Final answer:
Life on Earth has indeed evolved over time, starting from single-celled organisms to the complex life forms we see today, driven by the process of natural selection and evidenced by the fossil record.
Step-by-step explanation:
The statement that life on Earth has evolved over time is true. Life began at least 3.5 to 4 billion years ago as simple, single-celled organisms.
Over time, these early forms of life evolved through a process known as natural selection, leading to the vast diversity we see today. The characteristics of organisms are inherited through their genes, allowing advantageous traits to be passed down from one generation to the next.
The fossil record, including evidence of microbial mats dating back to about 3.5 billion years ago, supports the idea of gradual evolution and there are various hypotheses about the natural origin of life on Earth with scientific evidence backing them.
The study of life's history is a fascinating tale of adaptation and survival, shaped significantly by various environmental changes, including mass extinctions such as the one that facilitated the rise of mammals after the dinosaurs' extinction 65 million years ago.