Much of the earliest recorded history of biology is derived from Assyrian and Babylonian bas-reliefs showing cultivated plants and from carvings depicting veterinary medicine. Illustrations on certain seals reveal that the Babylonians had learned that the date palm reproduces sexually and that pollen could be taken from the male plant and used to fertilize female plants. Although a precise dating of those early records is lacking, a Babylonian business contract of the Hammurabi period (c. 1800 BCE) mentions the male flower of the date palm as an article of commerce, and descriptions of date harvesting extend back to about 3500 BCE.
Another source of information concerning the extent of biological knowledge of these early peoples was the discovery of several papyri that pertain to medical subjects; one, believed to date to 1600 BCE, contains anatomical descriptions; another (c. 1500 BCE) indicates that the importance of the heart had been recognized. Because those ancient documents, which contained mixtures of fact and superstition, probably summarized then-current knowledge, it may be assumed that some of their contents had been known by earlier generations.