Tuesday, May 11, 2010


Biosolids (treated sludge) are nutrient-rich organic materials that are created through the treatment of domestic wastewater generated from sewage treatment facilities. At the facility, the sewage goes through physical, chemical and biological processes to remove the solids and separate water. If necessary, the solids get treated with lime to raise the pH level to eliminate odor problems. The wastewater treatment processes sanitize wastewater solids to control pathogens and other organisms that can cause diseases. In Toronto, biosolids are treated at the Ashbridges Bay Treatment Plant (77%) and the Highland Creek Treatment Plant (23%) and generates about 195,000 tonnes every year (about 72% of this is water). Biosolids are used as sustainable agricultural fertilizer to improve and maintain productive soils and to stimulate plant growth. They have been used by farmers and gardeners to promote the growth of agricultural crops, fertilize gardens and parks, and reclaim mining sites.

Wastewater Treatment

Source: http://www.omafra.gov.on.ca/english/nm/nasm/info/brochure.htm#1

In this picture, municipal wastewater enters the treatment plant in which it undergoes primary treatment where heavier solids settle out. These heavier solids are sent to either an aerobic or anaerobic digester where the organic solids are converted by micro-organisms into a stable form. When that process has been completed, biosolids get transported to a land application site or a storage facility.

The cleaner wastewater resulting from primary treatment undergoes secondary treatment where chemicals are added to precipitate out phosphorus in chemical compounds, and promote the coagulation or aggregation of other solids that still remain in wastewater. The water from secondary treatment gets subjected to chlorination (disinfection) and then gets discharged to the surface water outlet.

Quality of Biosolids

Nutrients and Phosphorus in Biosolids

Biosolids contain large amount of nutrients such as nitrogen and phosphorous, and contain trace elements such as sulfur, magnesium, calcium, copper, and zinc. Nutrients are important for crop production and growth. Plants obtain nutrients from the soil and return them to the land when it dies and decays. This natural cycle is interrupted when agricultural harvesting removes part or all of the plant from the land. Farmers can replace nutrients in the soil with biosolids.

Organic Matter

Biosolids are mainly composed of organic matter. Application to land can help restore organic matter that is removed from the soil by tilling and harvesting. The organic matter in biosolids makes soils more absorbent, improves the circulation of air and water and provides space for plant roots. This results in better plant growth, greater resistance to unfavourable weather conditions and better soil manageability. Most cultivated soils in Ontario contain less desirable amounts of organic matter but when its added with biosolids, organic matter gets added.

Metals in Biosolids

Biosolids contain small quantities of metals such as iron, manganese, zinc, copper, boron, molybdenum and cobalt. This is linked to insoluble inorganic and organic components. As a result, metals added to soil are stable and will not easily migrate into surrounding ground and surface water. Plant uptake of metals in the soil is small. Field crops remove less than 0.4 kg/ hectare per year of metals from the soil. Uptake of metals added to the soil will vary depending upon the crop grown, soil pH, soil organic matter, clay content, soil aeration and the concentrations of nutrients and metals originally in the soil.

Uses of Biosolids

Biosolids are used in different areas: agriculture, mine reclamation, land scraping and forestry.


Biosolids are used to fertilize fields for raising crops. Agricultural use of biosolids has made significant improvements in crop growth and yield. It reduces the farmer’s production costs and replenishes the organic matter that has been depleted from the soil. The organic matter increases the soil’s ability to absorb and store moisture.

Mine Reclamation

Biosolids have been used at mine sites to establish sustainable vegetation. The organic matter, inorganic matrix and nutrients in the biosolids reduce the bioavailability of toxic substances that are found in mine soils and they also regenerate the soil layer. This regeneration is very important for reclaiming abandoned mine sites with little or no topsoil.

Source: http://www.rdn.bc.ca/cms/wpimages/wpID1140imgID1072.jpg


Biosolids composted with sawdust, wood chips, yard clippings, or crop residues makes excellent mulches and topsoils for horticultural and landscaping purposes. Many professional landscapers use composted biosolids for landscaping new homes and businesses. Home gardeners also find composted biosolids to be an excellent addition to planting gardens.


Biosolids have been found to promote rapid timber growth that is allowing quicker and more efficient harvest of an important natural resource.

Source: http://cfc.cfans.umn.edu/research/images/biosolids3.JPG

Toronto Biosolids

Throughout the world, biosolids are returned to the environment in a variety of ways. Although the city of Toronto continually pursues beneficial reuse options, we currently use a combination of methods to manage biosolids. The table below shows where our biosolids went in 2008:

2008 Biosolids Reuse/Disposal Methods Management Percentage
Landfill 41%
Incineration at Highland Creek 23%
Land Application 11%
Pelletization 16%
Alkaline Stabilization 5%
Site Remediation 4%

Source: http://www.toronto.ca/water/biosolids/index.htm

Advantages of Biosolids

  • Biosolids are rich in both organic matter and essential plant nutrients
  • It can be utilized as a soil amendment and fertilizer.
  • Biosolids act as a soil amendment through the contribution of organic matter.
  • Increased organic matter improves soil physical properties including moisture holding capacity, aggregation, porosity and tilth.
  • A reduction in fertilizer costs
  • Biosolids serve as a fertilizer by providing essential micro (e.g. zinc, copper and iron) and macronutrients (e.g. nitrogen, phosphorus and potassium).

Disadvantages of Biosolids

  • Biosolids can cause odor problems especially in residential areas
  • Some metals in biosolids can create problems with human health and plant growth.
  • The soil can have an excess of nutrients.
  • Biosolids may have pathogens, which can cause diseases


Biosolids can improve and maintain productive soils and stimulate plant growth so it has been used by farmers and gardeners widely. It contains lots of nutrients such as nitrogen and phosphorous, and trace elements such as sulfur, magnesium, calcium, copper, and zinc. Biosolids can be used in a variety of areas such as agriculture, mine reclamation, land scraping, and forestry. It can improve crop growth and soil productivity in agriculture and landscaping. It can establish suitable vegetation in mine reclamation and promote timber growth in forestry.
Increased organic matter improves soil physical properties including moisture holding capacity, aggregation, porosity and tilth. Improvement of these properties facilitates transport of air, water and nutrients throughout the soil, benefiting the establishment and growth of vegetation. Biosolids serve as a fertilizer by providing essential micro (e.g. zinc, copper and iron) and macronutrients (e.g. nitrogen, phosphorus and potassium) that increase vegetation growth and productivity. The stabilized biosolids provide a slow release source of nutrients that can be utilized by plants for several years following application. Farmers and gardeners can save money by using biosolids to fertilize.

On the other hand, there are disadvantages in using biosolids. Biosolids can cause odor problems especially in residential areas. It may contain some pathogens that can cause disease. Some metals present in biosolids can create problems with human health and plant growth. For example, arsenic (a metal present in biosolids) can cause health problems in a child eating a soil mixed with biosolids. Nickel (another metal present in biosolids) can deteriorate plant growth. The soil can only store a certain amount of nutrients so the excess moves to surface water or groundwater. That can cause high nitrate concentrations in forage that can kill animals consuming the forage.

When comparing the advantages and disadvantages of biosolids, I find that there are more advantages than disadvantages. For successful utilization of biosolids, we need a combination of proper application methods, best management practices, and nutrient management planning. When biosolids are applied to land according to regulatory requirements, risks to environment and human health are negligible. Therefore, I believe that it is beneficial to use biosolids to maintain plant growth and soil productivity.


Sunday, May 2, 2010

Advances in Medical Technology

Medical technology is an important component of medical health care and can provide significant benefits to patients. It can help us to understand internal body systems (digestive, circulatory or respiratory), diagnosis, and treatment. It includes diagnostic devices (e.g. defibrillator, MRI, CAT scans), and treatment procedures (e.g. joint replacements, therapies, surgeries). Medical technology has made a significant contribution to the development of fast, precise and gentle diagnostic procedures and new therapies. It makes the process of medical practice efficient for people in the medical field and also for the patients. There are different types of medical technology that can contribute to the understanding of all internal systems such as X-rays, MRI, CT scans, etc and some help us to understand a particular type of internal system (e.g. Defibrillator is used for the circulatory system)

In the beginning of the 20th century, medical technology became revolutionized using tools such as stethoscopes, microscopes, thermometers and X-ray machines. With these medical devices, doctors are able to see and hear patient’s organs such as lungs and heart.

Medical technology (Diagnostic devices):

  • Computerized Axial Tomography (CAT): In the present time, scientists have combined X-ray technology with computer technology to get a better view of the body organs. In the computerized axial tomography (CAT) scan procedure, many X-rays are taken from many angles and reassembled to make three-dimensional images. CAT scans provide information of different structures and these images get stored in the computer with their location and angle. CAT scans can distinguish between gases, liquids, and solid tissues are useful for detecting blood clots in the head.
Source: http://www.clarian.org/ADAM/doc/graphics/images/en/19237.jpg

Other diagnostic devices include:

  • X-rays: It uses electromagnetic radiation to make images. The image is recorded on a film, called a radiograph. The parts of the body appear light or dark because of different rates that tissues absorb the X-rays. Calcium in bones absorbs X-rays the most, so bones look white on the radiograph. Fat and other soft tissues absorb less, and look gray. Air absorbs least, so lungs look black. Health care professionals use them to look for broken bones, problems in the lungs and abdomen, cavities in teeth and many other problems. For example, mammograms use X-rays to look for tumors or suspicious areas in the breasts. X-ray technology.
  • Blood tests: A laboratory analysis performed on a blood sample that is usually extracted in the vein from an arm using a needle. Blood tests are used to determine physiological and biochemical states, such as disease, mineral content, drug effectiveness, and organ function. The blood then gets stored in a test tube.
  • Magnetic Resonance Imaging (MRI): It uses the spinning motions of the atomic nuclei to produce a map of the internal structure of human body tissue and to reveal how organs are functioning.
  • Nuclear imaging: It uses radionuclides to view organs and tissues of the body. The radionuclides that they use are the nucleii of unstable atoms that emits rays of energy. It gets injected into the body to collect in the target organs. Different radionuclides are used to identify different organs (ex. A thallium isotope can be used to identify heart imaging.
  • Stethoscope: It is used to hear sounds within the body. Doctors use it to listen to sounds from the heart, lungs, intestinal tract, and blood flow. Therefore, they are able to detect normal and abnormal cardiac, respiratory, arterial, venous, intestinal, uterine, and fetal sounds.
  • Defibrillator: It is used to detect heart rates that are too fast or too slow and correct them by using an electrical current. It can maintain or correct the rhythm of the heart.

Medical technology has helped us to provide new treatments and therapies with improved success of medical care to patients.

  • Laser Eye Surgery: It is an advanced medical technology that corrects vision problems. In this surgical procedure, light rays are bent or refracted by the cornea so that they are directed on the retina. (The retina is a layer of cells that senses light). There are two procedures of eye surgery. Each reshapes the cornea, the curved front surface of the eye. In both cases a “cold” laser is used, which prevents damage to the surrounding eye tissue. And in each case the eye gets healed by itself. During the first kind of procedure, the surgeon uses a laser beam to reshape the surface of the cornea to correct the vision. During the second kind of procedure, the surgeon cuts a flap in the cornea, lifts it, and then uses a laser to remove calculated amounts of tissue from inside the cornea, and then closes the flap.
Source: http://www.torontolasiksurgery.com/wp-content/uploads/2008/09/laser-eye-surgery-chart.jpg
  • Chemotherapy: In this treatment, drugs are used to destroy cancer cells. Chemotherapy is the most popular cancer treatment worldwide. It stops or slows down the growth of cancer cells. It is applied to treat leukemia (a kind of cancer of the bone marrow which causes uncontrollable and abnormal growth of white blood cells) and lymphoma (cancer in lymph or nodes).The functions of chemotherapy are that it cures and controls cancer, and eases cancer symptoms. Cancer cells can no longer grow back when they are destroyed by chemotherapy. Source: http://pharmaknow.com/wp-content/uploads/2008/05/chemo.jpg
  • Radiation Therapy: It is the medical use of ionizing radiation as part of cancer treatment to destroy malignant cells. It is one of the several treatments that can be used to treat cancer by itself or in a combination of other forms of treatment such as surgery or chemotherapy. Radiation therapy is also known as radiotherapy.

Source: http://www.nlm.nih.gov/medlineplus/ency/images/ency/fullsize/9805.jpg

  • Pharmacotherapy: In this treatment, disease is treated through the administration of drugs. Pharmacists are experts in pharmacotherapy and are responsible for ensuring the safe, appropriate, and economical use of medicines.

    Source: http://webjct.com/pics_for_pages/pills.jpg

One other treatment include:

  • Joint replacement: In this treatment, a damaged joint is removed and is replaced with an artificial joint, which is made of metal and plastic. An orthopaedic doctor will replace or fix only the damaged parts of the joint through surgery.

    Medical Technology in Canada

Canada is slow to adopt the latest medical technology forcing Canadian patients to rely on old and often outdated medical equipment for treatment according to the Fraser Institute.

Another key indicator of Canada’s performance is PET scanners (Positron Emission Tomography) which is used in cancer detection and treatment as well as for Alzheimer’s disease, epilepsy, and in cardiology.

The study finds that Canada ranks below average and ahead of only Finland, Spain, the United Kingdom, and the Netherlands among developed nations in the number of PET scanners per million people.

There have been studies that Canada is a late adopter of advanced medical technologies. It has not been strongly committed to investment in medical technology in the past or has restricted the introduction of new technology. Canada lags behind a number of other nations in the rate of expansion in the inventory or application of technologies. Canada also often relies more on less sophisticated forms of technology than might be optimal.


Improvements in medical technology can have dramatic effects in heath care field by improving health and quality of life for patients. Medical technology can advance the identification and treatment of diseases, provide more comfortable treatment regimes and reduce pain, offer new treatment options for patients, and can provide a safer environment for both patients and providers.

Canadians having a high level of access to the latest medical technology should be an objective of health policy in Canada. If they don’t, it would be a failure of the health care system.

Doctors can use advanced medical technology to observe and learn more about the structures and their functions, and location of disease without arranging for surgery. For example, a PET scan can detect a lung cancer that has spread to other body parts, which can avoid a surgery. It can also determine if liver tumours can be safely removed and can help determine if chemotherapy treatment is working, or whether the drug cocktail being provided needs to be changed.

Advances in medical technology had a great impact in society. They allow for greater accuracy, speed, and efficiency in diagnosing medical problems. They also provide less invasive procedures for the diagnosis of disease, which can facilitate earlier and more localized treatment. Compared to older medical technologies, they are more reliable and need less maintenance. They also provide a higher quality output and are more accurate and safer for both patients and health care providers.


• Nelson Biology 11


Monday, March 8, 2010

Artificial Selection in Plants and Animals

Artificial selection is a type of selection in which the individuals of a species are chosen to ensure the presence or absence of certain traits. This selection is usually repeated in successive generations until those attributes approach in the descendents of offspring. Artifical selection is known as selective breeding or unnatural selection. It is a great principle to farmers and breeders because they can use it to change the traits of their plants and animals. This can satisfy their needs and makes their lives easier. Artificial selection is commonly used to produce new breeds from the variable offspring of hybrid crosses. It can be accelerated by techniques such as plant tissue culture and the artificial insemination of livestock. Artificial selection can greatly affect the lives of farmers and breeders when they choose the desirable traits for their plants and/or animals such as disease resistance and high crop yield in plants, and high production and new desirable traits in animals.

When an organism undergoes an advantageous change that is passed to successive generations, it is known as natural selection. Artificial selection was utilized by Charles Darwin to be contrasted with natural selection in which differential reproduction of organisms with certain traits is attributed to improved survival or reproductive ability (“Darwinian fitness”).

Using artificial selection, farmers and breeders choose desirable traits for their plants mainly the ones that are disease-resistant and high crop yield. Plant breeders start off with variable hybrid plants and then apply selection to produce new crops, trees, and flowers with desirable traits. Plants without any desirable trait is less likely to survive as they do not have fertilizers and pesticides. In fact, they will eventually evolutes.

The domestication of plants began with wheat, peas, and olives and dramatically increased the amount of food produced, which helped support human production growth. The seeds from wild plants were actively collected, planted and cultivated. As food was harvested, seeds from best plants were selected for the planting of subsequent crops.

Farmers have cultivated numerous crops from the wild mustard by artificially selecting them for certain attributes.

Source: http://evolution.berkeley.edu/evolibrary/article/_0_0/evo_30

These vegetables were cultivated from wild mustard. This evolution came through artificial selection.

Source: http://www.gly.uga.edu/railsback/1122/Brassica2.jpeg

The dramatic results of artificial selection that can be seen in Brassica; six different vegetables – kale, Brussels sprouts, broccoli, kohlrabi, cabbage, and cauliflower. They all have the sea cabbage, Brassica oleracea as their single common ancestor.

Ontario has a large agricultural sector which produces a wide range of foods. Among Ontario’s most valuable food crops are vegetables such as tomatoes, carrots, onions, and potatoes; grains such as wheat, oats, and barley; corn (mostly for use as livestock feed); canola (for oil); soybeans; and fruits such as apples, pears, peaches, grapes, and strawberries.

Over many years of artificial selection, the frequency of desirable gene variants increases in the population.

Source: http://evolution.berkeley.edu/evolibrary/news/070201_corn

This process has produced all of the major crop plants from their wild ancestors. By figuring this out, scientists are discovering clues about how to improve crops to change human needs. Most importantly, they would like to find out which gene variants were favored by ancient people (which genes were the targets of selection).

Using artificial selection, these plants have improved by quality. The one of the left was before artificial selection was used and the one on the right was after artificial selection.

Wild sunflowers Domestic sunflowers 

Wild tomatoes Domestic tomatoes

Teosinte plants Corn plants

Source: http://evolution.berkeley.edu/evolibrary/news/070201_corn

With artificial selection in plants, plants can greatly improve by quality. Through artificial selection, the plants with the desired traits of each generation were selected to reproduce, creating the next generation. This was used by a technique (plant tissue culture) in which selected plants can be cloned and grown directly into new plants. These plants can cultivate vegetables, which are beneficial for farmers because they can sell it and make good money.

With artificial selection, animal characteristics can be changed by using a technique (artificial insemination of livestock). Farmers and breeders can change the characteristics of their animals by selecting for reproduction those individuals with the most desirable qualities such as speed in racehorses, milk production in cows, trail scenting in dogs.

Pigs are artificially selected to produce the largest amount of meat.


Source: http://www.windows.ucar.edu/tour/link=/cool_stuff/tour_evolution_7.html&br=gr

This picture shows how selecting for different traits of breeding has caused different dog breeds to have distinctive characteristics. (Dog breeds from left to right: top row- Alaskan Malamute, Basset Hound, Llasa Apsa; middle row- Beagle puppy, Shar Pei, Chow; bottom row- Pekinese, Tibetan Terrier, Pug.)

Breeding a male horse with excellent racing qualities with a healthy female horse so that the offspring will have the desired traits such as the racing qualities. Hens could be artificially selected to produce more eggs and cows can be artificially selected for a high milk production.

Advantages of Artificial Selection

  • It creates new desirable traits for plants and animals.
  • Animals can produce a lot of products (ex. pigs produce meat, hens produce eggs, and cows produce milk).
  • Farmers and breeders can attract a lot of consumers by selling their plants and the products produced by animals in their new desirable trait.
  • Artificial selection rules out weakness and disability.

    Disadvantages of Artificial Selection
  • If there is an environmental factor occurring on plants and animals that were domesticated through artificial selection, there will be a higher possibility of extinction.
  • With artificial selection, the society will be highly competitive.
  • This is very expensive so only wealthy farmers and breeders can afford it.
  • It is not according to God’s plan of creation.
  • It is inhumane so it can cause mutations or produce new problems.

In artificial selection, plants and animals can have their traits changed.to satisfy the needs of humans. Personally, I find artificial selection similar to genetic screening in designer babies that I did in my Unit 5 blog based on its facts, advantages, and disadvantages. The advantages of artificial selection include creating new desirable traits for plants and animals, animals producing a lot of products, farmers and breeders making good money, and also it gets rid of weakness and disability. Artificial selection gives farmers and breeders an opportunity to change the traits of their plants and animals. Based on my images that I showed about artificial selection in plants, they improved by quality and charcateristics such as disease-resistant and high crop yield. Animals can produce a lot of products. Pigs and produce the largest amount of meat and hens can produce a lot of eggs. There can be high milk production in cows and high speed in racehorses. On the other hand, there are disadvantages for artificial selection. From what I have learned from Unit 2 SBI 3U1, biodiversity is important to ensure survival. So if we completely create plants and animals with desirable traits and an environmental factors occurs, there will be a higher possibility of extinction but if there are different plants and animals with different traits, it will not affect the entire population so the resistant ones will reproduce and pass the genes and create a greater biodiversity. Artificial selection is very expensive so only wealthy farmers and breeders can afford it. It is not according to God’s plan of creation. It is God who created plants and animals and have given them traits so farmers and breeders cannot make any preferences. As I find that there are more disadvantages than advantages for artificial selection and there are severe consequences, artificial selection should not be used in plants and animals.


Sunday, January 3, 2010

Is Perfection A Reality?

Question: "Designer babies" is the term being used by the media to describe the future of modifying or selecting our children's genes for desirable characteristics (medical and cosmetic). Are things getting out of hand with our research into genetic processes? In the blog investigate social and ethical implications of this research and technologies that have been developed from it.

Designer babies are babies whose genetic makeup has been artifically selected by genetic engineering using InVitro Fertilization (IVF) to ensure the presence or absence of particular genes or characteristics. It is the usage of genetic screening that creates babies to meet certain criteria. It is very beneficial for parents to have "the perfect baby." They get an opportunity to choose certain traits and/or sex of the unborn baby. Genetic screening can be used to alter anything from gender to certain factors such as disease, appearance, personality, and IQ (measure of intelligence). It has given us the ability to eliminate genes that are associated with disease, genetic defects, and terminal illness. Even though parents can design the type of baby that they want using genetic screening, designer babies can affect the society in a negative way as well. In this blog, I am going to talk about the positive and negative consequences of designer babies.

Source: http://www.australasianbioethics.org/Images/cloning-8.JPG

Here is a news article on Designer Babies: Creating the perfect child:


There is also a video on designer babies:


Advanced Reproductive Technologies

The two technologies that have been developed on designer babies are: InVitro Fertilization (IVF) and Pre-implanation Genetics Diagnosis (PGD).

The InVitro Fertilization (IVF) is used to fertilize eggs with sperms in test-tubes outside the mother's body in a laboratory. This allows parents and doctors to reduce the chance that a child will be born with a genetic disorder. Thus, the resulting embryo goes back into the mother's uterus.

Source: http://www.defeatinfertility.com/wp-content/themes/NicheProfitPressV2/images/ivf-diagram.gif

This diagram shows the process of InVitro Fertilization (IVF).

IVF can be used to choose the sex of the embryo. Doctors do this by sorting out a sample of the father's sperm and only fertilize the egg with either 'male' sperm or 'female' sperm or by using Pre-implanation Genetics Diagnosis (PGD).

The Pre-implanation Genetics Diagnosis (PGD) is used to screen embryos conceived through IVF and choose which ones will or will not be implanted.

Source: http://www.arhp.org/uploadImages/cloning_7.jpg

This diagram shows the process of Pre-implanation Genetic Diagnosis.

Advantages of Designer Babies

  • It reduces the baby's chances of being born with genes of certain hereditary disorders or birth defects.
  • It gives parents an opportunity to choose certain traits and sex of their unborn baby.
  • It is possible to create the perfect baby because scientists can give its specific characteristics such as physical ability, intelligence, and appearance if its genes are altered.

Source: http://static.guim.co.uk/sys-images/Guardian/Science/pix/2007/08/01/embryoblue_2.jpg

Disadvantages of Designer Babies

  • It is not according to God's plan of creating human beings in his own image.
  • If there is an environmental factor occuring on designer babies, there will be a higher possibility of extinction.
  • With designer babies, the society will be highly competitive.
  • As many people will be going for high-paying jobs, there won't be enough people for low-paying jobs (construction workers, garbage collectors, janitors, etc.)
  • There can be an increase of unreasonable fear or hatred towards foreigners or anyone who appears different.
  • There is fear that parents and doctors will be able to choose certain genes and/or traits for babies using a genetic technology.
  • This is very expensive so only wealthy families can afford it.


Using InVitro Fertilization (IVF), babies' genetic makeup can be selected by genetic engineering to change its certain genes or characteristics. This gives parents an opportunity to create "the perfect baby".

Advanced reproductive technologies are used for three main reasons:

  • To help infertile couples have children.
  • To screen embryos for genetic disorders and select healthy ones.
  • To determine the sex of the baby. This is done to ensure that there is no genetic disorders. Males can have a genetic disorder such as Muscular Dystrophy so couples can choose to have a female child and thus have a healthy baby.

With genetic screening, genes relating to disease, genetic defects, and terminal illness can be eliminated. There are many people in the world who have genes of certain hereditary disorders (Huntington's chorea, Cystic Fibrosis, Muscular Dystrophy). The advantages of designer babies include reducing the chance of the baby having genes for certain hereditary disorders and creating the perfect baby based on its appearance, skills, and intelligence. Parents can also choose the sex of the unborn baby. On the other hand, one of its disadvantages are that it is not according to God's plan. In the bible, we are told "God formed man from the dust of the ground, and breathed into his nostrils the breath of life; and the man became a living being." (Genesis 2:7) It is God who gave us life and children are a gift from him so parents cannot make any perferences. From what I have learned from Unit 2 SBI 3U1, biodiversity is important to ensure survival. So if we completely create designer babies and an enivronmental factors occurs, there will be a higher possibility of extinction but if there are different people, it will not affect the entire population so the resistant ones will reproduce and pass the genes and create a greater biodiversity. With designer babies, the society will be highly competitive. Therefore, there wouldn't be enough people for low-paying jobs (construction workers, garbage collectors, janitors, etc.). Genetic engineering is a very expensive process so only wealthy families can afford it. There is also fear that parents and doctors will be able to choose certain genes and/or traits using a genetic technology. Therefore, I recommend that genetic engineering should not be used as creating "the perfect baby" based on all of these disadvantages.


Thursday, October 15, 2009

Deforestation and its Effects

Question: Many scientists consider humans as the most invasive species, as humans can greatly change an environment and impact living things that reside there. Are we being stewards of the world? Take a look at an issue in which human intervention has positively or negatively affected the biodiversity of our ecosystems.

Humans are considered as the most invasive species that can greatly change the environment and impact the living things that reside there. This is because of our increased consumption of natural resources that destroy every other living thing in that ecosystem. Our actions have a negative impact on the biodiversity of the environment. In this blog, I am going to talk about deforestation and how human intervention has affected its habitants and the entire ecosystem.

Deforestation is a permanent destruction of indigenous forests and woodlands. It is a very dangerous issue that has many effects on the ecosystem. It occurs when human beings cut down forests for their needs. Even though it is to satisfy their needs, it cannot be justified because it creates a major problem for the biodiversity of the environment. Biodiversity is essential to the strength of the entire ecosystem. We must save forests because they are essential in keeping and sustaining global ecosystems. Forests are a habitat for many living species. They give mankind a variety of gifts that contribute to our quality of life. They absorb carbon dioxide from the atmosphere and produce oxygen needed for living organisms.
Causes of Deforestation

The main causes of deforestation are:
  • Urban and construction purposes: We cut down trees to make lumber for building materials, furniture, and paper products. Forests are also cleared in order to accommodate expanding urban areas.
  • Growing Crops: Deforestation is used to clear the land so that crops can be grown.
  • Creating Grazing Land: Forests are cut down in order to create land for grazing cattle.
  • Fuel: Trees are used as firewood or turned into charcoal, which are used for cooking and heating purposes.
  • Paper: We cut down trees for paper. We use paper for study materials, reading, and writing.
Some of the other causes of deforestation include: clearing forests for oil and mining exploitation and making highways and roads.
Consequences of Deforestation
Deforestation has a negative impact on the environment. They affect:
  • The carbon cycle: During photosynthesis, trees absorb carbon dioxide from the atmosphere to form carbohydrates. When deforestation occurs, carbon dioxide is released that can cause an increase in atmospheric carbon dioxide concentration. Carbon dioxide is a major contributor to greenhouse emissions. Deforestation can also affect cellular respiration because all the other organisms won’t be able to get enough oxygen from trees.

Source: http://eo.ucar.edu/kids/green/images/carboncycle_sm.jpg

This is how the carbon cycle works and deforestation can have a negative effect on this cycle.

  • The water cycle: Trees draw ground water up through their roots and release it into the atmosphere (transpiration). In Amazonia over half of all water circulating through the region’s ecosystem remains within the plants. When there is deforestation, the region cannot hold enough water. This can lead to drought and heat waves. When deforestation affects the water cycle, it can lead to several problems:
  • Soil erosion: With the loss of a protective cover of vegetation, more soil is lost. Soil erosion can cause silting of water bodies such as lakes and dams.

    Source: http://earthobservatory.nasa.gov/Features/Deforestation

This picture shows an eroded hillside along a river in Amazonia that shows an infertile soil typical of tropical environments (pinkish-tan) topped by a very thin layer of fertile soil and forest detritus (brown).

  • Extinction of species: Most of the organisms depend on the forest for survival. Forests contains more than half of all species on our planet. As the habitat of these species is destroyed, the number of species decline.

Source: http://earthobservatory.nasa.gov/Features/Deforestation/

Here is an image of a number of species that have been endemic, which is represented by a dark-blue colour.

Deforestation can lead to other issues:

  • Global warming
  • Biosphere instability
  • Desertification
  • Climate change

Source: http://www.umich.edu/~gs265/society/deforestation.htm

The effects of deforestation are widely ranging and can be irreversible if not stopped.

Statistics of Deforestation

  • 81% of its original forest cover is permanently lost in Niagara.
  • The tropical rainforests of Brazil are less by 90-95%.
  • The forests of Central America are down by two-thirds lowlands.
  • India, Mexico, Philippines, Thailand, Indonesia, Bangladesh, Myanmar, China, Sri Lanka, the Congo and Ghana have lost more than 50% of their rainforest cover.
  • Harvesting of forest cover has left Afghanistan with approximately 25% of forests.

Solutions of Deforestation

We can stop deforestation by:

  • Recycling
  • Reforestation
  • Cutting down less trees
  • Reducing the use of fossil fuels
  • More awareness

Deforestation is one of the greatest tragedies and threats that can negatively affect the biodiversity of our ecosystems. People use forests for their needs such as paper, fuel, urban and construction purposes, growing crops, grazing cattle, oil and mining exploitation and making highways and roads. Deforestation can cause many severe consequences. Its most severe impact is the loss of habitats and extinction of living species. Deforestation can also affect the carbon and water cycle.

We wouldn‘t have to deal with the problem of deforestation if we thought of the consequences beforehand. We should try to lessen our dependency on forests for our needs. Based on my solutions on how to stop deforestation, the best option will be reforestation because there will be a balance of ecosystem and the rate of deforestation will diminish. Trees and plants are one of the best gifts that God has given to mankind. God wants us to be the stewards of this earth. He has given us dominance over all species so we should take care of our earth for our future generations. We should be environmentally conscious and use eco-friendly products for our daily needs. If we give more time and effort for the world’s conservation, the possibilities of reaching that goal will be high.

Here is a video on stopping deforestation: