EVOLUTION EXPLAINED TO A CHILD

I often get asked by some parents how best they could teach their children the theory of evolution. The first step to teaching any theory, of course, is to understand it enough to do so. So it is important for parents to take some time to actually study the theory and understand it properly. However, in this article, I have constructed a little chit-chat between a dad and his daughter in which he attempts to explain the theory to her in as simple a way as possible. Parents may need to use pictures and other forms of visual aid and may consider purchasing resources that help their children learn about it in a fun and informative way.

 

Daughter: Hey, daddy.

Dad: Hellooo, beautiful! How was school today?

Daughter: Not bad. Just a bunch of new stuff in elementary science and math.

Dad: Tell me about it.

Daughter: Well, my teacher said something about how humans came to be. She said that science teaches that humans came from chimpanzees.

Dad: Oh, really? Is that what she said?

Daughter: Sort of. She also told us that she's a Christian and thinks that God created us in his image, so she doesn't accept the idea that we came from chimpanzees.

Dad: Well, the truth is, we do not come from chimpanzees. At least that's not what science says. We and chimpanzees come from another species. We call that species our common ancestor.

Daughter: What's an ancestor?

Dad: An ancestor is like a great-great-grandparent that died a long time ago, so long that we can't remember them. But we know they lived because they gave birth to those who gave birth to us.

Daughter: Okay.

Dad: Think of it this way. You know your uncle, Tunde? He's Sola's dad.

Daughter: Yes. I miss Sola, daddy.

Dad: Don't worry. You'll spend the next holiday with her.

Daughter: Yaaaay!

Dad: Now, back to Sola's dad. He's my brother, and so he and I have the same dad. Sola is your cousin, and so you and Sola have the same granddad. When you have children and Sola does too, both your children will have the same great granddad. That great grandad, to both your children, will be a common ancestor.

Daughter: Okay dad, I think I get this. But my great grandad is a human being, not another species. How is it possible that another species can give rise to a human being?

Dad: Great question! Now you'll need to pay close attention here because this is the tricky part. Your uncle Tunde is my brother, and because of that, we look very much alike. But you also notice that he and I are not identical. He is taller and fairer than I am, but my fingers are slightly longer than his.

Daughter: That's true.

Dad: Good! Even though we both came from the same parents, we are not identical. And that's because there are some things in my body that make me different from him. They're called genes.

Daughter: What's a gene?

Dad: A gene is a part of something called DNA in my body. My genes tell my body what to do. For example, my genes tell my body to make longer fingers, and they tell your uncle's body to make fair skin and long bones, which give him a tall look.

Daughter: Okay, but what does that have to do with another species giving birth to human beings?

Dad: We'll get there soon, honey. So here's the thing—when the cells that formed me were being formed in my mum's and dad's bodies, something happened in there. The genes that led to the cells that made me were slightly changed. This happens for everybody when they are still in their parents' bodies. Scientists call this change mutation.

Daughter: Okay.

Dad: So, in every generation—your uncle and I are in a generation, and you and Sola are in another generation—genes are changed (mutation) for each person before they are formed in the womb. And these changes are why we all do not look the same—except for Taye and Kehinde in your class, who are identical twins.

Daughter: Okay, dad. Are we there yet?

Dad: Patience, darling, we're getting closer. Now, let's pretend that we were living in the jungle 20 million years ago and we were seeing ancient species that led to us. They will also have a lot of children who have different mutations. Some mutations will make some of the children (scientists call them 'offspring') able to live longer and have their own children in that environment. Some mutations will reduce some children's chances to live long and have their own children in that same environment.

Daughter: How does that work?

Dad: I'll use an example. Imagine that, in that environment, an animal with brown fur will have a better chance of living longer (maybe because brown fur helped it to avoid lions that want to kill it) but white fur makes an animal more likely to live a shorter life (maybe because white fur helped lions to see white animals and kill them more).

Daughter: That sounds bad!

Dad: Yes, honey. Some people call it 'the survival of the fittest'. Scientists call this process 'natural selection'. They call it that name because it acts as if nature selects the animals in a species with brown fur in that environment, since they have mutations that help them to live longer and have more children. The opposite is, unfortunately, true for the animals with white fur.

Daughter: Okay, dad.

Dad: But if this keeps happening for a long, long time—millions of years, for example—the species with brown fur will get plenty other mutations that will make it look very different from what it originally looked like. These mutations can change what it likes to eat, where it prefers to live, the shape of its nose and ears, the way it stands and walks, lots and lots of things. And when these changes are plenty enough, the species will look so different from what it originally looked like, such that if it wants to have children with an organism with its original look, it will not be able to give birth to the right kind of children who can have their own children. When this happens, we say that the organism has become a new species. Scientists call this process speciation.

Daughter: Oh, okay. So that means it is this speciation that made our common ancestor give birth to humans?

Dad: Well, you're getting close, honey. Because of how slow and gradual the process is—remember, it can take millions of years sometimes—the common ancestor itself did not give birth to humans. The change happened veeeeery slooooowly!! Just like my dad gave birth to me but I look different from him, and even more different from my grandfather, and even more different from my great grandfather, and even more different from my great-great-grandfather, we also look different from that older common ancestor.

Daughter: Okay. But if it takes millions of years for this to happen, how do we know that it did?

Dad: We know that we and chimpanzees come from a common ancestor for several reasons. These reasons count as evidence of it. For instance, just like your uncle Tunde and I have similar features despite not being identical, we and chimpanzees have lots of similar features that scientists think are best understood as having come from the same ancestor. They call them homologous features. 

Daughter: What could those be?

Dad: Your thumb, for instance. They are called opposable thumbs because they can separate from the rest of the fingers in another direction. This helps humans and chimpanzees to grip things firmly. Opposable thumbs were useful for the common ancestor because they enabled it to climb trees.

Daughter: Okay, dad. But are we still evolving?

Dad: Yes, humans as a species are still evolving. Every time a new child is born, a new set of genetic changes is added to the gene pool, which means the total quantity and frequency of genes in the population changes. The gene pool is the total collection of genes in all the people in a population. When the gene pool of a population changes, evolution technically happens.

Daughter: So what are we evolving into?

Dad: Evolution is a rather blind natural process, dear. We are not evolving into anything specifically. You see, the earlier apes did not really plan to evolve into humans. Evolution just follows the pattern of mutation, selection and speciation. Those mutations happen randomly, and any species that gets a beneficial mutation tends to survive and make it to the future. So there is no end goal. Lions are not trying to become tigers, and humans are not trying to become something higher.

Daughter: But why are there still chimpanzees?

Dad: Well, honey, that's because chimpanzees are successful until now in their own environment. This means that chimpanzees have all the mutations that let them live long enough to keep surviving and having children. But if there is a change in their environment that makes surviving long enough to have children difficult (scientists call such change evolutionary pressures), then chimpanzees will either have to gain new mutations that help them survive in that environment or they will all die. Scientists call the death of every member of a species extinction.

Daughter: Okay, daddy.

Dad: Any more questions, smartypants?

Daughter: One more, dad. If evolution is true, why does the Bible say that God created us from dust?

Dad: You know, honey, different books and cultures have different opinions about how humans came about. The part of the Bible that says that was written many millennia ago and those people did not know about evolution, just like everyone else who tried to explain how humans came to be with the level of knowledge they had in their timings and placements in history. Science has given us a definitive answer about where humans come from, and because there are many ways that we know that the scientific theory is right, it's preferable for us to follow its evidence. But people can accept the scientific theory of evolution as true and still have their religion. 

Daughter: I like evidence, daddy. It lets us know what is true.

Dad: That's right, honey. And if you learn a lot in school and think carefully about nature, maybe someday you'll find revolutionary evidence for a scientific theory. You'll be a great scientist, like Marie Curie and Mary Schweitzer!

Daughter: I like the sound of that. Thank you, daddy. 😊