When talking about the theory of evolution, it is important to understand the scientific definition of the word "theory". In conversational English, "theory" usually refers to an idea that is unproven, but in science it means something quite different. Scientific theories are hypotheses that have been rigorously tested and are supported by multiple lines of evidence-. This is why gravity is also technically a theory - we are constantly finding evidence to support the idea that masses have an attractive force in space. In other words, theories are constantly being added to or altered on the basis of facts.

Ever since the theory of evolution was proposed ~200 years ago, scientists have discovered a wealth of information which supports it. A search on PubMed (a database for scientific articles) shows that from 1971 to today, over 460,000 papers have been published with "evolution" in the description (and that doesn't include the millions of articles published in the field of biology that are based on evolutionary principles)!

As Theodosius Dobzhansky (an evolutionary biologist) said in 1973, "Nothing in biology makes sense except in the light of evolution". Research that has given us lifesaving medicines and technology has all been fueled by this theory, and could not have been possible without it.

This doesn't mean that scientists have stopped investigating evolution or finding ideas that sometimes challenge our preconceived notions of how evolution works. In fact, DNA was not even discovered until after the theory of evolution was proposed. In the 1940's, Barbara McClintock discovered transposons, which drastically expanded our view of how genomes could mutate and evolve (for more info, check out transposable-element ). In every case, however, the theory of evolution has been modified or substantiated - there hasn't been a single (legitimate) line of evidence that completely contradicts or disproves the theory of evolution.

Based on how thoroughly evolution has been studied (and applied in research with successful results), it would take an astounding amount of contradictory evidence to cause scientists to treat it as anything other than a well-established fact. Creationists often point to missing evidence (such as an incomplete fossil record) as proof that evolutionary theory is wrong, while ignoring the substantial evidence that already exists. We will never have a "complete" fossil record (which is really a misnomer, since evolution creates branches of speciation, rather than a straight line of species leading to the "perfect" organism). However, this is not the way science works - scientific theories are built by constantly challenging our assumptions whenever we find new evidence, and seeing if they still hold true.

Other arguments against evolution have been proposed, but they don't come close to challenging the theory of evolution as we know it, usually because they aren't based on scientific evidence and/or they contain multiple logical fallacies.

If you're interested in learning more about the kinds of arguments made against evolution and why they aren't supported by evidence, I recommend going to neurologicablog (a blog written by prominent skeptics) and clicking on the Creationist/ID tab.

The theory of evolution is true. There is no proof against it. We are still learning some of the details about how evolution works. One way that species survive and evolve if they are the best at fighting other species. ['Nature Red in Tooth and Claw'] That was one of the first understandings of how evolution works. There are also newer understandings. One of these is 'Reproductive Fitness': Species that produce more offspring out-compete species that have fewer offspring. Now we are discovering that it's not just our Genetic Code that determines our fitness; there are also small chemical changes made to our genes that affect our fitness. This is 'Epigenetics.' For example, Methyl groups (CH3- groups) can be added at certain places on the DNA.

If you google 'proof against evolution,' the main 'proof' you find is the book of Genesis in the Bible, which says that God created all life. Creationists believe in this, but it's not scientifically true.

There's a Wikipedia article about Objections to Evolution that explains what's wrong with the objections.

And there's an article in Scientific American: 15 Answers to Creationist Nonsense - Scientific American

No,there is not any proof against the theory of evolution; the theory of evolution is well-supported by the evidence. There are a number of details in which our theory of evolution is incomplete, but this is true of any theory we have, even something as rock-solid as the theory of gravity. As such while we don't know everything about evolutionary biology and the theory of evolution does not explain everything, we are pretty certain that something resembling what we call the theory of evolution does indeed happen.

Additionally, the theory of evolution that we are using now is different from the theory that Charles Darwin and Alfred Russell Wallace originally proposed: for example, Darwin and Wallace did not understand where genetic variation in organisms came from or how it is maintained (Gregor Mendel solved that one), and they also thought that most now-extinct species died out because they couldn't compete with superior organisms that replaced them (now we suspect that most extinction is instead due to changes in the Earth's climate).

Some of the unanswered questions in the theory of evolution include the exact mechanisms by which species become extinct, how important each of the several different (known) mechanisms by which species can be created are, whether or not there are more ways that species can come into being that we don't yet know about, whether there is an inevitable direction to evolution and what that direction is (e.g. is intelligent life inevitable?), and why certain traits so ubiquitous to life are so common (e.g. sexual reproduction).

There are many people out there who pose oppose the theory of evolution. Some of their common criticisms are its lack of observation, unreliable evidence, unreliable chronology, and it is mere improbability. Most of these claims come from creationists and religious groups. They claim that mutations and genetic drift lead to small changes within species and organisms, but there is no evidence for animal A turning into animal B. Another crucial point made is that we, as living organisms, had to start somewhere, and that there’s no way that life could have come from a non-life form. All in all, there are tons of articles, arguments, and websites on both sides of this tug of war, and for now, it’s up to you to decide where you stand.

This question is really difficult because it is a generally accepted fact that evolution happened and continues to happen. There are few well thought out arguments but in order to act in good faith as scientists we should consider the opposition.

One argument people make is that if evolution was real, we would be seeing it happen now. In the roughly 150 years since Charles Darwin published On the Origin of Species, some people would argue that we haven’t observed any considerable change in the plant and animal species around us. This actually isn’t true though, speciation events (a mechanism of evolution) are happening all around us. First let’s define speciation event, which is when a portion of a population of organisms evolve in such a way that they can no longer breed with the rest of the population. This creates two distinct species. One clear example of this is the London Underground Mosquito which has lived exclusively in the subways of London for the past hundred years. The underground mosquitos have gained various adaptations like, year round breeding, cold intolerance, and a larger prey variety and since they’ve changed so much from their above ground relatives, the two cannot interbreed anymore. This is a perfect example of speciation which is one of the major ways that we can observe evolution in action.

Another argument made against evolution points toward the lack of intermediate species in the fossil record. People like to argue that there should be more steps between the distinct species we find in fossils but this exposes a lack of understanding of how evolution works. While evolution is a constant process, the successes that result from mutations stay around much longer than the failures. Intermediate species were surely less viable than the species we categorize. This may sound a little confusing but the basic idea is that the good species had much larger populations and survived much longer than intermediate species. Since it is pretty rare for an organism to turn into a fossil, chances are that only the organisms with high populations make it into the fossil record. People that argue that intermediate species are absent from the fossil record and therefore must not have existed: evolution is a lie, are missing key knowledge about how both evolution and fossils work.

I hope that this information is enough to answer your question. People attempt to disprove evolution for a variety of reasons, and that is actually a good thing for science. Science is based off of questioning ideas and rigorously testing them so it fine to have our current model scrutinized. This is the only way that we can be sure that we are correct about an idea. It is important to remember that all arguments need to be evaluated, and in the case of the arguments against evolution, you can see that their beliefs fall flat. Thank you for your question!