Intelligent Design advocates like to claim that evolution can’t explain the existence of “irreducible complexity” in humans and other species. But they would be much better served worrying about the far greater difficulty Intelligent Design faces: how to explain mistakes and flaws in the “design” of humans and their world — or to put it another way, how to explain “blunders” by the intelligent designer. (After all, the intelligent designer is God, and God is supposed to be infallible.)
The latest example of a design “oversight” in humans was reported yesterday by EurekAlert!. Researchers at the Univ. of Calif San Diego School of Medicine have discovered the existence of certain T-cell molecules called “Siglecs”, “immune-dampening proteins that bind to sialic acids” which
“. . . regulate T cell activation in chimpanzees [and other non-human primates] by restricting the degree of signaling from the T cell receptor, which normally triggers the response of T cells in the immune system.
“Siglecs are like ‘brakes’ that can slow down the activation of an immune cell upon stimulation,” said Ajit Varki, M.D., UCSD Professor of Medicine and Cellular and Molecular Medicine and co-director of UCSD Glycobiology Research and Training Center. “During human evolution, we seem to have shut off these brakes on our T cells, allowing them to become hyper-active.”
The result is that primates other than humans have built-in protection against autoimmune diseases which result from hyper-active T-cells.
“The study raises warning flags about the stimulatory and potentially destructive potential of the absence of Siglec molecules in human T cells, compared to chimpanzees and other nonhuman primate counterparts.
This may explain some major differences in susceptibility to certain diseases between humans and great apes. One example is the lack of progression to AIDS in the great majority of chimpanzees infected with HIV virus. It could also account for the rarity of T-cell mediated liver damage, such as chronic active hepatitis, cirrhosis and cancer, following Hepatitis B or C infection in chimpanzees. In addition, several other common human T cell-mediated diseases, including bronchial asthma, rheumatoid arthritis and type 1 diabetes, have, so far, not been reported in chimpanzees or other great apes.”
From an ID perspective you would have to say that God created chimps, bonobos and gorillas with special protection against auto-immune diseases, but “forgot” to provide humans with the same protection.
Or maybe in His infinite goodness He was just punishing us. In which case God might less aptly be considered ID than MD (malevolent designer).
A synposis of the study can be found here.