Most science enthusiasts around the world have probably heard at some point that human and chimp DNA are 98 or 99 percent similar. This includes many people without a biology background, who likely came across this claim through popular articles or videos rather than the original scientific papers.
However, when such statements are made in content meant for the general public, it’s important to provide proper context—specifically, whether the percentage refers only to alignable DNA sequences. I’m quite sure that most people who believe the “98/99% similarity” claim have no idea that a significant portion of the human and chimp genomes can’t even be aligned. How would they know unless it’s clearly explained?
They were misled by popular science communicators who left out key context and presented only part of the truth.
I’m glad this topic is being discussed on platforms like YouTube. Let the public get a fuller understanding of the facts.
Hi Midhun, did you actually read Erika’s full post? You’d see there’s nothing unusual or misleading about the way these numbers are reported, as this is even how geneticists report sequence-similarity measures in papers intended for other geneticists to read. It’s not some sort of nefarious plot to leave out details for laypeople.
Can’t be aligned without introducing gaps in one or both genomes you mean, because they’re simply not the same length. And that the same issue is true for any two arbitrarity picked human beings in the same population (and any two individuals for any species).
Once this context is provided, the idea that anyone has been misled appears to lose all it’s force.
While on that topic, it’s a completely standard measure of similarity even within the primary literature (when scientists write papers for other scientists) to do sequence-identity for equal-length sequences.
Again, did you even read the OP?
If you think they’ve been misled, what is the significance of the similarity in your view? What is the take-home message people are supposed to get from the unequal-length measure, as opposed to the same-length sequence identity measure? What are we to infer from one we can’t do from the other?
I’m glad of that too, but notice that “discussion” is coming entirely from the side of evolutionists, who are presenting all the data, publishing, and explaining how the different measures are arrived at. It is the ID people who hid the data and then lied about it.
Yes, but if you put in all the methods, context, qualifications, and state of research, you go from being the popular article to a scientific survey paper. Those are great, but then you have lost most of your original audience.
Some popularizers do like to play up the awe factor. That said, the 98% similarity, rounding down, is not misleading.
I believe that when a book, article, or video is aimed at the general public, these numbers should be presented with proper context. As I mentioned earlier, I’m pretty sure most people who believe the claim that human and chimp DNA are 98–99% identical don’t know anything about non-alignable DNA or gap divergence.
I don’t see a problem with how scientific papers report these numbers, including the recent nature paper, because they provide the full context.
Whether we’re comparing human to chimp or human to human, the underlying fact stays the same. The popular claim that “human and chimp DNA are 98–99% identical” just isn’t true because it leaves out a crucial detail: it only applies to alignable parts of the genome.
Maybe, maybe not. That’s for the reader to decide. But like I said earlier, that doesn’t change the fact itself. The important thing is to present the fact honestly, without leaving out key context.
My interpretation, your interpretation or anyone else’s — they’re all just ways of understanding a known fact. But what happens if the fact itself is misunderstood? That’s a bigger issue, don’t you think?
Who was responsible for making the 98-99% identity claim popular among the general public without enough context? Was it supporters of ID, or it’s opposers? I’m not blaming the whole evolution community — but definitely some of them.
The popular claim that human and chimp DNA are 98–99% identical is definitely misleading unless it mentions “alignable DNA.” That’s exactly what has happened. As I said before, most people who believe this claim don’t know anything about non-alignable DNA or gap divergence
The sort of public that is having a discussion on YouTube tends to come from places where they are not particularly barred from obtaining a fuller understanding of the facts, at least not by explicit prohibition.
I’m not sure if you read all of Casey’s articles…but many of the quotes he pulls DO specify that they are talking about “genes”, “gene sequence”, and even “sequence identity”. (see the list at the bottom here: “1% Difference” Now Overturned | Evolution News and Science Today )
I do think that science communicators can always be clearer (I have been to the best of my ability by mentioning all the numbers and what they mean) but when half the quotes Luskin or Klinghoffer could find actually do make the distinction… it suggests to me that they don’t actually know the difference (or didn’t at the time).
Personally I’ve almost always seen “96-99%” as the range for humans/chimps. I also think those are the most appropriate numbers to report. I am not comfortable with “85%” for humans/chimps or “87%” for humans/humans because while the former may be a bit off base the latter could be actively dangerous. The fact is the differences in alignment are not, evidently, meaningful in a functional sense but when presented without context could erroneously lead people to think humans can be vastly different from one another…which obviously could be wildly misused.
Luskin’s preferred methods set a perilous precedent.
Even the Smithsonian plaque he was complaining about said “There is only about a 1.2 percent genetic difference between modern humans and chimpanzees throughout much of their genetic code”, and the most objectionable thing about that, to me, is using the phrase “genetic code” to mean “genome”. If we’re actually talking about the “genetic code”, i.e., the translation between codons and amino acids, humans and chimps are identical! But taking the obvious meaning of “much of their genetic code” as “much of their genomes” it’s…pretty much fine.
Also, strictly speaking, the majority of scientists aren’t ID opposers but ID ignorers. So ‘scientists’ would be option 5.
It should be easy enough to find out. Just look for sources that say human and chimp DNA is 98-99% identical, and note their affiliation.
The only ones I can find are from (i) journalists, and (ii) Casey Luskin.
I also noticed that while Luskin refers to claims of “1 percent of DNA”, many of the sources he cites actually refer to ‘gene sequence’, ‘genomic regions’, etc, not to DNA. Nor are any of them scientific studies.
So unless you can find better information, the answer is: