Question

The concept of entropy, and the second law of thermodynamics have often been used ( usually misused in reality) to " explain" all kinds of things. It is frequently up to chemists to set the record straight in such cases. One argument that has been used to "disprove" evolution goes something like this: "Living beings are more complex than nonliving systems. Furthermore, humans are more biologically complex than lower life forms such as monkeys. Entropy is a measure of randomness, the opposite of complexity. The evolution of life from non life, or of a more complex organism from less complex ones must then increase the organizational complexity, and thus decrease the entropy." The second law of thermodynamics tells us that in a spontaneous process the entropy must increase and can never decrease. Therefore spontaneous evolution, either as the ultimate source of life, or or in the development of more complex living systems, is impossible. From the thermodynamic perspective, this statements fatally flawed. A. Explain why it is flawed B. What would a correctly applied entropy argument say about evolution?

Answer 1

evolution happened in open system but second law applied to closed system. so statement is flaw.

The idea of evolution is simply that random genetic mutations which will occasionally occur that lead an individual organism to have some trait that is different from that of its predecessors. Now, it is true that these mutations, being random, would probably tend to increase the "entropy" of the population as a whole if they occurred in isolation (i.e., in a closed system). That is, most of the mutations will create individual organisms that are less "ordered" (i.e., less complex) and only some will create individual organisms that are more complex, so overall, the complexity goes down.

However, evolution does not take place in a closed system, but rather requires the existence of outside forces - i.e., natural selection. The idea is that there can be some environmental effect that makes organisms with a particular mutation (one that makes them more "complex") more likely to survive and pass their genes on to the next generation. Thus, as generations go by, the gene pool of the species can get more and more complex, but notice that this can only occur if the gene pool interacts with the outside world. It is through the course of that interaction that some other form of entropy (or disorder) will be generated that increases the entropy of the universe as a whole.