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?…