Fossils can show change in animal's bone structures. For an example, some fossil shows some birds that had claws at the tip of their wings. But over time their fossils show that bird's claws slowly disappeared. This may occurred because the bird's way of living didn't need the claws anymore.
Firstly, one bird having smaller claws than another don't prove that one is older than the other. Secondly if you look it up there are no missing links between species that have been fownd. Take humans evolving slowly from apes for example. Have you ever noticed that all of the animals drawn on the charts of human evolution have human feet and hands. This is because that of all the ancient human sceletons that have been fownd, only a few fragments have been fownd which isn't enough to test.
Sorry, I may have not been clear. Fossil's age can be checked with relative dating and radioactive dating. ( In this case) The fossil with the bird that has claws is older than the fossil with a bird without claws. Also these two birds have been checked genetically and have been proved that they the same species (or close).
Evolution can be also proved by common traits of animals. Lizards in a continent and lizards in an island have different appearance but genetically, they are similar.
The method of radio active carbon dating can only be used it things less than 50,000 years old and it is not accurate as it assumes that the amount of C14 has stayed constant which it hasn't and all other measuring of other elemonts also assume that their level has remailed con stand thoughout hI story. . However, there is uranium dating that supposidly dates to up to 4 billion years. But I doubt that there was any uranium in old bones to biggin with as it would kill them.
"Radioactive carbon dating can only be used with things less than 50,000 years old"
Yes, this is true. But 50,000 is a long time. Evolution is still possible in a short period of time.
("short period of time" 1000~10,000 years)
Evolution is also proved by Genetic Commanalities. For an example, A human has about 96% genes in common with chimpanzees, and other animals such as cats, mice and birds. This proves that human and these animals came from one ancestor who went through an evolution.
A cloud is 99.9% water and a watermelon is 95% water but no one would say that they evolved from each other. Natural evolution can only produce variations in a kind. For example, Darwin's finches. Finches from different islands of the galapagos have different charictoristics but they are all still finches. It is like the difference between a European and an African and I'd hope that you wouldn't call theme different species.
Darwin's finches from different islands of the Galapagos are both finches. But do you know why they have different characteristics? It is because they evolved to suit their environment.
Bateria also evolved through time. People made medicines to kill bateria. These medicine worked when it was invented. But these medicine soon became less efective. The bateria have made some kind of wall for these medicine! Now this is proof for evolution.
A bacteria that becomes immune to a chemical is still the same bacteria but with a slightly different charictoristi. (This could be termed as macro-evolution. This states that variations in a kind (species) can occur. This means that people can be of different hight or skin colour and dogs can be breed to be more docile. This is obviously real but no matter how selective you are with breeding dogs, your end product will always be a dog rather than a cat.
Evolution is proved by similiar appearance of embryo. Developing embryos of mammal, fish, amphbian, birds, and repitile share common features, such as tails and gill-like structures. These similarities suggest that the species share a common ancestor.
Fossils, patterns of early development, and similar body structures all provide evidence that organisms have changed over time. Is there anymore reason you'd like to say to prove "There is no proof of evolution."