Four Biological Tasks
Anyway, I'm going to try and use some of these differences to illustrate The principles of evolution in terms of plant biology. One of the beauties of being a botanist I suppose, is that regardless of where we are in the evolutionary record, or what part of the planet we happen to be looking at the basic biology of photosynthetic eucaryotes remains constant. This chart shows you the four basic biological tasks that all photosynthetic multi-cellular eucaryotes have to perform.
At the very top of this quartet of biological functions is the capture of
sunlight. In a very crude sense, plants are photovoltaic cells. They
must capture solar radiation to feed the fires of photosynthesis. In
addition, plants whether they're aquatic or terrestrial, have to cope
with mechanical forces. They have to deal with the compressive effects of
gravity.They have to deal with the dynamic motion of water or air. These
are normal aspects of their physical environment. They also are very
good at dealing with the physics and the chemistry of hydraulics. Like
all large organisms, plants have to conduct fluids. They conduct water in
their cells, some times in specialized cells. They conduct nutrients also,
in larger plants typically in highly specialized cells and tissue types.
Lastly, reproductive biology resonates throughout the biological world but
certainly plants have to reproduce. Many of them do so asexually but of
course, sexual reproduction is the principle way in which genetic variance
is introduced into populations. The important message, at least for me,
is that every single one of these biological tasks can be quantified
in extraordinarily rigorous ways with the application of principles and
rules of physics or chemistry .So, it can actually be easy to use plant
biology to get across many of the fundamental aspects of the physical
sciences.
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