"Animals: approaches from biological, human and social sciences"
"Are human beings animals?"
-Let's consider together the way natural history,
the way zoology,
consider the classification of human beings
and classifications in general.
The science of classification is called systematics.
Intuitively, we might wonder what takes precedence in this science.
Is it about considering human beings for their differences from animals
or for their similarities?
Traditionally,
our culture prompts us to consider our differences with animals.
Human beings tend to overdefine themselves,
we try to define what makes us human,
by contrast with animals which are never defined by exclusion.
Differences are what tend to prevail when we talk about it with the public.
However, in science, this is not how we proceed.
We have to consider three basic mental operations,
the first one being separating,
the second one being gathering,
and the third one being assigning.
When separating,
we have a sample from the real world that we have to navigate
and we draw a line through the sample
and leave individuals that have one trait on the right
and those who do not on the left,
tall individuals on the right and short individuals on the left, etc.,
to guide us through usually numerous samples
until, in the end, we can reach a species name.
This is what we do when we use identification keys.
Through successive separations and choices,
we navigate a paper chase that leads us to making a choice.
These operations are purely pragmatic,
they do not reflect the world or any concepts.
Their goal is simply to guide us.
However, in the middle, we create sets by uniting.
We take entities from the real world and group them together
when they share at least one common trait.
At best, these sets are nested in each other,
thus enriching the discourse over their shared traits.
And on the right, assignation involves,
similarly to tidying up a room,
taking a sample and adding it to the right preexisting set,
as to a preexisting cabinet, to the right drawer,
based on the object's traits.
We must not get these operations mixed up.
When we do, we end up creating irrational sets.
For instance,
invertebrates.
What did we do with invertebrates?
We got combining mixed up with separating.
We put species with vertebrae on the right
and species without vertebrae on the left.
Saying a snail or a worm does not have vertebrae
does not say much about it.
It is more a reflection on human beings who act as outside references.
In science, we do not use separations but commonalities,
which are nested in each other.
Human beings, as defined by their own traits,
share with their neighbors
more general traits,
thus forming a set including the previous species,
and so on until we have a general definition of the animal
and a general overview of the living world.
The sum of slotted commonalities make up the classification.
The sets are nested in each other, they are not piled up.
Here, we have a chart from Charles Bonnet in 1745
which reflects concepts piled up under the name "The Great Chain of Being"
which dates back
much further to Aristotle.
Today, we are no longer using this system.
Today, we classify using nested sets and commonalities.
When we draw a line between two sets at different levels,
the result is a graph which is commonly called a tree.
This tree is going to reflect the origin of the commonalities
using genealogy.
Indeed,
including under the same set or concept living beings based on what they share
means they share common ancestors.
The correspondence between commonalities and ancestors
dates back to Charles Darwin in 1859.
His classification system was made operational by Willi Henning in 1950.
This is why the main classification system of natural history
is represented by a massive tree of life
where commonalities are considered as inherited.
More general common traits mean the inheritance goes back further,
and thus older ancestors.
In summary,
what should be avoided in science is classifying using differences,
such as me versus the others, Paris versus the suburbs,
Paris versus other cities,
which are not defined as themselves but as being different from Paris,
vertebrates versus invertebrates.
We should tend to avoid using differences
in all scientific fields.
Following these principles, we may wonder what an animal is.
Animals are all living beings
which share common traits such as collagen,
a fibrous protein that is found in our skin
and which is responsible for the texture of our organs, in a way,
specific spermatozoids
which have a small hood at the top of its head, at the front,
snaps between cells which are called tight junctions
and are responsible for the cohesion of animals,
and a series of common traits regarding genetic structure
which make animals a group with unique origins
including one ancestor and all its descendants.
From then on,
animals can be sponges, jellyfish, ants, crabs,
mollusks, salamanders, and so on,
including human beings since we have these traits.
Human beings are animals from a zoological standpoint.
Although we may be human because we have articulate speech,
we are still vertebrates because we have vertebrae,
we are still animals because we have collagen.
Although human beings may be animals because they have collagen,
they are still human based on additional traits,
including articulate speech.
Using nested commonalities and classifications are thus much richer,
as they promote inclusion over exclusion.
Hence why our classifications
are made up of nested groups, or taxons.
Humans are defined and animals are also defined.
Humans are animals, humans are vertebrates,
humans are also apes,
let's see why.
Apes are traditionally defined
by the fusion between the right and left frontal lobes
and the fusion between the right and left mandibles.
On the left, we have a wolf skull.
We can see a suture in the center so the lobes have not merged.
There is also a dental suture,
which shows that the mandibles have not merged.
But on the right, on the human skull,
there are no sutures between the lobes or the mandibles.
Human beings are thus apes from a zoological standpoint.
To conclude,
today's classification and the science of classification
no longer rely on putting human beings at the center of everything,
which was called anthropocentrism.
The classification does not rely either
on projecting onto animals, which remain undefined,
traits which we believe to be intrinsically human,
which would be called anthropomorphism.
On the contrary, we are using reverse anthropomorphism.
So, we now accept to see in ourselves
the pieces of our anatomical mosaic which make us animals,
which make us vertebrates or apes.
In a way, with this classification system and in connection with evolution,
Darwin is not anthropomorphizing animals.
On the contrary, Darwin encourages us to zoologize humans.