Darwin's Theory of Evolution

Charles Darwin's book titled "On the Origin of Species" introduced the theory that populations evolve over the course of generations through a process of natural selection. Darwin's book was the culmination of evidence he had accumulated on the voyage of the Beagle in the late 1830s and expanded through continuing investigations and experiments after his return.

Essentially the concept of natural selection means that individuals best adapted to their environments are more likely to survive and reproduce. As long as there is some variation between them, there will be an inevitable selection of individuals with the most advantageous variations. If the variations are inherited, then differential reproductive success will lead to a progressive evolution of particular populations of a species, and populations that evolve to be sufficiently different might eventually become different species.

One of the locations visited by Darwin during his voyage on the Beagle was to the Galapagos Islands. On the Galapagos Islands he noticed the slight variations that made tortoises from different islands recognizably distinct. He also observed a whole array of unique finches that exhibited slight differences from island to island. In addition, they all appeared to resemble, but differ from, the common finch on the mainland of Ecuador, 600 miles to the east. Galapagos finches are the famous example from Darwin's voyage. Each island of the Galapagos that Darwin visited had its own kind of finch (14 in all), found nowhere else in the world. Some had beaks adapted for eating large seeds, others for small seeds, some had parrot-like beaks for feeding on buds and fruits, and some had slender beaks for feeding on small insects. One used a thorn to probe for insect larvae in wood, like some woodpeckers do. (Six were ground-dwellers, and eight were tree finches.) (This diversification into different ecological roles, or niches, is thought to be necessary to permit the coexistence of multiple species.) To Darwin, it appeared that each was slightly modified from an original colonist, probably the finch on the mainland of South America, some 600 miles to the east. It is probable that adaptive radiation led to the formation of so many species because other birds were few or absent, leaving empty niches to fill; and because the numerous islands of the Galapagos provided ample opportunity for geographic isolation. Similar conclusions were drawn from observing the Galapagos tortoises.

During our Environmental Studies class we observed many different turtles and tortoises. There is a clear indication that through natural selection, the different species I examined have over time, developed adaptations specific to their habitats that have allowed them to survive.
For example the snake-necked turtle has a unusually long neck. This unique characteristic gave the snake-necked turtle the ability to survive over other species because of their extended reach making it easier to capture prey.
Another turtle we observed was the soft shell turtle. The adaptation developed by this turtle is a smooth streamlined shell allowing it to swim at faster speeds than other turtles, decreasing its chances of being captured by predators.
The adaptations found on the different species around the world were developed over long periods of time through the process of natural selection, making each specie special and unique.


Sources
Evolution and Natural Selection
http://www.globalchange.umich.edu/globalchange1/current/lectures/selection/selection.html
Wikipedia.org

Mini Project # 5: Pollution in Your Neighborhood

Superfund is the name given to the environmental program established to address abandoned hazardous waste sites. It is also the name of the fund established by the Comprehensive Environmental Response, Compensation and Liability Act of 1980. This law was enacted in the wake of the discovery of toxic waste dumps such as Love Canal and Times Beach in the 1970s. It allows the EPA (Environmental Protection Agency) to clean up such sites and to compel responsible parties to perform cleanups or reimburse the government for EPA-lead cleanups.

The Superfund cleanup process is complex. It involves the steps taken to assess sites, place them on the National Priorities List, and establish and implement appropriate cleanup plans. This is the long-term cleanup process. In addition, the Agency has the authority to:

• Conduct removal actions where immediate action needs to be taken;
• To enforce against potentially responsible parties;
• To ensure community involvement;
• Involve states;
• Ensure long-term protectiveness.

The blueprint for these activities is the National Oil and Hazardous Substances Pollution Consistency Plan (NCP), a regulation applicable to all federal agencies involved in responding to hazardous substance releases. Over the past 20+ years, they have located and analyzed tens of thousands of hazardous waste sites, protected people and the environment from contamination at the worst sites, and involved others in cleanup.

The Superfund site closest to my house is called Davie Landfill and it is located on SW 142nd AVE in Davie, FL. According to the Superfund website "under current conditions at this site, potential or actual human exposures are under control". This means that the site has been cleaned and is not a risk to humans or wildlife. Many other Superfund sites are listed on the website that are near my home and it is disturbing to know that these sites are highly contaminated and pose a threat to humans and wildlife.

To find out what Superfund sites are near your home visit: http://www.epa.gov/superfund/sites/index.htm

Sources

U.S. Environmental Protection Agency Superfund at http://www.epa.gov/superfund/index.htm

Mini Project # 4: Grocery List

An article written by Deborah Whitman called, Genetically-Modified Foods: Harmful or Helpful?, explains that the term GM foods or GMOs (genetically-modified organisms) is most commonly used to refer to crop plants created for human or animal consumption using the latest molecular biology techniques. These plants have been modified in the laboratory to enhance desired traits such as increased resistance to herbicides or improved nutritional content. For example, plant geneticists can isolate a gene responsible for drought tolerance and insert that gene into a different plant. The new genetically-modified plant will gain drought tolerance as well.
Some genetically-modified foods that are on sale for public consumption include tomatoes and cantalopes that have modified ripening characteristics, soybeans and sugarbeets that are resistant to herbicides, and corn and cotton plants with increased resistance to insect pests. Not all these products are available in supermarkets yet; however, the prevalence of GM foods in U.S. grocery stores is more widespread than is commonly thought. While there are very, very few genetically-modified whole fruits and vegetables available on produce stands, highly processed foods, such as vegetable oils or breakfast cereals, most likely contain some tiny percentage of genetically-modified ingredients because the raw ingredients have been pooled into one processing stream from many different sources. Also, the ubiquity of soybean derivatives as food additives in the modern American diet virtually ensures that all U.S. consumers have been exposed to GM food products.

Genetically-modified foods have the potential to solve many of the world's hunger and malnutrition problems, and to help protect and preserve the environment by increasing yield and reducing reliance upon chemical pesticides and herbicides. Yet there are many challenges ahead for governments, especially in the areas of safety testing, regulation, international policy and food labeling. Many people feel that genetic engineering is the inevitable wave of the future and that we cannot afford to ignore a technology that has such enormous potential benefits. However, we must proceed with caution to avoid causing unintended harm to human health and the environment as a result of our enthusiasm for this powerful technology.

For more information on Genetically-Modified Foods please visit:

Sources
Genetically-Modified Foods: Harmful or Helpful? at http://www.csa.com/discoveryguides/gmfood/overview.php
U.S. Department of Agriculture at http://www.ers.usda.gov/briefing/biotechnology/

Mini Project # 3: Endangered Species

Colombia, located in South America, has a rich and diverse ecosystem. The country is home to one of the world’s greatest varieties of birds, as well as hundreds of different kinds of mammals and thousands of types of insects and plants. Yet the varied ecosystems of Colombia’s Andean ridges and valleys are becoming increasingly endangered, due mainly to deforestation and smuggling.

An article called Despatches: Americas written by Timothy Ross, a reporter with BBC News, states that "seven-million creatures every year are captured, smuggled out and sold abroad. Parrots, toucans and macaws, the golden lion tamarin, marmosets, ocelots and margay cats, even baby alligators, are victims of a savage traffic."

The following list represents the animals that are endangered in Colombia according to the 1994 - 2004 IUCN Red List of Threatened Animals.

The Caiman

Colombian Weasel

The Condor

Cotton-top Tamarin

Dryland Mouse Opossum

Ecuadorian Sac-Winged Bat

Giant Armadillo

Giant Otter

Green Turtle

Loggerhead Turtle

Magdalena River Turtle

Mountain Tapir

Olive Ridley

Pacarana

Variegated Spider Monkey

White-Footed Tamarin

This list represents the birds that are endangered.

Sources:
MSN Encarta
Animalinfo.org
IUCN Red List of Threatened Species

Mini Project # 2: Carbon Cycle

The Carbon Cycle is the bio-geochemical cycle by which carbon is exchanged among the Earth's atmospheric, terrestrial and oceanic carbon reservoirs. The cycle is usually thought of as three major reservoirs of carbon interconnected by pathways of exchange.

These reservoirs are:

• The atmosphere.


• The terrestrial biosphere, which is usually defined to include fresh water systems and non-living organic material, such as soil carbon.


• The oceans, including dissolved inorganic carbon and living and non-living marine biota.

The U.S. Carbon Cycle Program is an organization which seeks to better understand past changes in atmospheric carbon dioxide, deliver credible predictions of future atmospheric carbon dioxide levels and strengthen our understanding of climate change and the effect carbon has on the Earth.

The National Oceanic & Atmospheric Administration contains detailed information explaining the carbon cycle, the effect carbon has on the Earth and ways we can limit the amount of carbon released in the atmosphere.

Image and information from:
Wikipedia.org
U.S. Carbon Cycle Program
National Oceanic & Atmospheric Administration

Mini Project # 1: Environmental Organizations

The following links belong to respected organizations which are dedicated to the conservation of the environment and the protection of its natural resources and wildlife.

Wild Spot Foundation
http://www.wildspotsfoundation.org/moreaboutwsf.html

National Resouce Defense Council
http://www.nrdc.org/about/mission.asp

GreenPeace
http://www.greenpeace.org/international/about/our-core-values

My task is to determine which of the following organizations do I wish to join.

After reviewing each organizations mission statement,
I would like to join the National Resource Defense Council (NRDC).

The NRDC's purpose is to safeguard the Earth: its people, its plants and animals and the natural systems on which all life depends by finding new ways in which humankind can be sustained indefinitely without fouling or depleting the resources that support all life on Earth.

I feel that their mission closely resembles my passion to find alternative ways to sustain humankind in an efficient and safe manner which minimizes the cost we place on the Earth. Alternatives such as solar and wind power, hydrogen or electricity to power automobiles, etc.