The earth is full of your creatures. There is the sea, vast and spacious, teeming with creatures beyond number —living things both large and small. (Psalm 104:24–25)
This passage implies that God packs Earth with as much life as physically possible. Psalm 104:29–30 goes on to say that though all life dies off, God re-creates new life, renewing the face of the earth.
Research has shown that mass extinction events followed by mass speciation events, similar to the scenarios described in Psalm 104, are crucial for maximizing both the quantity and longevity of Earth’s life. By ensuring that the right quantities and kinds of life are present at the right times, a Creator can use those organisms to remove the just-right quantities of greenhouse gases from Earth’s atmosphere. So as the Sun brightens, the atmosphere’s capacity to trap heat decreases by the just-right amount. Thus, from a creation model perspective, one would expect God to intervene periodically to remove life no longer appropriate for compensating for a brightening Sun and then replace it with life that is.
In 2007, astronomer Gennady Kochemasov showed that Earth resides in a planetary system with unique asteroid and comet belts and that Earth has the best possible orbit in the solar system to receive the frequency and kind of asteroid and comet collisions needed to cause the required mass extinction events.1 However, if the extinctions were totally random, then the planet would not contain such rich, diverse reservoirs of biodeposits available for humans. And worse, the atmosphere’s heat-trapping capacity could get so out of sync with the Sun’s luminosity as to permanently sterilize Earth.
The nonrandom nature of mass extinction events was first noted in 1984.2 In 2010, University of Kansas astronomers found a 27-million-year periodicity (cycle) over the last 500 million years, meaning that such episodes appear to occur about every 27 million years.3 In 2012, however, geologists published a comprehensive revision of the geological time scale.4 Consequently, the Kansas astronomers performed a reanalysis to determine if their claimed periodicity would survive.5 Not only did it survive, but also the statistical significance of the periodicity actually improved.
The research team concluded that mass extinction events exhibit a “highly regular period” and a “relatively narrow bandwidth.”6 We at Reasons to Believe note that such features are consistent with Psalm 104’s depiction of God frequently intervening in life’s history to ensure that humans have the best possible environments and biological resources to fulfill the purpose for which God created us.