Many believers want the ‘Kingdom of Life’ to be simple, like it was when they played with their model farmyard animals as infants; they want clearly defined cows, sheep, lions and elephants. Reality seems to support that view because the more obvious creatures don’t appear to change much for centuries…
However, that is a false impression conferred by the shortness of our lifespan and our recorded existence on this planet.
If we could live for millions of years, we would be able to observe changes happening. We would see floods, eruptions and earthquakes separating populations into factions, preventing groups from breeding with their forebears, pushing them to adapt to the new environmental conditions in different ways, or causing them to die out.
We would watch continents, seas, forests and deserts disappear and reappear. We would see ferns being superseded by conifers, and then seed plants such as grasses and deciduous trees would become the dominant vegetation. We would watch the large dinosaurs become extinct and the small ones gradually turn into birds, generation by generation. We would see small shrew like mammals evolve into large ones like horses, elephants and whales.
If we could do that, we would realize that giving organisms names and putting them into classes is a bit futile – after all, they won’t stay like they were when we did that… Nothing is fixed; everything constantly changes.
And once that penny drops, we can understand that naming and classifying are just useful human fabrications. During our short lives we want to know what we’re talking about so we give creatures names and put them into boxes but, in the long term, they will escape!
Meanwhile, we can argue about how we’ve done the nomenclature and taxonomy…
The recent discovery of a skull of a ‘human cousin’ in a cave in South Africa sparked a discussion on whether they should be designated ‘apes’. Of course, according to how specialists have constructed the classification system, humans ARE apes. ‘Ape’ is not a species, nor is it a genus, it’s not even a family, it’s a ‘superfamily’ called Hominoidea; a taxonomic group of tailless old world simians, extant and extinct. https://www.abc.net.au/news/2020-11-10/archaeologists-find-skull-of-human-cousin-two-million-years-old/12869110?
We are constantly embarrassed by our ‘species’ breaking their definition – several creatures previously classified as different species have procreated together and have produced fertile offspring. And vice versa – creatures once considered to be a single species have turned out to be separate non-interbreeding populations.
There are seven types of seemingly identical giraffes and, last month, we discovered that the Gentoo penguins are actually four separate ‘species’ https://www.bbc.co.uk/news/science-environment-54817124
There is no watertight definition of ‘species’. Why would there be – nature doesn’t have to fit into our boxes… In fact, viewed from the perspective of sufficient time, there are no such boxes – just a continuous smear of changing flora and fauna.
Remember this: we just make up names and classes in order to make it possible to communicate about the living things that share our snapshot of a lifetime. Names are just names, but scientific names are universal – the same in every language – they wouldn’t be useful otherwise would they…
Image: By Ditsong National Museum of Natural History – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=11931381