Evolving (part 1) - agency and purpose

I read about spitting cobras the other day. Not a critter I'd like to meet. 

The headline of the article read: Spitting cobras may have evolved unique venom to defend from ancient humans.

I pondered: not only can the cobra spit venomous liquid some distance, it chose to purposefully develop this capacity in order to poison humans.

A planning and spitting cobra! Definitely not a critter I'd like to meet!!

This sounds a bit ludicrous, sure. We know that's not how evolution works, but that is implied in the heading: choice, intention and purpose about changing physiology on the part of snakes. 

It's just one of many examples of the strange ways we talk about evolution and about life forms evolving. 

I think how we talk about evolution says a lot about us, and not very much about evolution! 

The theory of evolution

The earth teems with approximately eight million different species all adapted to (i.e. fitting into) their specific surroundings (and quite a few of them spit at humans). 

For millennia, humans have understood this rich diversity of life on earth through stories of creators who made everything. Creation stories serve to explain the origin and diversity of life, and humanity's relationship to other life-forms. Rich and varied, these stories can be found in all societies. Many of these stories place humanity at the peak of creation. 

In the 1800s, the theory of evolution provided a new explanation of how this vast diversity came to be. It explained how certain types of change in living organisms lead to the emergence of new species. That's why Darwin called his book: On the origin of species, or to paraphrase: How does a new species appear? 

Evolution explains HOW organic life changes to generate new species, not WHETHER living things change over time, that's an observable fact. Evolution has nothing to say on the origin of life; Darwin left that to a Creator. It also says nothing about the status of humanity with regards other life-forms. Evolution just serves to explain biodiversity.

And it is not an easy story to tell.

So what exactly is evolution? This simple definition is from Wikipedia: 

♦️ Evolution is change in the heritable characteristics of biological populations over successive generations.   

So evolution is change.¹

The ideas encapsulated in evolutionary theory are by far the strongest (coherent, testable, etc.) that we have to explain how the Earth came to feature such incredible diversity of species and how a new species can come into existence. If you want to understand it better, start with the Wikipedia definition and follow the links. 

I want to focus instead on our everyday use of the words evolution and evolve, first when we talk about organic life (this post) and then when we talk about things that are not actually alive, like societies, businesses, and language (a future post). 

What exactly is it that 'evolves'? 

If evolution is change (according to its definition), what exactly is it that evolves? Following is a brief dive into the somewhat tedious details of evolutionary theory, with a focus on the words:

• Genes frequently change (mutate²) during the process of reproduction; some changes persist, the vast majority do not.
• Individuals live their life, reproduce or not. Nothing evolutionary to see here, what an individual does or likes doesn't matter.³
• Environmental niches change, come into being or stop being, resulting from natural system changes in weather, geology and geography. 
• Individuals that 'fit'⁴ into the changed environmental niche are more likely to survive to reproduce; alternatively some genetic changes allow individuals to 'fit better' into existing environmental conditions, so they are more likely survive to pass on their changed genes.
• Over many generations, we see change in the number of individuals that 'fit better' with these (new) characteristics within a given population⁵. Over considerable time, these changes may mean these individuals cannot interbreed with others in the population, representing a break. 
• This reproductive break with the old population is the origin of a new species. Species appear or disappear at various times.

Change happens at the genetic, environmental and population levels. The individual doesn't do anything. Some of them never change, as I'm sure you know. As the characteristics of a genetic change are seen more often over (many) generations in a population of plants, fungi or animals, a new species may appear (or disappear). 

So, perhaps we could say that it is the population that evolves. 

Except, within evolutionary theory, 'evolving' is not something to DO. 

You and I (and any critter) can never be described as evolving because it's not something that individuals or groups do. Even saying that a population evolves is misleading, because it implies an active sense of 'doing' something. It is more accurate to say evolution is observed at the population level as the pattern of genes expressed as new characteristics in the population changes.

And that's an important wordly distinction, because it means no 'thing' - gene, individual, or population is actually doing any evolving. 

Not happy Charles

So, why don't we just say organic life changes over time; what are we adding by using the word evolve? 

Evolution explains HOW the complex interplay of various changes described above results in changes in organic lifeforms substantial enough so that new species emerge. It features random genetic change interacting in unpredictable ways with random environmental change over many generations. It explains how life flourishes in all parts of the Earth.

So, in terms of explaining how change happens ('a theory of change'¹), evolution includes no agent (no one acting to change), no intention (direction), and no purpose (goal). It features randomness and unpredictability. 

It's a sound theory with substantial evidence. 

Except we humans really, seriously do not like the idea of agent-less, intention-free, purpose-less, random and unpredictable change. 

We can't hold onto these ideas easily. We can't tell stories about the world and about evolution without agents, intention and purpose. 

So, we just add them. And we use the word evolve to carry these elements. 

The human relationship to change 

The spitting cobra story⁶ above includes all these aspects: an animal (agent) deliberately developing (intention) a new bodily capacity for a specific reason (purpose). Perhaps after a cobra brainstorming session.  

Yes, that sounds silly as well as misrepresenting evolution. But I think these ideas seep into our thinking about the world all the time. 

I've written before about how humans have a need for coherent explanations for the way the world is and why things happen. We look for or make up 'explanatory stories': the gods are angry, so they sent us wild thundery storms; the giraffe needed to reach the high leaves, that's why it grew a long neck; people who work hard can change their lives to create wealth and comfort. 

We need to identify who or what made a change happen, and what motivated them, and sometimes who to blame or who to avoid in the future, in order to feel safe, in control and to make plans. It's just how we are: we have an aversion to random change, to unpredictability, and to things we can't control. 

Our understanding of the world is replete with stories - each with an agent (someone who does it), intention and a purpose or goal. 

So, we impose these elements onto the way we talk about evolution. 

Making evolution make sense (to us!)

When talking about evolutionary theory - a theory about how change happens - we alter the words evolve and evolution to incorporate ideas about change that are important for our comfort. We add storytelling to descriptions of evolutionary change.

In the examples below, pay attention to the way the information is shaped around a being with agency (an individual/species deliberately acting on the world), intention (to meet a need or fix a problem) and purpose (becoming safer, more attractive, stronger, cleverer).  

• "In the Cuban rainforest, vines have evolved leaves shaped like satellite dishes that amplify the signals propagated by echolocating bats to direct them to its flowers, increasing pollination." Source

Such clever little goal-directed vines they are!

• "Dogs only recently developed the ability to raise their eyebrows – a trait likely developed to communicate more effectively with humans. So it seems puppy dog eyes really were “created” just for us." Source

Your dog wanted to be closer to you, so it changed its facial muscles; how sweet!

• Describing the domestication of wild grasses, Harari suggests that wheat had manipulated humans to its own advantage. "If wheat didn’t like stones, humans had to clear them from their fields; if wheat didn’t want to share its space with other plants, people were obliged to labour under the hot sun weeding them out; if wheat craved water, people had to lug it from one place to another, and so on." Source 

From the wonderful SMBC

You really do need to question your life choices if grasses are pushing you around, I think! 

• "However, evolution could be finding a way to curb humanity’s alcohol addiction by creating new variants of ADH [Alcohol DeHydrogenase] that affect our tolerance to booze and our body’s ability to convert acetaldehyde to acetate. Essentially, it means we would feel ill after just a small amount of drink." Source 

Who knew? Evolution is a wowser! 

• Writing about human's large brains: "It could be that our environments were challenging, and we evolved big brains to conquer it. Or it could be that because we survive best as social creatures in groups, we need the big brains for our complicated social lives." Source

"I'm not sure I understand you Fred, just let me evolve a bigger brain!" We need to understand purpose. 

We use the word evolve in sentences and stories that imply that someone/thing (an agent) had an intention to change for a purpose - an active process of evolving. 

Vines aiming to attract bats, dogs seeking effective communication, wheat making humans work, evolution trying to stop you drinking too much. Lots of agency, lots of intention to achieve something, and lots of purpose-driven change. 

All the elements of storytelling.⁷

In defence of Charles

In summary, the way we use the words evolve and evolution reveal our human needs and our assumptions about change. Our use of the words says more about us that it does about the world these words describe. Humans understand the world through stories featuring agency, intention and purpose.

So, it is no surprise that we struggle with the randomness and lack of purpose inherent in evolution. And the complete lack of stories!

Interestingly, Darwin himself didn't call his theory evolution. And he included the word evolved only once in On the origin of species, in the very last word of the very last sentence of the book. Instead, he referred to his ideas as 'descent with modification'. 

Darwin avoided the words evolution and evolving because, in the mid-1800s, the words were already used with a meaning very different from his ideas that random and unpredictable change results in the emergence of new species. 

The integration of the words evolve and evolution (with their loaded meanings) into later interpretations of Darwin's theory is a story of belief and moral judgement.

A story that starts with humans' use of words, of course.

Part 2 continue this evolutionary tale to where it starts to get dangerous.

Footnotes

1. Or more precisely, evolution is 'a theory of change'. When scientists use the word theory, they refer to a group of principles or laws developed over many years through rigorous hypothesis testing. Such theories are backed up with mathematical formulas and lines of evidence that when taken together explain a series of observations. Gravity is a fact because it summarises a number of observations that can be made by anyone. Despite the fact there are different theories explaining gravity (Newton’s law, Einstein’s theory of relativity and more recently, quantum field theory), no-one would say gravity does not exist. So, the word theory doesn't mean that evolution itself is just an idea. It means the purpose of evolution theory is to explain HOW change happens, not why or what those changes will be. 
2. We say mutate because it's a random mistake in the process. But the upshot is that the gene is changed.
3. An individual might change how they act (e.g. hiding from a new type of predator) so they can 'fit' into a new biological niche, but unless this change has an expression at the genetic level it won't be inherited.  We'll get to culture later.
4. 'Fit' refers to 'fitting into' a biological niche that enables the lifeform (animal, plant, fungi) to stay safe while getting enough food to reproduce and pass on its genes. It means 'survival' of the ones that 'fit' the best, or the 'fit-est'. It is not about being match-fit or running faster, fighting harder, competing more ruthlessly. It is also not about being fitter or stronger than other individuals, just about fitting in better than other individuals without the same (changed) genes. More of 'survival of the fittest' later; we misunderstand it about animals, but we are pretty terrible when we apply it to humans.
5. In ecology, a population is a group of organisms of the same species within a particular geographical [contained] area that are capable of interbreeding. 
6. Of course that's the way it's written for the public; I can't be sure who made the story part of it, I'd like to think genuine evolutionary scientists don't talk like that.
7. You might say, sure, but these are examples of media presenting complex research in ways we can understand. But to do so, the writers have to adopt our common use of these words.

Image credits

• Spitting cobra from Snakes are Long  [CC BY-NC-ND]
• Quotes on evolutionary definition and process by the author using text from Wikipedia 
• Cobra meeting screen shot from video from Helicopter_yatra on Instagram  [Public domain]
• Quote from Graeber and Wengrow by the author using text from The Dawn of Everything: A New History of Humanity, Allen Lane, 2021.
• Cranium cartoon from Saturday Morning Breakfast Cartoon [© SMBC]
• Extract from On the origin of species, 1859 version from Darwin Online [Public domain]