Natural Selection and Evolution

Size and Age of Universe

Many scientists believe that the vast expanse of the universe and its extreme age offset the poor odds associated with the origin of life, but they never present calculations to support this conclusion. Instead, they assume that it must be true because life exists, and they rely on the naturalistic axiom to support their position. By definition this approach is science. Nevertheless, why not do the calculation?

       For chemical evolution, both the vastness and age of the universe help. For biological evolution only time helps because if life exists on other planets it is extraordinarily rare. Biological evolution also benefits from large populations. This chapter will show that when large populations are given several billion years to evolve, the knowledge that they create is insufficient to explain the origin of many proteins.

        This chapter only considers two cases: 1) The evolution of the very first genes and proteins. These arose shortly after self replication evolved. 2) The evolution of molecules capable of self replication. Thus, the scope of this chapter is limited to the earliest stages of evolution.

Consider a trapped scientist with a 12-word combination. If the scientist enters 12 words every 30 seconds, then he will enter approximately 1 million combinations over the course of a year. If the scientist lives for 5 billion years, and his basket contains 20 blocks labeled with words, then the odds that the scientist will open the door are 6 times in 10 tries. So in this case, time will most likely solve the problem by allowing chance to overcome a step in knowledge. Each word contains 4.32 bits of information (see chapter 1). So the 12 word combination contains 52 bits of knowledge, 12 x 4.32 =52.

       Thus, given 5 billion years and 1 million tries a year chance can probably overcome a 52 bit step in knowledge. The door in figure 15.1 is shown open because the scientist eventually enters the correct combination.

15.1: A Barrier That Chance Can Overcome

Now suppose that the door’s combination is 21 words. This combination contains 21 x 4.32 = 91 bits of knowledge. The odds of opening the door are now 1 in 2.5 x 10²⁷. After 10 billion years with 1 million tries a year, the odds that the scientist will open the door improve to 1 time in 250 billion tries. The door stays shut.

Figure 15.2: A Barrier That Chance Cannot Overcome

Time can be represented as a growing tree (figure 15.3). The tree grows very slowly. After 5 billion years, the tree is almost 52 bits high. This allows the scientist to climb the tree and jump onto the ledge.

Figure 15.3: Time Represented by a Tree

As we will see in the next few sections natural selection plays a huge role in the number of tries that evolution accumulates.

Next: How Does Evolution Accumulate Tries

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