The evidence is abundant and irrefutable. Life has changed drastically over earth's history. Since the first complex multi-cellular forms appeared about 650 million years ago organisms have lived, died and adapted to their environments through many violent upheavals on the planet. Evolution is the great shaper of all life on earth. Today, evolution is the unifying principle of biology.
Nothing makes sense without it.
True, it remains a very active field of research and many subtle and fascinating questions remain to be answered. However, that life has adapted and changed through time is as well established as the fact that the earth goes round the sun. Evolution is science, and as such belongs in science classrooms. By contrast scientific creationism just doesn't make the grade. None of the arguments which scientific creationists make against evolution withstand scrutiny and most were first refuted nearly a century ago.