The conventional evolutionary argument is overrated by evolutionists themselves
A new report, which was published in the Materials of the National Academy of Sciences, suggests that the generally accepted value of> 98% similarity between chimpanzee and human DNA is incorrect. Roy Britten, the author of the study, cited a figure of about 95%, taking into account insertions (insertions) and deletions (erasure / loss of a chromosome or chromatid portion). The important thing is that these studies mean a lot more than people realize.
A similarity of> 98.5% is incorrect, as this similarity depends on what the scientists were comparing to derive that percentage. There are many significant differences that are difficult to assess. A review by Ganex and Varki listed genetic differences between humans and great apes. These differences include “cytogenetic differences, differences in the type and amount of repetitive genomic DNA and moving genetic elements, content and localization of endogenous retroviruses, presence and size of allelic polymorphisms, cases of inactivation of specific genes, differences in gene sequence, gene duplication, single nucleotide polymorphisms, differences in gene expression, and changes in messenger RNA splicing”.
The following are some examples of these differences:
1. Humans have 23 pairs of chromosomes, while chimpanzees have 24. Evolutionary scientists believe that one of the human chromosomes was formed from the fusion of two small chimpanzee chromosomes, rather than an inherent difference arising from a separate act of creation.
2. At the end of each chromosome is a repeating strand of DNA called a telomere. Chimpanzees and other primates have about 23 kbp. (1 kb is equal to 1000 nucleic acid heterocyclic base pairs) repeating elements. Humans are unique among all primates, their telomeres are much shorter: only 10 kb in length. (kilobases).
3. While the 18 pairs of chromosomes are “nearly identical,” chromosomes 4, 9, and 12 indicate that they have been “remade”. In other words, the genes and marker genes on these chromosomes in humans and chimpanzees are not in the same order. It is more logical to think that this inherent difference is due to the fact that they were created separately, and were not "remade" as evolutionists claim.
4. Chromosome Y (sex chromosome) is particularly different in size and has many marker genes that do not match (when lined up) in humans and chimpanzees.
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5. Scientists have prepared a comparative genetic map of the chromosome of chimpanzees and humans, in particular the 21st chromosome. They observed "large, non-random patches of difference between two genomes." They found a number of sites that "could correspond to insertions that are specific to the hereditary human lineage."
6. The chimpanzee genome is 10% larger than the human genome.
These kinds of differences are usually not counted when calculating DNA percent similarity.
In one of the most extensive studies comparing human and chimpanzee DNA, researchers compared over 19.8 million bases. Despite the fact that this number seems large, it is less than 1% of the genome. They calculated an average identity of 98.77% or 1.23% difference. However, this study, like others, took only substitutions into account and did not account for insertions or deletions, as was done in Britten's new study. A nucleotide substitution is a mutation where one base (A, G, C, or T) is replaced with another. Insertions or deletions are found where nucleotides are missing when comparing two sequences.
Comparison between base substitution and insertion / deletion. You can compare two DNA sequences. If there is a difference in nucleotides (A instead of G), then it is a substitution. Conversely, if the stem is missing, then it is considered to be an insertion / deletion. It is assumed that the nucleotide was inserted in one of the sequences, or it was deleted from another sequence. It is very often difficult to determine whether the difference is due to an insertion or due to a deletion. In fact, the inserts can be of any length.
Britten's study looked at 779 kilobases of nucleic acids in order to carefully examine the differences between chimpanzees and humans. Britten found that 1.4% of the bases were swapped, which was consistent with previous studies (98.6% similarity). However, he found many more inserts. Most of them were only 1 to 4 nucleotides long, while at the same time there were several nucleotides, the length of which was more than 1000 base pairs. Thus, insertions and deletions added 3.4% additional differing base pairs.
Whereas previous research has focused on base substitution, it has overlooked the largest contribution to genetic differences between humans and chimpanzees. The missing nucleotides from a human or chimpanzee appear to be twice the number of nucleotides replaced. Although the number of substitutions is approximately ten times greater than the number of insertions, the number of nucleotides involved in insertions and deletions is much larger. It was noted that these inserts are present in the same amount in the human and chimpanzee sequences. Therefore, insertions or deletions have occurred not only in chimpanzees or only in humans, and can be interpreted as an intrinsic difference.
Will evolution be questioned now that the similarity in chimpanzee and human DNA has dropped from> 98.5% to ~ 95%? Probably not. Regardless of whether the similarity drops even below 90%, evolutionists will still believe that humans and apes descended from a common ancestor. Moreover, the use of percentages hides a very important fact. If 5% of the DNA differs, then this corresponds to 150,000,000 DNA base pairs, which are different from each other!
A number of studies have shown significant similarities between nuclear DNA and mitochondrial DNA in modern humans. In fact, the DNA sequences of all humans are so similar that scientists tend to conclude that there is "a recent common origin for all modern humans, with a common replacement for old populations." In all fairness, evolutionists' calculations of the origin of the "most recent common ancestor" (SOCA), that is, "recent single origin", led to the number 100,000-200,000 years ago, which is not recent by the standards of creationists. These calculations were based on comparison with chimpanzees and the assumption that the common ancestor of chimpanzees and humans appeared approximately 5 million years ago. But studies that used comparisons of a certain generation and genealogical comparisons of metachondrial DNA,pointed to the origin of the even more recent SNOP - 6,500 years!
Examination of observed mutations over a single generation points to a more recent common ancestor of humans than phylogenetic calculations suggesting a link between humans and chimpanzees. Mutation regions are thought to be responsible for the differences between these classes. However, in both cases, they rely on uniformitarian principles, namely that present percentages can be used to extrapolate the time of events into the distant past.
The above examples demonstrate that the conclusions of scientific research can vary depending on how the research is conducted. Humans and chimpanzees can have 95% or> 98.5% similarity in DNA, depending on which nucleotides are counted and which are excluded. Modern humans may have a single recent ancestor <10,000 years ago or 100,000-200,000 years ago, depending on whether a chimpanzee relationship is contemplated and what kinds of mutations are considered.
David DeWitt
