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:
“Evolution is easy” because living organisms come equipped with built-in mechanisms that boost mutation rates, shuffle genes, or transfer DNA – effectively smoothing the path for adaptation. Examples of such mechanisms are SOS response, horizontal gene transfer, stress induced movements of mobile genetic elements, duplications, epigenetic modifications, developmental plasticity, CRISPR-CAS, masking/releasing cryptic genetic variations, genome restructuring during interspecific hybridization, meiotic recombination etc.
I’ve written about these mechanisms in an earlier thread.
What is the creative power of evolution without these built-in mechanisms? Can evolution create so-called complex biological systems such as the flagellum, vertebrate eye, or photosynthetic machinery without these built-in mechanisms? If yes, show the evidence.
I have been asking the above questions since 2023, and no one here has been able to come up with the evidence, so far.
There are many more reasons that evolution is easy. I like your lists of biological phenomena that are relevant to evolution and I applaud your interest in mechanisms that explain the “creative power of evolution.”
You seem to be assuming (or asserting) that those mechanisms are “built-in” (whatever that means) and furthermore that because they are “built-in” that they are somehow different from an explanatory perspective. I don’t care at all about your preference for viewing (say) evolutionary capacitance as something “built-in,” unless you try to claim that those things don’t have natural origins themselves. If you are saying that meiotic recombination is a gift from a god, I won’t tell you you’re wrong. Tell him hi for me.
Organisms don’t “come equipped” with anything as if organisms are lying around on some shelf the organism-manufacturer can decide to sell with or without certain extra features (pay extra for air-condition). They emerge slowly and graduallly from other cells in a process of growth and division.
Do they? Do these mechanisms actually reduce the ruggedness of the fitness landscape, as opposed to simply increasing the probability of mutations capable of crossing valleys (a higher mutation rate increases the probability of multiple mutations simultaneously, which therefore means higher probability of larger jumps)?
Yes and I see you never understood the point about randomness and the blindness of evolution to the future. You seem to have labored under the misapprehension that because certain environmental stressors, for example, can trigger elevated mutation rates, that means the organisms somehow “know” which mutations to induce in response to those environmental stressors, and can therefore knowingly pick out the mutations that are adaptive.
But if you’d read your references you’d have seen that this isn’t true for literally any article you refernece. In ALL cases large numbers of new mutations (be they substitutions, or transposon insertions or translocations) emerge at random in different individuals in the population, the vast majority of them are either deleterious or neutral, and only a few individuals are lucky enough to get a mutation that is adaptive. In other words, it’s textbook Darwinian evolution by mutation and natural selection. The rate of mutation going up and down isn’t changing this, when every new mutation is still the product of random chemistry and the organims suffering it has no idea what it’s effect will be.
So have you learned any of this since your previous thread?
If these built-in mechanisms have role in evolution (as recent data show), then they can easily fit with a design/creation view. Because it obviously supports the idea that organisms are designed to evolve.
You might now argue: couldn’t these built-in mechanisms themselves have arisen through standard darwinian processes (I mean, chance mutations plus fixation)? That’s why I wondered: without these built-in systems, what creative power does evolution really have? Could it have guided a simple self-replicating molecule all the way to the first modern cells?
If you have the time, please read this thread. There, I explain why I believe design is the most reasonable explanation for how the first modern-type cells appeared.
Evolution driven by built-in mechanisms has a clear advantage over evolution without them. I provided reference (see comment 81/145) to support my point, but you dismissed it by calling it “sheer numbers.”
Yes, those numbers point to the fact that one is less probable than the other.
I don’t need to “argue” whether biological systems can arise through known evolutionary processes (your “darwinian” qualifier is inane creationist-speak). There is no reason to separate some things (recombination, epigenetic mechanisms, etc) into a meaningless category called “built-in.” I read your previous comments and they are without merit. You think you are advancing arguments about evolution. You are not. You are confessing beliefs. And that’s just fine with me.
I’m glad you have realized that I was right, and that it’s still textbook evolution that is blind to the future and can’t induce specific adaptive mutations as if knowing beforehand. And that all the “built-in” mechanisms you allude to simply affect the rate of mutation up or down, some times constrained to a smaller locus in a certain cell type, or with biases scattered across the genome.
The rate of mutation is itself evolvable, and we have numerous examples of the rate changing in response to selection. That means the mechanisms themselves are subject to mutation and selection. They are just other adaptations that previously evolved.
It’s not “driven” by them, it’s aided by them. And yes nobody disputes that when there are systems that can increase or decrease the rate of mutation, this can help adaptation under many circumstances. It is an advantage. Agreed. And it can itself respond to selection.
What you call “dismissed” was an actual explanation of what is really going on. Remember that your original case was that organisms could control their own evolution, as if they could somehow intelligently respond to environmental changes and induce the right adaptive mutations. That the mutations weren’t “random” (as in blind to the future needs of the organism), appears to have been your original case.
I explained how this isn’t really what is going on (how they in fact are blind to the future, what is changing is the rate of mutation up or down), and you now appear to have understood why, but you’re somehow still trying to spin this as if you didn’t change your position or come to a new understanding and are still right about your old claim.
And thus you reveal your understanding has changed and updated from previously. Good, this is a good thing. It means you are able to change your mind in light of new information. We should all celebrate that, including you.
When DNA replication occurs, it is not always perfect. Errors occur, which we call “mutations”.
When these mutations occur in an individual organism, they will persist in the population for a greater or lesser period of time, and ultimately either disappear altogether, or become fixed in every member of the population. If the mutation makes it more likely that the organism will reproduce, it is more likely it will be fixed, and the converse is also the case. If it has no significant effect on reproductive success, then whether or not it is fixed will be determined by chance.
I am interpreting your claim that these processes are “built-in” as implying that God had to directly intervene so that these things would occur. That further implies that the natural state of affairs would be something else.
IOW, if God had not “built-in” the mechanism of mutations, then DNA reproduction would be perfect and would occur without ever making an error. Can you explain why you believe a naturally evolving system would be perfect, and only one designed by a god would produce errors? That seems counterintuitive to me.
Similarly, the odds of a mutation becoming fixed in a population seems to be exactly what would be expected if it occurred thru random chance, and without a god or other being influencing the process. Can you clarify what role you think God has played there?
