The craziest thing I learned today is that all living beings on Earth – and I mean all of them – share some of their DNA. It means that even this banana and me have some DNA in common – in fact, we share 20% of our DNA.

How is that possible? Well, we can thank LUCA for that. LUCA stands for Last Universal Common Ancestor. It was some sort of microbe that lived around 4 billion years ago. All living beings today are its descendants, including us – and this banana. How crazy is that?

Questions for Discussion

1. What does it mean for different species to share DNA, and why is it significant that even humans and bananas have DNA in common?
2. If all living beings are descendants of LUCA, how do you think we ended up with such diversity in life forms on Earth?
3. If we share DNA with all living things, should this influence the way we treat other living beings and the environment?
4. We share 99% percent of our DNA with chimpanzees. What conclusions do you draw from that? How does that make you feel?