Biodiversity, in its essence, is the breathtaking spectrum of life that thrives on our planet. It encompasses everything from the smallest units of heredity, genes, to the vast and intricate ecosystems, and all the species in between. This term, “biodiversity,” short for biological diversity, was coined by the renowned biologist and author E.O. Wilson, who eloquently described it as “the very stuff of life.”
For an astounding 3.8 billion years, Earth has been home to an evolving and complex web of life. Millions of species, each unique and playing a vital role, inhabit our lands, freshwater bodies, and oceans. Humans, along with every other species, are deeply interconnected, influencing and being influenced by each other and the environments they call home.
Biodiversity is not static; it’s a dynamic attribute of life. It changes over time as species disappear through extinction, and new ones emerge through evolution. Scientists often categorize biodiversity into three fundamental and interconnected levels: species diversity, genetic diversity, and ecosystem diversity. These levels are not isolated but are intrinsically linked, with changes in one level rippling through and affecting the others.
Defining Species Diversity
Species are the fundamental building blocks of biodiversity, and they manifest in an astonishing array of forms. From microscopic organisms only visible through powerful lenses to towering redwood trees that dominate landscapes, the variety is immense. Species encompass bacteria, protozoa, fungi, flowering plants, insects like ants and beetles, vibrant butterflies, diverse birds, fishes inhabiting every aquatic niche, and majestic animals such as elephants, whales, and bears. Each species represents a distinct group of organisms characterized by unique traits. Crucially, members of a species can reproduce successfully with each other, producing viable offspring, a defining characteristic that separates them from other species.
Our understanding of the total number of species on Earth and their intricate relationships with each other and their environment is still evolving. Current estimates suggest that there are around 10 million species inhabiting our planet, but only about 1.9 million have been officially identified, named, and cataloged by scientists. This vast unknown biodiversity underscores the urgent race against time for scientists to catalog species before they potentially disappear into extinction, often before we even know they existed. An “endemic” species holds particular scientific importance, as it is uniquely confined to a specific geographic area and found nowhere else on Earth, making it particularly vulnerable.
The discovery of new species is an ongoing process, driven by dedicated scientists around the world. For example, entomologist Dr. Jonathan Coddington from the Smithsonian National Museum of Natural History, along with his colleagues, announced the discovery of Nephila komaci in 2009, the largest web-spinning spider known to science. Similarly, in 2012, Dr. Terry Erwin and his team identified a remarkable 177 new species of parasitic wasps. Exploring the depths of coral reefs using submersibles, Ichthyologist Dr. Carole Baldwin continues to encounter and describe new species of fish, expanding our knowledge of marine biodiversity. The study of fossils also reveals species from the distant past that are now extinct, like the discovery by Paleobiologist Dr. Nick Pyenson and colleagues that the diversity of sea cow species was once significantly higher than it is today.
When a new species is identified, it undergoes a process of scientific naming that adheres to specific rules. It is assigned to a genus based on its evolutionary relationships with other organisms. The unique species name itself can reflect a distinctive characteristic, the location of its discovery, or even be named in honor of a colleague, adding a personal touch to scientific nomenclature.
In 2013, Smithsonian Mammalogist Dr. Kristofer Helgen and his collaborators made a notable discovery, naming the first new species of carnivorous mammal recorded in the Americas in 35 years. This creature, related to “olingos,” was placed in the genus Bassaricyon, and its species name, neblina, references the Andean cloud forests (neblina meaning “fog” in Spanish) where it was found. Another intriguing example is a new species of jellyfish, Tamoya ohboya, discovered by Dr. Allen Collins. Its species name was inspired by a teacher’s observation that people exclaimed “oh boy” upon seeing it, highlighting the sometimes-unconventional origins of scientific names.
Understanding Genetic Diversity
Biodiversity extends beyond species to encompass the genetic diversity within species. This refers to the variety of genes that each individual inherits from its parents and passes on to future generations. Genetic diversity is pervasive, manifesting in countless ways, from the diverse songs and plumage colors of birds to the variations in colors, tastes, and textures of apples and other foods we consume. Genetic variation is not merely aesthetic; it is fundamentally crucial for survival. It dictates the degree to which individuals within a species can adapt to changing environmental conditions. A population with high genetic diversity is more resilient and better equipped to withstand environmental stresses, diseases, and other challenges.
The entirety of an organism’s hereditary information, encoded in DNA, is known as its genome. Recognizing the profound importance of genetic diversity, scientists at the National Museum of Natural History are actively engaged in preserving Earth’s genomic heritage. They are meticulously collecting and cryogenically freezing hundreds of thousands of DNA samples, creating a vast repository for future research. This collection is a cornerstone for the burgeoning field of genomics, a scientific discipline dedicated to sequencing, assembling, and analyzing the function and structure of genomes. Genomics offers unprecedented insights into the past, present, and future of plants, animals, fungi, bacteria, and protists, even those that are already extinct. The Smithsonian’s DNA repository is a significant contribution to the Global Genome Project, a worldwide collaborative effort aimed at preserving genetic samples from every species on Earth, ensuring that this vital component of biodiversity is safeguarded for generations to come.
Exploring Ecosystem Diversity
The concept of biodiversity further extends to ecosystems, the complex and dynamic networks of life and their physical environment. Genes determine the traits of individual organisms, which in turn form populations of a species. Interactions between different species within a given area give rise to communities. These communities, in a constant interplay with non-living environmental components like water and minerals, constitute an ecosystem. Ecosystem diversity refers to the variety of different ecosystems within a region or on Earth as a whole.
Ecosystems vary dramatically in their complexity and the number of species they support. Tropical forests and coral reefs are renowned for their exceptional complexity and incredibly high species diversity, teeming with life in every imaginable form. In contrast, ecosystems like deserts and Arctic regions are characterized by lower complexity and, consequently, a smaller number of species. However, it’s crucial to recognize that every species within these seemingly less diverse ecosystems is ecologically significant, playing essential roles in the functioning of the ecosystem. Furthermore, some species are endemic to these ecosystems, meaning they are uniquely adapted to and found only in these specific environments. The loss of any ecosystem type diminishes overall biodiversity and can have far-reaching consequences for the planet’s ecological balance.
The Importance of Monitoring Biodiversity
Understanding and conserving biodiversity requires continuous monitoring and assessment. Many scientists at the Smithsonian Institution are at the forefront of developing methods to effectively monitor and measure biodiversity changes over time. For instance, scientists at the Smithsonian Conservation Biology Institute, Dr. Francisco Dallmeier and Dr. Alfonso Alonso, developed a comprehensive Framework for the Assessment and Monitoring of Biodiversity. This framework provides crucial guidance on designing and implementing biodiversity assessments and monitoring programs, effectively reporting collected data, and utilizing scientific information to track the health of ecosystems and the species they harbor. This systematic approach is vital for informed conservation efforts and policy decisions.
For over three decades, Smithsonian scientists and their collaborators in the Forest Global Earth Observatory (ForestGEO) have been dedicated to studying forest biodiversity and ecosystem function across more than 60 sites worldwide. Building upon this terrestrial expertise, a more recent initiative, the Marine Global Earth Observatory (Marine GEO), unites Smithsonian marine scientists from the U.S., Belize, and Panama with colleagues globally to monitor ocean ecosystems. These long-term, large-scale monitoring programs provide invaluable data on biodiversity trends and the impacts of environmental change.
Botanist Dr. John Kress played a leadership role in establishing the Consortium of Scientific Partners on Biodiversity in 2006. Initially founded by the Smithsonian and five other international scientific organizations, the Consortium has grown to encompass 24 major scientific organizations. This collaborative platform fosters innovative approaches to biodiversity research and seeks to develop effective solutions to address biodiversity loss as human activities continue to interact with and impact the biosphere. Through collaborative research, monitoring, and conservation efforts, scientists are working to deepen our understanding of biodiversity and ensure its preservation for future generations.
