Read the selections from sections three and four of Dawkins and answer the following in 900 words minimum.

 

  1. Why is every living entity on the surface of the Earth, no matter how wildly different they look and act, essentially the same?
  2. What is DNA and what does it do?
  3. If 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?
  4. A 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?
  5. 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 themselves?
  6. What does Dawkins suggest are the values of a simple nervous system?  What are the values of more complex nervous systems, including brains?
  7. Most 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?
  8. What 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 reasoning.

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.