The evolutionary biology is the branch of biology that studies the origin and changes in living organisms through time, the evolutionary processes that produced the diversity on Earth and the relationships among species. These evolutionary processes include natural selection, common descent, and speciation.
Biology deals with studying organisms in a comprehensive way, while evolutionary biology seeks to answer questions from a functional point of view and deals with explaining the adaptive sense of the elements that are being studied.
Simple scheme that symbolizes human evolution. Source: M. Gardederivative work: Gerbil
Julian Huxley, a British-born evolutionary biologist, refers to it as a discipline that synthesizes several previously unrelated fields around biological research. Those fields would be genetics, ecology, systematics, and paleontology.
Evolutionary biology is different from the exact sciences, because it deals with phenomena that there is no way to explain by means of laws, so they are considered to be unique. This branch of biology tries to find the answers to the question why?
It is generally not possible or inappropriate to obtain answers to evolutionary questions through experiments, so it is considered that this discipline is handled through a heuristic method known as historical narratives complemented with the comparison of various facts.
History
origins
Evolutionary biology as an academic discipline emerged between the 1930s and 1940s, when the theories of natural selection, genetics and random mutation converged. It emerges then as a result of neo-Darwinism.
However, its origins go back to the idea of evolution by natural selection proposed by Charles Darwin in 1859. The British scientist proposes it based on the idea that the environment favors or hinders the reproduction of living organisms.
It also supports three premises: the trait must be heritable, there is trait variability among the individuals of a population and this must impact the survival or reproduction of the individual of that species.
Another essential milestone for its formation is Mendelian genetics, that is, the laws proposed by Gregor Mendel between 1865 and 1866. His three laws attempt to explain how physical traits or characters are transmitted to offspring.
Neo-Darwinism
Finally we find neo-Darwinism as another of its main antecedents, whose architects were Ronald Fisher, John Burdon Sanderson Haldane and Sewal Green Wright. The so-called modern synthesis then unites two discoveries: the unity of evolution with the mechanism of evolution, that is to say, genes and natural selection.
But it was not until 1980 that evolutionary biology took up space in university departments. Today it covers various topics, where the relative importance of evolutionary forces is highlighted, that is, natural selection, sexual selection, genetic derivation, developmental limitations, mutation bias, biogeography.
It has also incorporated aspects of various areas such as molecular genetics and computer science.
What is studying (object of study)
Evolutionary biology studies the origin and changes of living things through time. Source: Thomas Hunt Morgan
The unifying concept of evolutionary biology is the change and transformation of species over time. Changes in biological populations posed by evolution can be both phenotypic and genetic.
Evolution explains past and current biodiversity, as well as morphological, physiological, and behavioral adaptations of plants and animals to the environment. But it also elucidates biological, behavioral and social aspects of the human species.
Evolutionary biology seeks to understand the historical paths and processes that have given rise to the current characteristics of organisms, it also deals with finding why these are the characteristics of those organisms and not different ones.
Evolutionary biologists' questions are often "what happened and when? How and why?" If we combine this approach with the various divisions or branches of biology, various subfields emerge, such as evolutionary ecology and evolutionary developmental biology. Some extensions such as evolutionary robotics, evolutionary engineering, evolutionary algorithms, and evolutionary economics can also be identified.
In addition, it is worth mentioning a new field in this discipline, developmental evolutionary biology that focuses on studying how embryonic development is recorded and controlled.
On the other hand, there are many other habits whose dependence is mainly psychological and not physiological. The withdrawal symptoms in this case are somewhat different. The brain interprets that it has lost a valuable reward, which is reflected in emotional distress and behavioral changes.
Applications
Evolutionary biology currently seeks to clarify phenomena that were wrongly explained in modern evolutionary synthesis. For example, in the evolution of sexual reproduction, in aging, in speciation, as well as in the capacity for evolution. They are also being applied in the genetic area to determine the architecture of evolutionary phenomena such as adaptation and speciation.
The contributions of this discipline are key in organismal ecology, in the theory of the history of life, molecular knowledge, studies on the genome, as well as in fields of paleobiology, systematics, health and phylogenetics.
Main concepts
- Evolution: refers to the change in the characteristics of populations of organisms, or groups of such populations, through the course of successive generations.
- Element: substance that cannot be broken into a simpler form by ordinary chemical means. They are basic structural units of tiny atoms made up of protons, neutrons, and electrons.
- Species: refers to the state of the evolutionary process by which a group of individuals with the actual or potential ability to interbreed give fertile offspring.
- Genotype: sum total of the genetic information of an organism contained in its chromosomes.
- Phenotype: set of identifiable characteristics of an organism (structural, biochemical, physiological and behavioral) determined by the interaction of the genotype and the environment.
- Natural selection: particular type of selection that occurs non-teleologically in natural populations. This does not admit intentionality, direction or progress unlike the artificial selection that is executed by the human being with a specific purpose.
- Mutation: variation of an allele due to alteration in its base sequences that occur between one generation and the next.
- Neordarwinism: it is also known as the synthetic theory of evolution, it is one that fuses classical Darwinism with modern genetics, paleontology, geographical distribution, taxonomy, and any discipline that allows understanding the evolutionary process.
- Creationism: set of beliefs inspired by religious doctrines, according to which the Earth and the beings come from an act of divine creation and was carried out according to a transcendental purpose.
- Saltationism: also known as mutation theory, it corresponds to the occurrence of sudden and large-scale changes from one generation to another. He opposes Darwinian gradualism.
- Fixism: that theory that maintains that each species remains unchanged throughout history in the way it was created, so it is opposed to the theory of evolution.
- Transformism: that theory that considers that the species have an independent origin, but they can change mainly due to the use or disuse of organs according to the needs that arise in the environment.
- Uniformity: it is a principle that states that natural processes are repetitive, that is, the same processes that acted in the past are those that act in the present and will appear in the future.
- Microevolution: refers to the small-scale changes that are registered in the allele frequencies of a population, over a few generations. It is a change at or below the species level.
- Macroevolution: it is the occurrence of great changes, showing patterns and processes that affect populations at higher levels.
Featured Evolutionary Biologists
Evolutionary biology has been forming a key discipline in today's scientific world thanks to the contributions of biologists specialized in the area such as:
- Charles Darwin (1809-1882) who raised biological evolution through natural selection and did so through his work The Origin of Species.
- Gregor Mendel (1822-1884) who described the laws that describe genetic inheritance.
Gregor Mendel, considered the father of Genetics. Source: By Bateson, William (Mendel's Principles of Heredity: A Defense), via Wikimedia Commons
- Sewall Wright (1889-1988) is considered one of the main founders of population genetics and is known for his great influence on evolutionary theory.
- George Gaylord Simpson (1902-1982) is one of the leading theorists of synthetic evolutionary theory.
- Ernst Mayr (1904-2005) contributed to the conceptual revolution that allowed the modern synthesis of the theory of evolution and thanks to his contributions the biological concept of species was developed.
- George Ledyard Stebbins (1906-2000) geneticist and one of the founding members of modern evolutionary synthesis. He managed to include botany within this theoretical framework.
- Ronald Fisher (1890-1962) used mathematics to combine Mendel's laws with natural selection proposed by Darwin.
- Edmund B. Ford (1901-1988) is considered the father of genetic ecology and was a great researcher on the role of natural selection in species.
- Richard Dawkins (1941) popularized the evolutionary view of genes and introduced terms such as meme and memetics.
- Marcus Feldman (1942) although he is a mathematician by training, his contributions to evolutionary theory have been thanks to the computational studies that he has carried out.
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