Charles Darwin spent some thirty pages in 'The Origin' discussing difficulties with his theory. He says, 'Some of them are so grave that to this day I can never reflect on them without being staggered...'. However, the problems that the theory still faces, 150 years after 'The Origin', are almost invariably ignored in both school textbooks and in media references to the theory.

Indeed, in the latter case the theory is usually treated as an unquestionable background fact. Based on such sources of information one would be hard-pressed to discover the issues that challenge the theory and to make an informed decision about its credibility. Fortunately, Darwin's Theory is such that we can all readily understand what it asserts, and discover and assess the facts relevant to it - without having to be experts in Biology and Palaeontology (my own background is mainly in Physics/Maths, which I taught in Further Education).

Darwin's Theory Of Evolution has enormous scope, in claiming to be the complete explanation of the development of all life, but it can be expressed in just two basic propositions:

1 - All organisms alive now or that have ever lived have been arrived at by extremely gradual changes along sequences made up of, as Darwin puts it in 'The Origin', 'inconceivably great' numbers of 'intermediate and transitional links'

2 - The mechanism of change along the sequences is dependent on Natural Selection preserving those characteristics that are inheritable and advantageous for survival

Evolutionary change is sometimes represented by a 'tree of life'. If we put vertebrates alive today in their appropriate places on such a 'tree', we find that there are localized numerical 'explosions' as species of fish, amphibians etc. mount up. However, we do not find sequences of life forms, corresponding to descendants of the supposed intermediates, to populate the trunk and branches of the tree, linking together the different distinct groups. All we have are a handful of curious individuals - these include monotremes, suggested as a link between reptiles and mammals - of these, Molecular Biologist, Michael Denton (in his 1985 'Evolution - A Theory In Crisis') says: 'Instead of finding character traits which are obviously transitional we find them to be basically reptilian or basically mammalian so...they afford little evidence for believing that any of the basic character traits of the mammals were achieved gradually in the way evolution envisages.'

When Darwin was writing 'The Origin' he knew that there were no fossil sequences to directly support his theory of gradual organic change. He wrote: 'That our paleontological collections are very imperfect, is admitted by everyone' - so presumably he expected that the fossil evidence his theory required would turn up as fossil collections became progressively more complete.

So what's the situation now, after 150 years of fossil-hunting? Dr. Niles Eldredge says (Guardian Weekly - 26th Nov. 1978): '...geologists have found rock layers of all divisions of the last 500 million years, and no transitional forms were found in them.' And Michael Denton says (ibid., page 162): '... while the rocks have continually yielded new and exciting and even bizarre forms of life ... what they have never yielded is any of Darwin's myriads of transitional forms...'.

As with the living, the fossils throw up individuals commonly referred to as 'missing-links'. However, to characterize such an individual as a 'link' is to assume the once existence of a chain from which it was a part - but that is to assume the very thing for which the evidence does not exist i.e. the reality of such chains of organic change.

Darwin's Theory was consistent with the overall structure of the then (1859) known fossil record - but the concern he expressed in 'The Origin' that 'Geological research...has done scarcely anything in breaking down the distinction between species, by connecting them together by numerous, fine, intermediate varieties' is as true now as it was in 1859. Couple this with the parallel fact that there are no sequences amongst the living corresponding to descendants of his 'inconceivably great' numbers of 'intermediate and transitional links', and it seems that Darwin's proposed huge sequences of organic change have no more correspondence to a demonstrable physical reality than do faces seen in the clouds.

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There are a number of 7th grade science project ideas that a student can choose from to demonstrate concepts learned in class. A few such projects include:

• Collect water from a nearby stream or pond and view a drop of it under a microscope. Note what kinds of things you see and make drawings of them. Which are plants and which are animals? What is greater in your sample, plants or animals? What factors might affect the numbers of each that you find?

• Draw a cell and label all of its parts. What function does each part of the cell serve? Are there differences between plant and animal cells? If do, what are they?

• Name the four different blood groups found in humans. What type is the rarest? The most common? How does the blood type of a person's parents affect the outcome of their own (i.e. if a person with type A blood marries someone with type O, what type will any offspring have)?

• Draw a picture of a red blood call from a human and label all of its parts. Now draw a picture of the red blood cell from an animal, like a cow and label all of the parts. Are there any differences? If so, what part do you think these differences play in the function of the cell?

• Build a 3D model of a single-celled animal from cake. Use different tints of frosting to make the different structures inside the animal. Licorice laces can be cut up to represent the cilia. Before the cake is eaten, hand out a sheet that has the different parts labeled with call-outs, but not filled in. Allow people to view the cake and fill in the papers as to what each structure is. Just before the cake is cut, put out a poster that shows what everything is. Let the person who has the most right answers for these 7th grade science project ideas have the first piece of cake.

• Take a sample of cells from the inside of the mouth and view them under a microscope. Stain the material with a drop of food coloring. Describe what you see. Make a drawing of any clear cells and label all of the structures present.

• Plankton is made up of several kinds of single cell plants and animals. Find out what they are and make drawings of several different kinds of each. What animals use plankton as a food source. What kinds of changes in the environment could change plankton's survival in the water? Has plankton levels risen or fallen in recent years? Why?

• Different bacteria exist all around us. Where are they found? What role do they play? In what cases should bacteria be encouraged to grow? In what cases should they be discouraged? Give an example of how or why they should be encouraged, and why they should be discouraged.

With a little bit of careful thought it is possible to find any number of 7th grade science project ideas that can be turned into a science project for the inquisitive student.

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When you look at delicious food, you are experiencing a conditioned response. In other words, your thoughts say "Wow! That looks delicious and tasty!". Your thoughts then stimulate your brain which tells your digestive organs to get ready for some action.

When you smell food, what happens in your nose is entirely physical. The alluring aroma of tasty food gets transmitted by molecules which come off the surface of your food. These molecules settle on the membrane lining of your nostrils and stimulate the receptor cells on the olfactory nerve fibers. The olfactory nerve fibers stretch from your nose all the way back to your brain. The receptor cells communicates with your brain "Hey, there is good food here!".

Your brain will then send messages which alerts your mouth and your digestive track. The message your brain sends to your mouth is to start the saliva flowing. It will send a message to your stomach to warm up the stomach glands and will also send a message to your warm up your small intestine. Basically, the sight and scent of food can make your mouth water and your stomach hungry.

But wait a minute! What if you hate what you are smelling or seeing? For some people even the thought of liver and onions can make them want to vomit, or at least leave the room. At the current time, your body is trying to protect you. You are experiencing an rejection reaction. Which is similar when babies are given something that tastes sour or bitter. Your mouth sags and your nose wrinkles trying to keep the food as far away as possible. Your throat will also tighten and your stomach will turn. Not a very pleasant moment. But if you like what is on your plate, go ahead and take a bite.

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The Leadership in Energy and Environmental Design (LEED) is a certification awarded by US Green Building Council to "encourage adoption of sustainable green (environment friendly) building and development practices through creating and implementing universally understood and accepted tools and performance criteria". In layman's terms, it is a third party certification and a benchmark for design, construction as well as operation of green buildings.

The professional accreditation for LEED is also given to individuals, project managers, architects, contractors, construction managers, interior designers, landscape architects and even lenders and government officials to improve sustainability records.

Why is LEED Education so Important?

As the world wakes up to the necessity of creating and maintaining sustainable properties which do not create environmental degradation, both in the US and abroad, stricter laws are being implemented with respect to building design, construction and maintenance. Read on for a free leed guide which gives more information on the examination procedure.

The green associate exam is an accepted international accreditation which gives a professional edge to its holders. For projects in the USA as well as for international projects, corporate houses increasingly prefer people well versed with the LEED parameters, who can work with related departments to complete building processes and maintain them according to LEED guidelines.

The LEED ap exam or LEED Accredited Professional exam earlier had several versions depending on the versions of the LEED system, including LEED NC (new construction and major renovation), LEED EB (existing building) and LEED CI (commercial interior). The LEED EB has been discontinued, and the other two will also give way soon to the new version which comes into effect from September 15, 2009.

The new LEED 2009 credentials will have two tiers. Tier I will require passing of a 2.5 hour exam, and the individuals will become LEED Green Associates. Tier II level will comprise of a 1.5 hour exam, which will qualify the individuals as LEED AP with speciality. The computerized multiple choice format questions give instant results and cost around $300 for professionals of member companies and $450 for others. The LEED AP exam has 80 questions, with a maximum score of 200 and 170 required to pass. LEED APs are generally recognized as experts in sustainable design.

Many people take the LEED ap exams, and there are numerous green exam prep centres offering their services and even free LEED exam over the internet. However, study material is free and plentiful, from the USGBC, the Green Building council and other sources.

To crack the exams, the information collected and memorized must be reproduced quickly, completing the multiple choice questions in the stipulated time. Examinees must prepare extensively through leed training classes and leed practice tests. Like most other multiple choice formats, the essential secret to be successful at the exams is to repeatedly practice mock free LEED exam papers. This is where the flash cards of LEEDedu scores an edge over the other study material providers. Its LEED exam prep courses offer extensive and carefully screened questions from expert advisors to give many practice sessions before appearing for the main exams.



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I am amazed at the inventiveness of early researchers in pursuit of the secrets of heredity. With no idea of the true chemistry of genes, investigators designed experiments to reveal genetic facts.

Geneticists of the 1930's and '40's believed, incorrectly, that genes must be made of protein. Yet during this time, George Beadle made his "one gene-one enzyme" discovery. The discovery came about because Beadle wondered what genes actually do in order to cause traits.

First Beadle investigated fruit fly eye colors. Normal eye color in these flies is a deep-red mixture of red and brown pigments. Two bright-red mutant colors are vermilion and cinnabar; these contain no brown. From mutant larvae, Beadle transplanted vermilion and cinnabar eye discs into normal larvae. The eyes developed normal color in the adult flies. Cross-mutant transplantation showed Beadle that the brown pigment resulted from a series of chemical reactions: a starting substance got changed to vermilion, which got changed to cinnabar, which got changed to brown. Each mutant lacked one of these reactions, but it was time-consuming to figure out which one.

To speed up his investigation, Beadle switched from fruit flies and eye colors, to red bread mold and the nutrients it manufactured. Beadle X-rayed the bread mold to cause mutations, then tested spores from the mold to see if they could grow on a minimal food containing only sugars and salts.

If a mold couldn't develop on the minimal food, this meant it was missing a nutrient because of a mutation. Beadle tested to see if the mutation was in a single gene. If so, Beadle then added a supplement, such as a vitamin or an amino acid. If that didn't make the mold grow, he tried a different supplement, until he found the missing nutrient.

During growth, each mutant mold accumulated a chemical. This chemical came from the reaction step where the mutant got stuck. The mutants could be arranged in order, according to where they got stuck, and this order showed the reaction steps in the manufacture of the supplement nutrient.

Beadle knew that each chemical reaction is controlled by an enzyme. So each mutant mold must be missing the enzyme that could change its accumulated chemical to the next one in the series. Since each mutant was missing a single gene, each of those genes must give rise to a single enzyme. "One gene-one enzyme!"

Julie Simon Lakehomer is writing a book about DNA. The book tells the life stories of thirteen geneticists, eager to ferret out the secrets of inheritance. These researchers committed themselves to conversation with the DNA universe until, revelation by revelation, they transformed what was known about heredity.



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Unlike an equation, which shows balance or harmony among two expressions, an inequality shows imbalance. That is, an inequality states that one expression is bigger than or less than another expression. Linear inequalities involve expressions which are lines, or linear equations. These inequalities are solved much the same way as equations with one key difference. Read on to enter this curious world.

Let us take the linear equation 2x + 1 = 5. You know to solve for the unknown, x, you subtract 1 from both sides and then divide by 2. Thus x = 2. If we replace the "=" symbol by an inequality symbol such as "<", less than, or ">" greater than, we have a linear inequality. If we choose the former we have 2x + 1 < 5, which establishes the "imbalance" between the left and right hand sides of the expression. What this says mathematically is that the quantity 2x + 5 is strictly less than the quantity 5. (Note: we can also use the inequality symbols < and > with the = symbol to get <=, or less than or equal to, and >= greater than or equal to. In these cases, the "=" symbol permits the right and left sides of the expression to be equal.)

To solve an inequality, we carry out the exact same steps as if it were an equation, keeping the inequality symbol intact. Thus in 2x + 1 < 5, we subtract 1 from both sides and divide by 2 to get x < 2. Whereas equations place strict requirements on the value of the solution, an inequality permits a broad array. To be precise, 2x + 1 = 5 permits x to be only 2; in 2x + 1 < 5, however, x can be any value less than 2. If we allow x to be any kind of number---integral, rational, or irrational---we have infinitely many possibilities to choose x from.

You can visualize the inequality just solved as follows: picture a balance scale with a 5-weight on the right and a (2x + 1)-weight on the left. Since the inequality states that the 5-weight is bigger, the scale is tipping to the right. That is the left side is higher than the right side. Solving to get x < 2, tells us that in order for the "imbalance" to be maintained-for the right side to continue being lower than the left side-then x has to be any weight less than 2.

Take another example: 3y - 4 >= 8. In words, this inequality states that the quantity 3y - 4 is bigger than or equal to the quantity 8. Visually in terms of our balance scale, this inequality says that the left side is in balance with or bigger, that is tipping left, than the right side. To solve, we simply add 4 to both sides and then divide by 3. Doing so gives that y >= 4. Thus if we choose y to be any weight equal to or bigger than 4, our given "imbalance" or balance, in the case when both sides are equal, will be maintained.

The next time you see an expression involving one of the "imbalance" symbols, know that you have an inequality, and that to solve, really requires nothing new. There are some situations, however, that require a little more care. Those we get to in Part II.

Joe is a prolific writer of self-help and educational material and is the creator and author of over a dozen books and ebooks which have been read throughout the world. He is a former teacher of high school and college mathematics and has recently returned as a professor of mathematics at a local community college in New Jersey.



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