The first humans to arrive in Australia destroyed the pristine landscape, probably by lighting huge fires, the latest research suggests.The evidence, published in Science magazine, comes from ancient eggshells. These show birds changed their diets drastically when humans came on the scene, switching from grass to the type of plants that thrive on scrubland. The study supports others that have blamed humans for mass extinctions across the world 10-50,000 years ago. Many scientists believe the causes are actually more complex and relate to climate changes during that period, but, according to Dr Marilyn Fogel, of the Carnegie Institution in Washington,...