Human-Chimp Genomes

Elizabeth J. Bruce and Francisco J. Ayala wrote the following in a Nature article in 1978: “We have obtained estimates of genetic differentiation between humans and the great apes no greater than, say, those observed between physically indistinguishable sibling species of fruit flies.” “Humans And Apes Are Genetically Very Similar,”
Nature 276:264, Nov. 16, 1978

Jerry Coyne said in his book Why Evolution is True, “Looking at protein sequences taken from humans and chimps, they found that they differed on average by only about 1 percent. (More recent work hasn’t changed this figure much: the difference has risen to about 1.5 percent.)” (1)

Coyne goes on to explain, however, that this 1.5 percent difference is much more substantial than one might realize. “A 1.5 percent difference in protein sequence means that when we line up the same protein (say, hemoglobin) of humans and chimps, on average we’ll see a difference at just one out of every hundred amino acids. But proteins are typically composed of several hundred amino acids…To use an analogy, if you change only 1 percent of the letters on this page, you will alter far more than 1 percent of the sentences…That oft-quoted 1.5 difference between ourselves and chimps, then, is really larger than it looks; a lot more than 1.5 percent of our proteins will differ by at least one amino acid from the sequence of chimps.” (1)

Coyne then admits: “And molecular evolutionists have recently found that humans and chimps differ not only in the sequence of genes, but also in the presence of genes. More than 6% of genes found in humans simply aren’t found in any form in chimpanzees. There are over fourteen hundred novel genes expressed in humans but not in chimps. We also differ from chimps in the number of copies of many genes that we do share.” (1)

The “one percent myth”:

  • The original claim of 99% similarity was reported in 1975 by Allen Wilson and Mary-Claire King using ‘reassociation kinetics.’ Other studies reported 98.5% similarity.
  • The problem with this number:
    • From Science Daily: “Most of the big differences between human and chimpanzee DNA lie in regions that do not code for genes, according to a new study.” (2)
    • Wesley J. Smith with LifeSiteNews writes, “First, the 98% figure is probably overstated. An article in Science puts the actual figure at 94%. (Jon Cohen, ‘Relative Differences: The Myth of 1%,’ June 29, 2007). But even these figures are only measuring about 2% of our total genetic makeup – that is, those genes that code for proteins, the building blocks of our physical bodies and functions.” He then goes on to say, “Research continues as to the exact nature and functions of non-coding genes, but given the wide differences between human and ape non-coding DNA, even if the purported 98% genetic similarity to coding DNA is true, it is actually only 98% of a much smaller percentage of our total genetic makeup, perhaps as low as 98% of 2%!” (3)
    • David DeWitt with AiG writes: “The >98.5% similarity has been misleading because it depends on what is being compared. There are a number of significant differences that are difficult to quantify. A review by Gagneux and Varki2described a list of genetic differences between humans and the great apes. The differences include ‘cytogenetic differences, differences in the type and number of repetitive genomic DNA and transposable elements, abundance and distribution of endogenous retroviruses, the presence and extent of allelic polymorphisms, specific gene inactivation events, gene sequence differences, gene duplications, single nucleotide polymorphisms, gene expression differences, and messenger RNA splicing variations.” (4)

The latest findings:

  • The number was reduced from 98.5% to 95% by Roy Britten in 2002. (6)(7)
    • Roy Britten is a biologist at the California Institute of Technology.
    • He used a special computer program to compare nearly 780,000 base pairs of the human genome and a similar number from the chimpanzee genome.
    • Caltech Media Relations: “The problem with the old studies is that the methods did not recognize differences due to events of insertion and deletion that result in parts of the DNA being absent from the strands of one or the other species.” (7)
    • From the HumanOrigins website: “Geneticists have come up with a variety of ways of calculating the percentages, which give different impressions about how similar chimpanzees and humans are. The 1.2% chimp-human distinction, for example, involves a measurement of only substitutions in the base building blocks of those genes that chimpanzees and humans share. A comparison of the entire genome, however, indicates that segments of DNA have also been deleted, duplicated over and over, or inserted from one part of the genome into another. When these differences are counted, there is an additional 4 to 5% distinction between the human and chimpanzee genomes.” (8)
    • Todd M. Preuss, a primate evolutionist wrote in a 2012 article Human brain evolution: From gene discovery to phenotype discovery wrote, “One consequence of the numerous duplications, insertions, and deletions, is that the total DNA sequence similarity between humans and chimpanzees is not 98% to 99%, but instead closer to 95% to 96% (41,4849), although the rearrangements are so extensive as to render one-dimensional comparisons overly simplistic.” (9)

Human DNA similarities with other animals:

  • Humans and cats share 90% homologous DNA. (10)
  • Cows are 80% genetically similar to humans. (11)
  • Mice are 75% genetically similar (12)
  • About 60% of chicken genes correspond to a similar human gene. (13)
  • From a 2004 Science Daily article: “About 60 percent of chicken genes correspond to a similar human gene. However, researchers uncovered more small sequence differences between corresponding pairs of chicken and human genes, which are 75 percent identical on average, than between rodent and human gene pairs, which are 88 percent identical on average.” (13)

Conclusion:

  • The original “one percent” difference was based on a comparative analysis of only 2% of DNA. Even this number – although it sounds small – is indicative of MAJOR differences in human and chimp genomes as attested by Jerry Coyne, an evolutionist.
  • Now that more of the genomes have been compared, the number has been reduced to 95%, but even this doesn’t take into consideration the entire genomes.
  • Humans are 90% similar to cats, but we are not closely related to cats!
  • In the end, the similarities between human and chimp DNA can be attributed to common physical appearance and design and do not prove common ancestry.

SOURCES:

(1) Jerry Coyne, Why Evolution is True

(2) http://www.sciencedaily.com/releases/2006/10/061013104633.htm

(3) http://www.lifesitenews.com/news/humans-are-not-98-genetically-identical-to-chimpanzees

(4) https://answersingenesis.org/genetics/dna-similarities/greater-than-98-chimphuman-dna-similarity-not-any-more/

(5) http://www.pnas.org/content/99/21/13633.abstract

(6) http://www.caltech.edu/content/humans-and-chimps-have-95-percent-dna-compatibility-not-985-percent-research-shows

(7) https://answersingenesis.org/answers/research-journal/v6/comprehensive-analysis-of-chimpanzee-and-human-chromosomes/

(8) http://humanorigins.si.edu/evidence/genetics

(9) http://www.pnas.org/content/109/Supplement_1/10709.full

(10) http://genome.cshlp.org/content/17/11/1675.full

(11) http://www.sciencemag.org/content/324/5926/522.full#F1

(12) http://www.plosbiology.org/article/info:doi/10.1371/journal.pbio.1000112

(13) http://www.sciencedaily.com/releases/2004/12/041208230523.htm

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