Chemical and Biological Evolution Concepts Explained

Chemical Evolution

Chemical evolution refers to evolution-based chemical processes, not biological ones, including the changing of simple inorganic compounds into complex organic compounds. According to Oparin, this process could result in two important characteristics of living organisms:

1. Living matter is mostly composed of complex organic molecules. Chemical evolution must have produced these molecules from smaller building blocks.
2. Systems of organic molecules in organisms are surrounded by a capsule or exist as separate units. These units are the cells that form all living things. Encapsulation of materials was necessary for the emergence of life.

Biological Evolution

Biological evolution refers to the origin of life, development, and subsequent diversification through billions of years experienced by present plants, animals, and microorganisms. As a concept, it argues that all contemporary species did not originate in their current form; rather, they originated from other, now extinct, species. These species are the primary ancestors, and their descendants are, in most cases, simpler.

Early Homo Species Timeline

• H. habilis: 2.5–1.4 mya
• H. rudolfensis: 1.9 mya
• H. georgicus: 1.8–1.6 mya
• H. ergaster: 1.9–1.25 mya
• H. erectus: 2–0.3 mya
• H. cepranensis: 0.8 mya
• H. antecessor: 0.8–0.35 mya
• H. heidelbergensis: 0.6–0.25 mya
• Homo rhodesiensis: 0.3–0.12 mya
• Homo neanderthalensis: 0.23–0.024 mya
• Homo sapiens: 0.25 mya–present

Lamarckian Postulates

Transformer—Lamarck

Lamarck postulated two evolutionary forces that shaped a branching phylogenetic tree:

1. The inherent tendency of nature toward increasing complexity, noticeable when drawing a tree from simpler to more complex organisms.
2. The accommodation of organisms to external circumstances and the inheritance of such adjustments, which explains deviations from that regular gradation (branching).

The movement of fluids inside animals, which progressively accelerates with higher organizational complexity, and the influence of new circumstances as animals were exposed to them across different living quarters, were the two general causes that led different animals to their current state.

Natural Selection

Natural selection is an evolutionary mechanism defined as the differential reproduction of genotypes within a biological population. In its initial form, the theory of evolution by natural selection was the great achievement of Charles Darwin (and, independently, Alfred Russel Wallace). It was subsequently restated in the current theory of evolution, the modern evolutionary synthesis. In evolutionary biology, it is considered the main cause of the origin of species and their adaptation to the environment.

Neo-Darwinism

In the late nineteenth century, the term neo-Darwinism referred to the school of Wallace and Weismann. Against Darwin, who had admitted several evolutionary mechanisms, the Darwinists defended the exclusivity of natural selection as the mechanism of organic change, thus opposing the neolamarquistas.