What has caused the diversity of life on this planet?
In most schools nowadays, the standard answer is evolution.
Really? I remember my science teacher said that if a statement is too absolute, it is likely unscientific.
However, if you do an internet search for “evolution,” you won’t find this dissent or any other challenges to the evolution theory in at least the first 12 pages. If you are a student, evolution will be taught to you as a proven theory. If you are a researcher, you know that publishing a study challenging evolution could threaten your career. On Wikipedia, any theories about the origin of life that differ from evolution are labeled as “pseudoscience.”
Evolution is revered as an unquestionable faith, although it’s labeled as a “science” and thus has defeated creationism or intelligent design theory again and again in the Supreme Court.
An Introduction to Evolution and Its Evidence
According to a University of California–Berkeley website, “The central idea of biological evolution is that all life on Earth shares a common ancestor, just as you and your cousins share a common grandmother.”The “common ancestor,” or ”grandmother,” mentioned here is currently considered by some scientists to be a single-celled organism that lived near hydrothermal vents on the ocean floor. From there, the diversity of life is said to have been achieved through random DNA mutations and natural selection. Many mutations are harmful, but some lucky ones might make species better suited for their environment and are thus preserved through reproduction. As this process repeats for billions of years, different species are generated. Humankind was thus formed.
The key terms for the theory of evolution are “common ancestor,” “random DNA mutation,” and “natural selection.”
- one kind of Mexican tetra fish that lost its eyesight and silver color due to living in dark caves;
- bacteria developing resistance to antibiotics;
- moths changing color due to changes in their habitat.
Similarities as Proof of Common Ancestor
One of the main points of the common ancestor argument is the similarities between certain anatomical features, embryos, and molecular mechanisms to be found among all life.Darwin pointed out that the forelimbs of humans and many animals have similar bone structures, although the forelimbs are used for different purposes. Biochemistry has also found that almost all living things share a similar genetic code and mechanisms for transforming energy and building proteins.
However, do similarities definitely indicate a common ancestor?
There is a logical loophole here. It’s true that, if all species were evolved from a common ancestor, they would share some similar structures and mechanisms. However, it is not necessarily true if we say it the other way around: If all species share similar structures and mechanisms, they must be evolved from a common ancestor.
For example, we can say, if James is John’s older brother, James must be older than John. However, the reverse statement isn’t necessarily true: If James is older than John, James must be John’s older brother.
Same idea. If all species share similar structures and mechanisms, they could be evolved from a common ancestor. But there are other possibilities. For example, if all species were designed by a “designer,” they could share similar structures and mechanisms, too. Imagine a fashion designer creating a collection of garments and accessories. All the items in the collection embody the same style and have common technical details.
“Our survey seriously undermines the credibility of Haeckel’s drawings, which depict not a conserved stage for vertebrates, but a stylized amniote embryo. An interesting perspective was provided by Goldschmidt (1956) [in “The Golden Age of Zoology: Portraits from Memory,” by Richard Benedict Goldschmidt] ...
“‘Haeckel’s easy hand at drawing made him improve on nature and put more into the illustrations than he saw. ... One had the impression that he first made a sketch from nature and then drew an ideal picture as he saw it in his mind.’”
What Can and Can’t Be Achieved by DNA Mutation?
Some examples provided in my daughter’s school handout have been found to be caused by DNA mutations, like the eyeless Mexican tetra fish, antibiotic-resistant bacteria, and the moths’ color change. However, despite such mutations, a fish is still a fish, a bacterium is still a bacterium, and a moth is still a moth, just like a person with tattoos or sunglasses is still a person.How far can DNA mutations go? Can they accomplish the jump from one species to another? Dr. Michael Behe, a biochemistry professor at Lehigh University, has written excellent books on this topic.
Behe further explained the science about mutation in plain English. Mutations, or uncorrected mistakes that occur when DNA is copied, are rare. “On average, a mistake is made only once for every hundred million or so nucleotides of DNA copied in a generation,” he wrote. If more mutations need to be made in order to achieve a variation, the chance of getting this variation will decrease exponentially. Imagine, when playing the lottery, the difference in the odds of matching one number versus matching two numbers.
Behe used scientists’ persistent fight with malaria as an example. P. falciparum is a deadly single-cell parasite that causes malaria. Over the decades, various medicines have been developed to kill it. However, the parasite can develop resistance to drugs via amino acid changes resulting from certain DNA mutations. The resistance to the drug atovaquone can be developed within a few weeks, but the resistance to chloroquine was developed much more slowly. It took P. falciparum a few decades to fully defeat chloroquine.
The big difference is caused by the different number of amino acid changes needed to develop resistance. For atovaquone, a single-point mutation (one amino acid change) is needed. For chloroquine, a double-point mutation (two amino acid changes) is required.
Behe concludes: “On average, for humans to achieve a mutation like this by chance, we would need to wait a hundred million times ten million years. Since that is many times the age of the universe, it’s reasonable to conclude the following: No mutation that is of the same complexity as chloroquine resistance in malaria arose by Darwinian evolution in the line leading to humans in the past ten million years.”
Keep in mind that the odds we were discussing are for the chance of only two specific amino acid changes. How many amino acid changes are actually needed to “evolve” to humans from ape-men?
From HIV to the Edge of Evolution
In “The Edge of Evolution,” Behe examined an extreme case, the human immunodeficiency virus (HIV), to explore the edge of evolution. It’s the simplest form of life and can mutate 10,000 times faster than cells.“HIV mutates at the evolutionary speed limit—Darwinian evolution just can’t go any faster,” Behe wrote.
For the malarial organism P. falciparum to achieve a double-point mutation for chloroquine resistance, the odds are only once per year worldwide, but for HIV, it occurs once a day in every AIDS patient. Since it was found in the human body a few decades ago, HIV “has undergone more of at least some kinds of mutations than all cells have experienced since the beginning of the world.”
In other words, like pressing a fast-forward button, what has happened to HIV in the past few decades gives us a glimpse of what could have happened to larger organisms over the past hundreds of millions of years through random mutations.
However, studies have shown that “there have been no significant basic biochemical changes in the [HIV] virus at all” since it was discovered in humans decades ago. Mutating or not, the virus always binds to the same protein in the patient’s immune system. Billions of billions of mutations play the same trick: changing the shape of its proteins so that drugs can’t stick to and destroy the virus.
The study of malarial organisms and E. coli bacteria yielded the same observations.
Behe has confidence that “the results we have in hand for malaria and HIV are broadly representative of what is possible for all organisms” because “to a remarkable degree all of life uses very similar cellular machinery.”
Modern biochemistry has revealed life’s secrets on a molecular level that couldn’t have been imagined by Darwin and his contemporaries. Instead of a “simple little lump of albuminous combination of carbon” as deemed by Haeckel, the cell is a complex and coherent “factory” with intricate structures and amazing coordination among its functional units.
Evolution is said to be the basis of modern biology, but according to Behe, “if you search the scientific literature on evolution, and if you focus your search on the question of how molecular machines—the basis of life—developed, you find an eerie and complete silence.”
“The complexity of life’s foundation has paralyzed science’s attempt to account for it; molecular machines raise an as-yet-impenetrable barrier to Darwinism’s universal reach,” he wrote.
Indeed, if you can’t expect nature to assemble a bunch of parts by itself into a watch, then these “irreducibly complex” systems can’t be achieved without the involvement of intelligence.
As for what evolution can and cannot do, Behe wrote:
“The eminent geneticist François Jacob famously wrote that Darwinian evolution is a ‘tinkerer, not an engineer.’ He’s exactly right. Tinkering means looking for quick fixes, features that work for the moment—incoherent, patchwork change, doctoring machines with chewing gum and duct tape, stopping an invader by burning a bridge or breaking a lock, ‘improving’ a text by typing disjointed changes to words, letters, paragraphs, and chapters. If Darwinism is a tinkerer, then it cannot be expected to produce coherent features where a number of separate parts act together for a clear purpose, involving more than several components.
Fossils: Show or No Show?
Do all fossils support evolution? No.However, not all fossils are treated equally. Those thought to support evolution were promoted without much scrutiny; those contradicting the theory were suppressed and denigrated. Sometimes, fossils were forged or pieced together from different species.
The 1993 book “Forbidden Archeology: The Hidden History of the Human Race” by Michael A. Cremo and Richard L. Thompson gives a meticulous examination of the fossil records for and against human evolution.
Since the 19th century, several fossils have been considered to be the “missing link.” The most famous ones are Lucy in East Africa, Java Man in Indonesia, and Beijing (Peking) Man in China.
The assertive tone of teachers and the vivid skeletal reconstructions in museums have convinced students that the “missing link” has been found. Few, however, realized how fragmented the fossils are and how divided scientists are.
The controversies surrounding Java Man and Beijing Man are also documented in “Forbidden Archeology.” When the Java Man was excavated in the 1890s, only a skull cap, a tooth, and a thigh bone were found. In fact, the thigh bone was found a year later, 45 feet away. The discoverer, Eugène Dubois, believed that these three bones were from a chimpanzee. But after communicating with Haeckel, he was convinced that it was a “missing link.”
In 1895, when Dubois exhibited his findings in Europe, he got mixed feedback from scientific circles. Some supported the “missing link” claim, some thought it was a human, some thought it was an ape, and some doubted whether the thigh bone had any relationship with the skull cap and the tooth. This controversy continued for decades.
In the 1930s, Dutch researcher Gustav Heinrich Ralph von Koenigswald, who continued excavating in Java, got a grant from the Carnegie Institution. According to the book “Forbidden Archeology,” evolution was one of the Carnegie Institution’s most important areas of interest because it was central to influencing philosophy and beliefs of mankind. Von Koenigswald constructed a skull from 30 fragments he had collected and bought from natives, and sent it to Dubois.
By then, Dubois had concluded that Java Man was the remains of a gibbon, a species of ape unrelated to humans. He disapproved of von Koenigswald’s skull and accused him of falsification. However, Dubois’s opinion was no longer taken seriously. With the growing clout of evolution, both Java Man and von Koenigswald’s skull were revered as the forerunners of mankind.
Beijing Man’s excavation in Zhoukoudian, China, in the 1920s was funded by the Rockefeller Foundation. By 1927, with only three teeth found, the discovery of a new human ancestor was announced. Although the declaration was criticized by some scientists because of the lack of evidence, funding for the excavation and promotion continued.
Skulls and other fragments were later found in Zhoukoudian, together with traces of fire use and a collection of stone and bone tools showing a “mastery of rather complex methods of manufacture.” Many scientists doubted that Beijing Man, with such a small brain, could produce the fine tools and make fire. It could be “simply an apelike being who was hunted for food by Homo sapiens [humans].”
Probably all “missing links” were met with great challenges. Some were found to be mistakes or hoaxes. For example, Nebraska Man was considered to be “the first higher primate of North America” based on a single tooth found in Nebraska in 1917. Later, the tooth was proven to belong to an extinct pig.
From a Controversial Hypothesis to an Orthodoxy
The 1989 book “Eugène Dubois and the Ape-Man from Java'' by L.T. Theunissen describes the initial controversies surrounding evolution.Public opinion gradually shifted toward evolution due to relentless promotion. In 1968, the U.S. Supreme Court revoked an Arkansas law that prohibited the teaching of human evolution in public schools. Furthermore, in 1987, the Supreme Court ruled against a Louisiana law that required teaching creationism if human evolution was taught in public schools.
In the end, the hypothesis became orthodoxy. As genetics and biochemistry developed in recent decades, many of Darwin’s original statements didn’t hold up, but the core of his theory—that God or a creator had no role in the origin of mankind—is tightly embraced by many.
A Word for My Children
As I share with my children what I have learned about evolution, I hope they understand that science doesn’t necessarily equal truth. Science is limited. It is supposed to be a sincere pursuit of truth. But now, some aspects of it have degenerated into a servant of political correctness or a weapon of attack on religious beliefs.How much do we humans really know about the vastness of the universe and the wonders of life? Knowledge at the molecular level has already wowed scientists and overturned the perceptions of Darwin and his peers. What would we find if we could somehow observe everything at the atomic level? How can we be so sure that God or other higher beings don’t exist simply because we can’t see them or detect them with current science?
Jean Chen is originally from China and writes under a pen name in order to protect her family still inside China.
