The different worlds of classification in zoology

Taxonomy

In today’s blog post I will be diving into the basics one of the branches of science that helps us understand the diversity of life on our planet. You may have noticed at the start of each post I write on each organism there is a list which categorises each species otherwise known as taxonomizing. Taxonomy is like a roadmap, a giant filing system that helps scientists organize and categorize all these organisms based on their similarities and differences. Imagine strolling through a lush forest or snorkelling in a vibrant coral reef. Every living creature you encounter, from the largest mammals to the tiniest insects, belongs to a vast network of life forms.

At its core, taxonomy aims to answer one fundamental question: How are living things related to each other? To do this, taxonomists use a hierarchical system of classification that was pioneered by the great Swedish botanist Carl Linnaeus in the 18th century.

This classification system has a few main components being Domain, Kingdom, Phylum, Class, Order, Family, Genus, and Species. But what do these mean?

The highest level of classification is called the Domain, organisms are divided into three domains: Archaea, Bacteria, and Eukarya. Archaea and Bacteria consist of single-celled microorganisms, while Eukarya encompasses all organisms that have complex, membrane-bound cells, which include plants, animals, fungi, and protists. Within the domain called Eukarya, organisms are further divided into Kingdoms. Currently, there are six recognized kingdoms, Animalia (animals), Plantae (plants), Fungi (fungi), Protista (protists), Archaea (archaea), and Bacteria (bacteria). Each of these kingdoms are then subdivided into phyla. Phyla group together organisms that share certain key characteristics. For example, within the animal kingdom, there are phyla such as Chordata (which includes vertebrates like mammals, birds, reptiles, amphibians, and fish) and Arthropoda (which includes insects, spiders, and crustaceans). After the phylum level of organisation, organisms are further classified into increasingly specific categories. These include class, order, family, genus, and species. For example, humans belong to the following classifications: Animalia (kingdom), Chordata (phylum), Mammalia (class), Primates (order), Hominidae (family), Homo (genus), and sapiens (species).

By systematically categorizing organisms into the hierarchical levels listed above, it enables taxonomists to uncover evolutionary relationships and better understand the diversity of life on earth. However, it's essential to remember that taxonomy is not static, and as scientific knowledge advances, classifications of organisms may change as new evidence emerges. In addition to providing insights into evolutionary history, taxonomy plays a crucial role in fields such as ecology, conservation biology, and medicine. Understanding the relationships between organisms allows us to make sense of ecosystems, track biodiversity loss, and even discover new species that could even have potential medicinal properties.

IUCN Red List of Endangered Species

Another way in which I categorise organisms within my blogs, that you may have seen, is the IUCN Red List of Endangered Species. Sadly, the scenario where a world where majestic animals like tigers, gentle giants like elephants, and delicate plants like orchids are on the brink of extinction is a reality for many species today.

So, what exactly is the IUCN Red List?

The International Union for Conservation of Nature (IUCN) Red List serves as a comprehensive database that assesses the conservation status of species found across the globe. It evaluates the extinction risk of thousands of species based on rigorous scientific criteria. These assessments are conducted by experts from around the globe, including zoologists, botanists, ecologists, and conservationists.

Species are categorized into nine different threat levels based on their population size, trend, and distribution. The main categories of the IUCN Red List of Endangered Species are as follows:

Not Evaluated (NE): Species that have not yet been evaluated.

Data Deficient (DD): Indicating inadequate information to make a direct, or indirect, assessment of its risk of extinction based on distribution and/or population status.

Least Concern (LC): Species in this category are widespread and abundant, with no immediate threat of extinction.

Near Threatened (NT): Species that are close to being classified as threatened but do not yet qualify for that status fall into this category. It's a warning sign that conservation action may be needed in the future.

Vulnerable (VU): Species in this category face a high risk of extinction in the wild if their habitats continue to decline or if other threatening factors persist.

Endangered (EN): Species in this category are at a very high risk of extinction in the wild. Urgent conservation action is needed to prevent their disappearance.

Critically Endangered (CR): Species in this category are at an extremely high risk of extinction in the wild. Without immediate and intensive intervention, they may be lost forever.

Extinct in the Wild (EW): Species that survive only in captivity or cultivation, with no remaining populations in their natural habitats, are classified as extinct in the wild.

Extinct (EX): Species that no longer exist anywhere on Earth are classified as extinct.

These categories are usually displayed on my blog posts via a graphic designed by myself as seen below:

By assessing species against these criteria, the Red List provides crucial information for conservation planning and decision-making. It helps identify species in need of urgent protection, prioritize conservation efforts, and track changes in the status of biodiversity over time.

But why does the Red List matter?

The Red List serves as a wake-up call, alerting us to the escalating biodiversity crisis facing our planet. It highlights the human activities driving species to the brink of extinction, such as habitat destruction, climate change, poaching, and pollution. Moreover, the Red List is a powerful tool for raising awareness and mobilizing action. By shining a spotlight on endangered species, it inspires individuals, governments, and organizations to take steps to protect and conserve our planet's precious biodiversity.

Post by Ella Munro

Taxonomy image from Britannica

IUCN Red List graphic by Ella Munro

IUCN Red List logo from The IUCN