Kingdom phylum class order family genus species. Maybe you remember learning in some long-ago biology class that these seven categories are how we describe and identify every living thing on Earth.
Animalia chordata mammalia primates hominidae homo sapiens. That’s us: humans. Within the great tree of life, we are pretty odd; we are the only member of our genus. Put in terms of a family tree, it’s kind of like not having any siblings.
Even if you look at our extended family – our cousins – we’re pretty unusual. Our planet is home to just 5,400 or so kinds of mammals. (Though the discovery of new mammals is not as rare as many people think. The past decade has seen new types of shrews, bats, and dolphins – and even a few monkeys and apes – welcomed onto the list of mammals known to science.)
In comparison, there are nearly twice as many kinds of birds – birding checklists typically include over 9,000 recognized species. And there are about 31,000 known kinds of fish.
The plant kingdom boasts some 310,000 members, from mosses to grasses to shrubs to towering trees. It’s not unusual for a dedicated natural gardener to have hundreds of kinds of plants in their yard, with many or all of them being native species. It’s not just that there are a lot of species of plants in the world; a lot of species of plants are able to coexist within small areas.
The total number of plant species is still dwarfed by the total number of animal species, though, for one reason: beetles are a staggeringly prolific family, with over 360,000 species discovered, and many more likely waiting to be found.
If you lined up one representative of every species on Earth, fully one fifth of the creatures before you would be beetles. Only one would look like us.
All told, we share our planet with at least 1,899,000 other species, each of them living in their own way and making their own unique contribution to the amazing diversity of life on Earth. When we are able to see ourselves as just one out of many, we can find the grace and humility to share our world with all of our relatives.