The publication of Darwin's Origin of Species was followed by bitter controversy between those who believed in the divine creation of species, and those who were persuaded by the logic and power of Darwin's arguments. This controversy seemed to die down in the 20th century, and it became common to assert that science dealt with the material world and religion with the spiritual.

Now, at the beginning of the 21st century, there has been a resurgence of creationism, either in the guise of "science creationism" or "intelligent design". The simple fact is there is an enormous knowledge gap between evolutionary biologists who are familiar with the wealth of evidence in favour of Darwinian natural selection, and those who are unfamiliar with this evidence, and often do not even feel there is a need to examine it because they have blind faith in a divine creator. This is one of the divisions between religion and science.

Most religions seem to hold:

• a belief in an omniscient god or gods:
• a belief in miracles;
• a belief that the material human body is separable from a non-material soul;
• a belief that humans have free will, a conscience, and the God-given ability to choose between good and evil;
• a belief in an immortal after-life, and
• a belief in prayer, or direct contact between humans and a deity.

The belief in a non-material soul implies that it arises at some stage in human development, and this can be linked to the view that life itself is a mystery, and by implication, outside the realm and understanding of science. Commonly it is thought that the fertilisation of an egg by a sperm initiates life, and the embryo is therefore already a human being.

Modern molecular biology has effectively solved the so-called "mystery of life." In short, living cells consist of complex chemicals, and their even more complex interactions. There is absolutely no place for a "vital force" or any non-material entity either in the egg, the sperm, the fertilised egg, the embryo, the child or the adult. Thus, there is no non-material soul, nor an afterlife.

The amount of biological information that has been gathered in the last 50 years is too vast to communicate to those who continue to believe in a soul and an afterlife.

Another fundamental difference between science and religion is the issue of free will. Most individuals believe in free will because it is a matter of common experience that they feel free to make their own decisions. For the religious, free will is God's gift to man. However, once it is accepted that we are complex organisms composed only of molecules, a completely new light is thrown on the supposed existence of free will.

In making a simple choice, for example, between moving one's right or left arm, we feel completely free, but the fact remains a signal is transmitted to the muscles that comes from the brain. The brain is not capable of spontaneously creating energy, because if it did it would contravene the law of conservation of energy, so the signal must come from somewhere else. Because we are conscious of feeling free, the signal must come from another part of the brain which is part of our unconscious brain function. Thus, there are forces at work of which we are not aware.

These forces are determinants of our behaviour, and free will is no more than an illusion. Of course, some decision making is complex and may depend on knowledge, experience and external factors of which we are well aware, but this does not affect the basic conclusion that we do not have free will.

The two cultures are much alive, in spite of the best efforts of contemporary science writers to explain new advances to the public.

On the one hand there is a mass of information documenting the reality of Darwinian natural selection acting on mutations that are most commonly single changes in DNA sequence. Nowadays this depends on the sequencing of DNA, which documents in full detail the step-by-step changes in individual genes. On the other hand there are those who are totally ignorant of this evidence, and who simply assert there are "gaps" in evolution and that biological structures are too complex to be explained by mutation and natural selection.

It is said to be politically correct to be tolerant of all religions, but why should we be tolerant of the sets of untruths on which religions are based? It is not good enough for scientists to accept this political correctness. They should believe in the reality of what science has demonstrated over several centuries.

To act or believe otherwise is not intellectually rigorous, and is indeed a betrayal of the achievements of their own discipline. Experimental science has established itself as rational and reproducible, and there is no place for the contravention of natural laws, such as miracles, superstition and the occult.

Most people accept the reality of the advances in physics and chemistry, without understanding them. Unfortunately this is far from true of biology, and especially human biology. People think that they are free to believe in many features of a spiritual world, or to adopt irrational viewpoints.  Unfortunately,  the rejection of such beliefs  depends on  either  a detailed knowledge of what biology has achieved over many decades, or it depends on an acceptance of the   validity  of  the  whole  corpus  of  biological  knowledge.   A significance paradox is that many who hold spiritual beliefs are willing to accept sophisticated medical treatments which increasingly depend on fundamental biological research.