Stephen Gould wrote a whole book disputing this idea that the complexity of life increases: "Full House: The Spread of Excellence from Plato to Darwin." The bas

Stephen Gould wrote a whole book disputing this idea that the complexity of life increases: "Full House: The Spread of Excellence from Plato to Darwin." The basic argument is that almost all life on Earth is still prokaryotic...the rest of us are just a rounding error. He wrote several books about how evolution was not directional, notably "Wonderful Life" and "Time's Arrow". I'm not completely convinced by any of these, but worth reading.