By Dr. Georgia Purdom | AiG - U.S.
It is one of the most-asked questions we now receive at Answers in Genesis:
If human and chimp DNA are so similar, does this show a common ancestor?
When studying the human genome and its similarity to that of the chimp,
scientists have concluded that 96–98% of our genome is similar. Much of the
similarity lies in the regions of the DNA that result in proteins (the genes).
It seems logical that if a protein performs a certain function in one organism,
and that function is necessary in other organisms, then the same protein would
be utilized by multiple organisms. Just as paintings from the same painter look
similar, so do the proteins (and thus, genes) from a variety of organisms
designed by a common Designer.
It should be pointed out that most of the DNA sequence performs an unknown
function and has been largely dismissed as “junk” DNA. However, increasing
evidence supports the view that “junk” DNA performs an important role in the
regulation of genes/proteins and has relevance to this question of human/chimp
similarity. For example, a recent report from the ENCODE project
(ENCyclopedia of DNA Elements) found that many
“junk” DNA sequences differed among many mammalian species (including chimps and
humans).1 This may help
explain the differences in organisms that share many of the same genes (and
thus, proteins) but are very different physically, mentally, etc.
Thus, the physical and mental differences between humans and chimps may be
due to the differences in the sequences and, thus, functions of the so-called
“junk” DNA. This understanding should leave us more mindful of the awesome
complexity of the Creator and His creation of DNA.
Other areas of difference between human and chimp DNA appear to involve
regions which are structurally different (commonly called “rearrangements”) and
areas of heterochromatin (tightly packed DNA).
Here are some other interesting differences between the human and chimp
genomes which are often not reported:
- The amount of chimp DNA is 12% larger than what it is in humans.
- The 2–4% difference in the genomes is actually millions and millions of
bases (individual components of DNA).
- In many areas of the DNA sequence, major “rearrangements” seem apparent.
These account for perhaps 4–10% dissimilarity between humans and chimps.
- Chimps have 23 pairs of chromosomes and humans have only 22 (excluding pairs
of sex chromosomes for both species).2
While the differences between humans and chimps can be found in DNA, the
Bible makes it clear that chimps and humans are not related. Humans were made
separate from the animals, and humans were the only ones made in the image of
God (Genesis 1:26–27).
- Elliot H. Margulies et al., “Analyses of Deep
Mammalian Sequence Alignments and Constraint Predictions for 1% of the Human
Genome,” Genome Research 17(2007):760–764. Back
- This is sometimes used as evidence for evolution.
However, a closer examination refutes this claim. For more, see A Tale of Two Chromosomes. Back