Diversity of life – Genetic diversity

Biodiversity – The Series

The three main aspects of biodiversity are species diversity, the genetic diversity of a species and the diversity of habitats in a region. We cover all those aspects in dedicated articles. In this one, we take a closer look at the aspect of genetic diversity.

Genetic diversity

A species consists of individuals that are very similar but have small differences in their genetic information. If there are many of these small differences, then this species has the potential to adapt easily to new environmental conditions. For example, if some individuals in a population have the ability to reproduce despite high soil moisture and other individuals have the ability to do so in dry conditions, then the species is likely to survive even if the site conditions change.

Not all genes are always active

On average, around 30,000 genes are active in plants at different times and under changing conditions. Whether and how well a plant thrives, to what extent it can adapt to its environment and cope with climatic changes, therefore depends on how large the pool of genes that can be activated is. If we look at a single gene, its activation depends, among other things, on where and how the plant lives: Individually? In a dense population? In full sun or in the shade? Aspects such as moisture or the chemical composition of the soil also play a role.”

Not all individuals have to adapt

There are also plants that can even activate genes to send out “calls for help”. For example, they then produce scents that attract predators to eat pests. Experiments by scientists at the Max Planck Institute for Chemical Ecology have [shown](https://elifesciences.org/articles/04490) that it is sometimes sufficient for only individual plants within a larger population to develop this genetic trait in order to protect all neighboring plants.”

Diversity as the basis for evolution

Genetic diversity within a species is also the basis for the formation of completely new species. There are various concepts for this, which differ mainly in whether or not there is a spatial separation (through mountain and island formation, storms) of populations.

  • If this is the case, there can no longer be any genetic exchange between the groups and new species will eventually emerge through mutation and selection.
  • Species formation without spatial separation: due to spontaneous mutation of the reproductive organs, individuals can no longer reproduce among themselves. The altered population splits off from the original species.
  • Species formation despite gene flow: As shown at the beginning of the story, high genetic variability within a species can ensure that it can thrive in completely different locations. Over long periods of time, the smallest changes ultimately ensure that new species have emerged from these adapted populations

 

This article was featured as a story in the Flora-Incognita app in spring 2024. In this plant identification app, you can find exciting information about plants, ecology, species knowledge, and tips and tricks for plant identification. Check it out!

Diversity of life – Species diversity

Biodiversity – The Series

The three main aspects of biodiversity are species diversity, the genetic diversity of a species and the diversity of habitats in a region. We cover all those aspects in dedicated articles. In this one, we take a closer look at the aspect of species diversity.

Species diversity

The term species diversity describes the number of biological species in a given area. This applies to small areas as well as large ones: a single tree in the Amazon, an entire mountain range, a political state, or even just a grid cell in a city. Typically, the species diversity of such an area is divided into specific groups such as plants (or just trees), mammals, fish, insects – depending on the question or topic.

How many species are there?

In 2006, around 2 million species were scientifically described. This contrasts with estimates of 5 to 20 million species that actually exist worldwide. It is very difficult to give precise figures for these two, as different groups of organisms have different criteria for species delimitation, and modern classification methods also include genetic information. There are also a large number of synonyms, and most species are very small and live in areas that are not easy to reach. Nevertheless, around 12-13,000 new species are scientifically described every year.

Why is species diversity important?

Nature is crucial for our survival as it provides us with important ecosystem services such as food, medicines, water regulation and recreational opportunities. It also helps to regulate the climate, and each species plays a unique and important role. The absence of a species can lead to the disruption of complex ecological cycles. For example, the extinction of insect species can have a negative impact on birds that feed on these insects and on the pollination of plants (including crops).

What threatens species diversity?

First and foremost is the destruction of habitats through construction, clearing, or modification, e.g., through intensification of soil cultivation. Many species-rich habitats are nutrient-poor, as a few dominant species spread quickly on nutrient-rich sites. The input of nitrogen and phosphorus from pollutants poses a threat to these habitats. Finally, invasive species can also have a lasting impact on existing ecosystems by disrupting the complex interactions between the species that occur there and successfully displacing established species. Above all these factors is climate change, which is altering many established processes so rapidly that the adaptability of many species cannot keep pace.

How can species diversity be protected?

Restoring or maintaining diverse habitats is the most important measure for preserving species diversity – or at least slowing its decline. Examples include restoring floodplain landscapes along rivers, allowing standing and lying deadwood in forests, thinning dry grasslands, extensive year-round grazing, flowering strips with native wild herbs and shrubs on agricultural land and stopping the drainage of moors. But our own actions can also have an influence: Wild corners in the garden, partially mowing of meadows, use of peat-free soil, participation in work to remove invasive plants or political and educational work are valuable building blocks for the preservation of species diversity.

 

This article was featured as a story in the Flora-Incognita app in spring 2024. In this plant identification app, you can find exciting information about plants, ecology, species knowledge, and tips and tricks for plant identification. Check it out!

Diversity of life – Biodiversity

Biodiversity is not the same as species diversity

Biodiversity is a term you read in many places, but what exactly does it mean? In simple terms, biodiversity is the variety of life on earth. Many people use the term species diversity as a synonym for biodiversity, but this falls short. High biodiversity not only refers to the fact that there are many species of living organisms (e.g. animals, plants, fungi), but also to the fact that there is great genetic diversity among them. There is also a third component: the diversity of habitats. To explain these three forms of biodiversity to you in more detail, more Flora Stories will follow in the coming weeks, which will take a closer look at the individual forms. Don’t miss them!

Loss of biodiversity

In May 2019, the Global Assessment Report on Biodiversity and Ecosystem Services was published. The report highlights the alarming state of global biodiversity. Data from 1970 to 2018 for a total of 31,821 populations of 5,230 species from all over the world show that the population sizes of the observed mammals, birds, amphibians, reptiles and fish have shrunk by an average of 69 percent. The main reason for this is the loss of diverse habitats. The ever-shrinking populations inevitably lead to a loss of genetic diversity. This is why it is so important to protect or restore habitats. This is precisely the motto of this year’s Biodiversity Day.
Biodiversity Day (May 22)
International Biodiversity Day is celebrated every year on May 22. In 2024, the motto is ‘Be part of the Plan’. This motto is a call to action to stop and reverse the loss of biodiversity, because every human being interacts with the environment and can become part of the plan to conserve biodiversity.
Badge: Biodiversity Day
Flora Incognita was developed to make it easy for you to get to know plant species. Only those who know species can protect species! That’s why you can earn the Biodiversity Day badge on May 22nd. All you have to do is identify a variety of different plant species on this day with Flora Incognita. There are three levels: for 10, 20 and 30 different species. Have fun with this task!

This article was featured as a story in the Flora-Incognita app in spring 2024. In this plant identification app, you can find exciting information about plants, ecology, species knowledge, and tips and tricks for plant identification. Check it out!