Darwin, Experimentalist

Feb 12 2009 Published by under Biology

I am amusing myself with several little experiments; I have now got a little weed garden & am marking each seedling as it appears, to see at what time of life they suffer most.--

Charles Darwin

Letter to Joseph Hooker

21 March 1857

A few years ago, I was talking with one of my professors. We'd recently been at a seminar where a National Academy of Sciences member had presented some research. The research in question drew a number of good conclusions about the role of seawater chemistry on the history of life using an experimental setup that featured plastic cups arranged on cafeteria trays. The professor commented that the ability to design a "dinky little experiment" that could shed real light on enormously broad questions was the mark of the truly great scientists.

Over the summer, that comment popped back into my mind as I stood looking at a tiny patch of fenced-off ground in the middle of a bit of lawn.


I was on the grounds of Down House, looking at a recreation of Charles Darwin's weed garden. It's a small (six square foot) patch of ground. Darwin cleared the ground down to the dirt, watched, and waited. The ground was recolonized by weeds, each of which he marked and observed.

Seedlings, also, are destroyed in vast numbers by various enemies; for instance, on a piece of ground three feet long and two wide, dug and cleared, and where there could be no choking from other plants, I marked all the seedling of our native weeds as they came up, and out of the 357 no less than 295 were destroyed, chiefly by slugs and insects.

C. Darwin

On the Origin of Species

It's hard to imagine a dinkier experiment. One small, cleared patch of ground in the middle of the lawn, observed on a daily basis over a period of several months. But the conclusions from this experiment - particularly when combined with quite a few other dinky little data sets - are very revealing: many more organisms are born than survive to reproduce.

4 responses so far

  • MAL says:

    Oh heavens, do skim through The Formation of Vegetable Mould if you haven't already (I think Project Gutenberg has a free digital version online). Imagine Charles Darwin, with the help of his children, testing earthworm hearing with a piano, a bassoon, a whistle, and shouting. Or seeing if worms feel vibrations when placed on top of a piano and striking different notes. Testing their sense of smell by breathing on them (plain breath, after chewing tobacco, and while chewing cotton doused in perfume or vinegar). I laughed out loud at that bit. He and his kids dug holes at famous archaeological sites (including Stonehenge!) to determine how rapidly earthworms excavate and rebury. Years and years of fiddly little experiments all adding up over time - "It may be doubted whether there are many other animals which have played so important a part in the history of the world, as have these lowly organized creatures."

  • Mike Dunford says:

    At the moment, I'm actually about 75 pages into the worm book. I was hoping to have it done today, but it'll probably be another day or two before I'm done with it.

  • Crudely Wrott says:

    Darwin's hearty and persistent curiosity about living things reminds me of a gentle anecdote from childhood.
    One spring, while the family was busy spading up the garden, and collecting worms for the summer's fishing, my preschool brother approached my mother with a worm in his hands, alternately examining its two ends. Still caught up in his inspection he asked, "Mama, do worms have faces?"
    It's not the question that matters so much as the chain of thought it causes. In Darwin's case, well, you know. In my brother's case? He has been enjoying a rewarding career as a teacher who is known by his students as fully in favor of the odd question.
    Oh, Ma's answer to my brother's question is lost to memory amid the recall of sweet laughter and renewed vigor in applying the spade. I also recall that fishing was very good that year. I can only imagine that her reply was kind and probably suggested further research.

  • Jim Thomerson says:

    Many years ago, I visited with one of the professors at Tulane. He remarked that he wanted to see if he could publish research which could have been done by the Ancient Greeks. Yes, he did.