Evolution | Max Planck Society

Without evolution there is no life

“Nothing in biology makes sense except in the light of evolution.” This is the famous title of an article by Teodosi Dobžanski from 1973. In the article, the Russian-American evolutionary biologist describes evolution as the means by which God created life and created the earth. But what exactly is evolution?

In biology, evolution is defined as the gradual change of hereditary traits from generation to generation. So when an originally hairless species of rhinoceros develops a protective coat during an ice age, that’s evolution. Even if new variants of the corona virus keep appearing, it is called evolution.

Evolution occurs only when there is selection among the characteristics of a group of organisms. In this process, also known as natural selection, characteristics are passed on to the next generation with varying frequency: some become more common, others become rarer or disappear.

choice

Thus, selection is the driving force of evolution. In order for the election to be made, the following conditions must be met:

  • The characteristic must exist in different variants.
  • The characteristic must be hereditary.
  • Different manifestations of a trait must lead to differences in fitness.

British naturalists Charles Darwin and Alfred Wallace discovered these fundamental principles of evolution. They explain the enormous diversity of life on earth: individuals with different characteristics compete with each other for scarce resources and pass their characteristics on to offspring. As a result, individuals constantly adapt to new environmental conditions and thus produce a wide variety of forms and survival strategies.

An incredibly simple principle for such an incredibly diverse phenomenon as life!

Current Posts

A bacterial enzyme fueled the evolution of longhorned beetles

Gene duplications have increased the diversity and specificity of enzymes used by beetle larvae to break down important wood components.

Icon image for world languages.  A small globe rests on an open book

Linguists and computer scientists together create a comprehensive lexical database of several world languages

The great white shark may have contributed to the extinction of the megalodon

Zinc isotope analyzes shed light on the diet of the megalodon – the largest shark that ever lived

show more

Icon image for world languages.  A small globe rests on an open book

Linguists and computer scientists together create a comprehensive lexical database of several world languages

The great white shark may have contributed to the extinction of the megalodon

Zinc isotope analyzes shed light on the diet of the megalodon – the largest shark that ever lived

The spread of the black rat was closely related to the Romans

New research reveals how the black rat colonized Europe in Roman times and further into the Middle Ages

show more

In Darwin's footsteps

Eduardo Sampaio sailed another ten days along the MS Beagle route

Fish are his passion. Alex Jordan wants to know why they do what they do. Another interview with a behavioral biologist

Research highlights 2020

Max Planck scientists published many outstanding publications in 2020. We have made a selection and present to you 13 of the most interesting. Another review

show more

Gene Drive - turbo for genes

Infectious diseases, food shortages, invasive animal and plant species – there may be a solution to these pressing problems: “Gene Drive” is the magic term that should protect us from all of these

Where are our roots?

Where does the person we know today begin? Human evolutionary questions are as exciting and relevant today as they were in Darwin’s time. This film explains the work of modern evolution researchers such as Michael Tomasello and Timothy Bromage, who received the Max Planck Research Prize this year. The award, which is awarded with 750,000 euros each, is jointly awarded by the Alexander von Humboldt Foundation and the Max Planck Society. more

A wild mouse found an acorn and carries it in its mouth.  The animal is reflected in the water.

To this day, intensive research is being carried out in the field of evolutionary biology – among other things, to develop strategies for better protection of species. Anja Guenther wants to know how wild mice adapt more to changing environmental conditions

All together

Cohesion is the glue of all coexistence. In this feature-length podcast episode of the Research Quartet, Max Planck scientists Anna Baumert and Meg Crafoot, as well as population biologist Paul Rainey, talk more about moral courage, group decision-making in baboons, and cooperation between bacteria.

Evolution – just a theory?

When researchers draw conclusions from their research, they are called a hypothesis or theory. The “theory of evolution” is therefore not a purely hypothetical assumption, but was based on measurements and observations from the very beginning. Today, evolution can be simulated and examined in the laboratory. Today, it is a scientifically recognized fact that life on Earth developed according to the principles of evolution.

Organisms on Earth pass on their traits through their genetic makeup. All the information necessary for an individual’s function is stored in his DNA. In addition, there are chemical changes in the DNA molecule. Thanks to these so-called epigenetic changes, the organism can also pass on the traits it acquired during its life to its offspring.

For evolution to take place, the genome and/or epigenome must be modified. Such changes are called mutations. Changes in DNA occur more or less randomly as a result of environmental influences such as radiation or mutagenic substances. Even when cells divide and duplicate their DNA so they can distribute it to their daughter cells, copying errors can occur, creating new variants for evolution.

Max Planck researchers have discovered that some regions of DNA are better protected against mutations and why this is so. In this way, the cell repair machinery protects particularly important genes from potentially harmful changes. This discovery contradicts the prevailing dogma that mutations do not occur with the same frequency in important and less important genes – that is, they are not evenly distributed.

Thale cress plant, Arabidopsis thaliana

The discovery that plants protect their most important genes further changes our understanding of evolution

From start to finish

Thus, evolution has been taking place on Earth since, several billion years ago, molecules capable of reproduction first appeared and could pass on their properties and variants to the next generation. Many researchers now assume that RNA molecules were the first to be copied and duplicated. It is still not known how the first cells were formed. Tiny droplets of fat, which offered RNA molecules a protected space to react, may have played a role. Hot springs or freshwater pools could have provided suitable living conditions for this on early Earth.

During millions of years, life adapted to different environmental conditions in new stages of development and new habitats were opened. Thus, a biodiversity of as many as ten million animal and plant species was created on Earth. This diversity can in some ways be explained only in this way. So you can say: Evolution is life – and life is evolution!

Elixirs from the primordial soup

RNA molecules with enzymatic activity probably played a more central role in the origin of life on Earth

Progress is not always a snail’s pace

The evolution continues to this day. In many cases, it happens so slowly that we don’t notice its impact throughout our lives. However, some changes occur within a few years. In particular, organisms with a short generation time can adapt relatively quickly to new environmental conditions.

An example of this is the house mouse). The species split into western and eastern subspecies after the last ice age. Since then, the two lines have evolved so far that they are genetically distinct. However, the differences are not yet so great that the members of these two lineages cannot mix with each other. Researchers at the Max Planck Institute for Evolutionary Biology in Plön are using this to investigate key evolutionary processes based on differences.

The mouse bites through

Hardly any animal has adapted as well to the habitats we have created as the house mouse. For Diethard Tautz of the Max Planck Institute for Evolutionary Biology in Plön, it made sense to investigate small rodents as a model system for how evolution works. more

Bacteria have even shorter generation times than mice. Some of the microbes form several generations per day. Evolutionary changes can therefore be observed after only a few months. Bacteria are therefore an ideal model system for monitoring evolution live in the laboratory. And not only that – it can even be controlled. By changing the living conditions in culture vessels, researchers can direct the development of bacteria in different directions. Scientists from the Max Planck Institute for Evolutionary Biology discovered how bacteria Pseudomonas tolaasii they can combine to form clusters of cells. Thus, they found a possible path from unicellular to multicellular.

The birth of the collective

If bacterial cells clump together into mats, this could be the first step on the way to a higher organism

Evolution relies on the tried and tested

The results of Max Planck scientists and other research groups also show that evolution is often very conservative. It uses existing genes and gives them new tasks. This also explains why creatures as diverse as earthworms or fruit flies have so many genes that we humans also carry. Gene reassignment is a central principle of evolution and the environment plays a key role in this.

And the roundworm has teeth

For developmental geneticist and evolutionary biologist Ralf Sommer from the Max Planck Institute for Developmental Biology in Tübingen, nematodes and bugs are the protagonists, and the island of La Reunion is the background in a great drama: a didactic play about evolution, about diversity in nature and how it arises. more

.

Leave a Comment

Your email address will not be published.