How was the acceleration of the evolutionary process manifested?

The accelerated process of evolution of all life on earth is an integral process of the development of life itself on the planet. So, from the appearance of the first living organism on earth 4 billion years ago, to the complication and appearance of a multicellular organism and a eukaryote 2 billion years ago, a rather long period passed, but it gradually decreased, and already the distance in time between the appearance of Australopithecus and Homo sapiens was 2 million years. And the development of modern man itself proceeded rapidly, and in 60 thousand years he went from a cave and herd creature to a modern type.