice in the 1859 first edition of his work On the Origin of Species, in Chapter IV: Natural Selection, and in Chapter VI: Difficulties on Theory:

Slow though the process of selection may be, if feeble man can do much by his powers of artificial selection, I can see no limit to the amount of change, to the beauty and infinite complexity of the co-adaptations between all organic beings, one with another and with their physical conditions of life, which may be effected in the long course of time by nature's power of selection.

— Charles Darwin, On the Origin of Species

We are profoundly ignorant of the causes producing slight and unimportant variations; and we are immediately made conscious of this by reflecting on the differences in the breeds of our domesticated animals in different countries,—more especially in the less civilized countries where there has been but little artificial selection.

— Charles Darwin, On the Origin of Species

Animal breeding

Main article: Animal breeding

Animals with homogeneous appearance, behavior, and other characteristics are known as particular breeds or pure breeds, and they are bred through culling animals with particular traits and selecting for further breeding those with other traits. Purebred animals belong to a single, recognizable breed, and purebreds with recorded lineage are called pedigreed. Crossbreeds are a mix of two purebreds, whereas mixed breeds are a mix of several breeds, often unknown. Animal breeding begins with breeding stock, a group of animals used for the purpose of planned breeding. When individuals are looking to breed animals, they look for certain valuable traits in purebred stock for a certain purpose, or may intend to use some type of crossbreeding to produce a new type of stock with different and presumably superior abilities in a given area of endeavor. For example, to breed chickens, a breeder typically intends to receive eggs, meat, and new, young birds for further reproduction. Thus, the breeder has to study different breeds and types of chickens and analyze what can be expected from a certain set of characteristics before he or she starts breeding them. Therefore, when purchasing initial breeding stock, the breeder seeks a group of birds that will most closely fit the purpose intended.

Purebred breeding aims to establish and maintain stable traits, that animals will pass to the next generation. By "breeding the best to the best," employing a certain degree of inbreeding, considerable culling, and selection for "superior" qualities, one could develop a bloodline superior in certain respects to the original base stock. Such animals can be recorded with a breed registry, the organization that maintains pedigrees and/or stud books. However, single-trait breeding, breeding for only one trait over all others, can be problematic. In one case mentioned by the animal behaviorist Temple Grandin, roosters bred for fast growth or heavy muscles did not know how to perform typical rooster courtship dances, which alienated the roosters from hens and led the roosters to kill the hens after mating with them. A Soviet attempt to breed lab rats with higher intelligence led to cases of neurosis severe enough to make the animals incapable of any problem solving unless drugs like phenazepam were used.

The observable phenomenon of hybrid vigor stands in contrast to the notion of breed purity. However, on the other hand, indiscriminate breeding of crossbred or hybrid animals may also result in degradation of quality. Studies in evolutionary physiology, behavioral genetics, and other areas of organismal biology have also made use of deliberate selective breeding, though longer generation times and greater difficulty in breeding can make these projects challenging in such vertebrates as house mice.

Plant breeding

Main article: Plant breeding

Researchers at the USDA have selectively bred carrots with a variety of colors.

The process of plant breeding has been used for thousands of years, and began with the domestication of wild plants into uniform and predictable agricultural cultigens. These high-yielding varieties have been particularly important in agriculture. As crops improved, humans were able to move from hunter-gatherer style living to a mix of hunter-gatherer and agriculture practices. Although these higher yielding plants were derived from an extremely primitive version of plant breeding, this form of agriculture was an investment that the people who grew them were planting then could have a more varied diet. This meant that they did not completely stop their hunting and gathering immediately but instead over time transitioned and ultimately favored agriculture. Originally this was due to humans not wanting to risk using all their time and resources for their crops just to fail. Which was promptly called play farming due to the idea of "farmers" experimenting with agriculture. In addition, the ability for humans to stay within one place for food and create permanent settlements made the process move along faster.^[20] During this transitional period, crops began to acclimate and evolve with humans encouraging humans to invest further into crops. Over time this reliance on plant breeding has created problems, as highlighted by the book Botany of Desire where Michael Pollan shows the connection between basic human desires through four different plants: apples for sweetness, tulips for beauty, cannabis for intoxication, and potatoes for control. In a form of coevolution humans have influenced these plants as much as the plants have influenced the people that consume them

Selective plant breeding is also used in research to produce transgenic animals that breed "true" (i.e., are homozygous) for artificially inserted or deleted genes.

Selective breeding in aquaculture

Selective breeding in aquaculture holds high potential for the genetic improvement of fish and shellfish for the process of production. Unlike terrestrial livestock, the potential benefits of selective breeding in aquaculture were not realized until recently. This is because high mortality led to the selection of only a few broodstock, causing inbreeding depression, which then forced the use of wild broodstock. This was evident in selective breeding programs for growth rate, which resulted in slow growth and high mortality.

Control of the reproduction cycle was one of the main reasons as it is a requisite for selective breeding programs. Artificial reproduction was not achieved because of the difficulties in hatching or feeding some farmed species such as eel and yellowtail farming. A suspected reason associated with the late realization of success in selective breeding programs in aquaculture was the education of the concerned people – researchers, advisory personnel and fish farmers. The education of fish biologists paid less attention to quantitative genetics and breeding plans.

Another was the failure of documentation of the genetic gains in successive generations. This in turn led to failure in quantifying economic benefits that successful selective breeding programs produce. Documentation of the genetic changes was considered important as they help in fine tuning further selection schemes.

Quality traits in aquaculture

Aquaculture species are reared for particular traits such as growth rate, survival rate, meat quality, resistance to diseases, age at sexual maturation, fecundity, shell traits like shell size, shell color, etc.

• Growth rate – growth rate is normally measured as either body weight or body length. This trait is of great economic importance for all aquaculture species as faster growth rate speeds up the turnover of production. Improved growth rates show that farmed animals utilize their feed more efficiently through a positive correlated response.
• Survival rate – survival rate may take into account the degrees of resistance to diseases. This may also see the stress response as fish under stress are highly vulnerable to diseases. The stress fish experience could be of biological, chemical or environmental influence.
• Meat quality – the quality of fish is of great economic importance in the market. Fish quality usually takes into account size, meatiness, and percentage of fat, color of flesh, taste, shape of the body, ideal oil and omega-3 content.
• Age at sexual maturation – The age of maturity in aquaculture species is another very important attribute for farmers as during early maturation the species divert all their energy to gonad production affecting growth and meat production and are more susceptible to health problems (Gjerde 1986).
• Fecundity – As the fecundity in fish and shellfish is usually high it is not considered as a major trait for improvement. However, selective breeding practices may consider the size of the egg and correlate it with survival and early growth rate.

Finfish response to selection

Salmonids

Gjedrem (1979) showed that selection of Atlantic salmon (Salmo salar) led to an increase in body weight by 30% per generation. A comparative study on the performance of select Atlantic salmon with wild fish was conducted by AKVAFORSK Genetics Centre in Norway. The traits, for which the selection was done included growth rate, feed consumption, protein retention, energy retention, and feed conversion efficiency. Selected fish had a twice better growth rate, a 40% higher feed intake, and an increased protein and energy retention. This led to an overall 20% better Fed Conversion Efficiency as compared to the wild stock. Atlantic salmon have also been selected for resistance to bacterial and viral diseases. Selection was done to check resistance to Infectious Pancreatic Necrosis Virus (IPNV). The results showed 66.6% mortality for low-resistant species whereas the high-resistant species showed 29.3% mortality compared to wild species.

Rainbow trout (S. gairdneri) was reported to show large improvements in growth rate after 7–10 generations of selection. Kincaid et al. (1977) showed that growth gains by 30% could be achieved by selectively breeding rainbow trout for three generations. A 7% increase in growth was recorded per generation for rainbow trout by Kause et al. (2005).

In Japan, high resistance to IPNV in rainbow trout has been achieved by selectively breeding the stock. Resistant strains were found to have an average mortality of 4.3% whereas 96.1% mortality was observed in a highly sensitive strain.

Coho salmon (Oncorhynchus kisutch) increase in weight was found to be more than 60% after four generations of selective breeding. In Chile, Neira et al. (2006) conducted experiments on early spawning dates in coho salmon. After selectively breeding the fish for four generations, spawning dates were 13–15 days earlier.

Cyprinids

Selective breeding programs for the Common carp (Cyprinus carpio) include improvement in growth, shape and resistance to disease. Experiments carried out in the USSR used crossings of broodstocks to increase genetic diversity and then selected the species for traits like growth rate, exterior traits and viability, and/or adaptation to environmental conditions like variations in temperature. Kirpichnikov et al. (1974) and Babouchkine (1987) selected carp for fast growth and tolerance to cold, the Ropsha carp. The results showed a 30–40% to 77.4% improvement of cold tolerance but did not provide any data for growth rate. An increase in growth rate was observed in the second generation in Vietnam. Moav and Wohlfarth (1976) showed positive results when selecting for slower growth for three generations compared to selecting for faster growth. Schaperclaus (1962) showed resistance to the dropsy disease wherein selected lines suffered low mortality (11.5%) compared to unselected (57%).

Channel Catfish

Growth was seen to increase by 12–20% in selectively bred Iictalurus punctatus. More recently, the response of the Channel Catfish to selection for improved growth rate was found to be approximately 80%, that is, an average of 13% per generation.

Shellfish response to selection

Oysters

Selection for live weight of Pacific oysters showed improvements ranging from 0.4% to 25.6% compared to the wild stock. Sydney-rock oysters (Saccostrea commercialis) showed a 4% increase after one generation and a 15% increase after two generations. Chilean oysters (Ostrea chilensis), selected for improvement in live weight and shell length showed a 10–13% gain in one generation. Bonamia ostrea is a protistan parasite that causes catastrophic losses (nearly 98%) in European flat oyster Ostrea edulis L. This protistan parasite is endemic to three oyster-regions in Europe. Selective breeding programs show that O. edulis susceptibility to the infection differs across oyster strains in Europe. A study carried out by Culloty et al. showed that 'Rossmore' oysters in Cork harbour, Ireland had better resistance compared to other Irish strains. A selective breeding program at Cork harbour uses broodstock from 3– to 4-year-old survivors and is further controlled until a viable percentage reaches market size.

Over the years 'Rossmore' oysters have shown to develop lower prevalence of B. ostreae infection and percentage mortality. Ragone Calvo et al. (2003) selectively bred the eastern oyster, Crassostrea virginica, for resistance against co-occurring parasites Haplosporidium nelson (MSX) and Perkinsus marinus (Dermo). They achieved dual resistance to the disease in four generations of selective breeding. The oysters showed higher growth and survival rates and low susceptibility to the infections. At the end of the experiment, artificially selected C. virginica showed a 34–48% higher survival rate.

Penaeid shrimps

Selection for growth in Penaeid shrimps yielded successful results. A selective breeding program for Litopenaeus stylirostris saw an 18% increase in growth after the fourth generation and 21% growth after the fifth generation. Marsupenaeus japonicas showed a 10.7% increase in growth after the first generation. Argue et al. (2002) conducted a selective breeding program on the Pacific White Shrimp, Litopenaeus vannamei at The Oceanic Institute, Waimanalo, USA from 1995 to 1998. They reported significant responses to selection compared to the unselected control shrimps. After one generation, a 21% increase was observed in growth and 18.4% increase in survival to TSV. The Taura Syndrome Virus (TSV) causes mortalities of 70% or more in shrimps. C.I. Oceanos S.A. in Colombia selected the survivors of the disease from infected ponds and used them as parents for the next generation. They achieved satisfying results in two or three generations wherein survival rates approached levels before the outbreak of the disease. The resulting heavy losses (up to 90%) caused by Infectious hypodermal and haematopoietic necrosis virus (IHHNV) caused a number of shrimp farming industries started to selectively breed shrimps resistant to this disease. Successful outcomes led to development of Super Shrimp, a selected line of L. stylirostris that is resistant to IHHNV infection. Tang et al. (2000) confirmed this by showing no mortalities in IHHNV- challenged Super Shrimp post larvae and juveniles.

Aquatic species versus terrestrial livestock

Selective breeding programs for aquatic species provide better outcomes compared to terrestrial livestock. This higher response to selection of aquatic farmed species can be attributed to the following:

• High fecundity in both sexes fish and shellfish enabling higher selection intensity.
• Large phenotypic and genetic variation in the selected traits.

Selective breeding in aquaculture provide remarkable economic benefits to the industry, the primary one being that it reduces production costs due to faster turnover rates. When selective breeding is carried out, some characteristics are lost for others that may suit a specific environment or situation. This is because of faster growth rates, decreased maintenance rates, increased energy and protein retention, and better feed efficiency. Applying genetic improvement programs to aquaculture species will increase their productivity. Thus allowing them to meet the increasing demands of growing populations. Conversely, selective breeding within aquaculture can create problems within the biodiversity of both stock and wild fish, which can hurt the industry down the road. Although there is great potential to improve aquaculture due to the current lack of domestication, it is essential that the genetic diversity of the fish are preserved through proper genetic management, as we domesticate these species. It is not uncommon for fish to escape the nets or pens that they are kept in, especially in mass. If these fish are farmed in areas they are not native to they may be able to establish themselves and outcompete native populations of fish, and cause ecological harm as an invasive species. Furthermore, if they are in areas where the fish being farmed are native too their genetics are selectively bred rather than being wild. These farmed fish could breed with the natives which could be problematic In the sense that they would have been bred for consumption rather than by chance. Resulting in an overall decrease in genetic diversity and rendering local fish populations less fit for survival. If proper management is not taking place then the economic benefits and the diversity of the fish species will falter.

Advantages and disadvantages

Selective breeding is a direct way to determine if a specific trait can evolve in response to selection. A single-generation method of breeding is not as accurate or direct. The process is also more practical and easier to understand than sibling analysis. Selective breeding is better for traits such as physiology and behavior that are hard to measure because it requires fewer individuals to test than single-generation testing.

However, there are disadvantages to this process. This is because a single experiment done in selective breeding cannot be used to assess an entire group of genetic variances, individual experiments must be done for every individual trait. Also, due to the necessity of selective breeding experiments to require maintaining the organisms tested in a lab or greenhouse, it is impractical to use this breeding method on many organisms. Controlled mating instances are difficult to carry out in this case and this is a necessary component of selective breeding.

Additionally, selective breeding can lead to a variety of issues including reduction of genetic diversity or physical problems. The process of selective breeding can create physical issues for plants or animals such as dogs selectively bred for extremely small sizes dislocating their kneecaps at a much more frequent rate then other dogs. An example in the plant world is the Lenape potatoes were selectively bred for their disease or pest resistance which was attributed to their high levels of toxic glycoalkaloid solanine which are usually present only in small amounts in potatoes fit for human consumption. When genetic diversity is lost it can also allow for populations to lack genetic alternatives to adapt to events. This becomes an issue of biodiversity, because attributes are so wide-spread they can result in mass epidemics. As seen in the Southern Corn leaf-blight epidemic of 1970 that wiped out 15% of the United States corn crop due to the wide use of a type of Texan corn strain that was artificially selected due to having sterile pollen to make farming easier. At the same time it was more vulnerable to Southern Corn leaf-blight.

Earth system science

From Wikipedia, the free encyclopedia

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

An ecological analysis of CO
₂ in an ecosystem. As systems biology, systems ecology seeks a holistic view of the interactions and transactions within and between biological and ecological systems.

Earth system science (ESS) is the application of systems science to the Earth. In particular, it considers interactions and 'feedbacks', through material and energy fluxes, between the Earth's sub-systems' cycles, processes and "spheres"—atmosphere, hydrosphere, cryosphere, geosphere, pedosphere, lithosphere, biosphere, and even the magnetosphere—as well as the impact of human societies on these components. At its broadest scale, Earth system science brings together researchers across both the natural and social sciences, from fields including ecology, economics, geography, geology, glaciology, meteorology, oceanography, climatology, paleontology, sociology, and space science. Like the broader subject of systems science, Earth system science assumes a holistic view of the dynamic interaction between the Earth's spheres and their many constituent subsystems fluxes and processes, the resulting spatial organization and time evolution of these systems, and their variability, stability and instability. Subsets of Earth System science include systems geology and systems ecology, and many aspects of Earth System science are fundamental to the subjects of physical geography and climate science.

Definition

The Science Education Resource Center, Carleton College, offers the following description: "Earth System science embraces chemistry, physics, biology, mathematics and applied sciences in transcending disciplinary boundaries to treat the Earth as an integrated system. It seeks a deeper understanding of the physical, chemical, biological and human interactions that determine the past, current and future states of the Earth. Earth System science provides a physical basis for understanding the world in which we live and upon which humankind seeks to achieve sustainability".

Earth System science has articulated four overarching, definitive and critically important features of the Earth System, which include:

1. Variability: Many of the Earth System's natural 'modes' and variabilities across space and time are beyond human experience, because of the stability of the recent Holocene. Much Earth System science therefore relies on studies of the Earth's past behaviour and models to anticipate future behaviour in response to pressures.
2. Life: Biological processes play a much stronger role in the functioning and responses of the Earth System than previously thought. It appears to be integral to every part of the Earth System.
3. Connectivity: Processes are connected in ways and across depths and lateral distances that were previously unknown and inconceivable.
4. Non-linear: The behaviour of the Earth System is typified by strong non-linearities. This means that abrupt change can result when relatively small changes in a 'forcing function' push the System across a 'threshold'.

History

For millennia, humans have speculated how the physical and living elements on the surface of the Earth combine, with gods and goddesses frequently posited to embody specific elements. The notion that the Earth, itself, is alive was a regular theme of Greek philosophy and religion.

Early scientific interpretations of the Earth system began in the field of geology, initially in the Middle East and China, and largely focused on aspects such as the age of the Earth and the large-scale processes involved in mountain and ocean formation. As geology developed as a science, understanding of the interplay of different facets of the Earth system increased, leading to the inclusion of factors such as the Earth's interior, planetary geology, living systems and Earth-like worlds.

In many respects, the foundational concepts of Earth System science can be seen in the natural philosophy 19th century geographer Alexander von Humboldt. In the 20th century, Vladimir Vernadsky (1863–1945) saw the functioning of the biosphere as a geological force generating a dynamic disequilibrium, which in turn promoted the diversity of life.

In parallel, the field of systems science was developing across numerous other scientific fields, driven in part by the increasing availability and power of computers, and leading to the development of climate models that began to allow the detailed and interacting simulations of the Earth's weather and climate. Subsequent extension of these models has led to the development of "Earth system models" (ESMs) that include facets such as the cryosphere and the biosphere.

In 1983 a NASA committee called the Earth System Science Committee was formed. The earliest reports of NASA's ESSC, Earth System Science: Overview (1986), and the book-length Earth System Science: A Closer View (1988), constitute a major landmark in the formal development of Earth system science. Early works discussing Earth system science, like these NASA reports, generally emphasized the increasing human impacts on the Earth system as a primary driver for the need of greater integration among the life and geo-sciences, making the origins of Earth system science parallel to the beginnings of global change studies and programs.

Climate science

Climatology and climate change have been central to Earth System science since its inception, as evidenced by the prominent place given to climate change in the early NASA reports discussed above. The Earth's climate system is a prime example of an emergent property of the whole planetary system, that is, one which cannot be fully understood without regarding it as a single integrated entity. It is also a system where human impacts have been growing rapidly in recent decades, lending immense importance to the successful development and advancement of Earth System science research. As just one example of the centrality of climatology to the field, the mission statement of one of the earliest centers for Earth System science research, the Earth System Science Center at Pennsylvania State University, reads, "the Earth System Science Center (ESSC) maintains a mission to describe, model, and understand the Earth's climate system".

The five components of the climate system all interact. They are the atmosphere, the hydrosphere, the cryosphere, the lithosphere and the biosphere.

Earth's climate system is a complex system with five interacting components: the atmosphere (air), the hydrosphere (water), the cryosphere (ice and permafrost), the lithosphere (earth's upper rocky layer) and the biosphere (living things). Climate is the statistical characterization of the climate system. It represents the average weather, typically over a period of 30 years, and is determined by a combination of processes, such as ocean currents and wind patterns. Circulation in the atmosphere and oceans transports heat from the tropical regions to regions that receive less energy from the Sun. Solar radiation is the main driving force for this circulation. The water cycle also moves energy throughout the climate system. In addition, certain chemical elements are constantly moving between the components of the climate system. Two examples for these biochemical cycles are the carbon and nitrogen cycles.

The climate system can change due to internal variability and external forcings. These external forcings can be natural, such as variations in solar intensity and volcanic eruptions, or caused by humans. Accumulation of greenhouse gases in the atmosphere, mainly being emitted by people burning fossil fuels, is causing climate change. Human activity also releases cooling aerosols, but their net effect is far less than that of greenhouse gases. Changes can be amplified by feedback processes in the different climate system components.

Education

Earth System science can be studied at a postgraduate level at some universities. In general education, the American Geophysical Union, in cooperation with the Keck Geology Consortium and with support from five divisions within the National Science Foundation, convened a workshop in 1996, "to define common educational goals among all disciplines in the Earth sciences". In its report, participants noted that, "The fields that make up the Earth and space sciences are currently undergoing a major advancement that promotes understanding the Earth as a number of interrelated systems". Recognizing the rise of this systems approach, the workshop report recommended that an Earth System science curriculum be developed with support from the National Science Foundation.

In 2000, the Earth System Science Education Alliance (ESSEA) was begun, and currently includes the participation of 40+ institutions, with over 3,000 teachers having completed an ESSEA course as of fall 2009".

Related concepts

The concept of earth system law (still in its infancy as per 2021) is a sub-discipline of earth system governance, itself a subfield of earth system sciences analyzed from a social sciences perspective.

Science of morality

From Wikipedia, the free encyclopedia

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

Science of morality (also known as scientific morality or science of ethics or scientific ethics) may refer to various forms of ethical naturalism grounding morality and ethics in rational, empirical or scientific consideration of the natural world. It is sometimes framed as using the scientific approach to determine what is right and wrong, in contrast to the widespread belief that "science has nothing to say on the subject of human values".

Overview

Moral science may refer to the consideration of what is best for, and how to maximize the flourishing of, either particular individuals or all conscious creatures. It has been proposed that "morality" can be appropriately defined on the basis of fundamental premises necessary for any empirical, secular, or philosophical discussion and that societies can use the methods of science to provide answers to moral questions.

The norms advocated by moral scientists (e.g. rights to abortion, euthanasia, and drug liberalization under certain circumstances) would be founded upon the shifting and growing collection of human understanding. Even with science's admitted degree of ignorance, and the various semantic issues, moral scientists can meaningfully discuss things as being almost certainly "better" or "worse" for promoting flourishing.

History

In philosophy

Utilitarian Jeremy Bentham discussed some of the ways moral investigations are a science. He criticized deontological ethics for failing to recognize that it needed to make the same presumptions as his science of morality to really work – whilst pursuing rules that were to be obeyed in every situation (something that worried Bentham).

W. V. O. Quine advocated naturalizing epistemology by looking to natural sciences like psychology for a full explanation of knowledge. His work contributed to a resurgence of moral naturalism in the last half of the 20th century. Paul Kurtz, who believes that the careful, secular pursuit of normative rules is vital to society, coined the term eupraxophy to refer to his approach to normative ethics. Steven Pinker, Sam Harris, and Peter Singer believe that we learn what is right and wrong through reason and empirical methodology.

Maria Ossowska used the methods of science to understand the origins of moral norms.

Maria Ossowska thought that sociology was inextricably related to philosophical reflections on morality, including normative ethics. She proposed that science analyse: (a) existing social norms and their history, (b) the psychology of morality, and the way that individuals interact with moral matters and prescriptions, and (c) the sociology of morality.

In popular literature

The theory and methods of a normative science of morality are explicitly discussed in Joseph Daleiden's The Science of Morality: The Individual, Community, and Future Generations (1998). Daleiden's book, in contrast to Harris, extensively discusses the relevant philosophical literature. In The Moral Landscape: How Science Can Determine Human Values, Sam Harris's goal is to show how moral truth can be backed by "science", or more specifically, empirical knowledge, critical thinking, philosophy, but most controversially, the scientific method.

Patricia Churchland offers that, accepting David Hume's is–ought problem, the use of induction from premises and definitions remains a valid way of reasoning in life and science:

Our moral behavior, while more complex than the social behavior of other animals, is similar in that it represents our attempt to manage well in the existing social ecology. ... from the perspective of neuroscience and brain evolution, the routine rejection of scientific approaches to moral behavior based on Hume's warning against deriving ought from is seems unfortunate, especially as the warning is limited to deductive inferences. ... The truth seems to be that values rooted in the circuitry for caring—for well-being of self, offspring, mates, kin, and others—shape social reasoning about many issues: conflict resolutions, keeping the peace, defense, trade, resource distribution, and many other aspects of social life in all its vast richness.

Daleiden and Leonard Carmichael warn that science is probabilistic, and that certainty is not possible. One should therefore expect that moral prescriptions will change as humans gain understanding.

In futurism

Transhumanist philosophers such as David Pearce and Mark Alan Walker have extensively discussed the ethical implications of future technologies. Walker coined the term "biohappiness" to describe the idea of directly manipulating the biological roots of happiness in order to increase it. Pearce argues that suffering could eventually be eradicated entirely, stating that: "It is predicted that the world's last unpleasant experience will be a precisely dateable event." Proposed technological methods of overcoming the hedonic treadmill include wireheading (direct brain stimulation for uniform bliss), which undermines motivation and evolutionary fitness; designer drugs, offering sustainable well-being without side effects, though impractical for lifelong reliance; and genetic engineering, the most promising approach. Genetic recalibration through hyperthymia-promoting genes could raise hedonic set-points, fostering adaptive well-being, creativity, and productivity while maintaining responsiveness to stimuli. While scientifically achievable, this transformation requires careful ethical and societal considerations to navigate its profound implications.

On the opposite end of the spectrum, risks of astronomical suffering are possible futures in which vastly more suffering will exist than has ever been produced on earth so far in all of earth's history. Possible sources of these risks include artificial superintelligence, genetic engineering for maximum suffering, space colonization, and terraforming leading to an increase in wild animal suffering.

Views in scientific morality

See also: Moral psychology

Training to promote good behaviour

See also: Character education and Values education

The science of morality may aim to discover the best ways to motivate and shape individuals. Methods to accomplish this include instilling explicit virtues, building character strengths, and forming mental associations. These generally require some level of practical reason. James Rest suggested that abstract reasoning is also a factor in making moral judgements and emphasized that moral judgements alone do not predict moral behaviour: “Moral judgement may be closely related to advocacy behaviour, which in turn influences social institutions, which in turn creates a system of norms and sanctions that influences people’s behaviour.” Daleiden suggested that religions instill a practical sense of virtue and justice, right and wrong. They also effectively use art and myths to educate people about moral situations.

Role of government

Harris argues that moral science does not imply an "Orwellian future" with "scientists at every door". Instead, Harris imagines data about normative moral issues being shared in the same way as other sciences (e.g. peer-reviewed journals on medicine).

Daleiden specifies that government, like any organization, should have limited power. He says "centralization of power irrevocably in the hands of one person or an elite has always ultimately led to great evil for the human race. It was the novel experiment of democracy—a clear break with tradition—that ended the long tradition of tyranny.” He is also explicit that government should only use law to enforce the most basic, reasonable, proven and widely supported moral norms. In other words, there are a great many moral norms that should never be the task of the government to enforce.

Role of punishment

Main articles: Differential reinforcement and Prison

One author has argued that to attain a society where people are motivated by conditioned self-interest, punishment must go hand-in-hand with reward. For instance, in this line of reasoning, prison remains necessary for many perpetrators of crimes. This is so, even if libertarian free will is false. This is because punishment can still serve its purposes: it deters others from committing their own crimes, educates and reminds everyone about what the society stands for, incapacitates the criminal from doing more harm, goes some way to relieving or repaying the victim, and corrects the criminal (also see recidivism). This author argues that, at least, any prison system should be pursuing those goals, and that it is an empirical question as to what sorts of punishment realize these goals most effectively, and how well various prison systems actually serve these purposes.

Research

See also: Positive psychology and Moral development

The brain areas that are consistently involved when humans reason about moral issues have been investigated. The neural network underlying moral decisions overlaps with the network pertaining to representing others' intentions (i.e., theory of mind) and the network pertaining to representing others' (vicariously experienced) emotional states (i.e., empathy). This supports the notion that moral reasoning is related to both seeing things from other persons’ points of view and to grasping others’ feelings. These results provide evidence that the neural network underlying moral decisions is probably domain-global (i.e., there might be no such things as a "moral module" in the human brain) and might be dissociable into cognitive and affective sub-systems.

An essential, shared component of moral judgment involves the capacity to detect morally salient content within a given social context. Recent research implicated the salience network in this initial detection of moral content. The salience network responds to behaviourally salient events and may be critical to modulate downstream default and frontal control network interactions in the service of complex moral reasoning and decision-making processes. This suggest that moral cognition involves both bottom-up and top-down attentional processes, mediated by discrete large-scale brain networks and their interactions.

In universities

Moral sciences is offered at the degree level at Ghent University (as "an integrated empirical and philosophical study of values, norms and world views").

Other implications

Daleiden provides examples of how science can use empirical evidence to assess the effect that specific behaviours can have on the well-being of individuals and society with regard to various moral issues. He argues that science supports decriminalization and regulation of drugs, euthanasia under some circumstances, and the permission of sexual behaviours that are not tolerated in some cultures (he cites homosexuality as an example). Daleiden further argues that in seeking to reduce human suffering, abortion should not only be permissible, but at times a moral obligation (as in the case of a mother of a potential child who would face the probability of much suffering). Like all moral claims in his book, however, Daleiden is adamant that these decisions remain grounded in, and contingent on empirical evidence.

The ideas of cultural relativity, to Daleiden, do offer some lessons: investigators must be careful not to judge a person's behaviour without understanding the environmental context. An action may be necessary and more moral once we are aware of circumstances. However, Daleiden emphasizes that this does not mean all ethical norms or systems are equally effective at promoting flourishing and he often offers the equal treatment of women as a reliably superior norm, wherever it is practiced.

Criticisms

The idea of a normative science of morality has met with many criticisms from scientists and philosophers. Critics include physicist Sean M. Carroll, who argues that morality cannot be part of science. He and other critics cite the widely held "fact-value distinction", that the scientific method cannot answer "moral" questions, although it can describe the norms of different cultures. In contrast, moral scientists defend the position that such a division between values and scientific facts ("moral relativism") is not only arbitrary and illusory, but impeding progress towards taking action against documented cases of human rights violations in different cultures.

Stephen Jay Gould argued that science and religion occupy "non-overlapping magisteria". To Gould, science is concerned with questions of fact and theory, but not with meaning and morality – the magisteria of religion. In the same vein, Edward Teller proposed that politics decides what is right, whereas science decides what is true.

During a discussion on the role that naturalism might play in professions like nursing, the philosopher Trevor Hussey calls the popular view that science is unconcerned with morality "too simplistic". Although his main focus in the paper is naturalism in nursing, he goes on to explain that science can, at very least, be interested in morality at a descriptive level. He even briefly entertains the idea that morality could itself be a scientific subject, writing that one might argue "... that moral judgements are subject to the same kinds of rational, empirical examination as the rest of the world: they are a subject for science – although a difficult one. If this could be shown to be so, morality would be contained within naturalism. However, I will not assume the truth of moral realism here."

For moral sciences as the study of human life and activity, see Human science. For the (comparative) study of moral systems, thought and behavior across individuals, stages, cultures or species, see Moral psychology and Evolution of morality.

Science of morality (also known as scientific morality or science of ethics or scientific ethics) may refer to various forms of ethical naturalism grounding morality and ethics in rational, empirical or scientific consideration of the natural world. It is sometimes framed as using the scientific approach to determine what is right and wrong, in contrast to the widespread belief that "science has nothing to say on the subject of human values".

Overview

Moral science may refer to the consideration of what is best for, and how to maximize the flourishing of, either particular individuals or all conscious creatures. It has been proposed that "morality" can be appropriately defined on the basis of fundamental premises necessary for any empirical, secular, or philosophical discussion and that societies can use the methods of science to provide answers to moral questions.^[

The norms advocated by moral scientists (e.g. rights to abortion, euthanasia, and drug liberalization under certain circumstances) would be founded upon the shifting and growing collection of human understanding. Even with science's admitted degree of ignorance, and the various semantic issues, moral scientists can meaningfully discuss things as being almost certainly "better" or "worse" for promoting flourishing.

History

In philosophy

Utilitarian Jeremy Bentham discussed some of the ways moral investigations are a science. He criticized deontological ethics for failing to recognize that it needed to make the same presumptions as his science of morality to really work – whilst pursuing rules that were to be obeyed in every situation (something that worried Bentham).

W. V. O. Quine advocated naturalizing epistemology by looking to natural sciences like psychology for a full explanation of knowledge. His work contributed to a resurgence of moral naturalism in the last half of the 20th century. Paul Kurtz, who believes that the careful, secular pursuit of normative rules is vital to society, coined the term eupraxophy to refer to his approach to normative ethics. Steven Pinker, Sam Harris, and Peter Singer believe that we learn what is right and wrong through reason and empirical methodology.

Maria Ossowska used the methods of science to understand the origins of moral norms.

Maria Ossowska thought that sociology was inextricably related to philosophical reflections on morality, including normative ethics. She proposed that science analyse: (a) existing social norms and their history, (b) the psychology of morality, and the way that individuals interact with moral matters and prescriptions, and (c) the sociology of morality.

In popular literature

The theory and methods of a normative science of morality are explicitly discussed in Joseph Daleiden's The Science of Morality: The Individual, Community, and Future Generations (1998). Daleiden's book, in contrast to Harris, extensively discusses the relevant philosophical literature. In The Moral Landscape: How Science Can Determine Human Values, Sam Harris's goal is to show how moral truth can be backed by "science", or more specifically, empirical knowledge, critical thinking, philosophy, but most controversially, the scientific method.

Patricia Churchland offers that, accepting David Hume's is–ought problem, the use of induction from premises and definitions remains a valid way of reasoning in life and science:

Our moral behavior, while more complex than the social behavior of other animals, is similar in that it represents our attempt to manage well in the existing social ecology. ... from the perspective of neuroscience and brain evolution, the routine rejection of scientific approaches to moral behavior based on Hume's warning against deriving ought from is seems unfortunate, especially as the warning is limited to deductive inferences. ... The truth seems to be that values rooted in the circuitry for caring—for well-being of self, offspring, mates, kin, and others—shape social reasoning about many issues: conflict resolutions, keeping the peace, defense, trade, resource distribution, and many other aspects of social life in all its vast richness.

Daleiden and Leonard Carmichael warn that science is probabilistic, and that certainty is not possible. One should therefore expect that moral prescriptions will change as humans gain understanding.

In futurism

Transhumanist philosophers such as David Pearce and Mark Alan Walker have extensively discussed the ethical implications of future technologies. Walker coined the term "biohappiness" to describe the idea of directly manipulating the biological roots of happiness in order to increase it. Pearce argues that suffering could eventually be eradicated entirely, stating that: "It is predicted that the world's last unpleasant experience will be a precisely dateable event." Proposed technological methods of overcoming the hedonic treadmill include wireheading (direct brain stimulation for uniform bliss), which undermines motivation and evolutionary fitness; designer drugs, offering sustainable well-being without side effects, though impractical for lifelong reliance; and genetic engineering, the most promising approach. Genetic recalibration through hyperthymia-promoting genes could raise hedonic set-points, fostering adaptive well-being, creativity, and productivity while maintaining responsiveness to stimuli. While scientifically achievable, this transformation requires careful ethical and societal considerations to navigate its profound implications.

On the opposite end of the spectrum, risks of astronomical suffering are possible futures in which vastly more suffering will exist than has ever been produced on earth so far in all of earth's history. Possible sources of these risks include artificial superintelligence, genetic engineering for maximum suffering, space colonization, and terraforming leading to an increase in wild animal suffering.

Views in scientific morality

See also: Moral psychology

Training to promote good behaviour

See also: Character education and Values education

The science of morality may aim to discover the best ways to motivate and shape individuals. Methods to accomplish this include instilling explicit virtues, building character strengths, and forming mental associations. These generally require some level of practical reason. James Rest suggested that abstract reasoning is also a factor in making moral judgements and emphasized that moral judgements alone do not predict moral behaviour: “Moral judgement may be closely related to advocacy behaviour, which in turn influences social institutions, which in turn creates a system of norms and sanctions that influences people’s behaviour.” Daleiden suggested that religions instill a practical sense of virtue and justice, right and wrong. They also effectively use art and myths to educate people about moral situations.

Role of government

Harris argues that moral science does not imply an "Orwellian future" with "scientists at every door". Instead, Harris imagines data about normative moral issues being shared in the same way as other sciences (e.g. peer-reviewed journals on medicine).

Daleiden specifies that government, like any organization, should have limited power. He says "centralization of power irrevocably in the hands of one person or an elite has always ultimately led to great evil for the human race. It was the novel experiment of democracy—a clear break with tradition—that ended the long tradition of tyranny.” He is also explicit that government should only use law to enforce the most basic, reasonable, proven and widely supported moral norms. In other words, there are a great many moral norms that should never be the task of the government to enforce.

Role of punishment

Main articles: Differential reinforcement and Prison

One author has argued that to attain a society where people are motivated by conditioned self-interest, punishment must go hand-in-hand with reward. For instance, in this line of reasoning, prison remains necessary for many perpetrators of crimes. This is so, even if libertarian free will is false. This is because punishment can still serve its purposes: it deters others from committing their own crimes, educates and reminds everyone about what the society stands for, incapacitates the criminal from doing more harm, goes some way to relieving or repaying the victim, and corrects the criminal (also see recidivism). This author argues that, at least, any prison system should be pursuing those goals, and that it is an empirical question as to what sorts of punishment realize these goals most effectively, and how well various prison systems actually serve these purposes.

Research

See also: Positive psychology and Moral development

The brain areas that are consistently involved when humans reason about moral issues have been investigated. The neural network underlying moral decisions overlaps with the network pertaining to representing others' intentions (i.e., theory of mind) and the network pertaining to representing others' (vicariously experienced) emotional states (i.e., empathy). This supports the notion that moral reasoning is related to both seeing things from other persons’ points of view and to grasping others’ feelings. These results provide evidence that the neural network underlying moral decisions is probably domain-global (i.e., there might be no such things as a "moral module" in the human brain) and might be dissociable into cognitive and affective sub-systems.

An essential, shared component of moral judgment involves the capacity to detect morally salient content within a given social context. Recent research implicated the salience network in this initial detection of moral content. The salience network responds to behaviourally salient events, and may be critical to modulate downstream default and frontal control network interactions in the service of complex moral reasoning and decision-making processes. This suggest that moral cognition involves both bottom-up and top-down attentional processes, mediated by discrete large-scale brain networks and their interactions.

In universities

Moral sciences is offered at the degree level at Ghent University (as "an integrated empirical and philosophical study of values, norms and world views").

Other implications

Daleiden provides examples of how science can use empirical evidence to assess the effect that specific behaviours can have on the well-being of individuals and society with regard to various moral issues. He argues that science supports decriminalization and regulation of drugs, euthanasia under some circumstances, and the permission of sexual behaviours that are not tolerated in some cultures (he cites homosexuality as an example). Daleiden further argues that in seeking to reduce human suffering, abortion should not only be permissible, but at times a moral obligation (as in the case of a mother of a potential child who would face the probability of much suffering). Like all moral claims in his book, however, Daleiden is adamant that these decisions remain grounded in, and contingent on empirical evidence.

The ideas of cultural relativity, to Daleiden, do offer some lessons: investigators must be careful not to judge a person's behaviour without understanding the environmental context. An action may be necessary and more moral once we are aware of circumstances. However, Daleiden emphasizes that this does not mean all ethical norms or systems are equally effective at promoting flourishing and he often offers the equal treatment of women as a reliably superior norm, wherever it is practiced.

Criticisms

The idea of a normative science of morality has met with many criticisms from scientists and philosophers. Critics include physicist Sean M. Carroll, who argues that morality cannot be part of science. He and other critics cite the widely held "fact-value distinction", that the scientific method cannot answer "moral" questions, although it can describe the norms of different cultures. In contrast, moral scientists defend the position that such a division between values and scientific facts ("moral relativism") is not only arbitrary and illusory, but impeding progress towards taking action against documented cases of human rights violations in different cultures.

Stephen Jay Gould argued that science and religion occupy "non-overlapping magisteria". To Gould, science is concerned with questions of fact and theory, but not with meaning and morality – the magisteria of religion. In the same vein, Edward Teller proposed that politics decides what is right, whereas science decides what is true.

During a discussion on the role that naturalism might play in professions like nursing, the philosopher Trevor Hussey calls the popular view that science is unconcerned with morality "too simplistic". Although his main focus in the paper is naturalism in nursing, he goes on to explain that science can, at very least, be interested in morality at a descriptive level. He even briefly entertains the idea that morality could itself be a scientific subject, writing that one might argue "... that moral judgements are subject to the same kinds of rational, empirical examination as the rest of the world: they are a subject for science – although a difficult one. If this could be shown to be so, morality would be contained within naturalism. However, I will not assume the truth of moral realism here."