A common challenge to evolutionary theory is that while life does indeed change over time (what is known as microevolution), no one has ever seen one species evolve into another species (macroevolution).

If the tape was rewound and evolution started over from scratch, Conway Morris says, the evolutionary details would be different, but the end result would be similar: a species characterized by intelligence and complex civilization.

A complex biological structure with many interacting parts might appear, at first glance, as if it were originally created in its present form with all its interlocking components fully formed and intact. It doesn’t seem possible that they developed step by step via biological evolution. In Darwin’s Black Box, Michael Behe introduces a term that he and other proponents of Intelligent Design use for this concept: irreducible complexity.

Evolution is the biological model for the history of life on Earth. While some consider evolution to be equivalent to atheism, BioLogos sees evolution as a description of how God created all life. Evolution refers to descent with modification. Small modifications occur at the genetic level (in DNA) with each generation, and these genetic changes can affect how the creature interacts with its environment. Over time, accumulation of these genetic changes can alter the characteristics of the whole population, and a new species appears. Major changes in life forms take place by the same mechanism but over even longer periods of time. All life today can be traced back to a common ancestor some 3.85 billion years ago.

In this paper, Venema explores several examples in biology where random mutation and natural selection have indeed led to substantial increases in biological information. The question of how new specified information arises in DNA, far from being an “enigma”, is one of great interest to biologists.

A common argument against biological evolution is that the theory contradicts the second law of thermodynamics. The second law says that disorder, or entropy, always increases or stays the same over time. How then can evolution produce more complex life forms over time? The answer is that the second law is only valid in closed systems with no external sources of energy. Since the Earth receives continual energy from the Sun, the second law does not apply.