Wednesday, 17 June 2015

Toothed Whales Laughing At Creationists

Laughing at creationists
Mx1 and Mx2 key antiviral proteins are surprisingly lost in toothed whales - PNAS

More evidence today that the supposed 'intelligent designer' is neither intelligent nor a designer. It's not clear yet whether the ID industry will become honest as a result of all this evidence against their daft notion and give up exploiting gullible people, or whether they will ignore it all as usual and rely on their victims' aversion to reading any science literature which might shake their 'unshakeable' faith.

Researchers have shown that the toothed whales all have broken versions of two genes (Mx1 and Mx2) responsible for making key proteins to fight virus diseases. Without these genes, the immune systems of these whales must work in a different way to other mammals. Since the genes are absent in all toothed whales but are fully functional in the baleen whales, this mutation must have happened in a common ancestor to the toothed whales shortly after the two groups diverged.

The scientists reported finding a variety of mutations in the Mx1 and Mx2 genes including deleted sections which don't work at all and sections which truncate protein production before completion so producing useless protein fragments, wasting energy and resources.

So, assuming for a moment, the hand of a designer here, what we appear to have is a clear case of it designing a perfectly good system, then breaking it and designing a different one to do the same job, but also keeping the useless broken version as well. A bit like designing a car with perfectly good wheels, then breaking the drive shafts so the wheels don't work and fitting new wheels and different drive shafts but keeping the old useless ones as well.

Would you buy a new car from this 'designer'?

It's not clear why the common ancestor of the toothed whales lost both genes but some viruses are known to exploit these genes to circumvent the host's immune systems, so one speculative idea is that this ancestral species was subjected to intense selection pressure by a particularly virulent virus when, in the circumstances, not having these genes was an advantage. This group of mammals would then have evolved a different set of defences against viruses.

Significance
Everybody loves dolphins. And orcas. And Mx (Myxovirus) genes. Mx genes are important immune genes that help mammals fight many RNA and DNA viruses, including HIV, measles, and flu. We make a surprising discovery: dolphins, orcas, and likely all toothed whales lost both Mx genes soon after they diverged from baleen whales and ungulates, which preserve these important genes intact. Because both genes were likely lost simultaneously, we speculate that a viral outbreak exploiting the Mx genes may have forced the toothed whale’s ancestor to sacrifice both. Because the Mx genes are so important, and because all 56 nontoothed whale sequenced mammals carry Mx genes, our discovery makes an important contribution to help preserve these magnificent mammals.

Abstract
Viral outbreaks in dolphins and other Delphinoidea family members warrant investigation into the integrity of the cetacean immune system. The dynamin-like GTPase genes Myxovirus 1 (Mx1) and Mx2 defend mammals against a broad range of viral infections. Loss of Mx1 function in human and mice enhances infectivity by multiple RNA and DNA viruses, including orthomyxoviruses (influenza A), paramyxoviruses (measles), and hepadnaviruses (hepatitis B), whereas loss of Mx2 function leads to decreased resistance to HIV-1 and other viruses. Here we show that both Mx1 and Mx2 have been rendered nonfunctional in Odontoceti cetaceans (toothed whales, including dolphins and orcas). We discovered multiple exon deletions, frameshift mutations, premature stop codons, and transcriptional evidence of decay in the coding sequence of both Mx1 and Mx2 in four species of Odontocetes. We trace the likely loss event for both proteins to soon after the divergence of Odontocetes and Mystocetes (baleen whales) ∼33–37 Mya. Our data raise intriguing questions as to what drove the loss of both Mx1 and Mx2 genes in the Odontoceti lineage, a double loss seen in none of 56 other mammalian genomes, and suggests a hitherto unappreciated fundamental genetic difference in the way these magnificent mammals respond to viral infections.

Benjamin A. Braun, Amir Marcovitz, J. Gray Camp, Robin Jia, and Gill Bejerano
Mx1 and Mx2 key antiviral proteins are surprisingly lost in toothed whales
PNAS 2015 ; published ahead of print June 15, 2015, doi:10.1073/pnas.1501844112M

Its not clear either whether this different system is responsible for the frequent mass die-offs to which some toothed whales are subject but, if so, it could be that their immune system is second best. Has the 'intelligent' designer gone to all that trouble to come up with something worse?

Can anyone see any sign of intelligence in this system? The signs of incompetence abound.

Of course, if you abandon childish notions like an invisible magic man making things, the scientific explanation makes things like this make sense, so you don't need to ignore them or and try to make up increasingly absurd workarounds for having unsupported superstitions.

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