What is artificial selection?

Pollan, M. 2002. Introduction: The Human Bumblebee. pg. xiii-xxv in The Botany of Desire. Random House, New York & Toronto.

Diamond, J. 1999. Chapter 7: How to Make an Almond. pg. 114-130 in Guns, Germs, and Steel: The Fates of Human Societies. W. W. Norton & Company, New York & London.

This question was a minor point in Pollan’s introduction, but is what stuck with me after reading.  What he proposes is that it is becoming increasingly difficult to separate artificial and natural selection because humanity now has such a broad impact on all aspects of life on earth.  We are changing weather patterns, massively altering habitat, making some species astoundingly successful while causing mass extinctions of others, we are even changing the pH of the oceans and altering the amount of UV radiation reaching the planet.  So the point being, we have our fingers in every pot and are mixing, combining, and taking apart every aspect of the ‘natural world’.

If we are doing all of these things, how can we separate a natural evolution of a species compared to one that has been influenced by humanity.  Us changing the climate on planet earth alters all other species that live here, so in a sense one could say that artificial selection now impacts all natural selection.  This was an astounding revelation for me, and while it may or may not be defined as correct, I think that it very accurately shows how interconnected our world is.  Humans are not above nature, humans are nature.

In his introduction I think that this was Pollan’s goal, to deflate humanity’s ego by a small amount.  He describes how we tend to think of ourselves as the subject and of plants as the object.  “I choose the plants, I pull the weeds, I harvest the crops.”  This, while at a basic, technical level is correct, is not the entire truth.  We are a part of the system and we do not always posses the free will that we purport to.  Jared Diamond describes this idea well with his example of berry picking.  As humans we consciously, or subconsciously, choose the biggest, sweetest, and easiest to access berries.  This is in our advantage, but do we really have free choice in the matter?  My answer would be no.  So we are taking part in this system, just as the berry bush is.  We disperse and propagate these certain characteristics and the plant correspondingly is more successful.  Is the plant academically considering its options, weighing the options consciously, and making a decision?  No.  But humans don’t either.  On the surface we appear to and go through the motions, but I would argue that the choice is already present the entire time.

“Evolution doesn’t depend on will or evolution to work; it is, almost by definition, an unconscious, unwilled process.” (Pollan, Introduction, xxi)

I do not think Pollan’s ideas in his introduction will be popular, or even liked to any large degree.  For people who like to think of humans as above nature and apart from it, he proposes a profound interconnectedness.  And for those who are unhappy with the, arguably negative, influence that humanity has had on many species, he essentially steps back and says that successful crop plants have evolved well to work with humans, which in a sense automatically places plants who are not doing well alongside humans as simply being evolutionarily inferior.  If looked at purely from how well different evolutionary traits have worked for species, this is accurate thus far.  If we look to the future though, with possible massive climate change happening in the next few human generations, I think that the diversity of wild plant strains may very well prove to have the upper hand.

In the end, I think that any idea which sparks controversy is worth looking at closer because, whether it is a legitimate idea or not, it helps us consider our own beliefs about what is true in the world and consider why we hold on to these ideas.

“What would biology be without poets?”

Halle, F. 2002. In praise of plants. pg. 41 – 124; pg. 173 – 184. Timber Press, Portland, London.

“What would biology be without poets?” asks Francis Halle, which I think is a key point to this reading.  I think of poetry as taking the everyday and describing it in new ways and with new eyes so as to fully inscribe the meaning that is present all along.  This is vitally important in all aspects of life, particularly when presenting new ideas.  Putting the poetry back into biology allows us as readers to see Halle’s perspective on how we currently look at plants, why we have this perspective, and presents a new viewing model.

One of the most poetic sections is describing the time scale for plants and reflects on the question of whether plants are mobile.  There is an important distinction to make of plants being fixed, but certainly not immobile.  The poetry in this passage comes in changing ones perspective on the time scale in which we are looking.  We judge plants as immobile based on our human concept of time, an action that might be described by anthropologists as being ethnocentric.  This way that we as mobile humans view plants “makes us doubt that they are really alive.”   Halle describes that if we multiply our common time we look at by 100 an increasing number of times we can see the amazing mobility that plants possess.

“Multiply by still another 100, and now a minute of observation covers almost 2 years, Animals have completely disappeared, erased by their mobility.  As for the movement of plants, tey remain fairly calm in the shade of the understory.  This majestic calm is lost in the well-lighted upper strata, where things are more frenetic.  The lianas fight with each other in a sort of fierce swarming  then head toward the open canopy like arrows.  The sudden skyward launching of leader branches of the great emergent trees corresponds to the hasty and inexorable entombment of the supporting trunk under the network of roots of a strangler fig”

Another interesting idea that Halle explores (quite exhaustively) is the distinctive commonality in polarities that exist among most plants, and again among most animals.  Plants have a single polarity and radial symmetry, while animals generally have two polarities and bilateral symmetry.  This essentially means that one can look at a plant from any side along the horizon and it will have horizontal symmetry and vertical polarity, resulting from it being fixed to the ground underneath it.  If looked at from above, this plant will also be symmetrical.  Most animals on the other hand have dual polarity.  The vertical polarity again results from having contact with the substrate, but there is also horizontal polarity due to the forward motion of most animals.

I thought that this discussion on form was very interesting.  Halle made the point near the beginning of the reading that form is often ignored in science because it is qualitative.  I think that this is important to consider not only for the form of plants, but to expand this notion into looking qualitatively in other areas of science.

Overall, In Praise of Plants is an important new perspective on how astounding plants can be, and furthermore promotes looking at them with higher regard.  I thought that one of the sole pitfalls of this work was the manner in which it was written.  It provided long sections which did not seem to be making much of a point, but then periodically it would all be put together.  These moments rewarded the endurance of the reader and put all of the information in context.

This carrot certainly has form!  (Leif Douglass, Sooke British Columbia, Oct. 2009)