No, that is not true. Every single species evolves for as long as it exists, but the pace of evolution may be different for different species. For example for the last several million years crocodiles evolved relatively less than other species because of the lack of ecological changes or factors like predators and sexual compulsion. But when we move back in time, we witness an incredible evolution process as the conditions of Earth changes. But thanks to the selective perception of manupilators and the ignorance towards science an untrained eye might not see the differences between the fossils and the modern animals and they claim “They are the same.” or even look at a dolphin and a shark and say “Both of them are just fish.”
A trained Anatomist, Paleontologist, Physiologist and more significantly a Molecular Biologist and Genetist or an Evolutionary Biologist will see the changes on the organism.
Besides, it is impossible for an organism to remain unchanged. Our World is under constant radiation and this beams cause our DNA constantly to change. To think that an animal preserved its genetic material and protected it from the constant radioactive beams for 250 million years is childish and naive. Moreover, it is not only radiation, but also the speciation and Mechanisms of Evolution force all the organisms to change and evolve. The reason why is that, if an organism can not adapt to the changing environment, by means of Natural Selection, it would be “selected out” and it would not be able to pass its genes to its offspring.
On the other hand, we know the evolutionary history of cockroaches quite well. Manipulators who take photos of fossils from some 10 or 100 million years and modern animals and claim that they haven’t changed are, let alone of being a specialist or an expert of the subject, not even graduated from a university.
The order Mantodea (mantis and its derivatives), Isoptera (termites) and Blattaria, accrete under the superorder of Dictyoptera. Molecular evidences prove that the termites have speciated directly from the cockroaches.The oldest known cockroach fossil is 295 to 354 million years old. The most significant difference between those fossils and the modern samples are the ovipositor, a mechanism which helps in laying eggs, which disappeared in the modern samples. This antique species, Blattopteran, is known to be the ancestor of the modern cockroaches and mantises as mentioned above.
There are several scientific articles about this subject, too. An article about the evolution of soil-burrowing cockroaches, which apperead on the National Center for Biotechnology Information, is given here.
Scarcely, the non-scientific sources claiming that the cockroaches have not evolved are neither specialists nor graduates, let alone having written an article about the subject, they have not a single scientific article. Maekawa on the other hand, who is one of the authors of the article given above, has written or has contributed to 628 scientific articles. In addition he is a member of the Royal Society, one of the most popular scientific fellowship. But people cite from non-scientific sources and not from scientists who dedicated themselves and their lives for the subject concerned. This is thought provoking.