Text 5. Ecology and Evolution.

 

Ecology is closely allied with its sister discipline evolution. The two disciplines often appear together, such as in the title of one on the most highly cited journals in the field “Trends in Ecology and Evolution”. Ecology and evolution are scientifically connected because they both study hierarchy, networks, relations, and kinship among genes, cells, individuals, communities, species, and the biosphere. There is no sharp dichotomous boundary that separates the two disciplines and they differ more in their areas of applied focus than in their shared scientific philosophies on nature. Both disciplines find and explain unique properties and processes operating in different ways according the spatial or temporal scales being considered. Ecological theory is not necessarily invoked in evolutionary research, such as what role it played in the major transitions in the history of life. Evolution is concerned primarily with the nature of change through the guiding principals of natural selection, inheritance, and differential survival. While the boundary between ecology and evolution is not always clear, it is understood that ecology studies the abiotic and biotic factors that influence the evolutionary process.

 

Text 6. Ecological Crisis.

 

Generally, an ecological crisis occurs with the loss of adaptive capacity when the resilience of an environment or of a species or a population evolves in a way unfavourable to coping with perturbations that interfere with that ecosystem, landscape or species survival. It may be that the environment quality degrades compared to the species needs, after a change in an abiotic ecological factor (for example, an increase of temperature, less significant rainfalls). It may be that the environment becomes unfavourable for the survival of a species (or a population) due to an increased pressure of predation (for example overfishing). Lastly, it may be that the situation becomes unfavourable to the quality of life of the species (or the population) due to a rise in the number of individuals (overpopulation).

Ecological crises vary in length and severity, occurring within a few months or taking as long as a few million years. They can also be of natural or anthropic origin. They may relate to one unique species or to many species, as in an Extinction event. Lastly, an ecological crisis may be local (as an oil spill) or global (a rise in the sea level due to global warming).

According to its degree of endemism, a local crisis will have more or less significant consequences, from the death of many individuals to the total extinction of a species. Whatever its origin, disappearance of one or several species often will involve a rupture in the food chain, further impacting the survival of other species.

In the case of a global crisis, the consequences can be much more significant; some extinction events showed the disappearance of more than 90% of existing species at that time. However, it should be noted that the disappearance of certain species, such as the dinosaurs, by freeing an ecological niche, allowed the development and the diversification of the mammals. An ecological crisis thus paradoxically favoured biodiversity.

Sometimes, an ecological crisis can be a specific and reversible phenomenon at the ecosystem scale. But more generally, the crises impact will last. Indeed, it rather is a connected series of events, that occur till a final point. From this stage, no return to the previous stable state is possible, and a new stable state will be set up gradually.

Lastly, if an ecological crisis can cause extinction, it can also more simply reduce the quality of life of the remaining individuals. Thus, even if the diversity of the human population is sometimes considered threatened, few people envision human disappearance at short span. However, epidemic diseases, famines, impact on health of reduction of air quality, food crises, reduction of living space, accumulation of toxic or non degradable wastes, threats on keystone species (great apes, panda, whales) are also factors influencing the well-being of people.

Due to the increases in technology and a rapidly increasing population, humans have more influence on their own environment than any other ecosystem engineer.

 

After you read Texts 5 and 6. Answer these questions:

1. How are ecology and evolution connected?

2. Do you think there are some differences between ecology and evolution?

3. What are the reasons of occurring the ecological crisis problem?

4. What is the length of ecological crisis?

5. What spheres of environment does it cover?

6. What events can ecological crisis lead to?

7. Does this problem concern you personally? In what way?

Fast Facts

· Every ton of paper recycled saves 17 trees!

· The garbage in a landfill stays for about 30 years.

· Approximately only 10 percent of every landfill can be cleaned up.

· Each person throws away approximately four pounds of garbage every day.

· One bus carries as many people as 40 cars!

· More than 1/3 of all energy is used by people at home

· Most families throw away about 88 pounds of plastic every year

· We each use about 12, 000 gallons of water every year

· 1/3 of all water is used to flush the toilet.

· The 500 million automobiles on earth burn an average of 2 gallons of fuel a day.

· Each gallon of fuel releases 20 pounds of carbon dioxide into the air.

· Approximately 5 million tons of oil produced in the world each ear ends up in the ocean.

· The energy we save when we recycle one glass bottle is enough to light a traditional light bulb for four hours

· For every 2000 pounds of paper (1 ton) recycled, we save 7, 000 gallons of water free from chemicals.

· Recycled paper requires 64% less energy than making paper from virgin wood pulp, and can save many trees

· The amount of wood and paper we throw away is enough to heat 50 million homes for 20 years

· Earth is 2/3 water. But all the fresh water streams only represent one hundredth of one percent.

· 14 billion pounds of trash is dumped into the ocean every year

· It takes 90% less energy to recycle aluminum cans than to make new ones

· 5 billion aluminum cans are used each year

· 84 percent of all household waste can be recycled.

· Computers pose an environmental threat because much of the material that makes them up is hazardous. A typical monitor contains 4-5 pounds of lead.

· Ivory comes from dead elephants, its best not to buy it.

· Fur coats often come from endangered animals, it's best not to buy them.

· One gallon of motor oil can contaminate up to 2 million gallons of water. So dispose of properly!

· Here is an example of the water we use everyday: 3-7 gallons for toilet, 25-30 gallons for tub, 50-70 gallons for a 10 minute shower, 1 washing machine load uses 25-40 gallons, 1 dishwasher load uses 9-12 gallons

· Here is an example of how long it takes some things take to break down: plastics take 500 years, aluminum cans take 500 years, organic materials, take 6 months, cotton, rags, paper take 6 months.

Important Terms

A nthropogenic – Human-induced or human-caused, derived from the Greek root anthropos meaning " man."

B iological diversity (biodiversity) – The variety of different living organisms from all sources including terrestrial, marine and other aquatic ecosystems and the variety of different ecosystems that they form. This includes diversity within species, between species and of ecosystems, and the genetic variability of each species.

B iological resources – Includes genetic resources, organisms or parts thereof, populations, or any other biotic component of ecosystems with actual or potential use or value for humanity.

B iomass – The total amount of living organisms in a given area.

B iosphere – The global ecosystem; that part of the earth and atmosphere capable of supporting living organisms.

B y-Product – A useful and marketable product or service that is not the primary product or service being produced.

C limate change – The slow variations of climatic characteristics over time at a given place. Usually refers to the change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is, in addition to natural climate variability, observed over comparable periods.

C limate – The long term average condition of the weather in a given area.

C lassification – Classification attributes are environmental interventions/aspects listed in an environmental inventory/environmental effects register according to environmental impact categories.

C onservation – The long-term protection and sustainable management of natural resources in accordance with principles that ensure long-term economic and social benefits.

C o-Product – A marketable by-product from a process that can technically not be avoided. This includes materials that may be traditionally defined as waste such as industrial scrap that is subsequently used as a raw material in a different manufacturing process.

C ontaminant – Any biological, chemical, physical or radiological substance that has an negative effect on air, soil or water.

D amage – A deterioration in the quality of the environment not directly attributable to depletion or pollution.

D eforestation – The felling of trees, usually for commercial purposes.

D esertification – Land degradation in arid, semi-arid and dry sub-humid areas resulting from various factors, including climatic variations and human activities.

D epletion – The result of the extraction of abiotic resources (non-renewable) from the environment or the extraction of biotic resources (renewable) faster than they can be renewed.

E cosphere – Refers to the entire global ecosystem that comprises atmosphere, lithosphere, hydrosphere, and biosphere as inseparable components.

E cosystem – A dynamic and complex system of plant, animal and microorganism communities and their non-living environment all interacting as a functional unit within a defined physical location. The term may be applied to a unit as large as the entire ecosphere, but usually refers to a division thereof.

E mission – One or more substances released to the water, air or soil in the natural environment.

E ndangered species – A species threatened with extinction.

E nvironment – Surroundings in which an organization operates, including air, water, land, natural resources, flora, fauna, humans, and their interrelations. This definition extends the view from a company focus to the global system.

E nvironmental Aspects – Elements of an organization's activities, products or services which can interact with the environment (ISO 14004). A significant environmental aspect is an environmental aspect which has or can have a significant environmental impact.

E nvironmental Effect – Any direct or indirect impingement of activities, products and services of an organization upon the environment, whether adverse or beneficial. An environmental effect is the consequence of an environmental intervention in an environmental system.

E nvironmental Intervention – Exchange between the economy and the environment including resource extraction, emissions to the air, water, or soil, and aspects of land use. If resource extraction is excluded, the term used in this case is environmental release.

E nvironmental Inventory – An environmental inventory identifies and quantifies - where appropriate - all environmental aspects of an organization's activities, products and services.

E nvironmental Problem – An environmental problem is a description of a known process within the environment or a state of the environment which has adverse effects on the sustainability of the environment including society. They include resource consumption and environmental impacts.

E utrophication – Over-enrichment of a water body with nutrients, resulting in excessive growth of organisms and depletion of oxygen concentration.

E xtinct species – A species that no longer survives anywhere in the world.

F ossil fuels – Coal, oil, petroleum, and natural gas and other hydrocarbons are called fossil fuels because they are made of fossilized, carbon-rich plant and animal remains.

G lobal Warming – Strictly speaking, global warming and global cooling refer to the natural warming and cooling trends that the Earth has experienced all through its history. However, the term usually refers to the gradual rise in the Earth's temperatures that could result from the accumulated gases that are trapped in the atmosphere.

G reenhouse effect – A warming of the Earth's atmosphere caused by the presence in the atmosphere of certain heat-trapping gases (e.g., water vapour, carbon dioxide, methane). These gases absorb radiation emitted by the Earth, thereby retarding the loss of energy from the system to space.

G reenhouse gases – Those gaseous constituents of the atmosphere, both natural and artificial, that absorb and reemit infrared radiation and that are responsible for global warming. The most potent greenhouse gas, carbon dioxide, is rapidly accumulating in the atmosphere due to human activities.

H azardous waste – Refuse that could present dangers through the contamination and pollution of the environment. It requires special disposal techniques to make it harmless or less dangerous.

I ndustrial Revolution – The Industrial Revolution began in the early 1800's and heralded the birth of the " modern times." After the Industrial Revolution, work that was done by hand was accomplished through the use of machines. It brought on the advent of the steam engine, cotton gin, sewing machine, paper, telegraph, and railroad and it saw the beginnings of many of our present industries.

N atural resource – (e.g., tree biomass, fresh water, fish) whose supply can essentially never be exhausted, usually because it is continuously produced.

N on-renewable resources – Natural resources that are not naturally replenished once they have been harvested. Non-renewable resources can be used up completely or else used up to such a degree that it is economically impractical to obtain any more of them. Fossil fuels and metal ores are examples of non-renewable resources.

P ollution – Residual discharges of emissions to the air or water following application of emission control devices (EPA 1993b).

P revention of Pollution – The use of processes, practices, methods or products that avoid, reduce or control pollution. These may include recycling, treatment, process changes, control mechanisms, efficient use of resources and material substitution.

Recycling – The process of re-using material for the production of new goods or services on the same quality level. If the quality of the goods and services produced with recycled material is lower, then the process is known as downcycling.

Resources – Materials found in the environment that can be extracted from the environment in an economic process. There are abiotic resources (non-renewable) and biotic resources (renewable).

R euse – The additional use of a component, part, or product after it has been removed from a clearly defined service cycle. Reuse does not include reformation. However, cleaning, repair, or refurbishing may be done between uses.

S ystem – A collection of operations that perform a desired function.

S ustainable development – Development that ensures that the use of resources and the environment today does not compromise their use in the future.

T oxic – Harmful to living organisms.

U ltraviolet Radiation (UV) – Electromagnetic radiation in the wavelength range of 200 to 400 nanometres. (Also known as ultraviolet light).

W aste – An output with no marketable value that is discharged to the environment. Normally the term " waste" refers to solid or liquid materials.

 

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