Wednesday, March 18, 2009
HEALTHY FOOD THAT CAN CAUSE WEIGHT LOSS
Best food tips to help lose weight
Many people who want to lose weight find it difficult to know which foods to choose for the best weight loss results. Losing weight by swapping and changing to different diets is not the best way, we need to find a way of reducing energy content from the normal foods we eat every day. We need to learn certain food rules to help form better eating habits.
Feed the Muscle is all about BUILDING Your Metabolism
An increased metabolic rate means you can potentially:1. Exercise less
2. Enjoy your favorite foods
3. Still Enjoy social meets
4. Spend less on low-fat foods..and STILL Lose Fat Weight!
Learn more about Burn the Fat, Feed the Muscle Here!
We should learn to pick out the best foods from our normal daily diet and use them to form the basis for our new healthy eating habits. This gives familiarity to the new way of eating rather than the idea that the individual is "on a diet". Trying to lose weight on a specific diet relays the message that it will end some day. When a diet ends many people gain back most, if not all the weight lost.
Here are some suggestions on how to eat foods to help lose weight...
Try not to have too much variety of food for each meal
Evidence has shown humans always consume more food and calories when there is more choice on offer. For example, have you ever been at a buffet style meal where its “eat all you can” no matter how much we eat there always seems to be room for one more item maybe that delicious looking dessert or ice cream!
Many diets in the past have been based on a similar principle, the cabbage soup diet, the vegetable diet, etc.
Health experts state always eat a balanced diet which may seem to contradict the above statement. However, it is possible to select a balanced diet and lower amount of choice for each meal by eating regular small meals.
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Be careful what you add to healthy foods
Salads are one of the best foods for losing weight, they very popular for many dieters trying to lose the weight fast. The problem is people often add sauces or creams to add taste to an otherwise bland food. Mayonnaise is a common addition to salads but it is very high in calories and fat and a salad with too much Mayonnaise can be just as high in calories than some of the worst weight loss foods.
Baked potatoes are also a great food to help lose weight when part of a small, low calorie meal but again, some people spoil this great example by adding tons of butter. Filling a baked potato with baked beans or cottage cheese is probably the best way to add taste and more nutrition to this low calorie food.
The idea is when choosing the best foods to help lose weight try not to neutralize the food's possible weight loss benefits, be careful with what you add!
Eat a little high quality protein food with each meal or snack
One study in the UK for the atkins diet has shown that it wasn't the low carbs that were the reason the volunteers were losing weight, it also wasn't the ketosis which was causing the body to boost the metabolism. In fact it was believed to be the protein content. The protein in each meal was helping to dull the appetite causing volunteers to actually consume less calories than those on the low fat diet.
If Dr Atkins discovered protein's ability to suppress appetite then why don't we simply include some protein at each meal without the hassle or expense of completely changing our whole dietary foods in order to lose weight.
Adding protein food to each meal along with the idea of eating more meals in a day may be difficult to keep calories low enough to lose weight. This idea means adding another "choice", plus protein foods are often high in calories. To combat this problem some people combine protein foods, combining certain plant foods can help lose weight because they are usually low in calories, high in fiber and it limits the choice of foods within each meal as only two types of plant foods need to be combined.
FOOD THAT CAN CAUSE WEIGHT LOSS
THE 20 BEST WEIGHT-LOSS FOODS
Looking for an easy way to lose a few pounds? We've got the program. It's simple, and it works. So get with it.By Lisa Dorfman, M.S., R.D.
From the April 2009 issue of Runner's World
Many runners would like to lose a pound or 2. Maybe 5. Maybe more. Why? That's easy: to feel better, look better, improve their health, and run farther and faster.However, losing weight can be surprisingly difficult. In fact, national health surveys show Americans in general are getting fatter. Sure, regular runners should be ahead of the pack, but many are still losing the weight-gain war.What you need is a simple plan. Here it is, in just two parts: (1) Make a little more time to run; (2) Concentrate on a handful of dietary changes that, over the course of a year, can produce significant weight-loss results.Below we've listed 20 great diet changes that you'll find easy to achieve. Many of them will help you cut 100 calories or more from a single serving. Now do the math. Say you eat this particular food or meal three times a week. That's 100 x 3 x 52, or 15,600 calories saved in a year. Which comes to almost 5 pounds, since you'll lose one pound for every 3,500 calories cut from your food intake. Make another food substitution, and you're up to 10 pounds. Beyond that, the sky's the limit. Here's your meal-by-meal planner.
BREAKFAST
Don't skip breakfast. A good breakfast is the most crucial part of any healthy weight-loss effort, as it revs up your energy level and metabolism for the full day.Homemade raisin bran Description: Mix one cup of Total cereal, a packet of raisins, and 1 cup nonfat milk. This simple home recipe with 244 calories fortifies you with 100 percent of the Daily Value for most vitamins and minerals, boosts your protein intake by 12 grams, and gives you a sweet, natural fiber and sugar source.You'll Save: 50 calories, 6 teaspoons of sugar, and 5 grams of fat compared with ready-to-serve raisin bran doused with a cup of 2-percent milk.Scrambled whites with greensDescription: This low-fat, scrambled-egg alternative provides 54 grams of high-quality dietary protein in just 255 calories. First, spray your frying pan with fat-free Pam. Then pour the equivalent of four servings of Eggology egg whites (or Second Nature or Egg Beaters egg whites) in a bowl and blend with 1/2 cup spinach and 1/2 cup mushrooms. Heat the pan until the Pam starts to bubble, pour in the eggs, and fry until the eggs are nearly dry. You'll Save: 40 calories, 100 milligrams of cholesterol, and 13 grams of fat compared with two normal scrambled eggs.Balanced Diet ShakeDescription: For something cool, tasty, and nutrient-filled in the morning, try a shake or smoothie. The Balanced Diet nutritional drink provides 180 calories with lots of complex carbohydrates, vitamins, and minerals in a naturally flavored French vanilla or chocolate royale. Each serving includes 5 grams of dietary fiber and 10 grams of soy, or 40 percent of the daily minimum now recommended by the American Heart Association. You'll Save: 60 calories daily and nearly 6 grams of fat compared with many other similar drinks.Frozen fruit smoothieDescription: You can prepare your own personal antioxidant-filled fruit smoothie like the following one that runner Bruce Shapiro used to lose 30 pounds over the last few years. Combine and blend: one cup frozen, unsweetened blueberries; 1/2 banana; 1/4 cup wheat germ; and water.You'll Save: 200 calories for each 2- to 3-cup serving, compared with many store-bought and canned smoothie beverages. Toasted plain Lender's Bagel with natural jamDescription: Sure, a frozen bagel can't match a fresh one, but it's easier to obtain for many people, and a little toasting brings it to near perfection. Just spread with your favorite natural jam. You'll Save: Anywhere from 160 to 360 calories and more than 10 grams of fat compared with similar bagels bought at Dunkin' Donuts and other outlets where the bagels are spread with cream cheese.
LUNCH
Lunch is the second-most-important meal of the day in your weight-loss plan. It boosts your energy level and regulates your metabolism to keep you on an even keel.Boca Burger Grilled Vegetable burgerDescription: This zesty, soy-based vegetarian alternative to the high-saturated-fat American BBQ staple contains hints of zucchini, red-bell pepper, garlic, onion, and even a couple of cheeses. It tastes great and provides a good dose of protein. Add some lettuce, tomato, ketchup, or your other favorite toppings, and you'll hardly notice the difference from the traditional burger.You'll Save: Up to 180 calories and 19 grams of fat compared with a typically-grilled 3-ounce beef burger.Alvarado Street sprouted wheat tortillaDescription: It's easy to make your own delicious wrap and save hundreds of calories. With this tasty, organic, whole-wheat tortilla you'll have no trouble fixing a quick, hearty lunch. Boost your vitamin and mineral intake by loading on a handful of greens, shredded carrots, tomato, and peppers along with grilled chicken, lean meat, turkey, or a bean-based filler.You'll Save: Anywhere from 50 calories and 5 grams of fat to much more if you customarily buy a commercial wrap drowning in mayo, oily toppings, or greasy chicken.Subway roast beef sub sandwichDescription: Can't live without meat? You don't have to. Meat is a great source of protein, iron, and several important minerals, and the Subway lean 6-inch roast beef sub contains just 264 calories and 4.5 grams of fat in a meal perfectly balanced with lettuce, tomato, and vegetables.You'll Save: Nearly 100 calories and 12 grams of fat compared with a tuna salad sub, and more than 20 grams of fat compared with the classic meatball sub. Health Valley chili Description: The right soup is always a great part of your weight-loss arsenal. This can of fat-free chili is tasty, easy to prepare, and filled with healthy fiber. You'll Save: 200 calories and 22 grams of fat compared with other prepared and restaurant chilis. Tossed salad with croutons instead of salad dressing.Description: You know that green salads make an important contribution to your day's eating, but you've probably never thought of them as an expression of art and adventure. Here's your chance. Instead of drenching your salads in high-fat dressings, decorate them with croutons, beans, or fruit.You'll Save: 100 calories and 28 grams of fat when you add 1 ounce of croutons and 1/2 cup of beans, peas, and raisins to your salad in place of 1 ounce of an oil-based dressing. You'll also increase your intake of iron, folic acid, Vitamin C, and fiber.
HAVE A NICE VIEW. FROM JERRY
Looking for an easy way to lose a few pounds? We've got the program. It's simple, and it works. So get with it.By Lisa Dorfman, M.S., R.D.
From the April 2009 issue of Runner's World
Many runners would like to lose a pound or 2. Maybe 5. Maybe more. Why? That's easy: to feel better, look better, improve their health, and run farther and faster.However, losing weight can be surprisingly difficult. In fact, national health surveys show Americans in general are getting fatter. Sure, regular runners should be ahead of the pack, but many are still losing the weight-gain war.What you need is a simple plan. Here it is, in just two parts: (1) Make a little more time to run; (2) Concentrate on a handful of dietary changes that, over the course of a year, can produce significant weight-loss results.Below we've listed 20 great diet changes that you'll find easy to achieve. Many of them will help you cut 100 calories or more from a single serving. Now do the math. Say you eat this particular food or meal three times a week. That's 100 x 3 x 52, or 15,600 calories saved in a year. Which comes to almost 5 pounds, since you'll lose one pound for every 3,500 calories cut from your food intake. Make another food substitution, and you're up to 10 pounds. Beyond that, the sky's the limit. Here's your meal-by-meal planner.
BREAKFAST
Don't skip breakfast. A good breakfast is the most crucial part of any healthy weight-loss effort, as it revs up your energy level and metabolism for the full day.Homemade raisin bran Description: Mix one cup of Total cereal, a packet of raisins, and 1 cup nonfat milk. This simple home recipe with 244 calories fortifies you with 100 percent of the Daily Value for most vitamins and minerals, boosts your protein intake by 12 grams, and gives you a sweet, natural fiber and sugar source.You'll Save: 50 calories, 6 teaspoons of sugar, and 5 grams of fat compared with ready-to-serve raisin bran doused with a cup of 2-percent milk.Scrambled whites with greensDescription: This low-fat, scrambled-egg alternative provides 54 grams of high-quality dietary protein in just 255 calories. First, spray your frying pan with fat-free Pam. Then pour the equivalent of four servings of Eggology egg whites (or Second Nature or Egg Beaters egg whites) in a bowl and blend with 1/2 cup spinach and 1/2 cup mushrooms. Heat the pan until the Pam starts to bubble, pour in the eggs, and fry until the eggs are nearly dry. You'll Save: 40 calories, 100 milligrams of cholesterol, and 13 grams of fat compared with two normal scrambled eggs.Balanced Diet ShakeDescription: For something cool, tasty, and nutrient-filled in the morning, try a shake or smoothie. The Balanced Diet nutritional drink provides 180 calories with lots of complex carbohydrates, vitamins, and minerals in a naturally flavored French vanilla or chocolate royale. Each serving includes 5 grams of dietary fiber and 10 grams of soy, or 40 percent of the daily minimum now recommended by the American Heart Association. You'll Save: 60 calories daily and nearly 6 grams of fat compared with many other similar drinks.Frozen fruit smoothieDescription: You can prepare your own personal antioxidant-filled fruit smoothie like the following one that runner Bruce Shapiro used to lose 30 pounds over the last few years. Combine and blend: one cup frozen, unsweetened blueberries; 1/2 banana; 1/4 cup wheat germ; and water.You'll Save: 200 calories for each 2- to 3-cup serving, compared with many store-bought and canned smoothie beverages. Toasted plain Lender's Bagel with natural jamDescription: Sure, a frozen bagel can't match a fresh one, but it's easier to obtain for many people, and a little toasting brings it to near perfection. Just spread with your favorite natural jam. You'll Save: Anywhere from 160 to 360 calories and more than 10 grams of fat compared with similar bagels bought at Dunkin' Donuts and other outlets where the bagels are spread with cream cheese.
LUNCH
Lunch is the second-most-important meal of the day in your weight-loss plan. It boosts your energy level and regulates your metabolism to keep you on an even keel.Boca Burger Grilled Vegetable burgerDescription: This zesty, soy-based vegetarian alternative to the high-saturated-fat American BBQ staple contains hints of zucchini, red-bell pepper, garlic, onion, and even a couple of cheeses. It tastes great and provides a good dose of protein. Add some lettuce, tomato, ketchup, or your other favorite toppings, and you'll hardly notice the difference from the traditional burger.You'll Save: Up to 180 calories and 19 grams of fat compared with a typically-grilled 3-ounce beef burger.Alvarado Street sprouted wheat tortillaDescription: It's easy to make your own delicious wrap and save hundreds of calories. With this tasty, organic, whole-wheat tortilla you'll have no trouble fixing a quick, hearty lunch. Boost your vitamin and mineral intake by loading on a handful of greens, shredded carrots, tomato, and peppers along with grilled chicken, lean meat, turkey, or a bean-based filler.You'll Save: Anywhere from 50 calories and 5 grams of fat to much more if you customarily buy a commercial wrap drowning in mayo, oily toppings, or greasy chicken.Subway roast beef sub sandwichDescription: Can't live without meat? You don't have to. Meat is a great source of protein, iron, and several important minerals, and the Subway lean 6-inch roast beef sub contains just 264 calories and 4.5 grams of fat in a meal perfectly balanced with lettuce, tomato, and vegetables.You'll Save: Nearly 100 calories and 12 grams of fat compared with a tuna salad sub, and more than 20 grams of fat compared with the classic meatball sub. Health Valley chili Description: The right soup is always a great part of your weight-loss arsenal. This can of fat-free chili is tasty, easy to prepare, and filled with healthy fiber. You'll Save: 200 calories and 22 grams of fat compared with other prepared and restaurant chilis. Tossed salad with croutons instead of salad dressing.Description: You know that green salads make an important contribution to your day's eating, but you've probably never thought of them as an expression of art and adventure. Here's your chance. Instead of drenching your salads in high-fat dressings, decorate them with croutons, beans, or fruit.You'll Save: 100 calories and 28 grams of fat when you add 1 ounce of croutons and 1/2 cup of beans, peas, and raisins to your salad in place of 1 ounce of an oil-based dressing. You'll also increase your intake of iron, folic acid, Vitamin C, and fiber.
HAVE A NICE VIEW. FROM JERRY
Monday, March 16, 2009
Oceania Tourist Sites
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Oceania is a continent that is full of islands, coral reefs and beaches. The countries of Oceania offer wonderful Oceania tourist spots. Each year, tourists and adventurers from every corner of the world come to enjoy the Oceania tourist sites, which promise to offer you an unforgettable holiday experience. There are a plenty of Oceanian tourist sites. The continent of Oceania is home to a wide array of flora and fauna. The barren deserts, lush forests and the extraordinary wild habitat make for interesting Oceania tourist destination. The cultural and historical landmarks enable you to get a feel of the inner soul of the continent. A single trip to the Oceania sightseeings may compel you to visit the Oceanian tourist destination once more. Some of the top tourist sites of Oceania are Victoria Falls in Zimbabwe/ Zambia, Anse Lazio in Seychelles, Ingall in Niger, Cape Town in South Oceania, Pyramids of Giza in Egypt and Masai Mara in Kenya. One of the top Oceania tourist spots is Australia. Visit famous Australian destinations, such as Melbourne, Sydney, Cairns, Perth, Adelaide, Canberra, Brisbane, Gold Coast or Tasmania. Enjoy the Great Barrier Reef, Uluru, Opera House and other attractions. The beaches and beach-resorts give you a relax holiday outing. Visit the famous New Zealand cities like Wellington, Auckland, Christchurch, Hamilton, Napier, Queens Town and other places. Visit during the peak season of November to April, when the weather is more pleasant. Travelers may also check out the ski-resorts that make for a fine winter. Take part in the various water sports and tour New Zealand attractions like the national museum, Oriental Bay and so on. Visit Milford Sound and see the cascading waterfalls. Enjoy the playful seals and dolphins amidst their natural habitat. One of the favorite Oceania tourist spots are the Coral Coast and Nadi, located in Fiji. Enjoy the marine life underneath the crystal clear waters. Tahiti also offers tourist attractions like Bora Bora, Huahine, Manihi, Moorea, Papeete, Raiatea and others. For more information on Oceania tourist sites, visit Holidayshub.com. Travel.mapsofworld provides you an overview of the favorite tourist destinations in Oceania.
Oceania Travel
Countries in Oceania
Oceania Tourism
Tourist Attractions in Oceania
Oceania Tourist Information
Oceania Travel
Oceania Tourist Sites
Oceania Travel Destinations
Oceania Travel Guide
Oceania Tourist Map
Christmas in Oceania
New Year in Oceania
Tours to Oceania
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Tourist Attractions in Melbourne
window.google_render_ad();
Oceania is a continent that is full of islands, coral reefs and beaches. The countries of Oceania offer wonderful Oceania tourist spots. Each year, tourists and adventurers from every corner of the world come to enjoy the Oceania tourist sites, which promise to offer you an unforgettable holiday experience. There are a plenty of Oceanian tourist sites. The continent of Oceania is home to a wide array of flora and fauna. The barren deserts, lush forests and the extraordinary wild habitat make for interesting Oceania tourist destination. The cultural and historical landmarks enable you to get a feel of the inner soul of the continent. A single trip to the Oceania sightseeings may compel you to visit the Oceanian tourist destination once more. Some of the top tourist sites of Oceania are Victoria Falls in Zimbabwe/ Zambia, Anse Lazio in Seychelles, Ingall in Niger, Cape Town in South Oceania, Pyramids of Giza in Egypt and Masai Mara in Kenya. One of the top Oceania tourist spots is Australia. Visit famous Australian destinations, such as Melbourne, Sydney, Cairns, Perth, Adelaide, Canberra, Brisbane, Gold Coast or Tasmania. Enjoy the Great Barrier Reef, Uluru, Opera House and other attractions. The beaches and beach-resorts give you a relax holiday outing. Visit the famous New Zealand cities like Wellington, Auckland, Christchurch, Hamilton, Napier, Queens Town and other places. Visit during the peak season of November to April, when the weather is more pleasant. Travelers may also check out the ski-resorts that make for a fine winter. Take part in the various water sports and tour New Zealand attractions like the national museum, Oriental Bay and so on. Visit Milford Sound and see the cascading waterfalls. Enjoy the playful seals and dolphins amidst their natural habitat. One of the favorite Oceania tourist spots are the Coral Coast and Nadi, located in Fiji. Enjoy the marine life underneath the crystal clear waters. Tahiti also offers tourist attractions like Bora Bora, Huahine, Manihi, Moorea, Papeete, Raiatea and others. For more information on Oceania tourist sites, visit Holidayshub.com. Travel.mapsofworld provides you an overview of the favorite tourist destinations in Oceania.
Oceania Travel
Countries in Oceania
Oceania Tourism
Tourist Attractions in Oceania
Oceania Tourist Information
Oceania Travel
Oceania Tourist Sites
Oceania Travel Destinations
Oceania Travel Guide
Oceania Tourist Map
Christmas in Oceania
New Year in Oceania
Tours to Oceania
window.google_render_ad();
Tourist Attractions in Melbourne
Friday, March 6, 2009
EVOLUTION OF THE HUMAN
ABO BLOOD GROUP SYSTEM
Bonnie B. Glass
BY-590 Dr. McCall
Spring 2001
________________________________________________________
The purpose of this web page is to explain some basic facts about human ABO blood group system and to summarize the research and hypotheses regarding its evolution.
BACKGROUND
The ABO System -- A Polymorphism
(http://www.bayerpharma-na.com/children/RON/circu/chrc.0103.asp)
Humans can have blood types A, B, AB, or O. This is known as the ABO blood group system, and it is a polymorphism. A polymorphism is defined as a "genetic locus with two or more alleles that occur in appreciable (>1%) frequency in a given population" (http://www.as.ua.edu). The ABO blood group system was the first polymorphism discovered in humans. It is however only one of MANY systems involving the red blood cells.
Antibodies and Antigens
Understanding the difference between antibodies and antigens is essential to understanding the ABO blood group system and its evolution. Antibodies are substances produced by the body when it is invaded and act to protest it from the foreign substance. Antigens are found in the invading substance and elicit the production of antibodies. The two substances, thus, work in conjunction with each other.
(http://www.uen.org/utahlink/activities/view activity.cgi?activity ld=3037)
Typically, the body does not produce antibodies until AFTER it has been introduced to a new substance. The blood group antigens, on the other hand, are produced during the development of the circulatory system of the fetus.
Because these antibodies are present, blood of certain types will be incompatible. Before this was understood, death was often the result in transfusions and transplants.
This transfusion dilemma led Karl Landsteiner (pictured below) to
(http://daphne.palomar.edu/blood/ABO system.htm)
discover the ABO system in 1900. Interestingly, he used blood samples from his fellow lab staff. Fortunately for him, all blood types were represented so his system remains in use today.
Landsteiner's ABO System
In this blood group system, A and B are codominant thus humans may have the following phenotypes and genotypes and the corresponding antibodies and antigens.
Phenotype Genotype Antigens Antibodies
A
AA, AO
A
B
B
BB, BO
B
A
O
OO
None
A, B
AB
AB
A, B
None
Since Landsteiner's discovery, hundreds of specificities in human blood types have been determined (Socha et al., 1984). The ABO blood group system remains the most widely used.
To learn more about your blood, check out this interesting site by clicking here.
WHY STUDY THE EVOLUTION OF HUMAN BLOOD TYPES??
There are several reasons scientists are interested in studying the evolution of human blood types -- the predominant reason being it helps them to understand the place humans occupy in evolution's branching tree. In other words, by studying the similarities and differences between human and non-human primate blood groups scientists can determine who our closest common ancestors are and the degree of our relationship.
What Distinguishes A, B, and O blood types from each other?
The type of blood a person has is determined by alleles at a single locus at chromosome 9 (Martinko et al., 1993). These alleles encode for different amino acids called glycotransferases.
In order to be blood type A, cytosine at nucleotide site 793 translates to leucine 265 and guanine at nucleotide site 800 transloates to glycine 267.
In order to be blood type B, the cytosine at 793 translates to methionone 265 and the guanine at 800 to alanine 267 (Martinko et al., 1993).
Blood type AB occurs when both changes occur.
Blood type O is caused when an inactive or nonfunctional protein is coded for.
Martinko et al. (1993) remarked regarding these changes that it is "surprising that they have such a great effect on the A and B transferases" because the amino acids do not differ greatly from each other.
What About the Blood Types of Other Primates?
The ABO polymorphism exists in many primate species other than just humans and in all anthropoid primates (Diamond, 1997). Blood groups of primates have been studied since 1911 when Dungern and Hirszfeld found an A antigen on chimpanzee red cells (Socha et al., 1984). According to Socha et al., (1984), early studies indicated "striking similarities" between the A-B-O antigens of man and those of anthropoid apes. It was not until the 1960's that research methods improved enough to learn that many similarities existed between human and non-human primates as well as some subtle differences. In their 1984 study, Socha et al. stated that the two groups were "intimately serologically related."
Because of similarities in the immunological responses between human and non-human primates, the same techniques used for testing human blood were used for other primate species.
Scientists have studied certain primate species in much greater depth than others. As a result, we do not know equally about the blood groups of all primates. In the following sections, some of the most researched groups will be explained.
CHIMPANZEES
Of the Old World monkeys, the chimpanzee has been the most studied (Socha et al., 1984). Interestingly, they have predominantly blood type A and in rare cases blood type O, but NEVER blood type B (Socha et al., 1984). Most blood systems found in chimpanzees also exist in man, but there are some species specific characteristics. The chimpanzee is thought to be the ancestor of Cro-magnon man.
To learn more about chimpanzees click here.
GORILLAS
In contrast to chimpanzees, gorillas have been found to possess ONLY blood type B. Some evolutionary scientists believe the gorilla to be the ancestor of Neanderthal man.
To learn more about gorillas, click here.
BABOONS
Baboons, on the other hand, have been found to possess A, B, and O blood types. The hominoids, humans and the great apes, express the ABO antigens on red blood cells, but baboons do not. In baboons, the antigens were found in other tissue cells. Although the similarity in alleles exist in baboons and humans, the mutations which are in human O alleles are not found in baboon O alleles. This suggests a different origin for the O blood types in each species (Diamond et al., 1997). Unlike humans who have a large percentage of O, in baboons O has arisen several times but remains relatively rare. This suggests a possible selection working against type O in baboons.
Humans, baboons and orangutans have maintained their polymorphism. Because of the absence of B from chimpanzees and O and A from gorillas, the locus determining this phenotype must no longer be under strong selection pressure in the hominoids.
To explore a great web site which explains the differences between the evolutionary history of chimpanzees, gorillas and man, click here.
SO WHAT DOES ALL THIS MEAN?
Scientists have determined by using average mutation rate and considering the required mutations that the divergence of A and B (at nucleotides 793 and 800) must have occurred before humans, chimps, and gorillas had separated and likely before orangutans broke off. Thus A and B diverged at least 13 million years ago (Martin, 1990). In chimps and gorillas, the A and B allele seem to be fixed (Martinko, 1993). Some sources state that the two types are likely of separate origin (http://aol.com/ikaulins/expak), but that they are the original types, not O.
Other evidence used to trace man's evolutionary ancestors to these non-human primates is the MN blood system. Man is M and N; whereas chimps are anti-N and gorillas are anti-M. O is not the original blood type as was previously thought (http://members.aol.com/ikaulins/expak).
IS SELECTION AT WORK TODAY?
If these blood groups are being selected against, the agent is not restricted to humans because the system has been around for over 13 million years. There is only indirect evidence for the possibility of natural selection in the evolutionary pattern of ABO groups (Saitou and ). To link natural selection to the frequency of A, B, O phenotypic frequency requires more evidence. One such study was completed by Boren et al. (1993), in which a bacterium casing gastric disorders was linked to blood type (Saitou ). The researchers found there to be less receptors for the bacterium in blood types A and B, thus people with blood type O were more susceptible. If more blood types could be linked to microorganisms, there would be more evidence for natural selection.
Several question remain. For example, if natural antibodies help to protect the body against parasites, then why is O, which has both A and B, antibodies not at an advantage? Also, O is a nonfunctional allele, yet it is quite common in certain areas like South America where it is fixed in the population. This seems to contradict standard mutation drift selection which does not favor nonfunctional alleles (Nazzareno et al., 1995).
To learn more about the world distribution of blood types, click here.
There is also a question as to whether selection is at work today in the interacions between mother and fetus. Some studies have concluded that in mothers with type A blood who are carrying a fetus of type O (and vice versa), there is incompatibility which will result in the spontaneous abortion of the fetus.
In summary, it appears that humans, chimpanzees, and gorilla (and likely ornagutan) followed the same evolutionary origin when comparing their blood types. Because the A and O exist in chimps this is likely the ancestral form of these types found in humans today. The B type found in gorillas today was likely ancestral form found in humans. Thus,
ABO BLOOD GROUP SYSTEM
Bonnie B. Glass
BY-590 Dr. McCall
Spring 2001
________________________________________________________
The purpose of this web page is to explain some basic facts about human ABO blood group system and to summarize the research and hypotheses regarding its evolution.
BACKGROUND
The ABO System -- A Polymorphism
(http://www.bayerpharma-na.com/children/RON/circu/chrc.0103.asp)
Humans can have blood types A, B, AB, or O. This is known as the ABO blood group system, and it is a polymorphism. A polymorphism is defined as a "genetic locus with two or more alleles that occur in appreciable (>1%) frequency in a given population" (http://www.as.ua.edu). The ABO blood group system was the first polymorphism discovered in humans. It is however only one of MANY systems involving the red blood cells.
Antibodies and Antigens
Understanding the difference between antibodies and antigens is essential to understanding the ABO blood group system and its evolution. Antibodies are substances produced by the body when it is invaded and act to protest it from the foreign substance. Antigens are found in the invading substance and elicit the production of antibodies. The two substances, thus, work in conjunction with each other.
(http://www.uen.org/utahlink/activities/view activity.cgi?activity ld=3037)
Typically, the body does not produce antibodies until AFTER it has been introduced to a new substance. The blood group antigens, on the other hand, are produced during the development of the circulatory system of the fetus.
Because these antibodies are present, blood of certain types will be incompatible. Before this was understood, death was often the result in transfusions and transplants.
This transfusion dilemma led Karl Landsteiner (pictured below) to
(http://daphne.palomar.edu/blood/ABO system.htm)
discover the ABO system in 1900. Interestingly, he used blood samples from his fellow lab staff. Fortunately for him, all blood types were represented so his system remains in use today.
Landsteiner's ABO System
In this blood group system, A and B are codominant thus humans may have the following phenotypes and genotypes and the corresponding antibodies and antigens.
Phenotype Genotype Antigens Antibodies
A
AA, AO
A
B
B
BB, BO
B
A
O
OO
None
A, B
AB
AB
A, B
None
Since Landsteiner's discovery, hundreds of specificities in human blood types have been determined (Socha et al., 1984). The ABO blood group system remains the most widely used.
To learn more about your blood, check out this interesting site by clicking here.
WHY STUDY THE EVOLUTION OF HUMAN BLOOD TYPES??
There are several reasons scientists are interested in studying the evolution of human blood types -- the predominant reason being it helps them to understand the place humans occupy in evolution's branching tree. In other words, by studying the similarities and differences between human and non-human primate blood groups scientists can determine who our closest common ancestors are and the degree of our relationship.
What Distinguishes A, B, and O blood types from each other?
The type of blood a person has is determined by alleles at a single locus at chromosome 9 (Martinko et al., 1993). These alleles encode for different amino acids called glycotransferases.
In order to be blood type A, cytosine at nucleotide site 793 translates to leucine 265 and guanine at nucleotide site 800 transloates to glycine 267.
In order to be blood type B, the cytosine at 793 translates to methionone 265 and the guanine at 800 to alanine 267 (Martinko et al., 1993).
Blood type AB occurs when both changes occur.
Blood type O is caused when an inactive or nonfunctional protein is coded for.
Martinko et al. (1993) remarked regarding these changes that it is "surprising that they have such a great effect on the A and B transferases" because the amino acids do not differ greatly from each other.
What About the Blood Types of Other Primates?
The ABO polymorphism exists in many primate species other than just humans and in all anthropoid primates (Diamond, 1997). Blood groups of primates have been studied since 1911 when Dungern and Hirszfeld found an A antigen on chimpanzee red cells (Socha et al., 1984). According to Socha et al., (1984), early studies indicated "striking similarities" between the A-B-O antigens of man and those of anthropoid apes. It was not until the 1960's that research methods improved enough to learn that many similarities existed between human and non-human primates as well as some subtle differences. In their 1984 study, Socha et al. stated that the two groups were "intimately serologically related."
Because of similarities in the immunological responses between human and non-human primates, the same techniques used for testing human blood were used for other primate species.
Scientists have studied certain primate species in much greater depth than others. As a result, we do not know equally about the blood groups of all primates. In the following sections, some of the most researched groups will be explained.
CHIMPANZEES
Of the Old World monkeys, the chimpanzee has been the most studied (Socha et al., 1984). Interestingly, they have predominantly blood type A and in rare cases blood type O, but NEVER blood type B (Socha et al., 1984). Most blood systems found in chimpanzees also exist in man, but there are some species specific characteristics. The chimpanzee is thought to be the ancestor of Cro-magnon man.
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GORILLAS
In contrast to chimpanzees, gorillas have been found to possess ONLY blood type B. Some evolutionary scientists believe the gorilla to be the ancestor of Neanderthal man.
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BABOONS
Baboons, on the other hand, have been found to possess A, B, and O blood types. The hominoids, humans and the great apes, express the ABO antigens on red blood cells, but baboons do not. In baboons, the antigens were found in other tissue cells. Although the similarity in alleles exist in baboons and humans, the mutations which are in human O alleles are not found in baboon O alleles. This suggests a different origin for the O blood types in each species (Diamond et al., 1997). Unlike humans who have a large percentage of O, in baboons O has arisen several times but remains relatively rare. This suggests a possible selection working against type O in baboons.
Humans, baboons and orangutans have maintained their polymorphism. Because of the absence of B from chimpanzees and O and A from gorillas, the locus determining this phenotype must no longer be under strong selection pressure in the hominoids.
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SO WHAT DOES ALL THIS MEAN?
Scientists have determined by using average mutation rate and considering the required mutations that the divergence of A and B (at nucleotides 793 and 800) must have occurred before humans, chimps, and gorillas had separated and likely before orangutans broke off. Thus A and B diverged at least 13 million years ago (Martin, 1990). In chimps and gorillas, the A and B allele seem to be fixed (Martinko, 1993). Some sources state that the two types are likely of separate origin (http://aol.com/ikaulins/expak), but that they are the original types, not O.
Other evidence used to trace man's evolutionary ancestors to these non-human primates is the MN blood system. Man is M and N; whereas chimps are anti-N and gorillas are anti-M. O is not the original blood type as was previously thought (http://members.aol.com/ikaulins/expak).
IS SELECTION AT WORK TODAY?
If these blood groups are being selected against, the agent is not restricted to humans because the system has been around for over 13 million years. There is only indirect evidence for the possibility of natural selection in the evolutionary pattern of ABO groups (Saitou and ). To link natural selection to the frequency of A, B, O phenotypic frequency requires more evidence. One such study was completed by Boren et al. (1993), in which a bacterium casing gastric disorders was linked to blood type (Saitou ). The researchers found there to be less receptors for the bacterium in blood types A and B, thus people with blood type O were more susceptible. If more blood types could be linked to microorganisms, there would be more evidence for natural selection.
Several question remain. For example, if natural antibodies help to protect the body against parasites, then why is O, which has both A and B, antibodies not at an advantage? Also, O is a nonfunctional allele, yet it is quite common in certain areas like South America where it is fixed in the population. This seems to contradict standard mutation drift selection which does not favor nonfunctional alleles (Nazzareno et al., 1995).
To learn more about the world distribution of blood types, click here.
There is also a question as to whether selection is at work today in the interacions between mother and fetus. Some studies have concluded that in mothers with type A blood who are carrying a fetus of type O (and vice versa), there is incompatibility which will result in the spontaneous abortion of the fetus.
In summary, it appears that humans, chimpanzees, and gorilla (and likely ornagutan) followed the same evolutionary origin when comparing their blood types. Because the A and O exist in chimps this is likely the ancestral form of these types found in humans today. The B type found in gorillas today was likely ancestral form found in humans. Thus,
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