What is evolutionary biology

evolution

What does evolution mean and how does it work? We'll explain all of this to you in this post.

What is evolution

The first unicellular life forms appeared on our earth about 4 billion years ago. You describe all processes that have made our biodiversity possible today as evolution. Here, strictly speaking, you are talking about the biological evolution

The word evolution comes from Latin and means "to develop". Evolution thus explains the change in characteristics of a population of organisms over generations. For example, we humans have developed an upright gait over millions of years.

Important: Evolution does not stop, it still takes place!

Evolution in biology is the genetic and resulting phenotypic change in living beings or other organic structures such as viruses. The change takes place from generation to generation.

Evolution overview and history

Important scientists who recognized the process of evolution or helped to explain it were:

  • The naturalist Charles Darwin ("The Origin of Species"): He recognized the importance of diversity (variability) and selection by the environment (natural selection) for the first time. The combination of both enables evolutionary developments.
  • The monkGregor Mendel: His inheritance rules - the so-called Mendelian rules - explain how traits could be passed on to offspring. Darwin was not aware of that.
  • The medic Oswald Avery: He recognized the DNA as the carrier of our genetic information. Soon after, their structure was also identified.

From these and other findings from numerous disciplines, such as genetics, biochemistry or ecology, the evolution theory best founded today developed: the synthetic theory of evolution .

Evidence of evolution

Evolution is a slow, gradual process. You can neither observe it directly nor prove it experimentally. But some evidence for the evolution of living things is, for example:

  • Fossil Finds:Remains of living things from earlier earth ages; An evaluation of the finds shows that the animal and plant species have changed in the course of the earth's history.
  • Bridging animals : also mosaic shapes; Combines characteristics of two groups of animals; Example: Archeopteryx (reptile and bird characteristics).
  • Rudiments: Organs and structures receded in the course of evolution; Example: wisdom teeth in humans
  • Atavisms: Recurring traits in individual individuals that were reduced or disappeared in the course of evolution; Example: Extremely strong body hair in humans ("coat formation").
  • Embryonic development: The early stages of development of related organisms are more similar than individuals in adulthood (basic biogenetic rule).Example: gill intestine and gill spade in all vertebrate embryos.
  • Homologies:Characteristics that indicate a relationship between two living beings; have a common basic plan;Example: forelimbs of certain vertebrates such as birds and humans.
  • Analogies: Features with the same function; without common origin; The reason for the similarity is an adaptation to the same environmental conditions. Example: limbs of mole and mole cricket.

Would you have thought that human teeth and shark scales are homologous organs? We explain this and many more exciting examples to you in our extra video!

Evolution factors

But how exactly does evolution work? The “motor” or the “driving force” for the change in organisms are primarily five processes. You also call these mechanisms of evolution Evolution factors. Their interplay enables all evolutionary changes by changing the genetic structure of a population.

The five evolution factors are:

  • mutation: It provides modified genetic material (genes) and occurs randomly.
  • Recombination: It recombines the genes in different ways and happens randomly.

Mutation and recombination make for one genetic variability (Diversity) in a population.

  • selection : It leads to a directed selection ("filtering") of characteristics of the individuals based on their adaptation to the environment.
  • Genetic drift: It causes a random change in the gene pool of a population, for example through volcanic eruptions or floods.
  • isolation: It ensures a division of a population into subpopulations. This can lead to the formation of new species.

We have also prepared our own video on the evolutionary factors for you! Take a look to see how the individual factors interact with examples!

Evolution of new species

By dividing a population into sub-populations, new species can arise. You distinguish between two ways in which speciation can take place:

In the allopatric Species formation occurs the splitting of the original population through a spatial separation. A geographic barrier such as a river or a mountain range can be responsible for this.

In the sympatric speciation on the other hand, there is no separation by a geographical barrier. This means that the original species lives in one area and the new species arise in the same area. But how exactly do the two processes of speciation work? Check out our video and find out!

Evolution of man

Man began to emerge in Africa about 6 million years ago. From pre-man to today's modern man - the homo sapiens - it was a long way.