Final answer:
The statement is true: the fossil record is a key aspect of our understanding of the history of life on Earth. Fossils guide our knowledge of evolution and the biological history of species, despite sometimes being incomplete.
Step-by-step explanation:
Much of what we know about the history of life on Earth comes from the study of fossils, making the statement A True. Paleontologists and other scientists use the fossil record as a primary source of data to understand how life has evolved over millions of years. Studying fossils reveals information about species that lived long ago, their environments, and the changes that have occurred since then. For example, by examining various fossils, scientists have pieced together the evolutionary histories of humans and horses. The morphology of fossils, such as whale flippers, also shows connections between species, supporting the theory of common ancestry.
While today we have additional tools and methods for dating and analyzing past life and geological events, for much of scientific history, fossils were the main source of evidence for evolution. The incomplete nature of the fossil record is acknowledged by scientists, yet even with its gaps, it remains a critical resource for understanding the progression of life on Earth. The fossil evidence for life found in rocks dating back to 3.5 billion years suggests the existence of early microbial life.