Evolutionary Ideas in the 19th Century
The Origin of the Origin
On December 27, 1831, the young naturalist Charles Robert Darwin embarked on a journey around the world. He returned with a wealth of data and observations, the analysis of which led him to formulate new ideas on the origin of the diverse life forms inhabiting Earth. Two decades later, these ideas would ignite a debate whose echoes still resonate today. But Darwin’s ideas were not entirely unprecedented; other thinkers had sought to solve the same problem, sometimes with similar, sometimes with vastly different answers.
The Problem of Biological Diversity: Early Ideas
The search for an explanation for the origin and diversity of living things is reflected in various myths and beliefs.
“First devised the spot in the sky, also the causeway between water.
“That was the formation, devised, meditate on the perfection of his work.
“He said the created, created man:
– Is it just loneliness? Is it good that there’s silence under the trees and vines?
“It’s good to have guards told.
Then devised and appeared when the deer, birds. They gave their homes to the deer, the bird:
“Your beast on the causes sleep, will live in the jungle and you will 4patas, your bra will be told.
God Himself said so: produsca land of green grass and seed and plants that bear fruit after their kind and contain in themselves the seeds on earth, and is so hiso. Con land that produced the green grass and gives seed after his kind, and trees bearing fruit, of which each has its own seed by species.
God also said, produscan animated water reptiles living in the water and let birds fly above the earth under the firmament of heaven. After created the great Fish and all animals that live and move produced water according to its kind, every creeping thing according to its kind.”
Legend of the Uitotos Indians of Central
Since ancient times, certain special features of the living world, distinguishing it from the inanimate, have drawn human attention. Different explanations were offered for these characteristics, particularly two considered primary:
- The immense diversity of beings inhabiting Earth, expressed in various forms, behaviors, and sizes.
- The exquisite adaptation of each structure forming part of living beings. For example, the fins of aquatic animals facilitate swimming, while the legs of terrestrial animals enable movement on land.
Alongside these observations stood the puzzle of the origin of these diverse life forms. Diversity, adaptation, and origin constituted three problems requiring answers. Different responses emerged across cultures and epochs, from magical and religious explanations to the first attempts at rational explanations and modern scientific theories. This long journey forms the core of biology’s history.
“Seeks to explain not only the existence of the wide variety of plants and animals, but trying to know what is its place in the natural world, men have espectuado on the origins of life and on their own roots.”
Former Grace: A Cauldron of Ideas
The first ideas departing from magical or religious explanations for the origin and diversity of living things appeared in ancient Greece. Philosophers sought to explain the origin, function, and diversity of life without invoking supernatural forces. Two lines of thought emerged that would endure for centuries and can still be glimpsed today.
One proposed the immutability of things and beings in a static present, with no change, future, or past. Beings and things had no origin and no end. This line of thought was represented by Parmenides and Zeno, who lived between the 6th and 5th centuries BC.
The other line of thought, primarily represented by the Ionian philosophers, proposed mutability—the changing of things and beings over time.
Anaximander of Miletus (7th century BC), whose fragmented work “On Nature” survives, argued that living organisms arose from a primordial wet element and that higher animals evolved from lower animals. According to his vision:
“Living creatures came to wet element be evaporated by the sun. In the beginning as another man another animal, a fish.”
Anaximander’s proposal, though seemingly naive today, was courageous in its rejection of supernatural creative forces. It admitted the possibility of changes and transformations leading to diversity and placed humans as a particular, but not exceptional, product of these changes.
Interesting Ideas Developed by Empedocles
Empedocles posited four fundamental elements—earth, water, fire, and air—whose combinations and separations formed the universe. Love and strife were the forces uniting or separating these elements. He applied the same reasoning to the origin of life, suggesting that the world contained various animal and human parts (legs, heads, arms, etc.). Love combined these parts, resulting in all sorts of creatures, some monstrous or absurd. The rarity of these strange creatures was explained by their lack of viability; only those with survival-enabling characteristics prospered and propagated their lineage.
While some of Empedocles’ ideas seem odd today, his notion of linking the origin of living things with adaptation and survival was prescient.
Both Anaximander and Empedocles shared the view that life forms are not fixed. This idea of change was later lost, and a fixist conception dominated naturalistic thinking for over a thousand years. It wasn’t until the 18th century that thinkers like Buffon and Lamarck reconsidered the possibility that existing biological diversity might have arisen through gradual variation.
Aristotle: In Search of Perfection of the Cosmos
Aristotle (384-322 BC) profoundly influenced Western thought, and his particular way of seeing things still resonates today. He paid close attention to the living world, and his descriptions reveal a keen sense of observation. He likely dissected fifty different animal species and developed the first known attempt at animal classification. He considered embryological development fundamental for classifying living things and provided a remarkably accurate description of chick embryo development. Despite his observational prowess, he also made errors, such as claiming that women had fewer teeth than men.
“The guiding idea of Aristotle was a hierarchical organization that had everything to existing. Describing an attempt to interpret this organization to all beings as forming a long scale of the simplest to the most complex or the most imperfect to the most perfect.”
In Aristotle’s framework, plants occupied the lowest position on the scale of perfection, capable only of growth and reproduction. Animals, endowed with movement and senses, ranked higher. Humans, possessing three souls—a vegetative soul for growth and reproduction, a sensitive soul for movement and feeling, and a rational soul located in the heart—occupied the highest position.
Aristotle’s classification work on animals was mirrored by Theophrastus’s work on plants.
The Medieval Fixism
From the beginning to the fall of the Western Roman Empire, human concerns centered on engineering, warfare, and trade. In the life sciences, medicine took center stage. It wasn’t until the 5th century AD, with the fall of the Roman Empire, that the problem of the origin and diversity of living things regained attention. This time, the answers were found within religious faith, outside philosophical or naturalistic speculation. From the 6th century AD onward, explanations of the natural world, especially life, had to be consistent with or derived from biblical texts. These texts proposed that living things were products of God’s creative will and remained unchanged since their creation.
Thus, the medieval world crystallized the idea that each group of living beings emerged from a divine act of creation and remained unchanged through time.
“A creationist vision about the origin of life forms that inhabit the planet is a conception FIJISTA since he maintains that life forms, once created NO CHANGE OVER TIME.”
Although creationist fixism dominated medieval thought for nearly 1,000 years, a slow and painful process, marked by technological and trade developments, gradually undermined the image of an unchanging world. Access to the works of ancient Greek natural philosophers further challenged religious dogmas and allowed for freer thinking.
The Seventeenth-Century Scientific Revolution
The 17th century marked a break with religious justifications for natural phenomena. Astronomy, mechanics, and other fields were influenced by a new way of seeing things, with ideas of movement and change as central pillars. The birth of modern science, driven by physics, astronomy, and mathematics, laid the foundation for a new biology.
In Search of an Order for Life
Following the voyages of discovery initiated in the late 15th century, naturalists amassed vast collections of previously unknown plants and animals. The invention of the microscope in the 17th century revealed tiny life forms awaiting categorization. The task of ordering these collections and bringing order to the organic world became essential for understanding it. Thinkers faced contradictory elements in classifying life forms:
- Some viewed plants and animals as a continuous chain of beings with increasing degrees of perfection, culminating in humans as the most perfect.
- Others, following Aristotle, grouped animals hierarchically but without considering relationships between groups.
Two thousand years after Aristotle and Theophrastus’s pioneering work, and despite the discovery of new species, no new classification principles had emerged. The biological world had changed significantly, and classification needed revision.
One approach ordered organisms into well-defined, clearly separated groups based on a single unique morphological feature. For example, the presence of feathers uniquely distinguishes birds from all other animals.
Another approach grouped diverse organisms based on shared kinship, considering numerous features. This perspective recognized characteristics shared by birds with both current and fossil reptiles. This was the approach taken by one of the greatest naturalists of the 18th century, Carl Linnaeus.
Linnaeus: The Grand Systematizer
Carl von Linné (1709-1778), also known as Linnaeus, was a Swedish naturalist and professor. He classified over a thousand plant species and developed a hierarchical classification system based on the species as the most basic group. Similar species were grouped into genera, and genera into families. This allowed him to classify all known natural elements within three kingdoms: mineral, vegetable, and animal.
In his own words:
“All things are in the globe terrestrial known by the name of elemntos and natural body. Natural bodies are divided into three kingdoms of nature: mineral, vegetable and animal. Mineral growing, growing plants and animals living and growing, live and feel.”
Darwin – The Endless Doubt
are two chapters that open about evolutionary ideas during the nineteenth century. The first of these is one that INICA with Lamarck in France. the second chapter on the debate on the processor and the fixism species forces us to move to the British Isles. charles from there, back from a long trip on a ship that lasted almost 5 years and in which I visit most of the world, began to prepare a work which called The Origin of Species by Means of Natural Selection.
but not only were observations that gestated in the mind of Charles Darwin’s theory that it would be more revoluiionaria in the history of biology.