Posts Tagged ‘developmental biology’
This is the message that developmental biologist Jeff Hardin tries to get across to his students. Hardin constantly sees beauty in his work, so I thought I would spend some time explaining what he does. (Part 1 here, part 2 here, part 3 here.)
One of the best tools for studying development is the tiny roundworm C.elegans, which must be one of the most studied organisms in the world. Adult humans have around 50 trillion cells in their bodies, but human development is so complex and our bodies are so large and vary so much in size, that estimates vary from 10 to 100 trillion. C.elegans, on the other hand, is a relatively simple organism with about 1,000 cells.
One of the most striking (and useful) things about C. elegans is the ‘invariant lineage’ of its cells. As the embryo grows, development proceeds along a minutely prescribed pattern. A cell in the growing embryo replicates its DNA and divides in two. The ‘daughter cell’ will now follow instructions, either keeping the character of its parent or developing a new trait to form part of a different tissue. Each new cell has its fate mapped out in advance, so there is no room for teenage rebellion among the cells of the C. elegans embryo.
The other useful thing about this worm is its complete transparency, which has allowed biologists to trace the lineage of all 959 of its cells*, including the 131 cells that died along the way.
959. The life of a small organism can be completely prescribed: hatch, grow, moult four times, then mate. Most C. elegans adults are hermaphrodites – they make sperm, then switch to making eggs, and fertilise themselves. One could find this cycle depressing, but that’s not the take-home message for Hardin.
Biologists always seem to find their chosen organism beautiful, perhaps because they have come to appreciate its features in great detail. It certainly helps if you find beautiful the thing that you spend most of your days staring at. Being able to understand an organism in such detail is beautiful in itself. And the elegance of an animal that is so tiny and yet so detailed is astonishing. Long gone are the days when cells were thought to be homogenous, gelatinous blobs.
The world we inhabit is highly ordered and that order brings complexity. Creatures in some way make themselves, and reproduction is the best example of our being granted some part in the creative process. Even if we don’t completely understand the details, we get to ‘make’ whole new living things – worms on a Petri dish, geranium cuttings, kittens, children…
* Excluding the gametes, which have variable cell numbers
If you want to know more about C. elegans, you can read to your heart’s content in this online text book, http://www.wormbook.org, to which Jeff Hardin has contributed a chapter on epidermal morphogenesis.
“The first time I peered down a microscope at a living sea urchin embryo when I was a graduate student at Berkeley I was absolutely hooked on developmental biology. Christians, when they’re doing science, are experiencing something that I call ‘doxological fascination’. In other words, they’re locked in on the minute details of something – which academics tend to do – and yet they’re doing it for God’s glory, in the same way that Johann Sebastian Bach wrote SDG (Soli Deo Gloria) in all the margins of his manuscripts. [I know a scientist who writes SDG on all her lecture notes and in her lab book – Ruth]. They’re trying to, in Keplerian fashion, ‘think God’s thoughts after him’.
I teach two main courses, cell biology and developmental biology. In each of these courses I start by telling the students that my main goal for the semester is that they would think cells, or embryos, are cool. They laugh, but I go on with this quote that I love:
The most beautiful experience we can have is the mysterious. It is the fundamental emotion that stands at the cradle of true art and true science. Whoever does not know it and can no longer wonder, no longer marvel, is as good as dead, and his eyes are dimmed.
Albert Einstein, from The World As I See It
I want them to be much better than dead by the end of the semester! My students don’t yet understand how incredible embryos are, and my goal in teaching biology is that they would not be the sort that are sitting around ‘picking blackberries’. I think that this is a new idea to some of my students, and it’s a touch point that I have in common with them, whatever their faith commitments are.
In my introduction to developmental biology I use some ancient Hebrew poetry, from Psalm 139, where David is musing about embryonic development. Even when he was developing in the womb, God was there and David uses poetic language to talk about how his own body was formed. He doesn’t understand that process, but he knows it’s fearful and wonderful. So I tell my students, whether you share David’s worldview – as I as a Christian happen to – or you don’t, by the end of the semester I want you to share this sense of wonder about the incredible intricacy of developmental biology and the processes that we have the privilege of studying. Usually in the teaching evaluations at the end of the semester there are lots of comments saying, ‘Wow, he actually cares about this material’.”
I love this example of someone who is passionate about his work, and who works hard to transmit that passion to his students. I meet so many people who are surprised that a scientist might think in this way – they feel as if science somehow squashes all the life and meaning out of things – so the more people who get to hear stories like this one, the better!
I had the privilege of speaking at Greenbelt this summer, and while I was there I heard Rob Bell speak on the creative process in a talk entitled ‘Pure Undiluted Slog’. His main point was that creativity is primarily about how you see the world. In order to do anything at all creative you need to be able to look at things in a way that is somehow unique and articulate it in a way that people can identify with. He used the example of Moses’ encounter with God in the wilderness of Horeb. If Moses had been trudging around with his head down he wouldn’t have seen the bush that was on fire. If Moses hadn’t been an observant person he would not have noticed that the bush was still intact despite the flames, and God wouldn’t have been able to get his attention in the way that he did. And the bush is always burning – God is always trying to get our attention in some way or another.
I also spent some time this summer in Madison, meeting with a number of scientists (see my earlier post with Kathy Strabala). One of the scientists I met was Professor Jeff Hardin, Chair of Zoology at University of Wisconsin-Madison. Molecular biology and biotechnology have convinced me that science is a creative process, and when I asked Jeff about the part that awe and wonder played in his own work in developmental biology, he came up with exactly the same point as Rob Bell.
Elizabeth Barrett Browning was on to something when she wrote that ‘Earth’s crammed with heaven, And every common bush afire with God; But only he who sees, takes off his shoes, The rest sit round it and pluck blackberries’. Taking time is a fundamental aspect of this. For example, there’s the story of the burning bush in the book of Exodus. Moses takes the time to stop and observe what’s happening. I can’t help thinking whenever I read that story, that if Moses hadn’t really taken the time, if he had been too focused on his agenda (maybe thinking about the next grant application), how would God have grabbed his attention?
Science is a different sort of creative process to writing, sculpture or film-making, but it’s a creative nonetheless, and looking at the world and coming up with original ideas is about the most important aspect of doing science well.