The theory of evolution since Charles Darwin’s ”On The Origins Of Species” (1859) has always been controversial. And the very unique fact that it somehow defied creationism made it even more difficult to grasp. People who went (and who are still going) against it saw it as evil and manipulative rather than a scientific innovation.
But the main problem is that our brains can only tolerate miniscule amounts of time compared to the millions, or even billions of years, such as the 4.54 billion years (age of the earth) or 542 million years (Ediacaran extinction). Hence, it is much easier for humans to believe that the earth is just a few thousand years, rather than billions of years and that evolution simply never happened.
Is there evidence for an old earth?
First, in order for evolution to be true, we need an enormous amount of time. Otherwise, evolution cannot occur. On earth, for instance, it began 3.4 billion years ago with prokaryote organisms. Some people (Those who believe in early creationism) still have serious doubts about it, and that seems quite bizarre since there is massive evidence that points towards an old earth rather than the 6000 year old earth.
Paleontologists, Geologists as well as other scientists who work in that field, use various dating methods such as Uranium-Lead, Rubidium-Strontium or Potassium-Argon. And the beautiful thing about it is that all of these methods wonderfully fit together, giving us the same kind of results. Besides, even without using these methods, one can easily notice the immensity of geologic time scale by looking at the Alps, the Himalayas or the Andes. In fact, it takes millions of years for mountains to reach such heights. The Himalayas, for example, were formed after the collision between both Indian and Eurasian plates, some 45-50 million years ago. And we can still observe the mountains growing more than 1 cm per year, which totally supports the age attributed to that mountain range (And that’s just a single example among hundreds). Now what about the oldest whale fossils that were found in the Himalayas (the Himalayacetus subathuensis) ? What does that mean? Did they fly to get over there? It simply means they were transported with the mountain chain, millions of years ago.
Is there enough evidence to support evolution?
All these testable arguments undoubtedly indicate that the earth was created billions of years ago. When tolerating this idea, which after all, is a fact, evolution seems much more logical and true. Now what is evolution? It’s a theory that was proposed by Charles Darwin back in the 19th century and it states that species change and evolve with time due to gene mutations. The transition from fish to amphibians, that occured during the Devonian period (around 370 million years ago) is a good example of evolution. Do we have enough evidence to support that argument? over the years, paleontologists found numerous transitional fossils of organisms such as Panderichthys or Tiktaalik roseae. We now know that those species came between fish and tetrapods, which allows us to clearly visualize the passage from a specie to another. The same observations can be found in fossils of Archeopteryx or Sinosauropteryx that also show the clear transition from feathered dinosaurs to modern birds. Do we expect to find every single transitional fossil? surely not, since very few species are fossilized and preserved (compared to the uncountable number of organisms that walked the earth). But in any case, these remaining fossils are sufficient enough to support evolution.
Beside fossils, the study of DNA is an extremely robust way to confirm evolution. By comparing the genomes of animals, scientists found similarities between different species. For example we, humans, share 96 to 98 % of our DNA sequence with bonobos and chimpanzees, 90% with cats, 75% with mice. That means that we, homo sapiens, share with pan troglodytes (chimpanzees), a relatively close common ancestor, but a more distant common ancestor with cats, and so forth. And after comparing the genomes of all different groups of animals, we get a phylogenetic tree which gives us the degree of relationship among all species, just like a family tree that does the same thing with family members. But the interesting part is that both fossil records and phylogenetic tree work harmoniously, with no contradiction.
There are also other types of observations that validate evolution as in the case of the geographical distribution of fossils (fossils of closely related organisms are always located near one another as expected by Darwin’s theory) or even modern examples of evolution, namely the Italian wall lizards that evolved in less than 35 years: the lizards were introduced in 1971 in Pod Mrcaru, a croatian island, and few decades later, scientists went back to the island to study their descendants and realized they had literally evolved. In fact, the ”new” lizards had a new gut structure, bigger and longer skulls, as well as stronger bites. Of course, scientists didn’t expect to see the Italian wall lizards evolving into a new specie, but for such a short period of time, the results magnificently show that evolution works.
All of these arguments lead us to Darwin’s theory. For many people, including scientists, it should be considered as a fact while other people keep rejecting it no matter how strong the arguments are. Maybe evolution is contentious and polemical because it disagrees with some beliefs, but in the end, there are many adherents to certain faiths, who accept evolution as a fact at the same time, just like some previous popes or archbishops did.