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Every few years, as already mentioned, El Niño affects the western regions of North and South America in particular, and at such times, high levels of rain fall on the Galapagos, leading to increased plant growth and an abundance of seeds. Ground finches are therefore easily able to find the food they need, and their numbers accordingly increase after such rainy periods.
Grant and his colleagues witnessed a similar situation in 1982-83. With the rains, seeds became plentiful, and the average beak size of ground finches returned to the pre-1977 drought levels. This greatly surprised the observers, who were expecting a continuing "evolution" in beak size.
The change in Galapagos finches' average beak size actually has a different explanation: In years of drought when seeds are scarce, birds with beak a slightly larger than normal can open the remaining hard, large seeds with their more powerful beaks. Weaker individuals in the finch population, with smaller beaks, die off since they are unable to adapt to the prevailing conditions. And thus, the average beak size increases. In rainy periods, on the other hand, when there is an abundance of small, soft seeds, the process works in the opposite direction: Ground finches with smaller beaks can better adapt to their environment, and their numbers increase. Thus the average beak size returns to normal. In fact, Peter Grant and his student Lisle Gibbs admitted as much in an article published in Nature magazine in 1987.236
In short, facts clearly reveal no such thing as evolutionary change. Average beak size may fluctuate according to the rainfall, sometimes increasing or decreasing around a fixed level, but there is no question of a net change.
Aware of this, Peter Grant said that, "the population, subjected to natural selection, is oscillating back and forth."237 Some evolutionist researchers say that natural selection works in two mutually opposed directions.238
No matter how much a clock pendulum may swing back and forth, it never records any net progress. That will still apply if you operate a pendulum perfectly for millions of years.
Danny Faulkner, a professor of Astronomy and Physics at South Carolina University, states that the finch beaks' fluctuations cannot represent evidence of evolution:
"And so if you have supposed microevolution one direction and then later it reverts right back to where it started from, that's not evolution, it can't be."239
The average size of the Galapagos finches' beaks increases or decreases according to food resources, but the way that evolutionist researchers imagine they have found evidence for evolution in fluctuations in the finches' beak is completely ideologically based.
References
- Lisle Gibbs, Peter Grant, "Oscillating Selection on Darwin's Finches," Nature, Vol. 327, 1987, pp. 511-513. ↩
- Peter R. Grant, "Natural Selection and Darwin's Finches," Scientific American, pp. 82-87. ↩
- Jonathan Weiner, Op. cit., pp. 104-105. ↩
- Gailon Totheroh, "Evolution Outdated," 2001, http://www.cbn.com/spirituallife/ChurchAndMinistry/Evangelism/Evolution_Outdated.aspx ↩