This is not something I would normally blog about as it’s outside my bailiwick but it’s a question that I’ve been asked so many times recently, I thought I would provide a response. The question is, “if we evolved from monkeys, why are there still monkeys?”
The question comes from a Biblical perspective and so I will say up front that I do not intend to get into issues of religious faith here. My intension is to merely give an answer to the question on the basis of evolutionary theory. I’m honestly not trying to provide “atheist propaganda” I am merely attempting to clarify what the theory of evolution actually says and then you can make up your own mind from there.
The short answer is that we didn’t evolve from monkeys but I’ll expand on my answer by taking the analogy of linguistic evolution. (Not my original idea and so I’m not taking credit for it). Remember this is an analogy and so it’s not meant to be taken to extreme lengths. It’s merely being used as a method of explanation.
Just over 2,000 years ago the official language of the Roman Empire was Latin. Whether they spoke Latin in the same way scholars of Latin might speak it today is open to question. No one alive today was around during the time of ancient Rome, they didn’t have any sound-recording in those days and so no one has actually heard the way it was spoken. There is evidence that this language was spoken in ancient Rome because we have examples of their writing. But writing does not tell us about pronunciation, which would have undoubtedly been influenced by other languages of the time, such as ancient Greek.
As with any language, changes occurred over time. The ancient Romans did not travel to the same extent as we do today and so pockets of local dialect arose. No doubt, colloquial terminology and slang words developed and so the language slowly changed over time. From one generation to the next, the differences would not be as great so they could not understand each other, but these small step-wise changes accumulated over time. Over many years, Latin started to diverge and today we see two main derivative languages, Spanish and Italian. The two languages share many common words but generally it’s not possible for a Spanish speaker to hold an intelligible conversation with an Italian speaker. And yet both Italian and Spanish evolved from a common language - Latin.
Like Spanish and Italian, humans and the apes of today share a common ancestor. The human ancestor lived sometime in the Miocene period but is now long extinct. Humans, other species of apes and monkeys share common genes, in the same way Spanish and Italian share common words. The science of genetics and DNA analysis in particular allows us to track back that speciation over geologic time. The theory of evolution does not say that a gorilla in the zoo will give birth to a human, or indeed a cat will give birth to a dog. It does not predict that there should be intermediate forms between cats and dogs in the fossil record. That would be like asking for a hybrid Spanish-Italian language called Spanian. If an explorer came across a lost tribe speaking Spanian, then this would seriously question the theory that they were both derived from Latin. Likewise an intermediate cat-dog fossil (or a crocoduck) would be a big problem for the theory of evolution.
Those small changes in language from one generation to the next would be like what creationists call microevolution. The Spanish spoken in Spain today for example, is somewhat different to that spoken in South America. The two languages are similar enough so speakers can understand each other but there are a number of examples where the languages have diverged enough so misunderstandings can arise. The same situation is likely to have arisen with Latin and over many generations, microevolution became macroevolution and so Spanish and Italian became their own separate languages. At no point did a Latin speaker suddenly give birth to a Spanish or Italian speaker. The languages evolved by small almost imperceptible steps over many generations. If you accept microevolution but not macroevolution then you have to ask yourself, what mechanism is stopping those small changes accumulating over time in respect to the evolution of language or species.
Whilst language evolved over a few thousand years the evolution of species takes many millions. The average human lifetime is just 0.007% of a million years and so it’s not possible to observe the evolution of one species to another. But, as I said, it’s also not possible to observe the evolution of one language to the next and no one has actually heard the Latin of ancient Rome.
Of course many creationists believe the Universe was created less than 10,000 years ago. I am not going to comment on this as, I have said, my intention here is just to clarify what the theory of evolution says. It is certainly the case that many millions of years are required for evolution to produce the vast number of species seen on Earth today. The age of the Universe, as is the origins of life itself, is another topic.
Whilst on the analogy of language, the other assertion that often comes up is that there are no intermediate fossil forms between one species and another. There are actually many. Just a quick Google search came up with the University of California, Berkley and the Smithsonian but there seems to be an expectation that transitional forms between every generation must be produced as proof of biological evolution. This would be like trying to produce recordings of every generation from Latin to Italian in order to accept Italian was derived from its Latin ancestor. By not having this, would you deny Italian came from Latin?
I hope this explains why there are still apes and monkeys around today and why no one would expect a change in species over one generation. I understand that a fundamentalist Biblical perspective might lead to a rejection of the theory of evolution but if it’s going to be challenged then at least the basic constructs should be understood first. Now I have explained the principle, the answer to the question, “why are there still monkeys” is “because the presence of humans and monkeys together today is entirely consistent with the theory of evolution”.