Humans and Chimps Share 98% of their DNA?
The idea that human and chimp DNA overlap by 98 to 99 percent has been widely used to promote the idea that humans and chimps shared a common ancestor millions of years ago.[i] But have you considered how they came up with this estimate?
For starters, let’s look at the size of each genome. While estimates of the exact size of our genome has varied over the years, the last count has it at 3.097 billion base pairs. But the chimp genome is larger, at 3.231 billion. This means that chimps have at least 134 million more base pairs than we have. That makes their genome at least 4.3% larger than ours.[ii] So how is it possible that our DNA is 98% similar to theirs, when the chimp genome is actually 4.3% larger than ours? Right out of the gate you can see there’s something wrong with the sweeping 98% estimate that’s frequently used. They came up with this figure by cherry picking only the sections of our DNA that overlapped with theirs.[iii]
Let’s see how MinuteEarth, a secular training site that holds to an evolutionary perspective, describes it:
When researchers sat down to compare the chimp and human genomes, those single-letter differences were easy to tally. But the big mismatched sections weren’t. For example, if a genetic paragraph—thousands of letters long—appears twice in a human scroll, but only once in its chimp counterpart, should the second copy count as thousands of changes, or just one? And what about identical paragraphs that appear in both genomes, but in different places, or in reverse order, or broken up into pieces? Rather than monkey around with these difficult questions, the researchers simply excluded all the large mismatched sections–a whopping 1.3 billion letters of DNA—and performed a letter-by-letter comparison on the remaining 2.4 billion, which turned out to be 98.77% identical. So, yes, we share 99% of our DNA with chimps—if we ignore 18 percent of their genome and 25 percent of ours.[iv]
Wow—ignoring 18% of the chimp genome and 25% of the human genome—that’s a lot to ignore! In fact, this represents hundreds of millions of DNA letters in each side of the comparison! Could the sections they left out be responsible for coding most of the obvious differences we see between humans and chimps? They continue:
And there’s another problem: just as a small tweak to a sentence can alter its meaning entirely or not at all, a few mutations in DNA sometimes produce big changes in a creature’s looks or behavior, whereas other times lots of mutations make very little difference. So just counting up the number of genetic changes doesn’t really tell us that much about how similar or different two creatures are.
It certainly makes sense that “just counting up the number of genetic changes doesn’t really tell us that much about how similar or different two creatures are.” Indeed, human DNA and gene-level comparisons are frequently made to other mammals, such as mice, cows, and even dogs with high levels of overlap, and we are obviously quite different from these animals.
The high degree of similarity is because the human body has many molecular similarities to other living things. After all, they all use the same basic molecules. They share the same water, oxygen, and food sources. Their metabolism and therefore their genetic makeup resemble one another to occupy the same world. However, these similarities do not mean they evolved from a common ancestor any more than all buildings constructed using brick, iron, cement, glass, etc. means that they share origins.
DNA contains much of the information necessary for an organism to develop. If two organisms look similar, we would expect DNA similarity between them. The DNA of a cow and a whale should be more alike than the DNA of a cow and a bacterium. Likewise, humans and apes have many body similarities like bones, hair, and the ability to produce milk, so we would expect DNA sequences to match that. Of all known animals, the great apes are most like humans, so we would expect that their DNA would be most like human DNA.[v]
This is not always the case, though. Some comparisons between human genes and that of other animals in the literature are very interesting. Cats have 90% homologous genes with humans, dogs 82%, cows 80%,[vi] chimpanzees 79%, rats 69%, and mice 67%.[vii] Other comparisons include both fruit fly (Drosophila) and chickens with about 60%[viii] of genes corresponding to a similar human gene.[ix] These estimates suffer from the same problems that human-chimp comparisons do, but they illustrate the patterns of similarity that one would expect from a single divine designer.
Based on new data in 2018, researchers have now shown that the maximum human and chimp DNA similarity is actually only 84%, but this figure didn’t include the areas of human and chimp DNA that could not be matched up because they were so different, so the actual estimate is much lower.[x] This brings us from 98% to 84% maximum similarity between the comparable regions. Using the corrected 84% figure, plus the fact that their genome is over 4% larger than ours, shows there are far too many genetic changes to go from chimp to human in the last six million years at the rate their theory proposes.
This is really the crux of the matter.[xi] Let’s even assume for a minute that the DNA gap between chimps and humans is in fact only 1%. This would still represent over 30 million DNA letter differences between chimps and humans. Can random DNA mutations really produce 30 million meaningful changes to go from chimps to humans within the supposed 6 million-year timeframe? Secular scientists have closed the door on this possibility, even with conclusions drawn from evolution-based publications.
For example, population geneticist, Michael Lynch stated in the Journal of Molecular Biology and Evolution: “A central problem in the evolutionary theory concerns the mechanisms by which adaptations requiring multiple mutations emerge in natural populations.”[xii] Lynch calculated that it would take over 200 million years for just two specific mutations to become established in a pre-human population. That’s over 33 times longer than the supposed 6 million years to develop just two mutations! So, under the evolutionary model, if it takes 200 million years to produce just two mutations, how long would it take to produce 30 million (based on the 1% difference)? Or how about 300 to 400 million (based on the 16% difference figure)? Do you see how absurd this is?
Even though genetic researchers estimate there are about 100 new mutations per person, per generation[xiii] most mutations have a near-neutral effect, and are furthermore slightly deleterious.[xiv] Deleterious mutations randomly occur anywhere in the genome, so creating damage is easy. However, genetic changes that produce improvements are analogous to inserting just the right computer code into just the right place in a computer program for a specific benefit to emerge. It’s next to impossible. Not only does a specific letter need to mutate, it needs to fall into the genetic ladder at a specific location to actually result in some type of benefit. When it comes to how frequently these types of mutations occur compared to the evolutionary timescales, there’s just not enough time for it to happen. If it takes 200 million years for just two to emerge, and at least 300 to 400 million are needed to move from ape-like-creatures to human, one quickly understand that evolution from apes to humans is utterly impossible.
Evolutionary geneticists from Cornell University have confirmed the scientific impossibility of this ape-to-human idea in a study published in the Annals of Applied Probability which revealed the average waiting time to form a slightly longer DNA sequence of only eight specific mutations is about 650 million years.[xv] This estimate gets 100 times longer after accounting for genetic drift, increasing the time to about 65 billion years, which is four times longer than the supposed 13.7 billion years ago that evolutionists believe the universe began. Now it’s impossible again. There is simply no way to go from ape-like-ancestors to humans.
The fact is, the human and chimp genomes code for two completely different creatures. While both are mammals based on scientific criteria, God made man in His image and gave him a soul that is eternal. Human and chimp genomes code for two completely different things: Chimps, which are soul-less tree-dwelling animals; and humans, which are eternal souls wrapped in bodies that have vastly different capabilities than all animals because we were created in God’s image and charged to be caretakers over Creation—including chimps! Being made in the image of God and charged with taking care over God’s Creation would mean that humans would have several distinctions from chimps. Let’s take a look at just some of them.
First, humans are the only living thing on the planet that has a conscience and a sense of morality. Our conscience lets us know when we’ve failed or when we might fail to abide by either governmental laws or God’s laws. Primates know nothing of laws. They live only by instincts and very limited group “norms.”
Next, humans can speak. For example, the English language contains over 1 million words, and we can speak all of them, plus we can even learn or invent totally different languages. Apes cannot speak any of them. They do not even have a speech “program” installed in their brains. The parts of the human brain responsible for handling speech, called the Brodmann areas 44 and 45, are over six times larger in humans compared to chimps.[xvi]
Speaking of brains, ours are 400% larger than chimps. We’re also much smarter—having an average IQ of 100, when chimps can’t even take the test. Our brain cells’ DNA carries very unique methylation patterns that enable us to think the way we do.[xvii] DNA methylation is a biochemical process that helps determine which genes will be more or less active. It occurs during development from an embryo through adulthood. As Institute for Creation Research Science Writer Brian Thomas points out, “If humans and chimps are close relatives, then they should have similar DNA methylation patterns in the areas of chromosomes that they have in common such as similar gene sequences. However, research teams have identified major differences.”[xviii]
The human neocortex is disproportionately large compared to the rest of the brain,[xix] with a 60-to-1 ratio of gray matter to the size of the medulla in our brainstems compared to just 30-to-1 in chimps.[xx] Overall, humans have almost twice as many spindle cells than chimps, enabling us to pull out memories from past experiences and use them to plot our next actions. These functions activate when moral dilemmas present decisions we need to make that will directly affect other lives.
The insula part of our brains has 46 times the number of spindle cells compared to chimps—about 83 thousand for humans compared to only about 18 hundred for chimps. This makes sense because this part of our brains takes information from our skin, internal organs, and cardio system and converts it into subjective feelings such as empathy toward others who show signs of anguish or pain. We are expressive, sensitive, empathetic, and intuitive beings—but not animals.
Our DNA differences direct the construction of uniquely human physical attributes. For example, humans have opposable thumbs that give our hands a nearly infinite variety of motions. We are typically 38% taller than chimps, 80% heavier, and live twice as long. Humans have white sclera that surrounds the colored iris of the eyes for rich and nuanced non-verbal communication, which the vast majority of apes do not have (some apes have a small amount, but none are equal to humans).
We walk upright, while chimps—with their curved fingers, long arms, and unique locking wrist systems—are designed for living in trees and walking on all fours. Their knees also point outward for climbing in trees, whereas our knees point forward so we can walk or run all day if needed.
Humans cannot interbreed with chimps. We can’t even swap any of our internal organs with chimps. Humans build space shuttles, write songs, worship, pray, and sing. Chimps don’t do any of these things. God specially designed us, formed the first of us from dust into the image of God, and gave each of us an everlasting soul. We were charged to be caretakers over the entire animal kingdom; that’s why we put chimps in the zoo, and not the other way around.
Yes, we share vast DNA sequences with chimps, but we would expect this on the basis of Creation. We also share plenty of DNA with mammals other than chimps. After all, God made other mammals and man to metabolize the same food sources, grow the same basic materials like bones, teeth, muscles, skin and hair, and produce placentas and milk for the next generation. The fact that we have sections of DNA that are similar to these creatures’ only shows that our designer used similar DNA instructions for making similar features and functions. It does not mean that one creature led to the other, or that they are related by common ancestors.
Who in their right mind would say that one software program, car, or airplane led to another all by itself? Bible-believing geneticist Dr. Jeffrey Tomkins said, “The programmer doesn’t start from scratch each time he develops a new program. Instead, he uses the same general commands that he used for other projects. It shows the creator’s efficiency and ingenuity.” We see the same pattern of both similarity and differences in organisms’ genomes. Biblical creationists say the similarities in DNA arose because the same Creator adapted the same basic code for separate created kinds. If a gene in different creatures encodes a similar protein for a similar biochemical pathway, it is not due to evolution, but because of a single programmer. This similarity is a hallmark of all human-engineered systems, so why would we not expect to see it in God’s Creation?
Consider a 3-D printer, capable of creating objects of any shape based on the programming code input by the designer. Making even minor changes to the code results in an object that looks very different. It’s the same with the DNA programming our creator used for building humans and chimps. Sections of our DNA building instructions are similar, but this is because the same designer used similar coding for building the physical bodies of humans and chimps that have many similarities, but also many distinctions.
Clearly, overhyped stories of chimp-human similarities overlook some basic observations. They ignore huge sections of DNA. They exclude the possibility of intentional programming to explain similar DNA sequences, and they overlook unbridgeable physical, mental, and moral differences that all fit the Bible’s account of divine Creation.
Confronting Human-Chimp Propaganda
To close this section, let’s discuss a hypothetical exchange. How can you use the information in this section in conversation? First, the person makes the claim that “human and chimp DNA are genetically 98–99% identical or similar.” You can ask, “Do you know roughly how many bases are in the human and chimp genomes?” If they do, great. If not, then offer the fact that the human count is about 3.097 billion base pairs and the chimp count is 3.231 billion. This equates to about 134 million more base pairs than we have, making their genome at least 4.3% larger than ours. So how is it possible to say their genome is 98–99% the same as ours, when their total genome is actually 4.3% larger than ours? Next, you might want to point out that they excluded 25% of the human genetic material and 18% of the chimps when they came up with the 98% similarity figure.[xxi] If chimps and humans are significantly more than 1–2% different, as the data show they are, then there is not enough time in the supposed evolutionary timeline for that many changes to occur. It’s a gap evolution can’t bridge.
[i] Silvertown, Jonathan (ed), 99% Ape: How Evolution Adds Up. University of Chicago Press, 2009: 4.
[ii] Dr. Jeff Tomkins based these figures on the new 2018 PanTro6 build based on the Golden Path Length: Humans (3,096,649,726) and chimps (3,231,170,666) (http://uswest.ensembl.org/Homo_sapiens/Info/Annotation) and Chimps (https://uswest.ensembl.org/Pan_troglodytes/Info/Annotation). This results in Chimps having 134,520,940 more base pairs, or 4.34% larger than humans.
[iii] See Boyko, Adam R. “A Simple Genetic Architecture Underlies Morphological Variation in Dogs.” PLOS Biology (August 10, 2010); Cohen, Jon. “Relative Differences: The Myth of 1%.” Science Vol. 316 no. 5833 (June 29, 2007): 1836; Demuth, Jeffrey P. “The Evolution of Mammalian Gene Families.” PLOS ONE (December 20, 2006); Mahler, Kimberly L. “Sequence divergence of Mus spretus and Mus musculus across a skin cancer susceptibility locus.” BMC Genomics 9 (2008): 626. “The Chimpanzee Sequencing and Analysis Consortium. Initial sequence of the chimpanzee genome and comparison with the human genome.” Nature 437, (September 1, 2005): 69–87.
[vi] Elsik, Christine. et al. “The Genome Sequence of Taurine Cattle: A Window to Ruminant Biology and Evolution.” Science 324: 522–528.
[vii] Pontius, Joan. et al., “Initial Sequence and Comparative Analysis of the Cat Genome.” Genome Research 17 (2007): 1675–1689. See also: www.eupedia.com/forum/threads/25335-Percentage-of-genetic-similarity-between-humans-and-animals.
[ix] NIH/National Human Genome Research Institute. “Researchers Compare Chicken, Human Genomes: Analysis of First Avian Genome Uncovers Differences Between Birds and Mammals.” ScienceDaily (December 10, 2004).
[x] Tomkins, Jeffrey. “Separate Studies Converge on Human-Chimp DNA Dissimilarity.” Acts & Facts 47 (11) (2018); Tomkins, Jeffrey. “Comparison of 18,000 De Novo Assembled Chimpanzee Contigs to the Human Genome Yields Average BLASTN Alignment Identities of 84%.” Answers Research Journal 11 (2018): 205–209.
[xi] We are grateful to Dr. John Sanford for his contributions to the Dismantled movie that led to the development of this section. See also: Sanford, John et al., “The Waiting Time Problem in a Model Hominin Population,” Theoretical Biology and Medical Modelling 12, no. 1 (2015): 18.
[xii] Lynch, M & Abegg, A. “The rate of establishment of complex adaptations.” Mol Biol Evol 27 (6) (2010): 1404–1414.
[xiii] Dolgin, Elie. “Human mutation rate revealed: Next-generation sequencing provides the most accurate estimate to date.” Nature (August 27, 2009).
[xiv] Sanford, John. Genetic Entropy & the Mystery of the Genome. Elim Publishing, 2005.
[xv] Durrett, Richard & Schmidt, Deena. “Waiting for regulatory sequences to appear.” Ann. Appl. Probab 17, no. 1 (2007): 1–32.
[xvi] Schenker, N.M., Hopkins, W.D., Spoctor, M.A. et al. “Broca’s area homologue in chimpanzees (Pan troglodytes): Probabilistic Mapping, Asymmetry, and Comparison to Humans.” Cereb Cortex 20 (2010): 730–742.
[xvii] Zeng, J., et al. “Divergent whole-genome methylation maps of human and chimpanzee brains reveal epigenetic basis of human regulatory evolution.” American Journal of Human Genetics 91, 3 (2012): 455–465.
[xviii] Thomas, Brian, “Stark Differences Between Human and Chimp Brains,” Institute for Creation Research. www.icr.org/article/stark-differences-between-human-chimp/. Accessed September 1, 2015.
[xix] Taylor, Jeremy, Not a Chimp: The Hunt to Find the Genes that Make Us Human. Oxford, UK: Oxford University Press, 2009: 222.
[xx] Semendefer, K., Lu, A., Schenker, N., & Damasio, H., “Humans and Great Apes Share a Large Frontal Cortex,” Nature Neuroscience 5 (3) (2002): 272–6.