Today’s New Reason To Believe

Posted by Fazale ‘Fuz’ Rana, Ph.D.

Newly Discovered Example of Convergence Challenges Biological Evolution

Lately, my wife has had trouble hanging onto cell phones. Within the span of two weeks she lost not one cell phone, but two.

But my wife is not the only one who has lost the same thing over and over again. Recently, evolutionary biologists have discovered that birds lost the ability to fly on several separate occasions.

According to new research each time birds lost the ability to fly, the outcome was virtually identical. This remarkable result makes little sense within an evolutionary framework, raising significant questions about the validity of the naturalistic explanation for life’s history and diversity.

Evolutionary biologists have long had interest in understanding the origin of a group of flightless birds known as ratites. This group consists of birds like ostriches, emus, kiwis, rheas, cassowaries, and the extinct moas and elephant birds.

According to the standard evolutionary fare the ratites had a single origin, with all of them descending from a common flightless ancestor. The basis for this view stems from the fact that they all share common behavioral traits and anatomical features like the absence of keels in breast bones, smaller, simpler, and fewer wing bones, bigger leg bones, and non-aerodynamic feathers.

One nagging problem with this evolutionary model is the biogeographical distribution of the flightless birds. They are found all over the world, with ostriches in Africa, rheas in South America, emus and cassowaries in Australia and New Guinea, kiwis and moas in New Zealand, and elephant birds in Madagascar. One way that evolutionary biologists account for this pattern is by appealing to continental drift. Accordingly, the common ancestor of the flightless birds supposedly emerged before continental breakup. Then as the different lineages formed they became separated and distributed around the world as landmasses drifted apart.

As appealing as this explanation appears to be, it doesn’t quite mesh with other evolutionary studies that estimate the emergence of the various lineages of flightless birds to have occurred at times that don’t correspond to the breakup of the continental landmasses.

A new study helps resolve this problem, but in turn creates other more significant issues for the evolutionary explanation of flightless birds and the evolutionary paradigm in general.

As part of this study, scientists used 20 different regions of nuclear DNA taken from 18 different bird taxa to build an evolutionary tree for ratites. It turns out that they identified not one but three distinct lineages for the ratites. The lineages include: one for ostriches; one for rheas; and one for kiwis, emus, and cassowaries. In other words, flight was lost on three separate occasions in ratites, not once.

This result nicely accounts for the biogeographical distribution of ratites. Loss of flight occurring at separate times is not that hard to envision. What is difficult to fathom is how independent instances of loss of flight would yield practically the same behavior and anatomical adaptations. This makes little sense within the evolutionary framework because evolution shouldn’t repeat.

As the late evolutionary biologist Stephen Jay Gould highlighted in his book Wonderful Life, if one were to push the rewind button, erase life’s history, and let the tape run again, the results would be completely different each time.

The very essence of the evolutionary process renders evolutionary outcomes non-repeatable. According to the concept of historical contingency, chance governs biological and biochemical evolution at its most fundamental level. Evolutionary pathways consist of a historical sequence of chance genetic changes operated on by natural selection, which also consists of chance components. As a consequence, if evolutionary events could be repeated, the outcome would be dramatically different every time. The inability of evolutionary processes to retrace the same path makes it highly unlikely that the same biological and biochemical designs should appear repeatedly throughout nature among unrelated organisms.

Contrary to what’s expected, evolutionary biologists note that “biological convergence” is widespread. This term refers to the widespread pattern in nature in which unrelated organisms possess nearly identical anatomical, physiological, behavioral, and biochemical characteristics. (Go here, here, and here for some recent articles I wrote on biological convergence.) The loss of flight in the ratites, on three separate occasions, adds one more example of biological convergence to an already lengthy list.

by Jeffrey Zweerink

From a biblical perspective, the advent of continents plays a critical role in God’s transformation of Earth from “formless and void” to an environment teeming with diverse life-forms. In fact, the formation of continents warrants mention as one of the miracles performed on the third day of creation. The formation and motion of continents plays an important role in the history and development of Earth’s habitability from a scientific perspective as well.

A recent discovery provides further evidence that the Earth's continents have moved and changed dramatically over time. Around one billion years ago, the bulk of the continental landmass was clumped together into a supercontinent called Rodinia. Around 800 million years ago, Rodinia began to break up, causing Earth to plunge into the Cryogenian period. During this period, glaciers covered nearly the whole Earth numerous times in events called "snowball Earths".

Shortly (on geological timescales) after the end of the Cyrogenian era, diverse, complex organisms explosively appeared on Earth. The Avalon explosion and the Cambrian explosion represent two such events. Some scientists argue that the change in Earth’s surface that occurred during the Cyrogenian played a critical role in the subsequent introduction of diverse life. Many of these changes resulted from the breakup of the Rodinia supercontinent.

In typical models for Rodinia’s topography as shown above, the North American continent (referred to as Laurentia) sits next to East Antarctica. After the breakup of Rodinia, the continents drifted apart and back together a couple of times until they ended up in their current configuration. Recent finds in Antarctica support this model by demonstrating that rocks unique to North America also exist in Antarctica. Three lines of evidence point to a juxtaposition of East Antarctica with North America:

1. Geological: similar strata found in both locations
2. Dating: zircons in the rock formations of both continents date to the same age
3. Isotopic: the chemical composition of the granites in both locations match

For most of Earth’s history, only single-celled organisms lived. Yet shortly after the tumultuous Cyrogenian era, an abundance of advanced, multicellular organisms quickly appeared on Earth. The breakup of supercontinents led to dramatic changes on Earth’s surface and, in the case of the Rodinia breakup, led to environments where more-advanced life could not only survive, but flourish. Such results fit comfortably in a model where a supernatural Designer is transforming an otherwise desolate planet into an environment suitable for advanced life, particularly humans.

Kenneth Richard Samples

What can Christian apologists do to represent the arguments of others with fairness and intellectual integrity?

This series has focused upon the need to apply the biblical principle of the Golden Rule to the enterprise of Christian apologetics. In Matthew 7:12, Jesus states this critical moral maxim as follows:

So in everything, do to others what you would have them do to you, for this sums up the Law and the Prophets.

Since the Golden Rule applies to all endeavors in life, as believers we should strive to treat the viewpoints of others with care and evenhandedness. We certainly want to be treated that way.

Six Practices for Apologetic Fairness

In part five of this series, I began a list of practices that an apologist can implement to ensure a respectful critique of the opposition’s perspective. Here are the two points covered last time:

1. Identify Central Tenets of a Belief System.

2. Affirm Positive Features of a Belief System.

Now let’s examine two more points in this article.

3. Quote the Most Authoritative Sources.

Since I appreciate it when critics of my faith quote the best and most authoritative sources when examining historic Christianity, I owe them the same in return. It is important for Christian apologists to study the belief system in question so well as to know its most respected sources.

When critiquing naturalism in my book A World of Difference, I used quotes from well-respected philosophical sources that were fair in their basic, though critical, assessment. I also resourced respected texts written by naturalists themselves for explaining and defending their worldview. The point here is to refer to quality sources that represent the critiqued position in an objective and fair fashion.

4. Give the Critiqued Belief System the Benefit of the Doubt.

When examining the positions of others, read their views in the best light possible. For example, if a weak version of an argument is given, explain that there is a stronger version to that same argument and then proceed to critique the stronger position.

When I examine the theological positions of other Christian traditions, I make it a point to give some grace to my Christian brothers and sisters and frame their position in the most positive and charitable way possible. I like to think of myself as a “charitable Calvinist.” Treating the views of others with fairness and respect gives evidence of true intellectual integrity. God’s servants should perform the apologetic task with the goal of prizing truth and respecting people.

The last article in this series will conclude my discussion of the “Six Practices for Apologetic Fairness.”

For more on building intellectual virtue in the area of apologetics, see chapters 3 - 4 of my book A World of Difference: Putting Christian Truth-Claims to the Worldview Test.