|African straw-coloured bat|
OCD or Obsessive Compulsive Disorder is characterised by repeatedly and obsessively doing something which appears to have no aim, or at least an aim which isn't furthered by constant repetition.
Yet, when we look at biology, we see examples in great abundance of what would appear to be obsessive, constant repetition which actually achieves nothing, as though the designer is on some sort of mental treadmill and incapable of getting off it - assuming, that is, that you believe in a designer. This is not the act of a mentally healthy or intelligent being.
As though to illustrate this, we have an open access paper this week where the authors believe they have shown that bats and ebola viruses have been engaged in an arms race, possibly for 25 million years.
Biological factors that influence the host range and spillover of Ebola virus (EBOV) and other filoviruses remain enigmatic. While filoviruses infect diverse mammalian cell lines, we report that cells from African straw-colored fruit bats (Eidolon helvum) are refractory to EBOV infection. This could be explained by a single amino acid change in the filovirus receptor, NPC1, which greatly reduces the affinity of EBOV-NPC1 interaction. We found signatures of positive selection in bat NPC1 concentrated at the virus-receptor interface, with the strongest signal at the same residue that controls EBOV infection in Eidolon helvum cells. Our work identifies NPC1 as a genetic determinant of filovirus susceptibility in bats, and suggests that some NPC1 variations reflect host adaptations to reduce filovirus replication and virulence. A single viral mutation afforded escape from receptor control, revealing a pathway for compensatory viral evolution and a potential avenue for expansion of filovirus host range in nature.
Melinda Ng, Esther Ndungo, Maria E Kaczmarek, Andrew S Herbert, Tabea Binger, Ana I Kuehne, Rohit K Jangra, John A Hawkins, Robert J Gifford, Rohan Biswas, Ann Demogines, Rebekah M James, Meng Yu, Thijn R Brummelkamp, Christian Drosten, Lin-Fa Wang, Jens H Kuhn, Marcel A Müller, John M Dye, Sara L Sawyer, Kartik Chandran.
Filovirus receptor NPC1 contributes to species-specific patterns of ebolavirus susceptibility in bats.
eLife, 2015; 4 DOI: 10.7554/eLife.11785
The ebola virus attacks host cells by attaching a glycoprotein on its surface to a receptor on the surface of host cells known as NPC1. However, in at least one species of bat, the African straw-colored fruit bat, a single amino acid change in the NPC1 receptor makes them immune to the ebola virus because it can no longer bind to their cells. However, a single amino acid change in the virus' glycoprotein can restore its binding ability.
From an analysis of NPC1 from 13 species of bat, the researchers believe they have detected evidence of rapid evolution in this receptor in bats, most likely caused by a rapid arms race between host and parasite. They have also shown that a fragment of the ebola virus genome became incorporated into bat genome some 25 million years ago which strongly suggests this arms race has been underway for at least that long.
If you don't believe in evolution and believe everything is intelligently designed, you have to believe your hypothetical intelligent (sic) designer keeps redesigning bats to make them resistant to EBOV and then redesigning EBOV so it can overcome resistance in bats. In 'intelligent (sic) design' terms there can be no other reason for this other than that the designer is carrying out a repetitive action for no ultimate purpose but appears to be unable to get off this treadmill.
Can any creationists suggest a better reason for these examples of arms races, which absolutely pervade the natural world, to no-one's ultimate benefit, other than the product of a designer with OCD?
With evolution, of course, evolution IS a treadmill from which living things cannot escape and so have no option but to repeatedly keep reacting to the here and now, because falling off that treadmill is called extinction. Evolution IS obsessive and compulsive because it is inevitable and has no intelligence, aim or plan. This is how we can tell it isn't being intelligently driven.
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