Misconceptions about evolution: why transitional fossils exist

Part 3 in a series. Click here for part 2: why humans did not evolve from monkeys.

I can remember the morning I learned one of the most valuable lessons in arguing. My friend and I had been debating for days, and in the minutes before class I thought I had him beaten. As I prepared my final statements, I realized with horror that I had forgotten to define our terms. While my mind had focused on developing the final blows, I had allowed him to tweak our definitions and surreptitiously bring my argument crashing down.

Whale Vestigal Leg Bones Evolution Transitional Fossil True Exist Darwin

The vestigal leg bones in whale and their recent ancestors are prime examples of transitional species and fossils.

This lesson applies to science as well. While doing research or presenting results, a team must carefully define all terms as a foundation for its work. This is also important when addressing critics and naysayers. A prime example of this is the “debate” over transitional fossils. While some claim they do not exist, this argument can often be boiled down to people redefining scientific terms.

Why transitional fossils exist

Among Darwin’s chief concerns when publishing On the Origin of Species was the inadequacy of the fossil record. While his theory proposed a multimillion year process of biological change and adaptation, this necessitated a trove of “transitional fossils.” These fossils would be of so-called “between” organisms, creatures that showed a mixture of primitive and more highly developed traits. For example, since early birds evolved from dinosaurs, there would have to be a dinosaur-like creature with bird-like traits.

Darwin was right to be worried: limited nineteenth-century technology had produced only a small number of fossils, not nearly enough to convince the scientific population of his theory. Furthermore, none of them displayed clear characteristics of these transitional species. Though every organism is technically a transitional species (all species evolve), there were no bird-like dinosaurs or land-adapted sea creatures to be seen.

Archaeopteryx Bird Dinosaur Transitional Fossil Exist Real Darwin Evolution Artists Impression Artist's

An artist’s impression of Archaeopteryx, the famous transitional fossil discovered two years after Darwin published his work. (Image: BBC)

Fortunately for Darwin (and for science), two years later scientists unearthed Archaeopteryx, the first clear transitional fossil. This dinosaur displayed clear bird-like characteristics and served as a perfect example of Darwin’s conjecture. Since then, countless other transitional fossils have been discovered, rendering any related objections moot. Nonetheless, creationist groups today stick to the “there are no transitional fossils” argument like bread on butter.

My explanation for this instance is two-fold. As discussed last time, almost all groups that disparage science have ulterior motives. I suspect that many leaders and demagogues who spread this claim are lying to protect their own interests. My other guess is that this has to do with letting others define our terms. To some, the term transitional fossil likely brings about images of a fish with functioning legs or a dog with flippers (this is not how evolution works). When scientists are not careful about explaining these terms, those who are confused may voice their concerns, which creates a cascade of misinformation.

Note that all fossils are transitional, as all species are always evolving. There are currently catalogs upon catalogs of transitional fossils–if there’s one thing we know about them, it is that they exist. Next time you hear someone claim scientists haven’t found any, be sure to hand him a volume about evolution and transitional fossils.

Have you ever encountered this assertion? I’d be fascinated to hear who was saying it and why. Leave your thoughts in the comments below! As always, please like, share, or reblog this post if you enjoy it. That small click really helps me out! Be sure to check me out on Twitter and Facebook as well. Thanks for reading! Don’t forget to subscribe for new content every Wednesday! IT’S FREE!

Other related articles:

Bill Nye: Creationism is Not Appropriate for Children (Big Think)

Inside the Mind of a Creationist (Huffington Post)

Fossils Reveal Truth About Darwin’s Theory (LiveScience)

Misconceptions About Evolution: Why Species, Not Individuals, Evolve

Misconceptions About Evolution: Why Humans Did Not Evolve From Monkeys

Comment question of the week

Why do you think people claim there are no transitional fossils? You’ve read my thoughts–now I want to hear yours.


3 thoughts on “Misconceptions about evolution: why transitional fossils exist

  1. I’m currently reading Origin Of Species and in it darwin talks about the existence of intermediate forms being often found in the fossil record, archeopteryx was not the first transitional form ever found. It may have been the first ever predicted using his theory though, which is important. When scientists talk about how poor the fossil record is they mean given the hundreds of millions of species that have walked the earth. The implication that there are no well preserved lines or intermediates because of these statements is like someone saying that our lack of knowledge of most of the lost soldiers of the US civil war proves the war never took place. It would be simple to find historians waxing philosophical about how history is pieced together by the scantest of clues and try to use a series of such quotes to, for instance, deny the holocaust. But that would be bullshit.

    • Yes, agnophilo, well said. Thanks for the insight on the fossil record and Darwin’s writings. I love the civil war analogy–it perfectly illustrates how absurd it is to use the imperfection of the fossil record to contest evolution. I think I will weave that into future posts (with due credit, of course). Are there any aspects of On the Origin of Species that have surprised you? I’m always interested in hearing other’s thoughts on it. I find it fascinating how much Darwin’s conjectures differ from our understanding of evolution today. Thanks for the comment!

      • I actually am surprised at the reverse – how often he is addressing objections that are still repeated today. Several times while reading it I wished I had bought it rather than gotten it from the library so I could highlight select passages to just quote them in response to creationists. Then again this is a late edition so it was modified with those objections in mind. I was also surprised that darwin had done experiments to test aspects of his theory, rather than relying solely on fossil record predictions. For instance natural selection required most offspring not to survive to reproduce, so he planted plants in his garden and counted carefully the number of seeds they produced and kept track of how many flowered (a tiny percentage).

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