What was Darwinism?

Answer 1

Basically that species adapt to their environment by changing and developing gradually, thus becoming more successful and better suited to survive and multiply.

Species proliferate through variation (mutation) with common descent (inherited characteristics) and natural selection.

Darwin's theory proposes most of the species today arose through gradual changes in previously existing species. All mammals, for example, inherited traits from some common ancestor. Because whales are mammals, they would have evolved from some terrestrial mammal. All terrestrial vertebrates (mammals, birds and dinosaurs, reptiles, and amphibians) would share common ancestry with some amphibious ancestor that lived several hundred million years ago.

One bit of evidence in support of this theory is that all terrestrial vertebrates (including cetaceans) have inherited the same amphibious body plan for limbs, backbone, pelvis, and rib cage, similar to that of the sarcopterygian lungfish from which it appears they share common ancestry.

Reptiles, dinosaurs and birds are all diapsids. Mammals are synapsids. Turtles are anapsids. If evolution were wrong, there would be no reason for this to be the case.

Darwin's theory of evolution is often stated as: 'Survival of the Fittest" (though Darwin NEVER said this) or "Natural selection." More precisely, it amounts to the idea that when an organism differs from its family and neighbours in such a way that it can produce more young that in turn can successfully produce more young, its line will increase and eventually displace its less successfully reproducing rivals.That is what a revolutionary fitness amounts to. Note that not just any difference will do; the differences have to be heritable - they must pass on from parent to offspring, or they will have very little to do with evolution through natural selection.

Genetic mutations occur in every species. Sometimes these are beneficial. For example a calf born more muscular than the rest will be more likely to mate and consequently pass on his genes to his offspring.

There are hundreds of others, but the suggestion: 'Or Google "evolution Darwin" ' is strictly for people who already have a good basic understanding of the field. Although there is a lot of good stuff on Google, for every reliable article on evolution, you have to dig it out of a torrent of garbage. For some peculiar reason, Darwinism in one form or another has been selected as the arch enemy by every second dishonest evangelist (and there are thousands of them!) and a lot of evangelists that may be honest enough to preach, but not honest to get their facts on the subject straight. If they were to seriously study the subject, they could tell that it has practically nothing to do with scripturally based faith.

Remember a very important point if you begin to study evolution in Biology (or related concepts too, in fact): The principles are so simple that most people who first hear of them say something like: "Oh! How easy! I understand that; it is obvious!" The fact is that although the principles do seem easy, it does not follow that the whole subject is easy. It is a beautiful subject, but it requires serious work and careful thought to avoid making a fool of yourself, whether you are a genius or not. To imagine that because its principles are simple, a subject is simple, is an error. A brick may be easy to pick up, but it does not follow that a house made of bricks is easy to pick up. The basic principles of mathematics are simple too, but that does not mean that mathematics is a subject for the simple-minded. Much the same is true for evolution.

Don't let me put you off; it is a lovely, lovely subject, but it is not a subject that you can master by reading a book about it, not anyone's book.

Developments since Darwin The theory of (biological) evolution has advanced since Darwin's time. For example:

• Although Mendel lived in Darwin's time, his work on inheritance did not become widely known until later. In fact, in the introduction to his book, Darwin admits to being perplexed about the very question that Mendel answered. Mendel's conclusion was (in modern terminology) that every organism has 2 copies of each gene, one inherited from each parent (each chosen randomly). The emergent field of molecular Biology led to the demonstration that DNA is the medium on which genetic information is written, and to the discovery of its structure by 1953. Since that time advances in the field have lead to dramatic changes in our ideas of what a gene really is, and some of its implications for the theory of evolution.
• Furthermore, the relevance of Mendel's work to Darwin's theory was far from obvious; for some decades some people regarded the two bodies of work as being in conflict. It was not until the mid-20th century that they were united in what we now know as neo-Darwinism.People ignorant of the subject regard that as a criticism of evolutionary theory, but it is nothing of the kind; it was simply the addition of new knowledge and new insights to pioneering work (real work; not idle handwaving!) that already was brilliant in its own right. Neo-Darwinism is an enhancement of Darwinism, not a negation.
• Darwin assumed that all changes in a species must be gradual. But we now know that genetic information is stored digitally, from which it follows that even a small mutation can cause a large change in an organism - for example, a whole gene can be rendered useless by just one point mutation. Furthermore, since Darwin's time, science has come to terms with some erratic aspects of the world, such as chaos theory and quantum mechanics. Darwin's assumption was arguably a product of this limitation in the scientific thinking of his time.
• In the 1960s, Hamilton derived mathematically a solid basis for predicting the extent to which an organism will show altruism towards its relatives. His prediction was that it would treat what the evidence suggests should be its sibling as having roughly half the value of itself. What it sees as its own young usually is also worth roughly 1/2; a nephew 1/4; and so on. It is now possible to use game theory to analyze the behavior of organisms quantitatively. Previously, only qualitative arguments were possible.
• Apart from the more theoretical developments mentioned above, scientists sometimes change their minds about the exact relationships between different species. In particular, the recent availability of increasingly cheap techniques for genetic sequencing has created a new source of evidence. One surprising observation is that the relationships between single-celled organisms over billions of years do not appear to follow a tree-like structure. In other words, there has been exchange of DNA between very different species of single-celled organisms. It is also believed that certain parts of cells, called mitochondria and chloroplasts, were once independent organisms, which developed symbiotic relationships with their host cells.

I agree with the "Developments" paragraphs, but would like to remark about the bit: "...scientists sometimes change their minds about...": John Maynard Keynes said:"When the facts change, I change my mind sir. What do you do?" Remember that when scientists worthy of the name change their minds, it is because the facts at their disposal have changed.

One of Charles Darwin's theory is named The Origin of Species which he discovered during the visit of an archipelago of volcanic islands, Charles discovers a massive amount of diverse species. From this, he deducts that animals with variations better suited to their environment would have a better chance of survival and ability to breed. They would then pass on the favorable characteristics to their offspring.