2. History of the Science of Evolution

Part 2, Evolution

2. History of the Science of Evolution

Long ago religious supernatural explanations for life, love, and death had produced a body of ‘knowledge’ on human existence. Public acknowledgment of these ‘God-given truths’ for all individuals was, and in some countries still is, required. Severe punishment was and still is, dealt to those that do not comply, at least publicly. Since the Age of Reason, beginning with Galileo around 1600 CE, science and study were creating pathways of knowledge and analysis that broke the explanation of life free from the iron hand of religion.

In the first half of the mid-19th century, the wonderments of geology, from mountains to rocks to oceans to fossils, all indicated an ancient Earth, and the reproductive biology of plants and animals, including the history and changes in behavior and form of cultivated plants and animals, had stirred considerable interest in the fledgling sciences of geology and biology. In particular, the mysteries of animal reproduction, including humans, stirred considerable scientific interest in the ‘whys’ and ‘hows’ of the reproductive process of life. Without a microscope and without knowledge of the processes of biological reproduction, only explanations based on supernatural causation were available. For those looking to reason and reality for answers and theories, supernatural religion was incorrect and inadequate.

The seed of evolutionary science that The Age of Reason had birthed in the 17th century began to sprout with observation and reason when the 19th century was new.?Great minds through observation and analysis were observing the earth, the life that occupied it, and the changes in that life from domestication by humans.

Jean Baptiste Lamarck (1744-1829) published in 1801 his observations and analysis that all species, including humanity, are descended from other species. He then advanced his thoughts in 1809 in his Philosophie Zoologique, and repeated his opinions again in 1815 in his book on the natural history of animals, excluding vertebrates. His proposal was that species changed their behaviors to adapt to environmental change, and this stimulated changes in morphology and behavior, and these changes were then passed on to descending generations. This was the beginning of the publication of rational thought and analysis on life that established the science of biology in the mid 1800’s.

Charles Robert Darwin, (born 12 February 1809, died 19 April 1882) applied the fundamentals of science to the analysis of the biology of life on Earth, and the history and structure of the planet. Throughout his life, he studied biology, geology, and the history of life on Earth. He described the growth, development, and variety of life as a process of natural selection, and that was the foundation of the concept of biological evolution. Darwin defined evolution as ‘descent with modification’.

He proposed that ‘descent with modification’ and ‘natural selection’ for biological changes that aided the survival of the species over great ages of time could account for the variations of life on the earth. The obvious changes in the geology of the earth and the fossils in ancient rock formations were evidence of the great depth of time that must have occurred in the development of life on Earth.

Charles Robert Darwin’s famous books, The Origin of the Species, By Means of Natural Selection, and The Descent of Man, And Selection in Relation to Sex; did not burst upon the world as a Fait Accompli, a concept that introduced an explanation for everything biological and geological. But it was close to that. The concept of an ancient Earth and the capacity for changes in the forms of the life of domestic plants and animals were not unknown to humanity, but Darwin gave these concepts a firm scientific foundation. There were many unknowns, Darwin did not have all the answers, but he set the stage on where and how to look for answers. Darwin knew that the bare concept of natural selection did not explain how those differences originate. In a letter to his friend Thomas Henry Huxley he wrote “the laws governing inheritance are quite unknown.”

Unknown to Darwin, the basic answer to that question was the object of research by Gregor Johann Mendel, (now known as the ‘Father of Genetics’). He was a Czechoslovakian monk at St. Thomas’ Abbey in what is now known as The Czech Republic. Among other things, he was a botanist, and from 1856 to 1863 he diligently worked on inherited variations in the shape and color of the flowers of pea plants, Pisum sativum. He found that when pea plants that always produced green flowers were bred with plants that also always produced green flowers, the first generation, and the generations that followed, always produced only green flowers; and when plants that always produced yellow flowers were bred with plants that always produced yellow flowers, the first generation, and those that followed, always produced only yellow flowers. These were plants that were true breeders of the color of their flowers.

However, when true-breeding green-flowered plants were crossed with true-breeding yellow-flowered plants, the first generation always produced only yellow flowers. The trait of green flowers was completely absent. Then, when the second generation was bred, plants with green flowers reappeared, and at a constant ratio of one plant with green flowers to three plants with yellow flowers. It was proof that inheritance was not a blending of characteristics, but a particulate distribution of the factors (units) that determined inherited characteristics.?His work also demonstrated that one of these traits of color, yellow, was dominant over the other, green was recessive. ?Mendel studied seven inherited features of pea plans and found patterns of inheritance that were mathematically consistent in dominance and recessive traits. This was the base of the Fundamental Laws of Inheritance.?He termed this consistent pattern of variation as the production of dominant and recessive traits.?Gregor Mendel published an account of his work in 1866, Experiments on Plant Hybrids, in ‘Proceedings of the Brunn Society for the Study of Natural Sciences’. Unfortunately, the universal extent and meaning of his work was not established during his lifetime. It was not until the early years of the 19th century that the recognition of Mendel as the Father of Genetics, a developing science with the keys to life, was established.

Lamark, Darwin, Wallace, Mendel, and many other scientists in the mid to late-1800s were instrumental in putting the results of science into the concepts of the freethinking philosophers of the Age of Reason. In the first half of the mid-19th century, the wonderments of geology, from mountains to rocks to oceans to fossils, all indicated an ancient Earth, and the reproductive biology of plants and animals, including the history and changes in behavior and form of cultivated plants and animals, had stirred considerable interest in the fledgling sciences of geology and biology. In particular, the mysteries of animal reproduction, including humans, stirred considerable scientific interest in the ‘whys’ and ‘hows’ of the reproductive process of life.

By the mid-19th century, compulsory fundamentalist religion blocking the path of science was put into a state of either accepting the facts of biological science or denying the truths that science was discovering. Despite the expansion of scientific knowledge that now extends deep into genetics, evolution, and all facets of human existence, the schism between science and religion still exists today. Fundamentalist religions hold firmly to the concept that a supernatural god designed all the elements of the universe and designed, created, and directs every facet of life, especially human life. Now, many of the results of science are accepted by religion, but with reservations. Explanations, theories, assumptions, beliefs, many books, and also ridicule, are the religious ammunition for the refutation of pretty much all science that does not originate from and stays within the boundaries of religious belief. Science and understanding of reality are still often bent to accommodate and/or direct religious beliefs.

Evolution is not a difficult concept or theory to understand. In the broad view, it is obvious. Plants and animals are integral to the lands and waters of the earth, and this life exists as individuals in distinct, reproducing groups that we term species. Biological reproduction occurs within the genetic parameters of each species. The physical structure, life, and life span of the individuals that compose these species are directed by a set of genes, the genome, that is specific to each species and directs the biological development and behavior of each individual of that species. Mutations, small variations in the genetic structure of individuals, occasionally occur in every species. These small changes in the genetic directions for development and/or behavior may be inconsequential or may have a positive or negative effect on the survival of the individual. If that effect is negative, the individual may not survive to contribute to the next generation and that change in the genome will not survive. If the effect is positive and enhances survival, then that alteration of the genome may persist and eventually spread to an entire interbreeding population of that species. There may be other populations of that species in which that mutation did not occur, and over time, the mutated species may become a separate species that evolves with different characteristics that enhance the survival of the species in different environments. Over Deep time small genetic changes that improve adaptation to changing environments accumulate, and existing species diverge into other species that can adapt to changing environments. Evolution, slow and steady, modifies life to survive in changing environments.

Martin Moe?