This video is to be understood as a basic video on evolution - it serves both as an introduction to the topic and as a summary of the high school-relevant semester in biology. Although all relevant content such as the theories of evolution, evolutionary mechanisms and the results of evolution are discussed, for a more in-depth discussion - mainly for reasons of time - reference is made to other videos that I have already made on the individual topics. The world of organisms is subject to constant change. Many changes can be traced over geological periods of several million years using fossil evidence, but some evolutionary changes occur in fast motion, as the corona pandemic shows: In real time, we are experiencing how corona viruses constantly and rapidly mutate and produce new variants (and mutations, i.e. changes in the genetic material, are a driving factor for evolution = in this context, one says that the corona viruses evolve). But flu viruses also mutate so quickly that flu vaccines have to be developed anew every year - vaccines from the previous year are no longer effective against the current year's flu strain. These are just two examples of evidence of evolutionary changes that biologists have collected on such a large scale that we now speak of the theory of evolution when it comes to understanding and applying evolutionary changes. In contrast to a hypothesis or even a guess, the term theory is only used in scientific language when there is such comprehensive evidence for the respective phenomenon that it is generally accepted. Evolution is a fact that is taking place and has taken place - and this does not mean that it excludes other, religious ideas about the origin of the earth and mankind. Belief in the story of creation is also justified, but the religious understanding of the origin of life cannot be explained by the scientific understanding that follows. Evolution is therefore understood to be the phylogenetic change in the genetic material over generations. When the genetic structure of a population changes, then strictly speaking the frequency of gene variants, which are also known as alleles, changes. You know that a gene is a very specific section of DNA that contains the information for the synthesis of a protein - and this can be responsible for characteristics such as flower color. And such characteristics can occur in different variants, which are called alleles: For example, there can be an allele for the expression of purple flowers and an allele for the expression of white flowers. If the frequency of purple flower color in a population increases over generations, then evolution is taking place. Evolution can be calculated by the change in allele frequencies in populations over time (closely linked to: Hardy-Weinberg law). It was the English biologist and naturalist Charles Darwin who developed the theory of evolution as we know it today in the 19th century. Darwin was on a worldwide expedition for a total of five years, during which he examined countless animal and plant species and, based on his many observations, postulated that species are not immutable and are subject to change over time. Darwin was not alone with this hypothesis - others had also argued that evolution does exist. Much more revolutionary was his second hypothesis that different species go back to a common ancestor and developed from this over time. However, there was a lack of explanations for both hypotheses. He provided the explanation for the fact that individuals or species are subject to evolutionary change with his third hypothesis on natural selection. What is meant by natural selection, how it can be effective (keyword: stabilizing, directed and disruptive/splitting selection), how different evolutionary mechanisms can change the genetic structure of a population, and much more in this video. All the best and feel free to subscribe :p