Read the selections from sections three
and four of Dawkins and answer the following in 900
- Why is
every living entity on the surface of the Earth, no matter how wildly
different they look and act, essentially the same?
is DNA and what does it do?
genes are nothing more than patterns of nucleic acids (C, G, A, and T)
trapped inside cell nuclei, how can they possibly have any influence on
the structure and properties of a Giant Redwood or a Bengal tiger?
fundamental principle of Darwinian evolution is that genes are “selected”
by environmental conditions. But
again, genes are isolated in cell nuclei and never come in physical
contact with the environment of the plant or animal. How can the environment possibly select
between genes it has no direct contact with?
- Genes which drive the rapid reproduction of cancerous tumor
cells seem to be following one of Dawkins’ rules for what makes a
successful replicator (fecundity), but we consider them unhealthy. What makes such genes (sometimes
conceptualized as “rebel genes”) different from the other genes in our cells
which, as Dawkins claims, are also using our bodies to replicate
does Dawkins suggest are the values of a simple nervous system? What are the values of more complex
nervous systems, including brains?
of the genes in the gene pool of homo sapiens
developed millions of years ago; automobiles have only been around for
about a century. If your genes are
completely ignorant of automobiles and yet they constructed you, how can
you possibly know how to operate an automobile?
is Dawkins’ hypothesis about the origin of consciousness?
With these two readings, I hope it is becoming clear how to
answer “why questions” about plants and animals. For example, if I were asked why trees
generally have broad branch structures, I would respond: Trees may have begun
with tight branch structures, but by random chance, in one tree and then its
offspring appeared a gene which altered the developmental process in such a way
as to generate a slightly broader branch structure. This new structure caught more light than the
tighter branch structure of the other trees and so these new trees were more
successful in the competition for light.
More successful trees were healthier and thus capable of reproducing
more, so the broader-structure trees gradually overran the tighter-structure trees
in population. This process repeated
itself until additional broadening was counterproductive, or more expensive in
cost than productive in benefit.
Answer one of the questions below using a similar line of
9. a. Why can cheetahs run fast?
b. Why can
rabbits run fast?
c. Why do
gazelles drink water when dehydrated?
d. Why do
male sea lions seek female sea lions for mating?
It is difficult to overestimate this explanatory power of
Darwinian evolution. Once you learn and
really understand it, you may be amazed how you can walk around and use it to
explain almost everything about every plant and animal you see, even one
particular species of mammal you interact with quite frequently.