Human Evolution - The Evidence -

There is overwhelming evidence for human evolution. All human beings and all other life forms evolved from ancestral species. The four main lines of evidence for human evolution are:
1. Our relation to living primates;
2. Vestigal organs/structures such as the appendix;
3. The fossil record;
4. Genetics;

Hypothesis Testing

As a scientist and a rational human being, learn to question everything and strive to find answers on your own through research. 'Doubt' is the most sacred thing for a scientist and an adherent of the scientific method. This doubt keeps you on focused when you feel like surrendering or believing in something at face value without adequate scientific research. As scientists, we constantly strive to create a rational and lucid picture of the world by piecing together one fact at a time, through theorising and experimentation (Pilgrim, 2011). A Hypothesis means to “Ask a Question of Nature”. In Science we often need to test our hypothesis. A hypothesis is an educated guess, based on observation. Usually, a hypothesis can be supported or refuted through experimentation or more observation. A hypothesis can be disproven, but cannot be proven to be true (Helmenstine, 2010). To test the hypothesis we create an experiment that will yield one of two answers: Yes or No or True or False. The classical way to make statistical comparisons is to prepare a statement about a fact for which it is possible to calculate its probability of occurrence. This statement is the null hypothesis and its counterpart is the alternative hypothesis (Fraser, 2011). The null hypothesis is traditionally written as H0 and the alternative hypothesis as H1 or Ha. A statistical test measures the experimental strength of evidence against the null hypothesis. A Null Hypothesis is a statement that the difference between two values can be explained by random error. It is retained if the test for significance does not fail (H0). A null hypothesis assumes that the numerical quantities being compared are the same. The probability of the observed differences appearing as a result of random error is then calculated from statistical theory. The alternative hypothesis is therefore a statement that the difference between two values is too great to be explained by random error. The alternate hypothesis is accepted if a test for significance shows that the null hypothesis should be rejected (Ha or H1). Typical tests for significance are the F ratio test and the t-test. If we reject the null hypothesis at say, a 95% confidence level, there is a 5% probability that the null hypothesis was incorrectly rejected. An example of hypothesis testing is:

Let μ1 and μ2 be the means of two samples; If one wants to investigate the likelihood that their means are the same, then the null hypothesis is:
H0: μ1 =μ2
and the alternative hypothesis is:
H1: μ1 ≠μ2
but it could also be:
H1: μ1 >μ2
The first example of H1 is said to be two-sided or two-tailed because includes both μ1 >μ2 and μ1 <μ2; The second is said to be one-sided or one-tailed. The number of sides has implications on how to formulate the test (Fraser 2011).

References:

Fraser A.W., (2011), “Statistical Method Validation for Analytical Methods – a practical approach”
Helmestine A.M., (2010) “Scientific Hypothesis, Theory, Law Definitions” http://chemistry.about.com/od/chemistry101/a/lawtheory.htm (accessed 25 May 2011)
Pilgrim G. (2011) “Hypothesis versus Theory” http://www.buzzle.com/articles/hypothesis-vs-theory.html (accessed 25 May 2011)

Sue the Advertisers

The world did not end, which raises the question: should we sue the advertiser that predicted the Rapture / end-of-the-world for false advertising?

Humans from Monkeys?

I refer to your older article on the Waterberg and human evolution. Do you honestly believe humans come from monkeys? Johan, Pretoria Gem and Mineral Club


Hi Johan,

Well, no. We did not evolve from monkeys. Monkeys are our evolutionary cousins, so to speak. A common ancestor of all humans, apes and monkeys existed around 12 million years ago. This common ancestor gave rise to the Asian apes and the African apes. These species developed along their separate ways. About 6 million years ago, in Africa, what are known as the bipedal woodland apes – species such as the Australopithecines and our Homo Sapiens lineage evolved. Then at about 2.5 million years ago, also in Africa, the chimpanzee and the bonobo became separate lineages. I am certainly no expert on this subject and I would refer you to the literature available on the subject for more detail and accuracy that I can provide.

The Universe – Cause and Effect

The Universe is an unimaginably massive and complex system. Everything we know about the Universe points to it operating by absolute physical laws of cause and effect. The Universe, however, does not look like one in which an independent outside agent is intervening, nor is it a Universe in which miracles happen and physical laws are violated by an entity that is above these laws. The application of Occam's razor deletes the hypothesis of a supernatural origin of the universe. And every attempt to demonstrate the existence of any supernatural force affecting the universe fails through rigorous scientific examination. Cosmology provides explanations for how, out of a singularity and subsequent explosive expansion 13.7 billion years ago, the universe came into being.

Rock of Ages

A sample of the Acasta Gneiss. The Acasta Gneiss is dated at 4.2 billion years old. Specimen size: 5 cm. Specimen and picture: A. Fraser

It is generally accepted that the age of the Earth and the rest of the solar system is about 4.55 billion years (plus or minus about 1%). This value is derived from several different lines of evidence. Unfortunately, the age of the Earth cannot be determined directly from material that is solely from the Earth. Meteorites have been used to date the age of the Earth as these and the other planets were formed at the same time. The Earth is a dynamic planet and the processes of erosion and crustal recycling as a result of plate tectonics have destroyed the entire earliest surface of the Earth. The oldest known exposed rock outcrop found so far is that of the Acasta Gneiss in Canada. The Acasta Gneiss was dated by radiometric means at 4.2 billion years (4.2 Ga) in age (Tsuyoshi, 2007). And, I have a specimen of the Acasta gneiss!

Science Illiteracy – it’s just depressing

Scientific illiteracy is depressing. It is one of the reasons that creationism, intelligent design (ID) and a plethora of pseudoscience are accepted by so many. It seems that scientific illiteracy and the mistrust of science is on the rise. The media is replete with discussions of intelligent design (IDiocy) and climate change denial ostriches. Many people nowadays cannot address even the simplest scientific question.

How many adults understand what molecules are, and how many can identify DNA as a key to heredity or that the Earth is 4.56 billion years old and not 6000 years old. The lack of a basic understanding of how the earth works is also obvious whenever large earthquakes such as the occurrence 9.0 magnitude quake in Japan last week is covered in the news. The news anchors always ask the same dumb questions of geophysicists ….. how do earthquakes occur, are they on the rise and can we predict them? I am willing to bet that there are still people that believe that the Sun revolves around the Earth! No wonder people confuse scientific research with obsolete religious dogma or far-rightwing political discussions.