Friday, August 13, 2010

A dandelion's life

Here's a question I would love to pose to my sophomores:

Is the spark of life in humans more valuable than the spark of life in a dandelion?

I am not asking which organism is more valuable, more productive, more useful, or more sacred....though you might be surprised at how I answer those.

Is the flame of life, whatever that happens to be, identical for humans and dandelions?


Life, once gone, is gone for good. A chain that extends back more than 3 billion years, millions upon millions of millions of generations, has broken. The flame of life within you, that is you, has been lit since before the dinosaurs, before life came onto land, before oxygen filled the air.

Like fire, you can pass your life onto new creatures, who can spread the flame further and further again and again long after you have gone.

If you go back far enough, you and the dandelion sitting in your yard come from a common ancestral species. Everything alive comes from prior organisms that were alive. You and the dandelion are related. Literally.

Like fire, so long as even a small flame exists, it can spread, and remain the same fire, even as the original source of the flames is snuffed out. We deify the Olympic flame for a reason.


Witnessing the death of a human under your hands is rarely clean. Death happens in errant steps, but the final break is startling. I have seen more than my share fair of human deaths, and every one of them startled me. I have lost a few close people. Each death changes me. One nearly destroyed me.

Still, I think nothing of digging up a dandelion and tossing it in the compost bin.

Is there anything substantially different between the flame of the dandelion and the flame within me?

What's the point of the exercise, why should I use it for class?

We are studying biology, we are studying life, we are studying something that gets to the core of our existence. My lambs are at a wonderful age--young adolescents start to question pretty much everything as their bodies betray childhood.

Just about all of my students (and the rest of us as well) see life as discrete units--organisms. We grieve when we grieve because we lose organisms we love, not because the universe suddenly has a smidgeon less living mass.

The spark of life of my parents, dead as both are, still exists in me and my siblings. In me and my cousins. In me and all the descendants of those lives that first arose from the soup that existed when tides were violent and the Earth still quite warm.

The spark of life that was in my parents came from the same source that spark the dandelion.

We are all cousins.

Eye rolls:
OK, enough philosophy crap, Dr. D, what does this have to do with anything?
And will it be on the test?

We teach children that the DNA of the bacteria in their poop codes exactly the same way ours does. Indeed, human insulin today come from engineered E. coli. Yes, that E. coli.

We share many proteins with plants, coded with similar sequences of DNA, because we come from the same ancestors.

This is a big deal if you take time to think about it. We rarely take the time, because, well, the state test is coming, we still have to cover a few dozen more standards.

Still, if I can get the kids to see, really see, life as a messy web with all kinds of tentacles emerging from some common events a long time ago, then maybe, just maybe, I can get them to see plants as alive us we are.

If they get that, then evolution becomes interesting.

If a student passes the state exam without knowing that, then the state exam isn't worth the student's time.

OK, a few things:

Yes, I am aware that the Hadean period may have been a
lot cooler than earlier believed, the sun's output lower, etc.--
here's a nice summary of recent thinking on that from the New York Times.

No, we do not share 50% of our DNA with bananas--another topic for another day.

The dandelion is from Wikimedia, by Loyna

Vats of human insulin lifted from Scott's Web Log: January 2008. Credit attached.


Anonymous said...

I love this post. I wish I could take your biology class. I've been spending a lot of time this summer, for the first time, thinking of plants as ancestors and what I can learn from them. Shut up. Sit still. Be present.

The Science Goddess said...

If you really want to mess with their heads, ask them how old they are. Given that all cells come from pre-existing cells---are your sophomores really 15 years old?

doyle said...

Dear mrcmyoung,

Thanks for the warm words--I just saw your blog today. Well worth a visit!

Dear The Science Goddess,

Ah, I will! I love messing with their heads!

Anonymous said...

While the cells that make up our students might be younger than they are, the atoms that make up those cells are waaaaaaaaaaaaaay older than our solar system. So are the kids 15 years old, much younger, and billions of years old simultaneously? Whoa...

doyle said...

Dear fnoschese,

It's so wild!

One of my best class moments ever was when a student grabbed his head and barked at me to stop, I was making him think too much....