Which statement does describes why modern horses look the way they do is it aspects, of course anatomy evolved within a generation to suit their environment or aspects of horse anatomy evolved over hundreds of years to suit their environment or aspects of horse anatomy evolved over millions of years to suit their environment or aspects of horse anatomy evolved within a few generations to suit their environment

The statement that describes why modern horses look the way they do is: "Aspects of horse anatomy evolved over millions of years to suit their environment."