1
Scientific Exploration Campaigns to Inventory Existing Biodiversity and Hasten the Discovery of New Species

1.1. Introduction

Life on Earth first emerged at least 3.5 billion years ago. Since then, it has been constantly evolving, which has led to the phenomena of both diversification and extinction. The fossil records of marine and terrestrial organisms show that the diversity of life, both in the seas and on land, increased exponentially after the end of the Precambrian (Benton 1995), 540 million years ago. Such diversification, though, was punctuated by mass extinctions; the term "biotic crisis" is also employed. Most such extinction events struck marine and terrestrial organisms simultaneously. Within the geological time scale (Bergström et al. 2009), we see no fewer than five major crises, occurring during the Ordovician, the Devonian, the Permian, the Triassic-Jurassic transition and the Cretaceous-Tertiary transition. For example, the Permian-Triassic extinction, which took place some 252 million years ago, saw 95% of marine species and 70% of terrestrial species die out. During the Cretaceous-Tertiary extinction 66 million years ago, during which the dinosaurs rapidly perished, the mammals - who, up until that point, had coexisted with the dinosaurs - suddenly had the place to themselves (so to speak), and we see the group massively diversify. It is plain that the variety of living organisms on planet Earth has resulted from a lengthy and gradual, dynamic process, punctuated by crises. For over a quarter of a century, researchers have been asking whether the particularly proliferous demographic expansion of humans during the Holocene has profoundly altered Earth itself (Myers 1990), leading to a sixth mass extinction event. The extinction rates calculated by biologists tend to demonstrate that this crisis will occur at an even faster rate than the previous five biotic crises (Barnosky et al. 2011), erasing the planet's biological heritage even before it has been fully described.

1.2. A historical overview of diversity inventory

Reindeer, aurochs, mammoths, horses, bison. as early as 18,000 years ago, our prehistoric ancestors made paintings of animals. Whilst we do not yet know, in detail, what these paintings signified, it is undeniable that they constitute the earliest form of inventory of the surrounding biological diversity. Even in the earliest known literary work, the Epic of Gilgamesh (18th century BCE), the landscape in which the action takes place is described using imagery of fauna (for example, the buffalo) and flora (for example, the cedar). In Ancient times, Aristotle (384-322 BCE), in the Organon, devotes a great deal of time to the observation of animated beings (animals), drawing a contrast with inanimate beings (plants). Aristotle's pupil, Theophrastus (372-288 BCE), followed in Aristotle's footsteps, and in particular, developed the discipline of botany, producing a reasoned inventory of the plant life found in the Mediterranean Basin. These two authors offer us detailed observations and descriptions of various animal and plant species; they began to document and classify plants and animals. From the 16th century onward, major explorations by sea led to the discovery of new lands and previously unknown species. By way of example, Captain James Cook's voyages in the 18th century greatly enriched our knowledge of biodiversity; Cook brought back numerous specimens, which needed to be named. Around the same time, a method emerged for scientific description of the living world, gradually coalescing into classification and nomenclature systems with which to organize known species. The seminal work of Carl Linnaeus (also known as Carl von Linné), Systema Naturae, published in 1735, laid the foundations for modern taxonomy and greatly simplified the way in which species were named, proposing the binomial system and comprising a genus name, followed by a species label. This did away with the lengthy descriptive names in use until that point. The most active period for species description was the 19th century; the natural history collections of the major museums are extremely rich in specimens from that period, which was marked by large-scale scientific expeditions. Charles Darwin's observations during his voyage aboard the HMS Beagle are famed, in view of the major advances they brought about in the understanding of the evolution and diversity of species. This work led to the publication of Darwin's On the Origin of Species in 1859, advancing a convincing scientific theory on the origin of the diversity of the living world. France also played an important part: numerous explorations greatly enriched the collections of the National Museum of Natural History. These included Napoleon Bonapart's Egyptian Campaign (1798-1801), which included academics and artists who were charged with studying and documenting the history, architecture, fauna, flora and culture of Ancient Egypt. The expedition of La Coquille (1822-1825) is another example. Under the command of Louis-Isidore Duperrey, La Coquille sailed the seas of the world, notably focusing on the Pacific Ocean and the islands of the South Pacific. Naturalist research was carried out jointly by Jules Dumont d'Urville, who was in charge of botany and entomology, and René Primevère Lesson, who was in charge of zoology. These studies led to the discovery of numerous new species. After the tropics, its was the poles which captured explorers' attention, around 1900. In France, Commander Jean-Baptiste Charcot set out to explore both the South and the North Pole. The two World Wars hindered scientific exploration, but also led to major technological breakthroughs, such as the development of electron microscopy. Thereafter, biologists have largely turned their attention to the study of biochemistry and cell biology, to the detriment of species inventory.

1.3. The advent of molecular taxonomy

The discovery of DNA as the carrier of genetic information, and then the discovery of its structure, but above all, the invention of DNA sequencing techniques in the 1970s (Sanger et al. 1977), were giant leaps forward in molecular biology and genomics. DNA sequencing greatly changed the way in which we understood biodiversity, revealing entire sectors of the living world, thanks to phylogenetic methods, which can compare similar DNA sequences with a view to inferring the evolutionary links between specimens. These methods soon led to the discovery of a third domain of the living world: Archaea (Woese and Fox 1977), which, alongside true bacteria, make up the group of procaryotes (i.e. cells without a nucleus), in contrast to eucaryotes (cells which do have a nucleus). Aside from the discovery of this new sector of the living world, the use of DNA sequences as markers to differentiate species considerably sped up the scientific inventory of biodiversity, notably revealing a number of new cryptic species (Blaxter 2004). Paul Hebert (Hebert et al. 2003) proposed using DNA sequences in the same way as a barcode is used in the commercial world, to identify organisms, and thus create a library of the living (Le Gall et al. 2017). Utilizing technological advances, which allow for the handling of massive databases of sequences, the "Earth BioGenome" project (Lewin et al. 2022) aims to create a library, not for short genetic sequences, but for complete reference genomes (Earth BioGenome Project n.d.). In France, the ATLASea project will contribute to the broader international project, by sequencing the reference genome for 4,500 marine organisms.

1.4. Biodiversity: the emergence of a concept in the face of the crisis

The term "biodiversity", which is now widely used, is a very recent concept, which emerged some thirty years ago, when we became aware of the looming threat of an ecological crisis, caused by human activities. Raymond F. Dasmann is credited with coining the term "biological diversity" (Dasmann 1970), which was then taken up by Thomas Lovejoy, the then-Director of the World Wildlife Fund-US conservation program, who used the term in two 1980 publications. However, it was the Convention on Biological Diversity, ratified at the Earth Summit in Rio de Janeiro in 1992, that popularized the term "biological diversity", defining it as follows:

'Biological diversity' means the variability among living organisms from all sources including, inter alia, terrestrial, marine and other aquatic ecosystems and the ecological complexes of which they are part; this includes diversity within species, between species and of ecosystems.

The contracted form of "biological diversity" as "biodiversity" then gained widespread use. It is also a concept which has been enriched over time and now, beyond referring to the diversity of the living world, it also includes the way in which we perceive that biodiversity, and in particular, the functions and uses we make of it, not forgetting the symbolic aspects attaching to it.

The Convention on Biological Diversity also established a framework for research and training (article 12), which stipulates that each signatory country shall: "Establish and maintain programmes [sic] for scientific and technical education and training in measures for the identification, conservation and sustainable use of biological...