Life

The origin of life as seen by a geologist who loves astronomy

11-02-2019

THOMAS Pierre

Life on Earth was born about four billion years ago, shortly after the formation of our planet, 4.54 billion years ago. While the transition from…

Once upon a time when life appeared: chemistry in the earth’s ocean 4 billion years ago

02-04-2019

VALLÉE Yannick

Some 4 billion years ago, the Earth was largely covered by a huge ocean. This ocean contained a large number of small organic molecules, which…

Origin of the first cells: the engineer’s point of view

01-04-2019

DANCHIN Antoine

In a realistic scenario of the origin of life, a primeval metabolism begins in water at the surface of minerals. These promote the polymerization of…

Symbiosis and evolution: at the origin of the eukaryotic cell

01-04-2019

SELOSSE Marc-André, JOYARD Jacques

The cell of eukaryotic organisms (animals, plants, fungi) differs from that of prokaryotic organisms (Archaea and Bacteria) by the presence of several specialized organelles, such…

The first complex ecosystems

01-04-2019

VANNIER Jean

Today’s ecosystems are amazing in the complexity of the interdependent relationships between the organisms that make up them. Energy and biomass circulate through food webs…

The first terrestrial ecosystems

02-04-2019

GUÉRIAU Pierre, MONDEJAR FERNANDEZ Jorge

The establishment of complex continental ecosystems is probably the most important event in the history of multicellular life after the Cambrian and Ordovician radiations that…

The biosphere, a major geological player

01-04-2019

THOMAS Pierre

The biosphere, that is, the terrestrial environment and the living organisms that have developed there, deeply shapes the planet Earth. With the genesis of carbonaceous…

Crude oil: evidences for its biological origin

02-04-2019

BAUDIN François

“Will the defendant please rise! Please state your first and last name, age and origin?” Petra Oleum, Old and Biological would answer all the crude…

Massive extinctions in geological time

02-04-2019

LANGLOIS Cyril

At least five times in the past, a large number of species have disappeared in a short period of time [1]. The study of these…

The dangerous liaisons of oxygen and life

22-07-2020

LEQRAA Naoual, VALLÉE Yannick

Oxygen is life! In any case today many biological processes could not take place without molecular oxygen, O2, and many organisms die when they are…

What is biodiversity?

08-04-2019

JOYARD Jacques

Biodiversity concerns all living organisms, their interactions with each other and with their environment. All levels of life are concerned: from the gene to the…

Symbiosis and parasitism

06-05-2019

SELOSSE Marc-André, JOYARD Jacques

Living organisms are permanently closely associated with each other. Their interactions can be classified according to the level of association of the organisms involved, the…

Theory of evolution: misunderstandings and resistance

18-02-2019

BREGLIANO Jean-Claude

Modern evolutionary theory, based on Darwin’s work, constitutes a profound mental revolution for our representation of the world for at least two reasons. On the…

Lamarck and Darwin: two divergent visions of the living world

27-05-2019

BREGLIANO Jean-Claude

The last two decades have seen an accumulation of scientific data on so-called epigenetic phenomena, changes in the expression of genes induced by the environment…

Inheritance or convergence? The winding paths of species evolution

08-04-2019

MAZEL Florent, LAVERGNE Sébastien, DOUZET Rolland, THUILLER Wilfried

How can we explain that some species are more alike than others? Species are the product of their history: evolution. They represent the leaves of…

The adaptation of life to environmental constraints

08-04-2019

DESPRÉS Laurence

The diversity of living forms, or biodiversity, is reflected in phenotypic variations (expression of variable traits), themselves largely caused by genetic variations both within species…

The fixed life of plants and its constraints

05-12-2019

BRIAT Jean-François

Plants are fixed to the soil by their roots, which supply them with water and minerals, their leaves capturing solar energy to fix the carbon…

How do plants cope with alpine stress?

16-08-2019

STREB Peter, CORNIC Gabriel, BLIGNY Richard

At high altitudes, plants can be subjected to strong constraints: high light and UV radiation, low CO2 concentration, large temperature variations… These parameters vary over…

Reproductive strategies of alpine plants

09-03-2019

TILL-BOTTRAUD Irène, AUBERT Serge, DOUZET Rolland

When environmental conditions are difficult or peculiar, such as in high mountains, plants must adapt to ensure their reproduction. Two main strategies allow alpine plants…

DNA barcodes to characterize biodiversity

26-04-2019

POMPANON François, SHEHZAD Wasim

New high-throughput molecular biology techniques make it possible to identify species in our environment. By characterizing short fragments of DNA that persist in the environment,…

What biodiversity in the city ?

15-08-2019

MACHON Nathalie

Even if the urban environment imposes very strong constraints on the animals and plants that inhabit it, the biodiversity of our cities is rich in…

Adaptation: responding to environmental challenges

15-04-2019

BREGLIANO Jean-Claude

Since Jean-Baptiste de Lamarck and Charles Darwin, we know that living beings were not created once and for all by a divine force to constitute…

The genome between stability and variability

24-11-2020

BREGLIANO Jean-Claude

The genome of living beings is permanently affected by anomalies, due to accidental errors or agents inside and outside the body. Fortunately, enzymes correct most…

Genetic polymorphism and variation

23-03-2019

VEUILLE Michel

Genetic polymorphism is the existence of alternative states of DNA, determining the variation of the organism’s higher levels of integration. There are different kinds of…

Genetic polymorphism and selection

23-03-2019

VEUILLE Michel

Polymorphism has caused controversy about its role in evolution. But if it essentially follows a neutral evolution, it serves as a reference, in contrast, for…

Epigenetics: the genome and its environment

23-06-2020

KHOCHBIN Saadi

Modern biology is discovering so-called “epigenetic” mechanisms that allow the genome to modulate its functioning without modifying the information contained in the genes themselves. Knowledge…

A carbon cycle disrupted by human activities

23-04-2019

JOYARD Jacques, SOMMERIA Joël

All living beings are built from carbon atoms. These are extracted from atmospheric CO2 by plants, algae and certain bacteria, using solar energy: this is…

Light, vision and biological clocks

19-03-2019

LE TALLEC Thomas

Since life appeared on Earth, various selection forces have influenced the evolution of living organisms. Among these forces, light generated by our sun probably had…

Cellular impact of solar UV rays

23-04-2019

DOUKI Thierry

The Sun is essential to life, whether through photosynthesis in plants or the production of vitamin D in humans. However, it is a source of…

Biodiversity on rocky coasts: zoning and ecological relationships

23-04-2019

MANNEVILLE Olivier

The Atlantic rocky coasts, subject to tidal sway, make it easy to observe the organisms that colonize them. Depending on the level and living conditions,…

Plants that live on air

16-08-2019

BROUQUISSE Renaud, PUPPO Alain

Use nitrogen from the air to synthesize its essential biomolecules? Plants achieve this feat by establishing a mutually beneficial association with soil bacteria. After a…

Dialogue and cooperation among bacteria

03-12-2019

LAMI Raphaël, TEYSSEDRE Anne

Are social communication and cooperation the prerogative of animals? Absolutely not: they also exist in plants and unicellular organisms, such as bacteria. Among the latter,…

Shedding light on photosynthesis

04-03-2020

JOYARD Jacques, MOROT-GAUDRY Jean-François

What is the most essential for life on Earth? Water, of course; but probably light too… and photosynthesis that enhances it for the benefit of…

The path of carbon in photosynthesis

04-03-2020

MOROT-GAUDRY Jean-François, JOYARD Jacques

How is the carbon from carbon dioxide – CO2 – present in the atmosphere integrated into the organic matter that makes up living organisms, the…

How to feed plants while polluting less?

24-06-2020

BRIAT Jean-François, LEMAIRE Gilles

Is it possible to fertilize crops while respecting the environment? This question, at the heart of our society’s environmental concerns, has no simple answer. Plants…

Corals: Ocean engineers are under threat

23-04-2019

COURTIAL Lucile, ALLEMAND Denis, FURLA Paola

Coral reefs are one of the most complex and richest ecosystems on our planet. They are based on a bioconstructed mineral (or biomineral) structure built…

Peatlands and marshes, remarkable wetlands

08-04-2020

MANNEVILLE Olivier

Peatlands are wetlands whose vegetation produces peat that is very rich in organic carbon. The quantity of water entering the system and its chemical quality…

Microbes in extreme environments

23-04-2019

FRANZETTI Bruno

There are few sterile places on the planet. Glacial deserts, hot springs, ocean bottoms, hypersaline environments, rocks of the earth’s mantle… even these hostile environments…

Lichens, surprising pioneering organisms

21-08-2019

ASTA Juliette

Remarkable pioneers, lichens have conquered the most extreme environments. They are able to grow on the rocks of alpine peaks or those of rocky coasts…

Amazonia: a huge ecosystem in constant evolution

21-10-2019

PAVE Alain

The Amazon region is home to the second largest forest on the planet after the Siberian forest, but the first in terms of biodiversity. The…

What is the impact of air pollutants on vegetation?

02-05-2019

GARREC Jean-Pierre

Plants are at the forefront of air pollution because they are fixed organisms at the basis of the functioning of terrestrial and aquatic ecosystems. The…

When invasive plants also wander in the fields

21-03-2019

CHAUVEL Bruno

Biological invasions are easily perceived by the general public, who see the development of populations of exotic animals or plants on roadsides, ponds or urban…

Collembola: actors of soil life

02-05-2019

SALMON Sandrine

An unsuspected diversity of invertebrates swarms under our feet when we walk on the ground in a forest, meadow or garden. Invisible communities are active…

Nitrates in the environment

02-05-2019

GERMON Jean-Claude

The agricultural origin of nitrate leaks into the environment is no longer disputed. It results from the natural functioning of the nitrogen cycle and the…

What is the ecological impact of light pollution?

02-05-2019

LE TALLEC Thomas

Light pollution is a phenomenon associated with the use of artificial lighting by humans. In fact, it alters the natural cycles of light and alters…

Alpine alluvial landscapes and biodiversity

18-06-2019

GIREL Jacky

Riparian vegetation communities along watercourse provide specific habitats at the land-water boundary, where water, sediment and energy flows interact with the vegetation itself. River dynamics…

Mathematical models can help to better manage fishing

19-03-2019

AUGER Pierre, LETT Christophe

Fishing provides an important part of the food for people in some developing countries. This can lead to a worrying cascade of overfishing, collapsing catches…

Climate change and globalization, drivers of insect invasions

16-08-2019

ROQUES Alain, AUGER-ROZENBERG Marie-Anne

Global warming and globalization of trade have a decisive impact on the geographical distribution of insects. There is an exponential increase in the establishment of…

How do birds adapt to a changing climate?

22-08-2019

BLONDEL Jacques

What can be done, being a bird, to adapt to a climate that is inexorably warming? Three solutions: fleeing under milder skies, adapting locally or…

Lichens and environmental quality

04-12-2019

ASTA Juliette

Without structures insuring physical protection, like the plant cuticle, lichens are directly exposed to their environment. Rainwater and air directly enter the organism, dust is…

The Great Green Wall: a hope for greening the Sahel?

16-08-2019

GOFFNER Deborah, PEIRY Jean-Luc

The Great Green Wall of Africa (GGW) is a pan-African initiative to combat desertification in the Sahara Desert and the Sahel. Originally conceived as a…

Restoring savannas and tropical herbaceous ecosystems

24-07-2020

LE STRADIC Soizig, BUISSON Elise

When people think of savannas, they think of the vast African landscapes where elephants, wildebeest, giraffes or lions used to roam. With the seasons, the…

Biodiversity is not a luxury but a necessity

02-03-2020

BLONDEL Jacques

Biodiversity, a contraction of the term “biological diversity”, appeared in the public sphere at the Earth Summit (1992). Two meanings are recognized in the word.…

Biofuels: is the future in microalgae?

15-01-2020

MARECHAL Eric

Are we at the end of fossil fuels (coal, gas, oil) and will we know how to do without them? What alternatives are we considering?…