History of biology

See related Biology

An unrecorded history of biology began when human foragers first systematically started to accumulate information about the behavior of plants and animals in their environment, which they did for its importance in helping them acquire food for subsistence. Biological studies started therefore probably from the beginning of human existence.

Our species, Homo sapiens, emerged nearly 200,000 years ago, exhibiting unprecedented cognitive abilities in the biological world — cognitive abilities enabling them to operate as observational scientists of the type later known as ‘natural philosopher’ or ‘naturalist’. They could discern cause and effect widely in nature, they could speak and thus share knowledge and cooperatively accumulate it and pass it down the generations, and they could make tools — all prerequisites for a successful naturalist focusing on the study of food sources. Living as hunter-gatherers, so succesfully that their descendants populate the world today, they learned the behavior of animals and plants in the detail needed to subsist and thrive in the wild. How they organized and taught their ethology and taxonomy we can only speculate. Reports of direct observations of 19th and 20th century hunter-gatherer societies give some appreciation of the likely scientific biological expertise important for survival required of our hunter-gatherer ancestors.

Our prehistoric ancestors studied human behavior as well as the behavior of their biological food sources, extending their biological studies from ethology and taxonomy into psychology. Their ability to speak to each other, make correlations between events, and discern cause-effect, gave them a ‘theory of mind’ that facilitated tibal cohesiveness.

Eventually, their expertise in biology played a major role in developing agriculture, and encouraging experimental work to further develop crop yields, something present day biologists still pursue vigorously. After 190,000 years of hunter-gatherer free-roaming living, agriculture spawned fixed settlements, which ultimately led to modern civilization. With civilization came writing and recorded history, so this article can proceed next with a summary of the recorded history of biology, including the observations, experimental findings, and theory-building of individual biologists.

The biology of Aristotle, the founding father of biology

Aristotle (384-322 BCE) receives first credit as an individual for major contributions to the development of biology as a science. Nevertheless, he arrived on the biology scene after some 10,000 years of experiments in animal and plant domestication and breeding by unnamed individuals. He also followed and learned from earlier Greek thinkers who postulated biological explanations from observations of the everyday world, including:

• Thales of Miletus (640-550 BCE), who posited water as the source of all things, including life;

• Anaximander (610-540 BCE), who posited “…that man could not from the beginning have been what he was now, for if man, on his first appearance, had been so helpless at birth, and had required so long an adolescence, as in these later days, he could not possibly have survived”, and who seemed to have a clear idea of biological evolution ;

• Anaxagoras (500-428 BCE), who discovered respiration in animals and plants and attributed human intelligence to the development of bipedalism;

• Heraclitus (530-470 BCE), whose theory of all things changing favored the idea of evolution;

• Empedocles (ca. 445 BCE), who advanced a theory of evolution, attributing it to the combination of natural experiments and natural selection. Aristotle both acknowledges Empedocles’ ‘survival-of-the-fittest’ argument and rejects it on the basis that nature operates for a purpose and does not offer random variations;

• Leucippus (ca. 445 BCE) and Democritus (460-360 BCE), who rejected design in nature and described nature as a machine.

But Aristotle justifiably earned his title as the founding father of biology through his lifelong wide-ranging observations of biological phenomena, his sometime experimentation, his organization of information, and his philosophy that understanding reality required deductions and inductions from sense experience and not abstract postulations before the fact. He noted that despite the enormous variety of living things, they showed very small gradations from less to more complex forms, and, as Will Durant summarizes it, citing the primary sources:

…that life has grown steadily in complexity and in power; that intelligence has progressed in correlation with complexity of structure and mobility of form; that there has been an increasing specialization of function, and a continuous centralization of physiological control.

One can do little to improve on the detailed description given by Durant of Aristotle’s myriad observations of animal structure and behavior, relationships among animals, embryological phenomena, and even genetics. Nor could one much improve on Durant’s description of Aristotle’s myriad mistakes and misconceptions. Yet no one before had accumulated and organized so much biological knowledge, and raised so many specific questions, setting the foundation for the evolution of our understanding of the living world.

Aristotle also gave some thought to the question, "what is life?". He thought that a living thing existed in 'potentiality' in the seed or semen, that environment factors initiated the realization of that potential, and that that potential included the "nutritive power" to grow into the living thing. Corresponding to that triad of suppositions, though it takes more than semen to generate a human,   it might not have surprised Aristotle to learn that the potentiality of the human exists as molecules in the semen and ovum, that the fluid composition in the oviduct, where the living starts, enables the fusion or fertilization process that starts the life form, and that the zygote (the first cell of the human) has within itself the wherewithal to utilize its own organization to develop itself into a multi-cellular individual human.

Aristotle developed a coherent vision of the nature of living thing. His four components of the causes of complex natural things, anticipates the somewhat more refined modern systems biology approach to the question of life. A living thing comprises:

• A collection of organic and inorganic parts (molecules and ions; cells, organelles, organs and organisms) — Aristotle’s 'material' cause, the parts that make up the living thing; Aristotle only recognized some of the organs;
• Parts relating to each other to form structures (e.g., networks), how they interact with each other (e.g., network dynamics), and how the structures interact with each other in a coordinated dynamic and hierarchical manner — Aristotle’s 'formal' (form-like) cause, the form the living thing takes on from the parts; Aristotle thought in terms of sculpture;
• Parts and structures dynamically coordinated (e.g., gene expression; self-organization) — Aristotle’s 'efficient' (effect-producing) cause, how the living thing gets produced into its form; Aristotle thought about something putting it together;
• How the living system as-a-whole functions and behaves, and the properties that characterize it (e.g., reproduction; locomotion; cognition) — Aristotle’s 'final' cause, its function; Aristotle thought in terms of the thing's 'purpose' or 'goal';

Modern biologists go down the road started as a path by Aristotle, who would have been delighted to know he asked the right questions traveling down the path, even if he didn't know how to get the right answers. Unfortunately, the larger fraction of his writings have disappeared, so we cannot know the full breadth of Aristotle's curiosity and adumbrations. What he did leave had a major effect on Western thought for centuries.

Lucretius and evolution

Titus Lucretius Carus (ca. 94 to ca 55 BCE), a Roman poet, author of De Rerum Natura (On the Nature of Things), familiar with the materialist Greek Philosophers, in particular Democritus (ca 460 to ca 370 BCE), who developed the theory of atoms originated by his teacher Leucippus, and Epicurus (341-270 BCE), who extolled the virtues of intellectual pleasure and admonished against the fear of death and the gods, had a clear notion of the evolution of livings through a selective process, as revealed in the following excerpt from De Rerum Natura:

And in the ages after monsters died,

Perforce there perished many a stock, unable

By propagation to forge a progeny.

For whatsoever creatures thou beholdest

Breathing the breath of life, the same have been

Even from their earliest age preserved alive

By cunning, or by valour, or at least

By speed of foot or wing.