Transmission pathways of snake BovBs via parasites. The representatives of HTs of snake BovBs via parasites are shown. The thick and thin arrows show the direction of HT and the similarities of BovB sequences between taxa, respectively.
A repetitive theme in the creationism vs science 'debates' is that no new information can arise in a genome because of some vaguely understood, or rather completely misunderstood and misrepresented notion that there is an equivalence between information and energy, so it would violate the Second Law of Thermodynamics for new information to arise, apparently from nowhere.
Incidentally, I have never yet encountered a creationist who could explain what genetic information is, exactly or how it is subject to the laws of thermodynamics. For that matter, I have never encountered a creationist who could explain the Second Law of Thermodynamics, though I’ve encountered hundreds who cite it as though it supports them.
Of course, their claim ignores the common phenomenon of accidental gene duplication where additional copies of lengths of DNA are accidentally duplicated in the genome during mitosis or meiosis. It also ignores another, less common, method - horizontal gene transfer - where lengths of DNA from one species can be inserted into the genome of another, often unrelated species, giving it new genetic material, or at least a supply of new DNA which can be randomly mutated and eventually evolve into something useful.
Horizontal gene transfer was thought to have played a major part in the evolution of early, single-celled organism and is still common in bacteria which can swap pieces of their genome in the form of plasmids, or small loops of DNA. However, there is also, in multicellular organisms, a less common, though perhaps more common than is generally realised, method of horizontal gene transfer via a parasite such as a virus, possibly carried by an intermediate host parasite such as a tic or parasitic worm.
A retrovirus inserts the DNA template for its RNA into the host cell's genome (and so escapes detection by the immune system). Later, it will become active and produce RNA versions of itself from that embedded DNA and infect other cells and organisms. Sometimes, however, it will also convert chunks of the host's own DNA into its RNA and carry that to a new host, where it again inserts itself, together with the newly acquired DNA into the new host genome. If this is a cell in the organism's germline, then this will be passed on to future generations.
These genes can then become 'jumping genes', or retrotransposons, which replicate themselves and insert themselves in random parts of the genome, often creating multiple copies of themselves as they do so.
For example, more than 18 per cent of the cow genome is composed of a retrotransposon called Bovine-B (BovB) which originally came from a snake by horizontal gene transfer some 40-50 million years ago. About 10 years ago, Atsushi Kurabayashi at the Nagahama Institute of Bio-Science and Technology, Japan discovered that a Madagascan frog had a version of the BovB gene which was a 95% match for that found in cows.
Since then, Kurabayashi and his colleagues have analysed the DNA from 106 snake species, 149 frog species and 42 species of their shared parasites – like leeches and ticks. This has enabled them to chart the history of this retrotransposon as it jumped between species. They estimate that there have been 54 horizontal transfers between snakes and frogs between 85 and 1.3 million years ago. For some reason, Madagascar seems to be a hotspot for this transfer since it happened about 14 times in the last 50 million years and now 91% of the island's frogs carry the snake BovB gene. By contrast, over the same period, this seems to have happen only once in mainland Africa. The difference is probably due to the prevalence of certain parasites in Madagascar. Curiously, BovB doesn't appear to have any function in any animal.
The Nagahama Institute team's findings were published, open access, earlier this month in the journal Molecular Biology and Evolution:
Copyright: © 2022 The authors.Published by Oxford University Press on behalf of Society for Molecular Biology and Evolution. Open access.(CC BY 4.0)
AbstractBovB doesn't have any known function in any animal, so what creationists need to explain is why it's there. What purpose did their putative intelligent [sic] designer have in giving it to so many species?
Horizontal transfer (HT) of genes between multicellular animals, once thought to be extremely rare, is being more commonly detected, but its global geographic trend and transfer mechanism have not been investigated. We discovered a unique HT pattern of Bovine-B (BovB) LINE retrotransposons in vertebrates, with a bizarre transfer direction from predators (snakes) to their prey (frogs). At least 54 instances of BovB HT were detected, which we estimate to have occurred across time between 85 and 1.3 Ma. Using comprehensive transcontinental sampling, our study demonstrates that BovB HT is highly prevalent in one geographical region, Madagascar, suggesting important regional differences in the occurrence of HTs. We discovered parasite vectors that may plausibly transmit BovB and found that the proportion of BovB-positive parasites is also high in Madagascar where BovB thus might be physically transported by parasites to diverse vertebrates, potentially including humans. Remarkably, in two frog lineages, BovB HT occurred after migration from a non-HT area (Africa) to the HT hotspot (Madagascar). These results provide a novel perspective on how the prevalence of parasites influences the occurrence of HT in a region, similar to pathogens and their vectors in some endemic diseases.
Kambayashi, Chiaki; Kakehashi, Ryosuke; Sato, Yusuke; Mizuno, Hideaki; Tanabe, Hideyuki; Rakotoarison, Andolalao; Künzel, Sven; Furuno, Nobuaki; Ohshima, Kazuhiko; Kumazawa, Yoshinori; Nagy, Zoltán T.; Mori, Akira; Allison, Allen; Donnellan, Stephen C.; Ota, Hidetoshi; Hoso, Masaki; Yanagida, Tetsuya; Sato, Hiroshi; Vences, Miguel; Kurabayashi, Atsushi
Geography-Dependent Horizontal Gene Transfer from Vertebrate Predators to Their Prey
Molecular Biology and Evolution, Volume 39, Issue 4, April 2022, msac052, DOI: 10.1093/molbev/msac052
Open access
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)
But that's not the only problem this research represents for creationists: unless a creationist can explain how this method of acquiring new contents in the genome does not increase the amount of genetic information and so doesn't violate their claim that, because its analogous to energy, information can't be created, this looks like another example of how creationist frauds were able to pull the wool that fills the space between their ears, right down over their eyes. Genomes can increase in size (and decrease for that matter) without violating any basic laws of physics or chemistry.
Next time a creationist tells you that information can't be created, they will either be trying to fool you with a lie or repeating a lie they've been fooled with. The only question will be whether they are fools or liars.
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