Conservation in the United States

From Wikipedia, the free encyclopedia

 

Yosemite National Park

 

Conservation in the United States can be traced back to the 19th century with the formation of the first National Park. Conservation generally refers to the act of consciously and efficiently using land and/or its natural resources. This can be in the form of setting aside tracts of land for protection from hunting or urban development, or it can take the form of using less resources such as metal, water, or coal. Usually, this process of conservation occurs through or after legislation on local or national levels is passed. 

Conservation in the United States, as a movement, began with the American sportsmen who came to the realization that wanton waste of wildlife and their habitat had led to the extinction of some species, while other species were at risk. John Muir and the Sierra Club started the modern movement, history shows that the Boone and Crockett Club, formed by Theodore Roosevelt, spearheaded conservation in the United States.

While conservation and preservation both have similar definitions and broad categories, preservation in the natural and environmental scope refers to the action of keeping areas the way they are and trying to dissuade the use its resources; conservation may employ similar methods but does not call for the diminishing of resource use and rather a responsible way of going about it. A distinction between Sierra Club and Boone and Crockett Club is that Sierra Club was and is considered a preservationist organization whereas Boone and Crockett Club endorses conservation, simply defined as an "intelligent use of natural resources."

History

The High Peaks Wilderness Area in the 6,000,000-acre (24,000 km²) Adirondack Park is a publicly protected area located in northeast New York.

Philosophy of early American conservation movement

During the 19th century, some Americans developed a deep and abiding passion for nature. The early evolution of the conservation movement began through both public and private recognition of the relationship between man and nature often reflected in the great literary and artistic works of the 19th century. Artists, such as Albert Bierstadt, painted powerful landscapes of the American West during the mid 19th century, which were incredibly popular ages representative of the unique natural wonders of the American frontier. Likewise, in 1860, Frederic Edwin Church painted "Twilight in the Wilderness", which was an artistic masterpiece of the era that explored the growing importance of the American wilderness.

American writers also romanticized and focused upon nature as a subject matter. However, one of the most notable literary figures upon the early conservation movement proved to be Henry David Thoreau. Throughout his work, Walden, Thoreau detailed his experiences at the natural setting of Walden Pond and his deep appreciation for nature. In one instance, he described a deep grief for a tree that was cut down. Thoreau went on to bemoan the lack of reverence for the natural world: "I would that our farmers when they cut down a forest felt some of that awe which the old Romans did when they came to thin, or let in the light to, a consecrated grove". As he states in Walden, Thoreau "was interested in the preservation" of nature. In 1860, Henry David Thoreau delivered a speech to the Middlesex Agricultural Society in Massachusetts; the speech, entitled "The Succession of Forest Trees", explored forest ecology and encouraged the agricultural community to plant trees. This speech became one of Thoreau's "most influential ecological contributions to conservationist thought".

A basis for the philosophy curated by the prominent sportsmen, writers, anthropologists, and politicians came from observing Native Americans and how they interacted with the resources available to them. For example, George Bird Grinnell was an anthropologist who joined an expedition in 1870 which encountered different tribes such as the Pawnee for large, extended periods of time. He noted their use of every single part of an animal following a hunt and that they ceremoniously prepared for utilizing and taking any resource the land was able to provide them. These observations, fraught with condemning language toward the way European hunters and sportsmen treated wildlife and resources such as timber, were published in widely circulated journals and magazines at the time.

The early conservation movement in the United States was also successful due to the hard work of John Muir. Muir, who is often cited as one of the first American environmentalists, has earned multiple American honors for environmental work. His family home in Martinez, California, is honored as a National Historic Site and so is his childhood home in Portage, Wisconsin, Fountain Lake Farm which is a National Historic Landmark. He was a former carriage worker who was nearly blinded by an accident at work. After almost losing his sight, Muir decided to see "America's natural wonders". Based upon his travels throughout Yosemite and the Sierra Nevada Mountains, Muir wrote a collection of articles for Century magazine, entitled "Studies in the Sierra". In 1892, John Muir joined forces with the editor of "Century" Magazine, Robert Underwood Johnson, to establish the Sierra Club, an organization designed to protect America's natural resources and public parks. Early Americans recognized the importance of natural resources and the necessity of wilderness preservation for sustained yield harvesting of natural resources. In essence, the preservation of wilderness and landscapes were recognized as critical for future generations and their continued subsistence in a healthy environment. The foundation of the conservation movement is grounded during this period between 1850 and 1920. Ultimately, historical trends and cultural mind-sets were united, which influenced ideas and policy towards the early history of the conservation movement in the United States. 

In considering this foundation for the conservation movement he helped to lay, members of the Sierra Club have been noting the hypocrisy of John Muir's conservation efforts in these instances of documented racism through their recent posts. Ross Wakefield writes that although Muir would recognize Native Americans as human, he begrudgingly did so and that institutional racism impacted his views, influencing his thought that they could never attain the same level of purity and immaculateness that nature did. Environmental historians, like Carolyn Merchant, also cite Muir as someone who was unwilling to extend his efforts of conservation toward groups of people who were not white. She explains in Shades of Darkness that on his walking journey from Canada (where he took refuge in order to escape being drafted as a soldier in the Civil War) down to the Gulf of Mexico, he often came across groups of African American people and wrote of them with much disdain and lowliness. In his accounts and descriptions of the places he trekked through, he often contrasted the care and reverence that he felt nature deserved with remarks about black people being devilish and incapable of completing tasks as efficiently as white people could.

Early American conservation movement

The conservation of natural resources is the fundamental problem. Unless we solve that problem, it will avail us little to solve all others. Theodore Roosevelt

America had its own conservation movement in the 19th century, most often characterized by George Perkins Marsh, author of Man and Nature. The expedition into northwest Wyoming in 1871 led by F. V. Hayden and accompanied by photographer William Henry Jackson provided the imagery needed to substantiate rumors about the grandeur of the Yellowstone region, and resulted in the creation of Yellowstone National Park, the world's first, in 1872. In 1887, Theodore Roosevelt, George Bird Grinnell and other prominent sportsmen of the day formed the first true North American conservation organization, the Boone and Crockett Club, with the purpose of addressing the looming conservation crises of the day. Travels by later U.S. PresidentTheodore Roosevelt through the region around Yellowstone provided the impetus for the creation of the Yellowstone Timberland Reserve in 1891. The largest section of the reserve was later renamed Shoshone National Forest, and it is the oldest National Forest in the U.S. But it was not until 1898 when German forester Dr. Carl A. Schenck, on the Biltmore Estate, and Cornell University founded the first two forestry schools, both run by Germans. Bernard Fernow, founder of the forestry schools at Cornell and the University of Toronto, was originally from Prussia (Germany), and he honed his knowledge from Germans who pioneered forestry in India. He introduced Gifford Pinchot, the "father of American forestry", to Brandis and Ribbentrop in Europe. From these men, Pinchot learned the skills and legislative patterns he would later apply to America. Pinchot, in his memoir history Breaking New Ground, credited Brandis especially with helping to form America's conservation laws.

“

Conservation means the greatest good to the greatest number for the longest time.—Pinchot

”

Pinchot wrote that the principles of conservation were:

1. Development: "the use of the natural resources now existing on this continent for the benefit of the people who live here now. There may be just as much waste in neglecting the development and use of certain natural resources as there is in their destruction. … The development of our natural resources and the fullest use of them for the present generation is the first duty of this generation."
2. Conservation: "…the prevention of waste in all other directions is a simple matter of good business. The first duty of the human race is to control the earth it lives upon."
3. Protection of the public interests: "The natural resources must be developed and preserved for the benefit of the many, and not merely for the profit of a few."

In 1891, Congress passed the Forest Reserve Act, which allowed the President of the United States to set aside forest lands on public domain. A decade after the Forest Reserve Act, presidents Harrison, Cleveland, and McKinley had transferred approximately 50,000,000 acres (200,000 km²) into the forest reserve system. However, President Theodore Roosevelt is credited with the institutionalization of the conservation movement in the United States.

For President Roosevelt, the conservation movement was not about the preservation of nature simply for nature itself. After his experiences traveling as an enthusiastic, zealous hunter, Roosevelt became convinced of "the need for measures to protect the game species from further destruction and eventual extinction". President Roosevelt recognized the necessity of carefully managing America's natural resources. According to Roosevelt, "We are prone to speak of the resources of this country as inexhaustible; this is not so". Nonetheless, Roosevelt believed that conservation of America's natural resources was for the successful management and continued sustain yield harvesting of these resources in the future for the benefit and enjoyment of the American people. Roosevelt took several major steps to further his conservation goals.In 1902, Roosevelt signed the National Reclamation Act, which allowed for the management and settlement of a large tract of barren land. Then, in 1905, President Roosevelt helped to create the United States Forest Service and then appointed respected forester, Gifford Pinchot, as the first head of the agency. By the end of his presidency, Theodore Roosevelt, in partnership with Gifford Pinchot, had successfully increased the number of national parks as well as added area to existing forest reserves. 

The legacy of his actions as president at the turn of the twentieth century include estimated 230 million acres of land as public lands, through his aforementioned establishment of the United States Forest Service as well as dozens of national forests, national parks, and bird reserves, in addition to 4 game preserves. This legacy, though establishing what many consider the root of modern conservationism, remained within the hands of powerful men of white European heritage for years to come, often excluding the interests of Native Americans and other demographics within the United States. 

Despite these advancements, the American conservation movement did have difficulties. In the early 1900s the conservation movement in America was split into two main groups: conservationists, like Pinchot and Roosevelt, who were utilitarian foresters and natural rights advocates who wanted to protect forests "for the greater good for the greatest length", and preservationists, such as John Muir, the founder of the Sierra Club. Important differences separated conservationists like Roosevelt and Pinchot from preservationists like Muir. As a preservationist, Muir envisioned the maintenance of pristine natural environments where any development was banned. Whereas conservationists wanted regulated use of forest lands for both public activities and commercial endeavors, preservationists wanted forest to be preserved for natural beauty, scientific study and recreation. The differences continue to the modern era, with sustainable harvest and multiple-use the major focus of the U.S. Forest Service and recreation emphasized by the National Park Service. 

Although national parks can logistically fall under the category of preservation sites, certain marked National Conservation Area sites fall near or within proximity of national parks and share a common land history. The United States government began driving groups of Native American peoples out of popularly visited areas like Yellowstone around the late 1800s once they deemed them a conflict to tourists. Battles between federal troops and the Nez Perce tribe soon ensued, and eventually the tribe was driven out of the area. Conservation history fails to incorporate details like this when talking about the beginnings and context of the movement.

Modern American conservation movement

In 1956 the US Post Office began issuing postage stamps depicting wildlife to emphasize the importance of wildlife conservation in America.

 

By the mid-twentieth century, conservation efforts continued to gain ground with the creation and implementation of federal legislation aimed at protecting wilderness, natural resources, and wildlife. This trend on the part of the federal government towards a more protection minded approach to the environment began with the passage of the Federal Water Pollution Act in 1948 and the Air Pollution Control Act in 1955. While neither of these regulations themselves served to impose tight restrictions on either water or air pollution, they lay the groundwork for what would later become the Clean Water Act and the Clean Air Act, as well as serving to demonstrate the recognition on the part of the federal government of the need to codify regulations geared towards environmental protection.

Notable Events

Silent Spring

 

The 1962 publication of Rachel Carson's Silent Spring represented a major watershed moment in American conservation. In exposing the individual dangers presented to both people and nature through the use of chemical pesticides, Carson inspired an environmental revolution, helping to root the modern conservation movement in a scientific foundation. It would take another decade, however, before the use of DDT was banned in the United States.

A Wave of Legislation

Beginning in the late 1960s, the conservation movement scored a number of victories with the creation and implementation of a variety of environmental regulations aimed at the protection of wildlife, wild lands, and natural resources. In 1968 the Wild and Scenic Rivers Act was passed, followed two years later by the implementation of the National Environmental Policy Act ("NEPA"), the establishment of the Environmental Protection Agency ("EPA") and the National Oceanic and Atmospheric Administration ("NOAA"), as well as the celebration of the inaugural Earth Day. The momentum carried on into 1972 when the Clean Water Act, the Marine Mammal Protection Act, the Coastal Zone Management Act, and the Endangered Species Act were passed. Moreover, 1972 saw the banning of DDT by the EPA.

The Wilderness Act

On 3 September 1964, President Lyndon B. Johnson signed the Wilderness Act of 1964 into law. This milestone was achieved by the efforts of environmental conservationists dedicated to the protection of some of the wildest lands in the United States. Chief among these were Howard Zahniser and Olaus Murie and Mardy Murie, who dedicated much of their lives and their work to the protection and conservation of wild lands. By 1950 both Zanhiser and Olaus Murie were working for the Wilderness Society, Zahinser as Executive Secretary in Washington DC, and Olaus as President from his ranch in Moose, WY (now home to the Murie Center). From their positions at Wilderness Society, both men continued to work to organize and build broad-based support for the creation and protection of wilderness areas within the United States. Zahniser felt strongly that Congress ought to designate wilderness areas, as opposed to leaving it up to Agency discretion, and, in 1955, began working to convince members of Congress to support a bill that would establish a national wilderness preservation system. Meanwhile, in 1956, Olaus and Mardy Murie embarked upon an expedition to the upper Sheenjek River on the south slope of the Brooks Range in Alaska, which would galvanize them to campaign for the protection of the area as a wildlife refuge. The result of these efforts was the protection of 8 million acres as the Arctic National Wildlife Range, renamed the Arctic National Wildlife Refuge when it was expanded to 19 million acres in 1980. Moreover, the mission underlying the protection of ANWR, namely the preservation of an entire ecological system, became the underlying motivation for the preservation of other large tracts of wild lands.

While neither Zahniser nor Olaus Murie would live to see the Wilderness Act signed by President Johnson, it is unlikely that, without their tireless efforts, the preservation movement would have been able to achieve so huge a victory. On 3 September 1964, Mardy Murie stood proudly next to President Johnson in the Rose Garden at the White House and bore witness to the making of history, and the achievement of the very thing for which Zahniser and Olaus had campaigned so ardently.

Into the Twenty-First Century

Ultimately, the modern conservation movement in the United States continues to strive for the delicate balance between the successful management of society's industrial progress while still preserving the integrity of the natural environment that sustains humanity. In a large part, today's conservation movement in the United States is a joint effort of individuals, grassroots organizations, nongovernmental organizations, learning institutions, and various government agencies, such as the United States Forest Service. 

For the modern era, the U.S. Forest Service has noted three important aspects of the conservation movement: the climate change, water issues, and the education of the public on conservation of the natural environment, especially among children. In regards to climate change, the U.S. Forest Service has undertaken a twenty-year research project to develop ways to counteract issues surrounding climate change. However, some small steps have been taken regarding climate change. As rising greenhouse gases contribute to global warming, reforestation projects are seeking to counteract rising carbon emissions. In Oregon, the Department of Forestry has developed a small reforestation program in which landowners can lease their land for one hundred years to grow trees. In turn, these trees offset carbon emissions from power companies. Moreover, reforestation projects have other benefits: reforested areas serve as a natural filter of agricultural fertilizers even as new wildlife habitats are created. Reforested land can also contribute to the local economy as rural landowners also distribute hunting leases during the years between harvests.

In essence, projects, such as reforestation, create a viable market of eco-friendly services mutually beneficial to landowners, businesses and society, and most importantly, the environment. Nonetheless, such creative plans will be necessary in the near future as the United States struggles to maintain a positive balance between society and the finite natural resources of the nation. Ultimately, through dedicated research, eco-friendly practices of land management, and efforts to educate the public regarding the necessity of conservation, those individuals dedicated to American conservation seek to preserve the nation's natural resources.

Twenty-First Century Resource Protection

The increased consumption of many natural resources has sparked the need for protection. Many of these resources were barely touched less than half a century ago but have been drained in several situations. One of these resources, water, is key to survival of almost all life but is being used quicker than it is replenished in many states within the United States. This has created the need for greater conservation which has been met by new techniques and technologies for both reducing the amount of water being used and increasing how efficiently it is being used. Some of these methods are as simple as replacing the fixtures in government buildings and offering rebates to citizens, but are as complex as growing genetically engineered food crops so that farmers can consume less water for use on them. Another key resource that has been met with new legislation is the land that is used to grow the crops for farms. One fairly new United States government policy, the Farmland Protection Policy Act, is designed in order to protect this resource from being over consumed by the government. It does this by ensuring that any entity, both federal and non-federal, that uses government assistance such as acquiring or disposing of land, providing financing or loans, managing property, providing technical assistance, cannot convert agricultural land into land that is permanently used for other purposes if it can be avoided. If the overuse of these resources is not mediated, the eventual result would create the loss of another key resource for survival. That is, if either land for agriculture or water for the land and the people who inhabit it becomes insufficient, the population in the United States would begin to run out of food. Not only would cash crops of plants become insufficient to supply people, it would also become insufficient to feed the livestock and animals that also depend on plants that are grown on agricultural land. Because of this, the need for conservation is greater than ever, especially when current efforts have only been able to slow the gradual depletion of these two key resources while increased populations create the need for higher consumption.

Ecotourism

Ecotourists viewing a glacier.

 

The goal of ecotourism is to attract appreciation and attention to specific sites, which may include protected land for conservation, while minimizing the impact that tourism has on the land. It is a form of conservation because the area may be protected while tourists or businesses are also using the land for lodging or other types of accommodations that utilize resources in any way. This movement has gained international traction and recognition. The United Nations declared 2002 the International Year of Ecotourism. Ecotourism seeks to balance an interest and appreciation of protected lands with a commitment to preserving them. A study conducted by the University of Georgia reported that environmentalists should team up with ecotourists in order to have the best chance to preserve fragile ecosystems and lands. Tourism provides economic incentives to conserve lands, for if protected lands are seen as revenue-generating tourist destinations, there is monetary reason to ensure their conservation. Also, rather than simply relying on environmental messaging, ecotourism allows conservationists to pursue a leisurely and economic message.

Current Conservation Developments & Issues

Social Issues and Threats to Access

John Muir

 

At a 2014 event held at UCLA centered upon environmental figures like John Muir, a few historians and writers noted that the movements for conservation and preservation of the environment maintained a foundation in "economic privilege and abundant leisure time of the upper class." Jon Christensen, a historian of UCLA's Institute of Environment and Sustainability, notes among the other critics at the event that writings and actions from conservationists at the turn of the twentieth century have created a legacy for the movement as one of an older white demographic.

General concern among the current conservation movement deals with the accessibility of conserved/protected areas as well as the movement itself to communities of color especially. Richard White, a historian at Stanford University, makes the case that viewpoints of early conservationists came from an Anglo-Saxon, biblical point of view and that this is reflected in the current demographics of visitors to national parks and protected areas. At the same time, recent polls suggest that the Latino community in California tends to possess more environmental attitudes when it comes to voting than perceived by the general public. A highly cited historian of Southern California, D. J. Waldie, posits that conservation for the purpose of public enjoyment is usually geared for places inaccessible to minority demographics, such as skiing or backpacking in the Sierra Nevadas. Instead, he puts forth that the conservation areas of importance for these communities are local bodies of water or small mountain ranges, urban parks, and even their own backyards.

Events

Past Events

• Extinction of the Passenger pigeon
• Wholesale hunting of American Bison

Current Events

• Logging of old growth forests
• Mountaintop mining
• Draining and development of the Everglades

Enforcement

Game wardens or conservation officers are employed to protect wildlife and natural areas.

• Florida Department of Environmental Protection
• Louisiana Department of Wildlife & Fisheries - Enforcement Division
• Maryland Department of Natural Resources Police
• Maine Inland Fisheries and Wildlife
• Michigan Conservation Officers and Michigan Department of Natural Resources (Wildlife Division)
• New York State Department of Environmental Conservation Police
• Virginia Department of Game and Inland Fisheries

Projects

• Restoration of the Everglades

Political

On January 20, 2017, a bill was introduced to congress that aimed to roll back regulations on oil and gas drilling in National Parks. The bill would nullify the “General Provisions and Non-Federal Oil and Gas Rights” rule passed in November 2016, and this would remove protections to National Park lands and resources.

On February 28, 2017, Donald Trump signed an executive order to review the Clean Water Rule, a bill he and Scott Pruitt have pledged to eliminate since he took office. The Clean Water rule was enacted in 2015 and extended federal protection to millions of acres of lakes, rivers, and wetlands.

On March 16, 2017, Donald Trump released his preliminary budget proposal for 2018 discretionary spending. These budget proposals featured cuts to both the EPA and the Department of Interior. The 12% decrease for the Department of Interior is removing spending from land acquisition costs associated with the preservation and expansion of National Parks. The budget also completely defunded National Heritage Areas. Funding to National Heritage Areas is used in part to support tribal protection officers and provides grants to underrepresented communities, ones who have already been putting conservation in practice. The proposed budget would cut the staff of the Environmental Protection Agency by 3,200 and reduce their budget by $2.6 billion annually.

Trump's promise to eliminate 2 federal regulations for every new regulation proposed may impact lands set aside for conservation. The repeal of old regulations will put currently conserved land at risk: future perceived threats to conserved lands and resources might not be able to be stopped since the erasure of regulation that sought to combat past threats to conserved lands may be eliminated.

Ryan Zinke, Trump's appointed Secretary of the Interior, moved to reverse federal regulation that prohibits hunters from using lead ammunition in National Parks.

Key Figures

Some of the more notable American conservationists include:

• Theodore Roosevelt, former President of the United States and founder of the Boone and Crockett Club
• Ansel Adams, best known for his black and white photographs of Yosemite National Park
• Aldo Leopold, influential in the development of modern environmental ethics and in the movement for wilderness preservation
• George Perkins Marsh
• Rachel Carson
• John Muir, founder of the Sierra Club a major conservation organization
• Wendell Berry
• John Wesley Powell
• John Burroughs

Outback

From Wikipedia, the free encyclopedia

Outback
Area
View across sand plains and salt pans to Mount Connor, Central Australia
Country	Australia
Population
• Total	undetermined

Tourism sign post in Yalgoo, Western Australia

 

The Outback is the vast, remote interior of Australia. "The Outback" is more remote than those areas named "the bush", which include any location outside the main urban areas. 

While often envisaged as being arid, the Outback regions extend from the northern to southern Australian coastlines and encompass a number of climatic zones, including tropical and monsoonal climates in northern areas, arid areas in the "red centre" and semi-arid and temperate climates in southerly regions.

Geographically, the Outback is unified by a combination of factors, most notably a low human population density, a largely intact natural environment and, in many places, low-intensity land uses, such as pastoralism (livestock grazing) in which production is reliant on the natural environment.

Culturally, the Outback is deeply ingrained in Australian heritage, history and folklore. In 2009, as part of the Q150 celebrations, the Queensland Outback was announced as one of the Q150 Icons of Queensland for its role as a "natural attraction".

The Dingo Fence near Coober Pedy

History

Aerial view of Kata Tjuta

 

Indigenous Australians have lived in the Outback for approximately 50,000 years and occupied all Outback regions, including the driest deserts, when Europeans first entered central Australia in the 1800s. Many Indigenous Australians retain strong physical and cultural links to their traditional country and are legally recognised as the Traditional Owners of large parts of the Outback under Commonwealth Native Title legislation.

Early European exploration of inland Australia was sporadic. More focus was on the more accessible and fertile coastal areas. The first party to successfully cross the Blue Mountains just outside Sydney was led by Gregory Blaxland in 1813, 25 years after the colony was established. People starting with John Oxley in 1817, 1818 and 1821, followed by Charles Sturt in 1829–1830 attempted to follow the westward-flowing rivers to find an "inland sea", but these were found to all flow into the Murray River and Darling River which turn south.

From 1858 onwards, the so-called "Afghan" cameleers and their beasts played an instrumental role in opening up the outback and helping to build infrastructure.

Over the period 1858 to 1861, John McDouall Stuart led six expeditions north from Adelaide, South Australia into the outback, culminating in successfully reaching the north coast of Australia and returning without the loss of any of the party's members' lives. This contrasts with the ill-fated Burke and Wills expedition in 1860–61 which was much better funded, but resulted in the deaths of three of the members of the transcontinental party.

The Overland Telegraph line was constructed in the 1870s along the route identified by Stuart.

In 1865 the surveyor George Goyder, using changes in vegetation patterns, mapped a line in South Australia, north of which he considered rainfall to be too unreliable to support agriculture.

Exploration of the outback continued in the 1950s when Len Beadell explored, surveyed and built many roads in support of the nuclear weapons tests at Emu Field and Maralinga and rocket testing on the Woomera Prohibited Area. Mineral exploration continues as new mineral deposits are identified and developed.

While the early explorers used horses to cross the outback, the first woman to make the journey riding a horse was Anna Hingley, who rode from Broome to Cairns in 2006.

Aerial photography of Australia showing the large arid (yellow/brown) areas that are generally considered to be "outback"

Environment

Global significance

MacDonnell Ranges in the Northern Territory are found in the centre of the country

 

Fitzgerald River National Park in Western Australia

 

A brumby in the Outback

 

The paucity of industrial land use has led to the Outback being recognised globally as one of the largest remaining intact natural areas on Earth. Global "Human Footprint" and wilderness reviews highlight the importance of Outback Australia as one of the world's large natural areas, along with the Boreal forests and Tundra regions in North America, the Sahara and Gobi deserts and the tropical forests of the Amazon and Congo Basins. The savanna (or grassy woodlands) of northern Australia are the largest, intact savanna regions in the world. In the south, the Great Western Woodlands, which occupy 16,000,000 hectares (40,000,000 acres), an area larger than all of England and Wales, are the largest remaining temperate woodland left on Earth.

Major ecosystems

Reflecting the wide climatic and geological variation, the Outback contains a wealth of distinctive and ecologically-rich ecosystems. Major land types include:

• the Kimberley and Pilbara regions in northern Western Australia,
• sub-tropical savanna landscape of the Top End,
• ephemeral water courses of the Channel Country in western Queensland,
• the ten deserts in central and western Australia,
• the Inland Ranges, such as the MacDonnell Ranges, which provide topographic variation across the flat plains,
• the flat Nullarbor Plain north of the Great Australian Bight, and
• the Great Western Woodlands in southern Western Australia.

Wildlife

The Australian Outback is full of very important well-adapted wildlife, although much of it may not be immediately visible to the casual observer. Many animals, such as red kangaroos and dingoes, hide in bushes to rest and keep cool during the heat of the day. 

Birdlife is prolific, most often seen at waterholes at dawn and dusk. Huge flocks of budgerigars, cockatoos, corellas and galahs are often sighted. On bare ground or roads during the winter, various species of snakes and lizards bask in the sun, but they are rarely seen during the summer months.

Feral animals such as camels thrive in central Australia, brought to Australia by pastoralists and explorers, along with the early Afghan drivers. Feral horses known as 'brumbies' are station horses that have run wild. Feral pigs, foxes, cats and rabbits are other imported animals also degrading the environment, so time and money is spent eradicating them in an attempt to help protect fragile rangelands.

The Outback is home to a diverse set of animal species, such as the kangaroo, emu and dingo. The Dingo Fence was built to restrict movements of dingoes and wild dogs into agricultural areas towards the south east of the continent. The marginally fertile parts are primarily utilised as rangelands and have been traditionally used for sheep or cattle grazing, on cattle stations which are leased from the Federal Government. While small areas of the outback consist of clay soils the majority has exceedingly infertile palaeosols. 

Riversleigh, in Queensland, is one of Australia's most renowned fossil sites and was recorded as a World Heritage site in 1994. The 100 km² (39 sq mi) area contains fossil remains of ancient mammals, birds and reptiles of Oligocene and Miocene age.

Industry

Pastoralism

Gosses Bluff crater, one of a number of meteor impact craters that can be found across outback Australia

 

The largest industry across the Outback, in terms of the area occupied, is pastoralism, in which cattle, sheep, and sometimes goats, are grazed in mostly intact, natural ecosystems. Widespread use of bore water, obtained from underground aquifers, including the Great Artesian Basin, has enabled livestock to be grazed across vast areas in which no permanent surface water exists naturally.

Capitalising on the lack of pasture improvement and absence of fertiliser and pesticide use, many Outback pastoral properties are certified as organic livestock producers. In 2014, 17,000,000 hectares (42,000,000 acres), most of which is in Outback Australia, was fully certified as organic farm production, making Australia the largest certified organic production area in the world.

Tourism

"Nothing says Australia quite like our Outback," states the national tourism web site. Tourism is a major industry across the Outback, and commonwealth and state tourism agencies explicitly target Outback Australia as a desirable destination for domestic and international travellers. There is no breakdown of tourism revenues for the "Outback" per se. However, regional tourism is a major component of national tourism incomes. Tourism Australia explicitly markets nature-based and Indigenous-led experiences to tourists. In the 2015–2016 financial year, 815,000 visitors spent $988 million while on holidays in the Northern Territory alone.

There are many popular tourist attractions in the Outback. Some of the well known destinations include:

• Alice Springs, Northern Territory
• Arkaroola and Wilpena Pound in the Flinders Ranges of South Australia
• Australian Stockman's Hall of Fame
• Birdsville, Queensland
• Broken Hill, New South Wales
• Broome
• Coober Pedy, South Australia
• Devils Marbles
• Kakadu National Park
• Kalgoorlie-Boulder, Western Australia
• Kata Tjuta (The Olgas)
• Katherine Gorge
• Kings Canyon (Watarrka)
• MacDonnell Ranges
• Monkey Mia
• Mount Isa, Queensland
• Mount Augustus National Park
• Tennant Creek, Northern Territory
• Uluru (Ayers Rock)
• Willandra Lakes Region

Mining

Fossicking field in Lightning Ridge

 

Other than agriculture and tourism, the main economic activity in this vast and sparsely settled area is mining. Owing to the almost complete absence of mountain building and glaciation since the Permian (in many areas since the Cambrian) ages, the outback is extremely rich in iron, aluminium, manganese and uranium ores, and also contains major deposits of gold, nickel, copper, lead and zinc ores. Because of its size, the value of grazing and mining is considerable. Major mines and mining areas in the Outback include opals at Coober Pedy, Lightning Ridge and White Cliffs, metals at Broken Hill, Tennant Creek, Olympic Dam and the remote Challenger Mine. Oil and gas are extracted in the Cooper Basin around Moomba. 

In Western Australia the Argyle diamond mine in the Kimberley is the world's biggest producer of natural diamonds and contributes approximately one-third of the world's natural supply. The Pilbara region's economy is dominated by mining and petroleum industries. Most of Australia's iron ore is also mined in the Pilbara and it also has one of the world's major manganese mines.

View of dunefields and mesa, Central Australia

Population

Aboriginal communities in outback regions, such as the Anangu Pitjantjatjara Yankunytjatjara lands in northern South Australia, have not been displaced as they have been in areas of intensive agriculture and large cities, in coastal areas.

The total population of the Outback in Australia declined from 700,000 in 1996 to 690,000 in 2006. The largest decline was in the Outback Northern Territory, while the Kimberley and Pilbara showed population increases during the same period. The sex ratio is 1040 males for 1000 females and 17% of the total population is indigenous.

Medicine

Sign on the Eyre Highway indicating that an RFDS emergency airstrip is ahead

The Royal Flying Doctor Service (RFDS) started service in 1928 and helps people who live in the outback of Australia. In former times, serious injuries or illnesses often meant death due to the lack of proper medical facilities and trained personnel.

Education

In most outback communities, the number of children is too small for a conventional school to operate. Children are educated at home by the School of the Air. Originally the teachers communicated with the children via radio, but now satellite telecommunication is used instead. Some children attend boarding school, mostly only those in secondary school.

Terminology

The concept of 'back' country, which initially meant land beyond the settled regions, was in existence in 1800. Crossing of the Blue Mountains and other exploration of the inland however gave a different dimension to the perception. The term "outback" was first used in print in 1869, when the writer clearly meant west of Wagga Wagga, New South Wales.

It is colloquially said that 'the outback' is located "beyond the Black Stump". The location of the black stump may be some hypothetical location or may vary depending on local custom and folklore. It has been suggested that the term comes from the Black Stump Wine Saloon that once stood about 10 kilometres (6.2 mi) out of Coolah, New South Wales on the Gunnedah Road. It is claimed that the saloon, named after the nearby Black Stump Run and Black Stump Creek, was an important staging post for traffic to north-west New South Wales and it became a marker by which people gauged their journeys.

"The Never-Never" is a term referring to remoter parts of the Australian outback. The Outback can also be referred to as "back of beyond", "back o' Bourke" although these terms are more frequently used when referring to something a long way from anywhere, or a long way away. The well-watered north of the continent is often called the "Top End" and the arid interior "The Red Centre", owing to its vast amounts of red soil and sparse greenery amongst its landscape.

Transport

Road sign warning of potentially dangerous conditions ahead

 

The outback is criss-crossed by historic tracks. Most of the major highways have an excellent bitumen surface and other major roads are usually well-maintained dirt roads. Tracks in very sandy or exceedingly rocky areas may require high-clearance four wheel drives and spare fuel, tyres, food and water before attempting to travel them, however most outback roads are easily traversed in ordinary vehicles, provided care is taken. Drivers unused to dirt roads should be especially cautious – it is recommended that drivers reduce their speed, drive with extra care, and avoid driving at night because animals can stray onto roads. Travelling in remote areas in northern Australia is not advisable during the wet season (November to April), as heavy tropical downpours can quickly make dirt roads impassable. In the remotest parts of Australia fuel sellers are located hundreds of kilometres apart, so spare fuel must be carried or refuelling spots calculated carefully in order not to run out of fuel in between towns. In addition, multiple trailer trucks (known as Road Trains) traverse these roads and extreme care must be taken when around these vehicles, due to their weight, length (often three full trailers long) and amount of dust thrown up by over 46 tyres. 

The Stuart Highway runs from north to south through the centre of the continent, roughly paralleled by the Adelaide–Darwin railway. There is a proposal to develop some of the roads running from the south-west to the north-east to create an all-weather road named the Outback Highway, crossing the continent diagonally from Laverton, Western Australia (north of Kalgoorlie, through the Northern Territory to Winton, in Queensland.

Air transport is relied on for mail delivery in some areas, owing to sparse settlement and wet-season road closures. Most outback mines have an airstrip and many have a fly-in fly-out workforce. Most outback sheep stations and cattle stations have an airstrip and quite a few have their own light plane. Medical and ambulance services are provided by the Royal Flying Doctor Service. The School of the Air is a radio-based school using the RFDS radios. 

Visitors to the outback often drive their own or rented vehicles, or take organised tours. Travel through remote areas on main roads is easily done and requires no planning. However travel through very remote areas, on isolated tracks, requires planning and a suitable, reliable vehicle (usually a four-wheel drive). On very remote routes considerable supplies and equipment may be required; this can include prearranged caches. It is not advisable to travel into these especially remote areas with a single vehicle, unless fully equipped with good communication technology (e.g. a satellite phone, EPIRB etc.). Many visitors prefer to travel in these areas in a convoy. Deaths of tourists and locals becoming stranded on outback trips occasionally occur, sometimes because insufficient water and food supplies were taken, or because people have walked away from their vehicle in search of help. Travellers through very remote areas should always inform a reliable person of their route and expected destination arrival time, and remember that a vehicle is much easier to locate in an aerial search, than a person, so in the event of a breakdown, they must not leave their vehicle.

Phenotypic plasticity

From Wikipedia, the free encyclopedia

Phenotypic plasticity refers to some of the changes in an organism's behavior, morphology and physiology in response to a unique environment. Fundamental to the way in which organisms cope with environmental variation, phenotypic plasticity encompasses all types of environmentally induced changes (e.g. morphological, physiological, behavioural, phenological) that may or may not be permanent throughout an individual's lifespan. The term was originally used to describe developmental effects on morphological characters, but is now more broadly used to describe all phenotypic responses to environmental change, such as acclimation (acclimatization), as well as learning. The special case when differences in environment induce discrete phenotypes is termed polyphenism.

Phenotypic plasticity is the ability of one genotype to produce more than one phenotype when exposed to different environments. Each line here represents a genotype. Horizontal lines show that the phenotype is the same in different environments; slanted lines show that there are different phenotypes in different environments, and thus indicate plasticity.

 

Generally, phenotypic plasticity is more important for immobile organisms (e.g. plants) than mobile organisms (e.g. most animals), as mobile organisms can often move away from unfavourable environments. Nevertheless, mobile organisms also have at least some degree of plasticity in at least some aspects of the phenotype. One mobile organism with substantial phenotypic plasticity is Acyrthosiphon pisum of the aphid family, which exhibits the ability to interchange between asexual and sexual reproduction, as well as growing wings between generations when plants become too populated.

Examples

Plants

Phenotypic plasticity of sorghum flowering time evaluated from seven environments. The identified photothermal time, a performance-independent index, quantifies the relevant environmental input and enables a systematic framework for modelling, explaining, and predicting phenotypic values under natural conditions.

 

Phenotypic plasticity in plants includes the timing of transition from vegetative to reproductive growth stage, the allocation of more resources to the roots in soils that contain low concentrations of nutrients, the size of the seeds an individual produces depending on the environment, and the alteration of leaf shape, size, and thickness. Leaves are particularly plastic, and their growth may be altered by light levels. Leaves grown in the light tend to be thicker, which maximizes photosynthesis in direct light; and have a smaller area, which cools the leaf more rapidly (due to a thinner boundary layer). Conversely, leaves grown in the shade tend to be thinner, with a greater surface area to capture more of the limited light. Dandelion are well known for exhibiting considerable plasticity in form when growing in sunny versus shaded environments. The transport proteins present in roots also change depending on the concentration of the nutrient and the salinity of the soil. Some plants, Mesembryanthemum crystallinum for example, are able to alter their photosynthetic pathways to use less water when they become water- or salt-stressed.

Because of phenotypic plasticity, it is hard to explain and predict the traits when plants are grown in natural conditions unless a explicit environment index can be obtained to quantify environments. Identification of photothermal time from a critical growth periods being highly correlated with sorghum flowering time enables such predictions.

Phytohormones and Leaf Plasticity

Leaves are very important to a plant in that they create an avenue where photosynthesis and thermoregulation can occur. Evolutionarily, the environmental contribution to leaf shape allowed for a myriad of different types of leaves to be created in the means of balancing energy production with the plants’ fitness. The shape of the leaf is important and not only depends on genetics, but also the environment that the plant lives in. Environmental factors, such as light and humidity have been shown to affect leaf morphology, giving rise to the question of how this shape change is controlled at the molecular level. Genotypes often give rise to specific phenotypes, however leaves have phenotypic plasticity. This means that different leaves could have the same gene but present a different form every time based on environmental factors. Plants are sessile beings so this phenotypic plasticity allows the plant to take in information from its environment and respond without changing its location and simultaneously increasing its fitness. In order to understand how leaf morphology works, the anatomy of a leaf must be understood. The main part of the leaf, the blade or lamina, consists of the epidermis, mesophyll, and vascular tissue. The epidermis contains stomata which allows for gas exchange and controls perspiration of the plant. The mesophyll contains most of the chloroplast where photosynthesis can occur. Developing a wide blade/lamina can maximize the amount of light hitting the leaf, thereby increasing photosynthesis, however too much sunlight can damage the plant. Wide lamina can also catch wind easily which can cause stress to the plant, so finding a happy medium is imperative to the plants’ fitness. The Genetic Regulatory Network (GRN) is responsible for creating this phenotypic plasticity and involves a variety of genes and proteins regulating leaf morphology. Phytohormones have been shown to play a key role in signaling throughout the plant, and changes in concentration of the phytohormones can cause a change in development. Studies on the aquatic plant species Ludwigia arcuata have been done to look at the role of Abscisic acid (ABA), as L. arcuata is known to exhibit phenotypic plasticity and has two different types of leaves, the aerial type (leaves that touch the air) and the submerged type (leaves that are underwater). ABA is a phytohormone responsible for regulating stress responses and is known to be specifically involved in drought stress response. When adding ABA to the underwater shoots of L. arcuata, the plant was able to produce aerial type leaves underwater, suggesting that increased concentrations of ABA in the shoots, likely caused by air contact or a lack of water, triggers the change from the submerged type of leaf to the aerial type. This suggests ABA’s role in leaf phenotypic change and its importance in regulating stress through environmental change (such as adapting from being underwater to above water). In the same study, another phytohormone, ethylene, was shown to induce the submerged leaf phenotype unlike ABA, which induced aerial leaf phenotype. Because ethylene is a gas, it tends to stay endogenously within the plant when underwater – this growth in concentration of ethylene induces a change from aerial to submerged leaves and has also been shown to inhibit ABA production, further increasing the growth of submerged type leaves. These factors (temperature, water availability, and phytohormones) contribute to changes in leaf morphology throughout a plants lifetime and are vital to maximize plant fitness.

Animals

The developmental effects of nutrition and temperature have been demonstrated. The gray wolf (Canis lupus) has wide phenotypic plasticity. Additionally, male speckled wood butterflies have two morphs: one with three dots on its hindwing, and one with four dots on its hindwings. The development of the fourth dot is dependent on environmental conditions – more specifically, location and the time of year. In amphibians, Pristimantis mutabilis has remarkable phenotypic plasticity. Another example is the southern rockhopper penguin. Rockhopper penguins are present at a variety of climates and locations; Amsterdam Island's subtropical waters, Kerguelen Archipelago's subarctic coastal waters, and Crozet Archipelago's subantarctic coastal waters. Due to the species plasticity they are able to express different strategies and foraging behaviors depending on the climate and environment. A main factor that has influenced the species' behavior is where food is located.

Temperature

Plastic responses to temperature are essential among ectothermic organisms, as all aspects of their physiology are directly dependent on their thermal environment. As such, thermal acclimation entails phenotypic adjustments that are found commonly across taxa, such as changes in the lipid composition of cell membranes. Temperature change influences the fluidity of cell membranes by affecting the motion of the fatty acyl chains of glycerophospholipids. Because maintaining membrane fluidity is critical for cell function, ectotherms adjust the phospholipid composition of their cell membranes such that the strength of van der Waals forces within the membrane is changed, thereby maintaining fluidity across temperatures.

Diet

Phenotypic plasticity of the digestive system allows some animals to respond to changes in dietary nutrient composition, diet quality, and energy requirements.

Changes in the nutrient composition of the diet (the proportion of lipids, proteins and carbohydrates) may occur during development (e.g. weaning) or with seasonal changes in the abundance of different food types. These diet changes can elicit plasticity in the activity of particular digestive enzymes on the brush border of the small intestine. For example, in the first few days after hatching, nestling house sparrows (Passer domesticus) transition from an insect diet, high in protein and lipids, to a seed based diet that contains mostly carbohydrates; this diet change is accompanied by two-fold increase in the activity of the enzyme maltase, which digests carbohydrates. Acclimatizing animals to high protein diets can increase the activity of aminopeptidase-N, which digests proteins.

Poor quality diets (those that contain a large amount of non-digestible material) have lower concentrations of nutrients, so animals must process a greater total volume of poor-quality food to extract the same amount of energy as they would from a high-quality diet. Many species respond to poor quality diets by increasing their food intake, enlarging digestive organs, and increasing the capacity of the digestive tract (e.g. prairie voles, Mongolian gerbils, Japanese quail, wood ducks, mallards). Poor quality diets also result in lower concentrations of nutrients in the lumen of the intestine, which can cause a decrease in the activity of several digestive enzymes.

Animals often consume more food during periods of high energy demand (e.g. lactation or cold exposure in endotherms), this is facilitated by an increase in digestive organ size and capacity, which is similar to the phenotype produced by poor quality diets. During lactation, common degus (Octodon degus) increase the mass of their liver, small intestine, large intestine and cecum by 15–35%. Increases in food intake do not cause changes in the activity of digestive enzymes because nutrient concentrations in the intestinal lumen are determined by food quality and remain unaffected. Intermittent feeding also represents a temporal increase in food intake and can induce dramatic changes in the size of the gut; the Burmese python (Python molurus bivittatus) can triple the size of its small intestine just a few days after feeding.

AMY2B (Alpha-Amylase 2B) is a gene that codes a protein that assists with the first step in the digestion of dietary starch and glycogen. An expansion of this gene in dogs would enable early dogs to exploit a starch-rich diet as they fed on refuse from agriculture. Data indicated that the wolves and dingo had just two copies of the gene and the Siberian Husky that is associated with hunter-gatherers had just three or four copies, whereas the Saluki that is associated with the Fertile Crescent where agriculture originated had 29 copies. The results show that on average, modern dogs have a high copy number of the gene, whereas wolves and dingoes do not. The high copy number of AMY2B variants likely already existed as a standing variation in early domestic dogs, but expanded more recently with the development of large agriculturally based civilizations.

Parasitism

Infection with parasites can induce phenotypic plasticity as a means to compensate for the detrimental effects caused by parasitism. Commonly, invertebrates respond to parasitic castration or increased parasite virulence with fecundity compensation in order to increase their reproductive output, or fitness. For example, water fleas (Daphnia magna), exposed to microsporidian parasites produce more offspring in the early stages of exposure to compensate for future loss of reproductive success. A reduction in fecundity may also occur as a means of re-directing nutrients to an immune response, or to increase longevity of the host. This particular form of plasticity has been shown in certain cases to be mediated by host-derived molecules (e.g. schistosomin in snails Lymnaea stagnalis infected with trematodes Trichobilharzia ocellata) that interfere with the action of reproductive hormones on their target organs. Changes in reproductive effort during infection is also thought to be a less costly alternative to mounting resistance or defence against invading parasites, although it can occur in concert with a defence response.

Hosts can also respond to parasitism through plasticity in physiology aside from reproduction. House mice infected with intestinal nematodes experience decreased rates of glucose transport in the intestine. To compensate for this, mice increase the total mass of mucosal cells, cells responsible for glucose transport, in the intestine. This allows infected mice to maintain the same capacity for glucose uptake and body size as uninfected mice.

Phenotypic plasticity can also be observed as changes in behaviour. In response to infection, both vertebrates and invertebrates practice self-medication, which can be considered a form of adaptive plasticity. Various species of non-human primates infected with intestinal worms engage in leaf-swallowing, in which they ingest rough, whole leaves that physically dislodge parasites from the intestine. Additionally, the leaves irritate the gastric mucosa, which promotes the secretion of gastric acid and increases gut motility, effectively flushing parasites from the system. The term "self-induced adaptive plasticity" has been used to describe situations in which a behavior under selection causes changes in subordinate traits that in turn enhance the ability of the organism to perform the behavior. For example, birds that engage in altitudinal migration might make "trial runs" lasting a few hours that would induce physiological changes that would improve their ability to function at high altitude.

Woolly bear caterpillars (Grammia incorrupta) infected with tachinid flies increase their survival by ingesting plants containing toxins known as pyrrolizidine alkaloids. The physiological basis for this change in behaviour is unknown; however, it is possible that, when activated, the immune system sends signals to the taste system that trigger plasticity in feeding responses during infection.

Reproduction

Hatch rates for red-eyed tree frog tadpoles depends on predation

 

The red-eyed tree frog, Agalychnis callidryas, is an arboreal frog (hylid) that resides in the tropics of Central America. Unlike many frogs, the red-eyed tree frog has arboreal eggs which are laid on leaves hanging over ponds or large puddles and, upon hatching, the tadpoles fall into the water below. One of the most common predators encountered by these arboreal eggs is the cat-eyed snake, Leptodeira septentrionalis. In order to escape predation, the red-eyed tree frogs have developed a form of adaptive plasticity, which can also be considered phenotypic plasticity, when it comes to hatching age; the clutch is able to hatch prematurely and survive outside of the egg five days after oviposition when faced with an immediate threat of predation. The egg clutches take in important information from the vibrations felt around them and use it to determine whether or not they are at risk of predation. In the event of a snake attack, the clutch identifies the threat by the vibrations given off which, in turn, stimulates hatching almost instantaneously. In a controlled experiment conducted by Karen Warkentin, hatching rate and ages of red-eyed tree frogs were observed in clutches that were and were not attacked by the cat-eyed snake. When a clutch was attacked at six days of age, the entire clutch hatched at the same time, almost instantaneously. However, when a clutch is not presented with the threat of predation, the eggs hatch gradually over time with the first few hatching around seven days after oviposition, and the last of the clutch hatching around day ten. Karen Warkentin's study further explores the benefits and trade-offs of hatching plasticity in the red-eyed tree frog.

Evolution

Plasticity is usually thought to be an evolutionary adaptation to environmental variation that is reasonably predictable and occurs within the lifespan of an individual organism, as it allows individuals to 'fit' their phenotype to different environments. If the optimal phenotype in a given environment changes with environmental conditions, then the ability of individuals to express different traits should be advantageous and thus selected for. Hence, phenotypic plasticity can evolve if Darwinian fitness is increased by changing phenotype. However, the fitness benefits of plasticity can be limited by the energetic costs of plastic responses (e.g. synthesizing new proteins, adjusting expression ratio of isozyme variants, maintaining sensory machinery to detect changes) as well as the predictability and reliability of environmental cues.

Freshwater snails (Physa virgata), provide an example of when phenotypic plasticity can be either adaptive or maladaptive. In the presence of a predator, bluegill sunfish, these snails make their shell shape more rotund and reduce growth. This makes them more crush-resistant and better protected from predation. However, these snails cannot tell the difference in chemical cues between the predatory and non-predatory sunfish. Thus, the snails respond inappropriately to non-predatory sunfish by producing an altered shell shape and reducing growth. These changes, in the absence of a predator, make the snails susceptible to other predators and limit fecundity. Therefore, these freshwater snails produce either an adaptive or maladaptive response to the environmental cue depending on whether the predatory sunfish is actually present.

Given the profound ecological importance of temperature and its predictable variability over large spatial and temporal scales, adaptation to thermal variation has been hypothesized to be a key mechanism dictating the capacity of organisms for phenotypic plasticity. The magnitude of thermal variation is thought to be directly proportional to plastic capacity, such that species that have evolved in the warm, constant climate of the tropics have a lower capacity for plasticity compared to those living in variable temperate habitats. Termed the "climatic variability hypothesis", this idea has been supported by several studies of plastic capacity across latitude in both plants and animals. However, recent studies of Drosophila species have failed to detect a clear pattern of plasticity over latitudinal gradients, suggesting this hypothesis may not hold true across all taxa or for all traits. Some researchers propose that direct measures of environmental variability, using factors such as precipitation, are better predictors of phenotypic plasticity than latitude alone.

Selection experiments and experimental evolution approaches have shown that plasticity is a trait that can evolve when under direct selection and also as a correlated response to selection on the average values of particular traits.

Plasticity and climate change

Unprecedented rates of climate change are predicted to occur over the next 100 years as a result of human activity. Phenotypic plasticity is a key mechanism with which organisms can cope with a changing climate, as it allows individuals to respond to change within their lifetime. This is thought to be particularly important for species with long generation times, as evolutionary responses via natural selection may not produce change fast enough to mitigate the effects of a warmer climate.

The North American red squirrel (Tamiasciurus hudsonicus) has experienced an increase in average temperature over this last decade of almost 2 °C. This increase in temperature has caused an increase in abundance of white spruce cones, the main food source for winter and spring reproduction. In response, the mean lifetime parturition date of this species has advanced by 18 days. Food abundance showed a significant effect on the breeding date with individual females, indicating a high amount of phenotypic plasticity in this trait.