Reptile teeth are all the same shape – spiky and great for grabbing and swallowing things whole, but not so good for chewing. Reptiles swallow their food whole.
But not this guy. His teeth are not reptilian, they’re mammalian. Mammalian teeth have different shapes and surfaces, allowing the teeth to tear, crush, and shear… in other words, chew.
Meet Cynognathus, a lovely transitional fossil. Cynognathus is a reptile that lived 230-225 million years ago. This guy and his cousins are called Cynodonts (“dog-toothed”). As a group they are informally known as the “mammal-like reptiles”.
The Fossil Record
The fossil record is unambiguous in two aspects: there is a sequential character to the appearance of life on earth, and newer species are descended from species that preceded them (p. 47).
There is a widely held perception that to believe evolution means to believe that one day a fish gave birth to an amphibian, a reptile gave birth to a mammal, or a cow gave birth to a whale. And of course, a chimpanzee gave birth to a human baby.
But that is to misunderstand the process of evolution, even basic biology. And it is certainly to misunderstand the nature of the fossil record.
Changes from one species to a different species, especially changes across classes or phyla or kingdoms, occur due to accumulated mutations over hundreds of thousands, millions, and billions of years. It is a continuum, not a jump.
So, according to the theory of evolution, what we would expect to see in the fossil record would be transitions, not sudden leaps…and that is exactly what we see.
The earliest recognizable amphibians have many fishy characteristics (gills, skulls). And in between, we find animals “in transition”. The older the rock, the more fish-like and less amphibian-like the animal. The newer the rock, the more amphibian-like and less fish-like. And on it goes…the earliest reptiles had many amphibian features. The earliest mammals were reptile-like mammals (and preceding them were the mammal-like reptiles, like my friend at the museum).
More examples? Land dwelling animals with definite whale characteristics are found in older rocks, but whales in newer and newer rocks show diminishing hind and fore limbs. Modern whales have unused pelvic bones not attached to anything and some even have skeletal rudiments of hind limbs.
We see the same transitional pattern in dinosaurs to birds – oldest fossils are bird-like dinosaurs, newer fossils are reptile-like birds.
Within specific animal groupings we also see transitioning. Nearly 55 million years ago, horses were no larger than house cats. Over the next 30 million years, horses diversified and many species of horses emerged. At one point, there were hundreds of horse species. Today, only one genus of horse remains (Equus) which includes all of the modern species (horses, zebras, donkeys). Three dozen distinct horse genera have lived on earth, but all are extinct except Equus (pp. 47-50).
Similarly, there have been twenty-two distinct elephant species in the last 6 million years. Only two species live today.
Suddenly, or Slow?
Is natural history a record of the sudden emergence of our living world in a single burst of creative energy? (p. 122).
Young Earth Creationism says that is exactly what happened – everything in six days, fully formed.
Intelligent Design says that each species of horse (for example) was designed separately and despite appearances, was not related to the other horse species in history. Intelligent design says that each of the animals in the fish to amphibian transition (as well as all other transitional fossils) were designed separately and were no relation to each other.
Intelligent Design claims that evolution could not be the mechanism for the diversity of life, but Intelligent Design does not pose an alternative mechanism.
Did each of the millions species (both extinct and modern) that lived across millions of years appear suddenly out of nowhere?
Was a newly designed species birthed by an existing species?
Over and over again, the imposition of intelligent design on the facts of natural history requires us to imagine a designer who creates successive forms that mimic evolution (Finding Darwin’s God, Kenneth R. Miller).
The Spark of Life
The natural history of the earth suggests that life unfolded in a process of change and adaptation. The first living organisms appeared about 3.5 billion years ago.
Over billions of years, life changed. Bacteria, insects, plants, animals…species lived, then became extinct. Sometimes the extinctions were dramatically catastrophic, but were then followed by great diversifications.
Life probed, explored, and colonized. Once lit, the spark of life spread everywhere on this great blue planet and has never ceased its endless process of change and adaptation (p. 123).
The reality of natural history is that living things are not one-case-at-a-time design projects.
Life doesn’t resist change but favors it, tolerates it, and channels it into useful variations. Ironically, the design of life is to change its own design (p. 124 – 127).
Americans and Scientific Confidence
Just a few weeks ago, an AP poll summarized Americans’ confidence in various scientific statements. You’ll be glad to know that only four percent of Americans doubt that smoking causes cancer.
Unfortunately, as religious belief rose, confidence fell regarding scientific evidence of evolution, the big bang, and the age of the earth. (An alarming number of Americans also doubt the safety and effectiveness of vaccines – there are definite similarities in the thought processes of anti-evolution folks and anti-vaccinators, but that is a topic for another post!).
It is not surprising that the more religious Americans are, the less they trust science. The originators of the Intelligent Design model very intentionally chose the term “design” for their movement. “Design” implies purpose, order, and meaning (p. 112-113). By contrast, any other explanation (i.e. evolution) is cold, purposeless, and meaningless. Traditional Creationism and its newest incarnation, Intelligent Design, have been tireless in making evolution the enemy of faith.
The good news for those of us who believe both science and God is this:
As it turns out, there really is a design to life, but it’s not the clumsy, interventionist one in which life is an artificial injection into nature, a contradiction of its physical laws. Rather, it is a design in which life emerges from the laws of the universe around us. That conclusion is unavoidable, robust, and scientific. The elegant universe is a universe of life. And the name of the grand design of life is evolution (p.134).
An elegant universe is not the enemy of faith.
Quite the contrary.
This series is a chapter by chapter overview of Kenneth R. Miller’s Only a Theory, with my discussion and commentary.
I believe that the heavens declare the glory of God.
I believe that day after day the cosmos pours forth speech and night after night the cosmos reveals knowledge.
I trust that the evidence and knowledge that is revealed is true because the Creator of the cosmos is Truth.