Discovering Religion: Episode 13 – Predictive Power of Evolution
Time and time again, the theory of evolution is able to make very specific and accurate predictions about the staggering diversity of life. No other scientific discipline can provide such a cohesive view of the world by answering such a wide variety of questions, ranging anywhere from why we should find the remnants of a pubis and femur in the blue whale to what happened to our missing 48th chromosome. Evolution by natural selection is a grand, unifying theory that encompasses all scientific fields of study and strengthens our collective ability to secure knowledge about the world and accurately interpret the results — an ability that would be undoubtedly much more feeble without the predictive power of evolution.
This is the Comet Orchid, and as you can see, the prominent feature is a very long spur in which its nectar is stored. How might the predictive power of evolution work in the case of this odd variety of flower? We are all familiar with how flowers are used in aiding a plant’s reproductive ability. Over millions of years of evolution, flowers have become specialists at cross pollination by producing enticing fragrances and sweet nectar for members of the animal kingdom to enjoy. As insects and other animals go around collecting the highly valuable source of energy, they unknowingly distribute pollen suck to their bodies to every subsequent flower they visit.
However, it would be wasteful of precious energy for a plant to produce nectar if the animals visiting it’s flowers were not spreading its pollen to other plants with whom it may reproduce. Therefore, in order to guarantee the plant’s gametes are only being spread to members of the same species, refined specializations have evolved that take advantage of certain characteristics of the animals responsible for spreading the flower’s pollen.
This concept is perfectly exemplified in the relationship between the carrion flower and the common housefly. Instead of producing a sweet fragrance to attract bees, this flower mimics the smell of a rotting carcass in order to attract flies. The carrion flower has cornered a niche within the animal kingdom that no other plant as evolved to exploit. Therefore, by using only one variety of animal to spread its pollen the carrion flower is able to ensure the successful propagation of its species.
And this brings us back to the Comet Orchid (Angraecum sesquipedale). A native of Madagascar, this species of flower was sent to Charles Darwin for inspection in 1862. Darwin surmised there must be a pollinator that evolved a proboscis, or tongue, that is long enough to reach the nectar at the end of the orchid’s spur. However, for this prediction to work the pollinator would need a proboscis almost 14 inches long, which at the time was not believed to exist. However, in 1903 a variety Hawk Moth was discovered, that just as Darwin predicted 40 years earlier, had a 14 inch proboscis. A full 21 years after Darwin died his prediction was finally confirmed.
Lets do a little experiment of our own to test predictive capability of Intelligent Design verse Natural Selection. Say we were to compare the complexity of an organ, such as the heart — a structure common to mammals, reptiles, birds, fish, and amphibians. What would be the differences in the type of prediction Intelligent Design and Natural Selection would make based on the explanation each gives for the origin of life?
Evolution tells us first there were fish, next amphibians, then reptiles, and finally came birds and mammals. Therefore, evolution makes a prediction that the complexity of the heart should increase linearly as you move from fish to higher organisms.
On the other hand, the Bible tells us all the animals that both swim and fly first appeared together on the 5th day of creation. Then, on day 6, God created all the animals that walk and crawl upon the ground. These verses suggest whales and birds appeared before terrestrial reptiles, such as the dinosaurs. Therefore, the Biblical prediction might state the complexity of the heart within all animals should be the same, or at the very least, the heart of a reptile is more complex than that of fish, birds and aquatic mammals. Either way, what we should not see is a linear progression in the complexity of the heart that evolution predicts.
And God said, “Let the water teem with living creatures, and let birds fly above the earth across the expanse of the sky.” So God created the great creatures of the sea and every living and moving thing with which the water teems, according to their kinds, and every winged bird according to its kind. And God saw that it was good. Now lets do a structural comparison of the heart found within the following 4 animal categories.
The heart of a fish does not have well defined chambers, with just one auricle and one ventricle leading directly into each other, pumping blood in only one direction. Deoxygenated blood coming from the body enters the heart and is pumped to the gills. As the blood passes through the gills and picks up oxygen from the water, it loses momentum on the return to the body. Therefore, Fish must be in a state of motion in order to effectively maneuver blood through their body, or eventually risk suffocation.
The heart of an amphibian consists of two auricles and one ventricle. However, deoxy blood returning from the body and oxygen rich blood coming from the lungs mix together inside the single ventricle. The mixing of two types of blood is extremely inefficient and amphibians cannot totally rely on their lungs to meet their respiratory needs. As an alternative to breathing, amphibians make use of their moist skin, which functions in gas exchange with the blood.
Reptiles on the other hand have a four chambered heart; however, the ventricles are separated by an incomplete septum. Although there is some mixing of the two types of blood, for the most part, reptiles can solely depend on their hearts to support their respiratory needs.
Finally, all mammals and birds have a four chambered heart in which deoxy and oxygen rich blood do not mix. In fact, in congenital heart disorders, such as a Ventral Septal Defect, the two types of blood are able to mix, resulting in a failure to thrive, congestive heart failure, and eventually the infant’s death if surgery is not performed.
As we can see, there is an obvious ascension of complexity in the structure of the heart, where more advanced hearts are more efficient and less advanced hearts are less efficient. But more importantly, the ascension of complexity within the heart follows the same linear path as the predicted order of animal evolution. Why should we find such inefficient, imperfect anatomical structures within lower life forms if all life was created at the same point in time by a supposedly efficient, perfect creator?
Some apologists might respond to this question by claiming all life was corrupted as punishment for Adam’s original sin. But why then, would humans retain the most efficient hearts if we were the ones responsible for the curse of corruption? Why would God choose to impose up fish, amphibians, and reptiles the sins of a man, with the severity of punishment inversely proportional to the order of anatomical and physiological complexity? That is, fish being less complex and more affected by original sin and humans being more complex but less affected by the original sin. Intelligent Design consistently fails in its account of the Earth’s natural history as well as the biology of all its flora and fauna.
As we have previously examined, evolution makes the predication that Humans and other primates share a common ancestor, and there is a great deal of evidence in support of this claim. So far we have discovered over 20 different species of hominid fossils, which include the key examples of Homo ergaster, Homo erectus, Homo heidelbergensis and Homo Neanderthalensis.
We have also discussed the mapping of the Neanderthal genome, the 96% genetic similarity between humans and chimps, as well as the human Chromosome 2 fusion from primate Chromosome 13. The more we continue to learn about ourselves, the more facts we accumulate in support of Evolution. And even though the theory of evolution contains powerful predictive capabilities, there are certain occurrences within the process of speciation that evolution would not be expected predict, such as the convergent evolution of human and koala skin.
Amazingly, humans and koalas share similar fingerprints that are virtually indistinguishable from one another, even though our evolutionary lineages could not be further apart. Although the theory of evolution might not be expected to predict such a phenomenon, it certainly can explain it, as the natural forces that independently shaped our two evolutions had similar influences when it came to the development of our skin.
However, Creationism has very little or nothing to say about such similarities between unrelated animal species. The beautify of life is nature’s objective, unintentional design, which blindly guides all organisms toward an unknown end, as they traverse the twists and turns on the journey of natural selection.
Evolution’s predictive accuracy is not solely limited to the structural elements of flora and fauna or reconfirming our evolutionary origins. The predictive power of evolution also guides medical research and provides key insight on how to design drugs to fight one of our smallest natural predators, bacteria.