The study of genetics—the inheritance of traits in living organisms—is a basic concept in biology. The same processes that provide the mechanism for organisms to pass genetic information to their offspring lead to the gradual change of species over time, which in turn produces biodiversity (the variety of life and the genetic differences among living organisms) and the evolution of n…
The term "evolution" has multiple meanings; it is most generally used to describe the theory that all organisms are linked via descent to a common ancestor. Evolution also refers to the gradual process during which change occurs. In biology it is the theory that groups of organisms, such as species, change or develop over long periods of time so that their descendants differ from the…
Although genetics clearly controls many of an organism's traits, it is simplistic and incorrect to assume that organisms, including humans, are completely defined by their genes. While there are some phenotypes (observable traits) that are exclusively controlled by either genetics or environment, most are influenced by a complex interaction of the two. Modern genetic study defines environme…
It has long been known that heredity affects health. Genetics, the study of single genes and their effects on the body and mind, explains how and why certain traits such as hair color and blood types run in families. Genomics, a discipline that is only about two decades old, is the study of more than single genes; it considers the functions and interactions of all the genes in the genome. In terms…
Over the course of the last decade, the definitions of health and disease have been transformed by advances in genetics. Genetic testing has enabled researchers and clinicians to detect inherited traits, diagnose heritable conditions, determine and quantify the likelihood that a heritable disease will develop, and identify genetic susceptibility to familial disorders. Many of the strides made in g…
In 1953 James Watson and Francis Crick described the double helical structure of deoxyribonucleic acid (DNA). Their molecular DNA structure was published in Nature on April 25, 1953, in an article that was little more than one page. Their article ushered in a new age of discovery in genetics and laid the foundation for the sequencing of the human genome. The word "genome" was derived…
The Human Genome Project defines three distinct types of cloning. The first is the use of highly specialized deoxyribonucleic acid (DNA) technology to produce multiple, exact copies of a single gene or other segment of DNA to obtain sufficient material to examine for research purposes. This process produces cloned collections of DNA known as clone libraries. The second kind of cloning involves the…
The dawn of the new millennium saw explosive advances in biotechnology. Technological breakthroughs offered scientists and physicians unprecedented opportunities to develop previously inconceivable solutions to pressing problems in agriculture, environmental science, and medicine. Simultaneously, researchers, politicians, ethicists, theologians, and the public were challenged to assess, analyze, a…
Rapid advances in genetics and its applications pose new and complicated ethical, legal, regulatory, and policy issues for individuals and society. The issues society must consider include how to protect and manage genetic information and who should have access to it; the consequences of knowledge about personal genetic information for individuals; and the repercussions of genomic information for …
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There are many published accounts of the history of genetics, but some of the most exciting versions were written by the pioneering researchers themselves. Although many sources were used to construct the historical overview and highlights contained in this book, James Watson's The Double Helix: A Personal Account of the Discovery of the Structure of DNA (New York: Simon & Schuster, …
Earth is a biosphere, a globe richly supplied with different types of living organisms, including animals, plants, fungi, and bacteria. Living organisms are named and categorized according to a taxonomy, a hierarchical system of order based on the natural relationships among all types of life. "Species" is a term assigned to a level of the taxonomy in which grouped organisms are cons…
Endangered species have different needs and require different conservation measures. Some fish are endangered only because of a history of overfishing. Halting or reducing fishing is sufficient for population recovery. In most cases, however, more active forms of intervention are necessary. The single most important conservation measure for many threatened and endangered species is habitat conserv…
Although large changes in climate are a natural part of Earth history, there is little doubt that human activities have caused observed patterns of global warming in the twentieth and twenty-first centuries. Global climate change has large implications for both humans and wildlife. Many threatened and endangered species, which already lead a precarious existence, are likely to suffer further decli…
Well over half the threatened and endangered species listed with the U.S. Fish and Wildlife Service are plants. There are a total of 714 threatened and endangered flowering plants (713 U.S. species, 1 foreign species), 5 threatened and endangered conifers and cycads (3 U.S. species, 2 foreign species), 26 listed ferns and allied species (all U.S.), and 2 listed lichen species (both U.S.). Listed U…
Approximately 1.4 pentillion tons (1,400,000,000, 000,000,000) of water cover the surface of the earth—466 billion tons for each of the six billion people on the planet. Amazing as it may seem, most of this water has been affected by human activity. Numerous aquatic species are in decline because of degraded water quality, development or alteration of aquatic habitats, and overhunting or ov…
Amphibians and reptiles are collectively known by biologists as herpetofauna. At present, there are over 5,000 described amphibian species and over 6,000 reptiles. New species in both these groups are being discovered every day, particularly in remote tropical regions that are only now being explored. Amphibians and reptiles are also among the world's most threatened groups. The World Conse…
The majority of threatened and endangered mammals are imperiled for the same reasons as other biological species—habitat destruction, pollution, competition with invasive species, and so on. However, some mammals have also been intentionally killed-off by humans. For example, in the nineteenth century, the quagga of southern Africa was hunted to extinction because it competed with sheep for…
Birds have always been among the best-studied biological groups, in part because of the efforts of countless amateur birdwatchers. In 2003 the World Conservation Union (IUCN) reported that 129 bird species have gone extinct, with another four species extinct in the wild. The rate of extinction among birds has increased every fifty years. Bird species have died out because of habitat destruction, h…
Insects are the most diverse group in the animal kingdom, with close to a million named and described species and countless species yet to be discovered. Insects have not been nearly as thoroughly studied as the vertebrate groups, and so there are likely to be many endangered insects whose desperate state remains unrealized. In 2004 there were 39 endangered insects (35 U.S., four foreign) and nine…
Humans have used wild animal and plant products for numerous purposes since prehistoric times. Clothing was made from animal skins, and tools from bones. In many societies, products from rare species symbolized wealth and success. For example, flashy feathers from South American birds were given as a tribute to Inca chiefs by their subjects, and women in nineteenth-century Europe sported ostrich f…
One of the reasons frequently given for conserving wildlife and habitat is the aesthetic and recreational value of natural places. Human beings derive pleasure from natural places in large numbers, and in a wide variety of ways. …
Most people living in the United States assume they will have plenty of clean, safe water for drinking, that crops and gardens can be regularly irrigated, and that sewage will be taken care of by their local treatment plant. In many parts of the world, however, the availability of water for personal and public use cannot be taken for granted. In fact, according to the World Health Organization (WH…
Water is a fundamental need in every society. Very few human activities do not require its use. Individuals use water for drinking, cooking, cleaning, and recreation. Industry uses it to make chemicals, manufacture goods, and clean factories and equipment. Cities use water to fight fires, clean streets, and fill public swimming pools and fountains. Farmers give water to their livestock, clean thei…
At any one time, more than 97% of all the water in the hydrologic cycle is contained in the earth's oceans. By comparison, the rivers contain only 0.0001% of the earth's water at any one time and its lakes 0.007%. Nonetheless, this tiny fraction of the total water supply has shaped the course of human development. Throughout human history, societies have depended on these surface wat…
Water lies beneath almost every part of the Earth's surface—mountains, plains, and deserts—but underground water is not always easy to find, and, once found, it may not be readily accessible. Groundwater may lie close to the surface, as in a marsh, or it may occur many hundreds of feet below the surface, as in some dry areas of the nation's West. The amount of groundwater lying within a half mile under the U.S. land surface is approximately four times the amount that …
Most water in the United States is used directly or indirectly from the tap. On average, Americans on community water supplies use about 100 gallons of water per person per day. People with private wells use slightly less. According to the American Water Works Association report Residential End Uses of Water (1999) (the latest data available), about sixty-nine gallons per day are used indoors and the rest is used for activities done outdoors. Of this daily supply, only a small portion is actuall…
A view of the Earth from a satellite shows an azure planet composed almost entirely of water. The oceans that cover two-thirds of the Earth's surface to an average depth of almost 2.5 miles contain 97% of the planet's water and have a profound influence on its environment. If the ocean basins were shallower, the seas would spread across the continents, and the only dry land areas would consist of a few major high mountain ranges projecting above a continuous layer of water.…
Wetlands are transition zones between land and aquatic systems where the water table is usually near or at the surface, or the land is covered by shallow water. Wetlands can take many forms, some of which are immediately recognizable as "wet." Other wetlands appear more like dry land, and are wet during only certain seasons of the year, or at several year intervals. In fact, the U.S. Army Corps of Engineers reports that most wetlands lack surface water and waterlogged soils during …
The United States is a nation relatively rich in water resources. According to the U.S. Geological Survey's Estimated Water Use in the United States in 2000 (the latest data available), in the lower forty-eight states the total renewable supply of water is about 1,400 billion gallons per day. Nevertheless, while the nation as a whole is water-rich, this abundance is not spread evenly throughout the country. Some areas have more water than others, while some have a higher need than others.…
Sulfur dioxide and nitrogen oxides are gases that occur naturally in the Earth's atmosphere. These gases react with water, oxygen, and other chemicals in the atmosphere to form various acidic compounds, including mild sulfuric acid and nitric acid. In nature, the combination of rain and these oxides is part of a natural balance that nourishes plants and aquatic life. However, when human activity increases the amount of acid-forming chemicals in the air, the results can be harmful to human…
Humans have always been explorers. When ancient peoples stumbled upon unknown lands or seas they were compelled to explore them. They were driven by a desire to dare and conquer new frontiers and a thirst for knowledge, wealth, and prestige. These are the same motivations that drove people of the twentieth century to venture into space. By definition space begins at the edge of Earth's atmo…
Once it became obvious that space exploration was an achievable reality, it became a national priority for rich and powerful countries. Following World War II there were only two superpowers in the world—the United States and the Soviet Union, and they considered each other enemies. Both superpowers had military, scientific, and political reasons to go into space. Outer space was a potentia…
Although NASA is the best-known space organization in the world, it is not the only one. The U.S. military has an active space program that existed even before NASA was formed. Most modern military space ventures center around ballistic missiles and data-gathering satellites. These are unmanned projects. There are also many foreign governments with space programs. Chief among these is the Russian …
The space shuttle was supposed to make space travel a routine and frequent occurrence. Its conceivers envisioned shuttles regularly transporting humans and cargo back and forth between the Earth and a fleet of orbiting space stations. The shuttle was expected to be much cheaper than previous spacecraft, because it would be reusable. This would mean low operational and maintenance costs and a quick…
A space station is an orbiting structure designed to accommodate visiting crewmembers for an extended period of time. In 1984 the U.S. government envisioned building a continuously manned space station in which scientists would conduct long-term research in a micro-gravity environment. The station was to be large and spacious, with room for up to ten crewmembers at a time. The U.S. space shuttle w…
Sending humans into space is expensive and risky. It takes great resources to protect them and sustain them every time they leave the planet. Losing a crewed spacecraft means loss of lives. This is a high price to pay to learn about the universe. This explains why robotic spacecraft are so vital to space science. Since the beginning of the space age satellites and probes have been sent out to take…
Enigmatic means mysterious. Mars has been a mystery to humans for thousands of years. Although we know much about it now, there is still much more to learn. Mars is the fourth planet from the Sun, and the planet most like Earth in the solar system. It is named after the mythical god of war who the Romans called Mars and the Greeks called Ares. Mars is also known as The Red Planet, because it looks…
The far planets are Jupiter, Saturn, Uranus, Neptune, and Pluto. They lie far from the Sun, in the coldest and darkest part of the solar system. In ancient times people noticed that some lights in the sky followed odd paths around the heavens. The Greeks called them asteres planetos, or wandering stars. Later they would be called planets. The ancients could see only two of the far planets in the n…
Humans seem to have an inherent desire to surmount great obstacles and push into new frontiers. There have always been brave people willing to risk their lives on bold and dangerous journeys into uncharted territory. They have climbed Mount Everest, traversed wild jungles, crossed barren deserts, and sailed stormy seas. Successful explorers become popular heroes. Their achievements thrill and deli…
We have not inherited the Earth from our fathers. We are borrowing it from our children. —Native American saying Photographs from outer space impress on the world that humankind shares one planet, and a small one at that. (See Figure 1.1.) Earth is one ecosystem. There may be differences in race, nationality, religion, and language, but everyone resides on the same orbiting planet. General …
Earth scientists are in the midst of a revolution in their understanding of how climate change occurred in the past. Researchers are discovering the geological and astronomical forces that have changed the planet's environment from hot to cold, wet to dry, and back again, over hundreds of millions of years. Dramatic climate change is nothing new for planet Earth. The climate of the past 10,000 years, during which civilization developed, is a mere blip in a much bigger history of climate c…
Ozone is a gas naturally present in Earth's atmosphere. Unlike regular oxygen, which contains two oxygen atoms (O2), ozone contains three oxygen atoms (O3). A molecule of regular oxygen can be converted to ozone by ultraviolet (UV) radiation, electrical discharge (such as from lightning), or complex chemical reactions. These processes split apart the two oxygen atoms, which are then free to bind with other loose oxygen atoms to form ozone.…
One of the consequences of a modern society is the generation of enormous amounts of waste. The scale of materials use by industrialized countries dwarfs that of a century ago. By 2000 the stock of materials drew from all ninety-two naturally occurring elements in the periodic table compared with just twenty in 1900. The U.S. Geological Survey (USGS) estimates that, in the United States alone, con…
According to the Environmental Protection Agency (EPA), the average person breathes in 3,400 gallons of air each day. Because air is so essential to life, it is important that it be free of pollutants. Throughout the world poor air quality contributes to hundreds of thousands of deaths and diseases each year, not to mention dying forests and lakes and the corrosion of stone buildings and monuments. Air quality is also important to the quality of life and recreation because air pollution causes h…
Water is precious for many reasons. It is an essential resource for sustaining human, animal, and vegetative life. A living cell is mostly water. An adult human's body is about 65 percent water; blood is 90 percent water. Agriculture is absolutely dependent on water to produce food crops and livestock. Water is crucial to tourism, navigation, and industry. Enormous amounts are used to gener…
Acid rain is the common name for acidic deposits that fall to Earth from the atmosphere. The term was coined in 1872 by English chemist Robert Angus Smith to describe the acidic precipitation in Manchester, England. Today scientists study both wet and dry acidic deposits. Although there are natural sources of acid in the atmosphere, acid rain is primarily caused by emissions of sulfur dioxide (SO2) and nitrous oxide (N2O) from electric utilities burning fossil fuels, especi…
Many of the substances naturally found in the environment or released by modern, industrialized society are harmful to humans and other living creatures. Common toxins include heavy metals (lead, cadmium, aluminum, mercury, and manganese), chlorine, organic chemicals (such as pesticides and herbicides), and radiation. These substances may be found in the home, workplace, or backyard, in the food a…
Human activity on Earth has always altered the land. When populations were small enough, and productive and accessible land was abundant, people could abandon land that had been damaged by overuse and move on. While some countries still have excess land available, if population growth continues at the expected rate, virtually all arable (fit for cultivation) land will be in use. …
Imagine an energy source that uses no oil, produces no pollution, cannot be affected by political events and cartels, creates no radioactive waste, and yet is economical. Although that might sound impossible, some experts claim that technological advances could make a renewable energy-based economy achievable by the mid-twenty-first century.…
Earth is richly supplied with different types of living organisms, including animals, plants, fungi, and bacteria. Various living organisms co-exist in their environments, forming complex, interrelated communities. Living organisms depend on one another for nutrients, shelter, and other benefits. The extinction of any one species can set off a chain reaction that affects many other species, partic…
The Endangered Species Act of 1973 (ESA) is generally considered one of the most far-reaching laws ever enacted by any nation for the preservation of wildlife. The passage of the ESA resulted from alarm at the decline of numerous species worldwide, as well as from recognition of the importance of preserving species diversity. The purpose of the ESA is to identify species that are either endangered…
The Endangered Species Act (ESA) is designed to protect plant and animal species in danger of extinction. During the 1990s there was a growing concern that traditional methods of species protection, which take a species-by-species approach, were ineffective. Many alternatives were proposed. One of the most popular was a method variously termed the "habitat," "ecosystem,"…
Humans have always been explorers. When ancient peoples stumbled upon unknown lands or seas they were compelled to explore them. They were driven by a desire to dare and conquer new frontiers and a thirst for knowledge, wealth, and prestige. These are the same motivations that drove people of the twentieth century to venture into space. By definition space begins at the edge of Earth's atmo…
According to the U.S. Geological Survey in "How Much Water Is There on (and in) the Earth?" (http://ga.water.usgs.gov/edu/earthhowmuch.html), about 326 million trillion gallons of water make up the total water supply of the planet. This provides an enormous aquatic habitat for a wide variety and number of animal and plant species. The aquatic environment is threatened by many human a…
People have always found ways to harness energy, such as using animals to do work or inventing machines to tap the power of wind or water. The industrialization of the modern world starting in the eighteenth century was accompanied by the widespread use of such fossil fuels as coal, oil, and natural gas.…
On August 27, 1859, Edwin Drake struck oil sixty-nine feet below the surface of the earth near Titusville, Pennsylvania. This was the first successful modern oil well, which ushered in the "Age of Petroleum." Not only did petroleum help meet the growing demand for new and better fuels for heating and lighting, but it also proved to be an excellent fuel for the internal combustion engine, which was developed in the late 1800s.…
Natural gas is an important source of energy in the United States. Methane, ethane, and propane are the primary constituents of natural gas, with methane making up 73 to 95% of the total. The natural gas industry developed out of the petroleum industry. Wells drilled for oil often produced considerable amounts of natural gas, but early oilmen had no idea what to do with it. Originally considered a…
Marine mammals live in and around the ocean. They are warm-blooded, breathe air, have hair at some point in their lives, give birth to live young (as opposed to laying eggs), and nourish their young by secreting milk. Dolphins, whales, seals, sea lions, walruses, polar bears, manatees, and dugongs (manatee relatives) fall into this category. Historically marine mammals have garnered a high level o…
Although it had been used to create energy for centuries, the first large-scale use of coal occurred during the Industrial Revolution in England from the mid-eighteenth to the mid-nineteenth centuries. At that time the sky was filled with billowing columns of black smoke, soot covered the towns and cities, and workers breathed the thick coal dust swirling around them. Most people then were not concerned with environmental issues because the Industrial Revolution meant jobs to the workers, and fa…
Nuclear energy is used in the United States to generate electricity and to power some navy ships. In the decades since the first commercial nuclear reactor went into operation in 1956, the nuclear power industry has had a difficult time persuading the American public of the safety of its enterprise. In the early 1970s most Americans favored the use of nuclear power because it appeared to provide c…
Imagine energy sources that use no oil, produce no pollution, cannot be affected by political events and cartels, create no radioactive waste, and yet are economical. Although it sounds impossible, some experts claim that technological advances could make wide use of renewable energy sources possible within a few decades. Renewable energy is energy that is naturally regenerated and is, therefore, virtually unlimited. Sources include the sun (solar), wind, water (hydropower), vegetation (biomass)…
Fish, clams, snails, and crustaceans are aquatic creatures. Fish are vertebrates, meaning they have an internal skeleton made of bone or cartilage. Clams, snails, and crustaceans are invertebrates. …
Fossil fuels and uranium are nonrenewable resources. Nonrenewable resources are defined as concentrations of solid, liquid, or gaseous hydrocarbons that occur naturally in or near the earth's surface. These resources must be currently or potentially recoverable for economic use. They are formed much more slowly than they are consumed, so they are considered nonrenewable. Knowing estimates o…
Once it became obvious that space exploration was an achievable reality, it became a national priority for rich and powerful countries. Following World War II there were only two superpowers in the world—the United States and the Union of Soviet Socialist Republics, and they considered each other enemies. Both superpowers had military, scientific, and political reasons to pursue space trave…
Since 1879, when Thomas Edison flipped the first switch to light Menlo Park, New Jersey, the use of electrical power has become nearly universal in the United States. …
Energy conservation is the efficient use of energy, without necessarily curtailing the services that energy provides. Conservation occurs when societies develop efficient technologies that reduce energy needs. Environmental concerns, such as acid rain and the potential for global warming, have increased public awareness about the importance of energy conservation.…
Amphibians and reptiles are collectively known by biologists as herpetofauna. At present, there are over 5,000 described amphibian species and over 6,000 reptiles. New species in both these groups are being discovered every day, particularly in remote tropical regions that are only now being explored. Most of the herpetofauna native to the United States are found in wetlands and riparian habitat (…
Although the National Aeronautics and Space Agency (NASA) is the best-known space organization in the world, it is not the only one. The U.S. military and many foreign governments also have active space programs. In fact, the U.S. military program existed even before NASA was formed. Most modern military space ventures center around ballistic missiles and data-gathering satellites. These are unman…
Terrestrial animals are animals that inhabit the land. Mammals are warm-blooded, breathe air, have hair at some point in their lives, give birth to live young (as opposed to laying eggs), and nourish their young by secreting milk. The biggest cause of terrestrial mammalian decline and extinction in the twentieth-first century is habitat loss and degradation. As humans convert forests, grasslands, …
Birds belong to the class Aves, which contains dozens of orders. Birds are warm-blooded vertebrates with wings, feathers, and light hollow bones. The vast majority of birds are capable of flight. According to the U.S. Fish and Wildlife Service (FWS), more than 800 species of birds spend all or part of their lives in the United States; more than 9,000 species of birds have been identified around th…
Insects are members of the Animalia kingdom and belong to the phylum Arthropoda, along with crustaceans. There are many classes of arthropods, including the insects and arachnids. Both are invertebrates, but insects have six legs, while arachnids have eight legs. The arachnids include spiders, mites, ticks, scorpions, and harvestmen. Insects are the most diverse group in the animal kingdom. Scient…
The space shuttle was supposed to make space travel a routine and frequent occurrence. Its conceivers envisioned shuttles regularly transporting humans and cargo back and forth between the Earth and a fleet of orbiting space stations. The shuttle was expected to be much cheaper than previous spacecraft, because it would be reusable. This would mean low operational and maintenance costs and a quick…
Plants belong to the Plantae kingdom. Biologists estimate that there are up to 350,000 species making up this kingdom. In general, there are two types of land-growing plants—vascular and nonvascular. Vascular plants have specially developed organs similar to veins that move liquids through their systems. This category includes the trees, shrubs, flowers, and grasses. Nonvascular plants are …
A space station is an orbiting structure designed to accommodate visiting crewmembers for an extended period of time. In 1984 the U.S. government envisioned building a continuously manned space station in which scientists would conduct long-term research in a micro-gravity environment. The station was to be large and spacious, with room for up to ten crewmembers at a time. The U.S. space shuttle w…
Sending humans into space is expensive and risky. It takes great resources to protect them and sustain them every time they leave the planet. Losing a crewed spacecraft means loss of lives. This is a high price to pay to learn about the universe. This explains why robotic spacecraft are so vital to space science. Since the beginning of the space age, satellites and probes have been sent out to gat…
Mars has been a mystery to humans for thousands of years. Although we know much about it now, there is still much more to learn. Mars is the fourth planet from the Sun, and the planet most like Earth in the solar system. It is named after the mythical god of war whom the Romans called Mars and the Greeks called Ares. Mars is also known as the Red Planet, because it looks reddish from Earth. Mars i…
The far planets are Jupiter, Saturn, Uranus, Neptune, and Pluto. (See Figure 8.1.) They lie far from the Sun, in the coldest and darkest part of the solar system. In ancient times people noticed that some lights in the sky followed odd paths around the heavens. The Greeks called them asteres planetos, or wandering stars. Later they would be called planets. The ancients could see only two of the fa…
Humans seem to have an inherent desire to surmount great obstacles and push into new frontiers. There have always been brave people willing to risk their lives on bold and dangerous journeys into uncharted territory. They have climbed Mount Everest, traversed wild jungles, crossed barren deserts, and sailed stormy seas. Successful explorers become popular heroes. Their achievements thrill and deli…
At the heart of the animal rights debate is the issue of how humans and animals should interact with each other. Are animals a natural resource for humans to use as they choose? Or are animals free beings with the right to live their lives without human interference? Is there an acceptable compromise somewhere in between? People answer these questions differently depending on their cultural practi…
According to Webster's dictionary, a right is "a power or privilege to which one is justly entitled." Sociologists James Jasper and Dorothy Nelkin define a right as "a moral trump card that cannot be disputed." The phrase "human rights" came into usage during the late 1700s to refer to generally recognized privileges (or freedoms) that every person …
Wildlife are animals that have not been domesticated by humans. This does not mean that wild animals live without human interference. Humans control, manage, manipulate, use, and kill wildlife for various reasons. Humans tend to think of wild animals in terms of the threat they pose to people or the value they hold for them. Some wildlife threaten human safety, health, property, and/or quality of …
Farm animals are animals that are kept for agricultural purposes. This includes such domesticated animals as cows and chickens, and wild animals that are raised in confinement, including mink and fish. Animals are farmed for a variety of reasons. Most are raised to be killed. Meat from cattle, hogs, and chickens provides the bulk of protein in the American diet, while animals with beautiful fur ar…
Research animals are animals that humans use solely for scientific and product testing. They are used in medical and veterinary investigations and training; in the testing of drugs, cosmetics, and other consumer products; and in educational programs. It is estimated that as many as 100 million animals per year (mostly mice and rats) may be used in research, testing, and medical and veterinary trai…
Webster's dictionary defines a sport as recreation that includes physical activity. Most people would think of a sport as an athletic competition that demonstrates skills such as physical strength, stamina, agility, and speed. Humans recognized centuries ago that many animals possess such skills naturally and could be used in sporting events. In the United States today, the major sports in …
Entertainment animals are those that perform or are displayed publicly to amuse people. These animals appear in circuses, carnivals, animal shows and exhibits, amusement and wildlife theme parks, aquariums, zoos, museums, fairs, and motion pictures and television programs. Although these venues are diverse, they all have one thing in common: They use animals for human purposes. Many of these purpo…
Service animals are those that work for humans doing particular tasks. These tasks may be as mundane as pulling plows or as sophisticated as finding underwater mines. Throughout history, animals have helped humans hunt wildlife, herd livestock, guard people and property, and wage warfare. Animals are also trained for more humanitarian causes, such as rescuing the lost and providing aid and comfort…
Pets are animals that humans keep for pleasure rather than utility. Their value is mostly emotional. They help to fulfill human desires for companionship, affection, entertainment, and ownership. The American Pet Products Manufacturers Association (APPMA) was founded in 1958 and is the nation's leading pet industry trade group. More than 750 companies were members of the association as of 2…
Genetics is the biology of heredity, and geneticists are the scientists and researchers who study hereditary processes such as the inheritance of traits, distinctive characteristics, and diseases. Genetics considers the biochemical instructions that convey information from generation to generation. Tremendous strides in science and technology have enabled geneticists to demonstrate that some genet…
