Question of the Week: Some critics of Christianity say that microevolution + time = macroevolution. How would you respond?
My Answer: Microevolution refers to changes that occur within a species due to four different natural processes: natural selection, mutations, gene exchange, and epigenetics. Macroevolution refers to the appearance of novel organisms, novel organs, or novel body structures. The claim made by naturalists and atheists is that microevolution, given sufficient time, will produce macroevolutionary events in the history of Earth’s life. Both atheists and theists accept that microevolution occurs through natural processes.
My initial response is that there is nowhere near enough time for macroevolution to occur without divine intervention. The universe is only about 13.8 billion years old and Earth is only 4.5662 billion years old. The claimed equation presumes that natural processes will produce constructive evolutionary outcomes. However, in the case of the chemical evolution necessary for a naturalistic origin of life, destructive outcomes occur about as frequently, or more so, than constructive ones. Furthermore, conditions would need to be kept constant and stable throughout the needed time period, which is not the case. See our books Origins of Life and Improbable Planet for details and documentation.
In the case of biological evolution, there are at least several instances in the fossil record, for example, the Avalon and Cambrian explosions, where the observed macroevolutionary changes occur without any measurable passage of time and later, after the passage of much time, the microevolutionary changes occur. In these instances, the diversification of phyla occurs first and simultaneously. Later, over a long time period, the diversification of species and genera occurs. As paleontologists Douglas Erwin, James Valentine, and John Sekoski wrote in a peer-reviewed paper, “The major pulse of diversification of phyla occurs before that of classes, classes before that of orders, and orders before that of families.”
These fossil record observations are the opposite of what naturalistic evolutionary models would predict but are precisely what one predicts from a biblical theistic perspective. For more, see Improbable Planet plus these articles: Cambrian Explosion Becomes More Explosive; Where Did the Cambrian Oxygen Come From?; and Cambrian Creatures’ Diverse, Complex Eyes Reinforce Creation Narrative.