Are We Really 99% Similar to Chimps?
Posted: Thu Jan 10, 2019 12:58 am
Here is a popular myth I looked into a while back:
Since 2003, false claims by evolutionary biologists started cropping up in the popular media stating that the human genome and chimp genome are 99% identical, thus proving evolution. This falsely implied that a COMPLETE genome of both was compared. This is a false claim on so many levels:
1) Back in 2003, there was no complete genome mapping of a human (that happened in 2005 and was not complete - only the protein-coding sequences). At that time we did not have a complete genome mapping of a chimp, therefore, a complete comparison between the two is impossible at that time. Since we only mapped the protein-coding sequences of humans and chimps, there is no real 100% comparison.
2) What was actually compared was ONLY the protein-coding sequences - which make up less than 5% of the total genome. Some studies show it to be as low as 1% of the total genome.
3) The comparison studies used mathematical algorythms rather than a direct genome-to-genome comparison which is considered too laborious at this time of technology.
4) The algorythms have been constantly improved and tweaked since the initial studies to more accurately reflect a real comparison. The 99% has slowly decreased in value. The 99% was initially downgraded to 98%, then 96%, then 85%, and the most current studies show 70% similarity.
5) The initial studies back in 2003 also claimed that the genome of humans and bananas had a 50% similarity. This credulously implied that we, as humans, are 50% banana! Undoubtedly, this 50% number is also too high. Nonetheless, evolutionary biologists with PhDs were quick to jump on the bandwagen and started telling the public that we were actually one-half of a banana! So much for academic intellectualism.
Nonetheless, the question is: Why should humans have any genomic similarity with bananas and chimps? This is why:
1) If we have no genomic similarity with bananas, we cannot assimilate (eat and digest) bananas. We must have at least SOME genomic similarity with the things we eat, otherwise we would starve.
2) All life on Earth is based on the same carbon/nitrogen/water-based system so we should expect some similarity since we share the same planet and foods. This should only make sense to any biologist.
3) Also, the chimp genome is 15% shorter overall than the human genome, according to the tables supplied by the 2005 study.
The human genome is about 3.2 Gb. and the chimp genome size used in the 2005 study was about 2.7 Gb. This is a difference of about 15%.
With this 15% difference in genome size, how do we still get a 99% similarity?
Let's first look at the size/length of the human genome:
"The human genome contains 3164.7 (3.1 Gb) million chemical nucleotide bases (A, C, T, and G)." (Human Genome News, 2001)
"The human genome is 3.3 Gb in length." (Integrated DNA Technologies, 2011)
So the human genome size is about 3.1 to 3.3 Giga base pairs.
Unfortunately, the chimp genome size they used in this 2005 comparison study was much smaller at 2.7 Gb. This is a size difference of about 15% in comparison to the 3.2 Gb human genome.
By size comparison, the chimp genome size used by the study is about 85% of the size of the human genome (2.7Gb/3.2Gb) = .85 or 85%.
Question #2: What about the remaining 15% of human genome? What was it compared to?
The only way to "perfectly align" both genomes, there would be a left-over of human genome of 15% since it is 15% larger. And with this 15% leftover of the human genome, this is still called a 99% similarity?
So the question is, how does the smaller chimp genome - which is only about 85% of the human genome in size - exactly align to a much larger human genome?
How exact is the alignment between two genomes separated by (3.2Gb - 2.7Gb) = 500,000 bp or 15 %? The chimp genome and human genome were supposedly 99% similar BUT they differ in total length by 15%!
If one genome is 15% shorter, how do they "align" by 99% except by some 'fudging' with the sequences and 'expanding' one genome to 'fit' and "exactly align' with the other by introducing 'gaps' to artificially lengthen the shorter genome to match the longer one?
To make the deception worse, the total Gb of supposedly perfectly aligned chimp DNA was only 88% or 2.4Gb. This 2.4 Gb represents only 75% of the 3.2 Gb human genome. And this is still called a 99% similarity!
Bottom line: if the chimp genome length is 15% SHORTER than the human genome, how do we get a 99% similarity overall? Unless you 'cheat' and space the chimp genome further apart then is natural to do - in order to get the DNA sequences to meet end-to-end with the human genome, there is no perfectly aligned match-up.
A better question is: why do we listen to bogus claims anyway?
Since 2003, false claims by evolutionary biologists started cropping up in the popular media stating that the human genome and chimp genome are 99% identical, thus proving evolution. This falsely implied that a COMPLETE genome of both was compared. This is a false claim on so many levels:
1) Back in 2003, there was no complete genome mapping of a human (that happened in 2005 and was not complete - only the protein-coding sequences). At that time we did not have a complete genome mapping of a chimp, therefore, a complete comparison between the two is impossible at that time. Since we only mapped the protein-coding sequences of humans and chimps, there is no real 100% comparison.
2) What was actually compared was ONLY the protein-coding sequences - which make up less than 5% of the total genome. Some studies show it to be as low as 1% of the total genome.
3) The comparison studies used mathematical algorythms rather than a direct genome-to-genome comparison which is considered too laborious at this time of technology.
4) The algorythms have been constantly improved and tweaked since the initial studies to more accurately reflect a real comparison. The 99% has slowly decreased in value. The 99% was initially downgraded to 98%, then 96%, then 85%, and the most current studies show 70% similarity.
5) The initial studies back in 2003 also claimed that the genome of humans and bananas had a 50% similarity. This credulously implied that we, as humans, are 50% banana! Undoubtedly, this 50% number is also too high. Nonetheless, evolutionary biologists with PhDs were quick to jump on the bandwagen and started telling the public that we were actually one-half of a banana! So much for academic intellectualism.
Nonetheless, the question is: Why should humans have any genomic similarity with bananas and chimps? This is why:
1) If we have no genomic similarity with bananas, we cannot assimilate (eat and digest) bananas. We must have at least SOME genomic similarity with the things we eat, otherwise we would starve.
2) All life on Earth is based on the same carbon/nitrogen/water-based system so we should expect some similarity since we share the same planet and foods. This should only make sense to any biologist.
3) Also, the chimp genome is 15% shorter overall than the human genome, according to the tables supplied by the 2005 study.
The human genome is about 3.2 Gb. and the chimp genome size used in the 2005 study was about 2.7 Gb. This is a difference of about 15%.
With this 15% difference in genome size, how do we still get a 99% similarity?
Let's first look at the size/length of the human genome:
"The human genome contains 3164.7 (3.1 Gb) million chemical nucleotide bases (A, C, T, and G)." (Human Genome News, 2001)
"The human genome is 3.3 Gb in length." (Integrated DNA Technologies, 2011)
So the human genome size is about 3.1 to 3.3 Giga base pairs.
Unfortunately, the chimp genome size they used in this 2005 comparison study was much smaller at 2.7 Gb. This is a size difference of about 15% in comparison to the 3.2 Gb human genome.
By size comparison, the chimp genome size used by the study is about 85% of the size of the human genome (2.7Gb/3.2Gb) = .85 or 85%.
Question #2: What about the remaining 15% of human genome? What was it compared to?
The only way to "perfectly align" both genomes, there would be a left-over of human genome of 15% since it is 15% larger. And with this 15% leftover of the human genome, this is still called a 99% similarity?
So the question is, how does the smaller chimp genome - which is only about 85% of the human genome in size - exactly align to a much larger human genome?
How exact is the alignment between two genomes separated by (3.2Gb - 2.7Gb) = 500,000 bp or 15 %? The chimp genome and human genome were supposedly 99% similar BUT they differ in total length by 15%!
If one genome is 15% shorter, how do they "align" by 99% except by some 'fudging' with the sequences and 'expanding' one genome to 'fit' and "exactly align' with the other by introducing 'gaps' to artificially lengthen the shorter genome to match the longer one?
To make the deception worse, the total Gb of supposedly perfectly aligned chimp DNA was only 88% or 2.4Gb. This 2.4 Gb represents only 75% of the 3.2 Gb human genome. And this is still called a 99% similarity!
Bottom line: if the chimp genome length is 15% SHORTER than the human genome, how do we get a 99% similarity overall? Unless you 'cheat' and space the chimp genome further apart then is natural to do - in order to get the DNA sequences to meet end-to-end with the human genome, there is no perfectly aligned match-up.
A better question is: why do we listen to bogus claims anyway?