Horizontal gene transfer

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Horizontal Gene Transfer is a rather… unusual phenomenon in biology. Under normal circumstances, a population will acquire new genes through mutations, and if the genes are beneficial they reproduce, but if not they won't. Horizontal gene transfer is where organisms acquire genes from other species.

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[edit] Simple absorption

Most commonly, this occurs in bacteria. A bacterium may consume DNA from its surroundings, and incorporate said DNA into its own. This can be an advantage since bacteria are most likely to acquire the DNA from the organisms that are most common in an environment, which are probably the ones that produce chemicals including proteins that help them even exist in said environment. It's especially useful for organisms that reproduce asexually, who can't pair their DNA with other 'successful' partners. The result is that organisms like Escherichia coli that exist in your intestines actually share some of your DNA.[1]

[edit] Virus mediated transfers

A virus is a chunk of RNA surrounded in a delicious candy coating protein shell that injects itself into another cell, fusing the RNA with the cell's DNA. The result is a 'reprogrammed' cell, or in other words, if you have a viral infection the virus is literally a part of you. The infected cell will usually mass manufacture more viruses until it bursts open (and dies), but sometimes the infected cell will continue functioning "normally" until later on, releasing viruses at a later date. HIV, for example, is notorious for creating such a "reservoir" of infected cells, where even wiping out every virus in your body won't end the infection.

In very rare cases, when adding to the DNA code the virus ends up adding genes from different organisms without the usual "mass produce more viruses to death" that usually occurs. This allows for things like fungi DNA making its way into a species of beetle, for example. If the altered cell happens to be a gamete (sperm or egg), the organism will contain genes that did not originate from either of its parents.

[edit] Artificial horizontal gene transfer (aka GMO)

Humans can attempt to induce a specific gene transfer from one organism to another via a number of methods. The goal of this, aside from being awesome, is to produce food that grows more efficiently, doesn't rot as quickly, is resistant to pests, or just looks cool[wp]. This is nothing that doesn't already happen in the wild; it's just faster and unlike the wild, regulated. So, ironically, safer than nature.

[edit] "Disproving" Evolution/Inevitable Creationist Drivel

The original model of evolution has undergone quite a bit of adaption since Darwin/Wallace first wrote it down. While the theory in its original form predicted some form of 'record keeping' that would enable offspring to inherit parents' attributes, Darwin did not know how this 'record' was stored and what altered it. Originally he conjectured that the record was stored in the blood; this was proven false by blood transfusion animal experiments conducted by Darwin's cousin Francis Galton. Galton would spend quite some time trying to determine the nature of the record, even performing experiments on snow peas, the same species that Gregor Mendel discovered Mendelian Genetics from. But Galton was too clever by half; his records were continuous while genetics is discrete. Darwin also conjectured Sexual selection as well as Natural selection, but Victorian sensibilities prevented people from accepting the idea that the female ever had any say in choosing who mates with her.

Even with the theory evolving since Darwin's day, and the discovery of DNA, DNA was thought to only be altered via mutation. And addition, deletion, duplication, inversion, shuffling, regular old errors, and OK there a lot of things that can happen. But not taken from completely foreign DNA.

Since something not predicted by the original models of evolution has been discovered, it obviously means that all of evolution is wrong and since there are only two possibilities for life on Earth, Creationism is right, right? Obviously not, but that doesn't prevent some people from quote-mining actual scientists. Nor does it help that the scientist spearheading the research into HGT, Dr Doolittle[2], is a tad arrogant and thinks he knows more than the scientists who work on other projects.[3]

[edit] Examples in the natural world

  • Sometime during the Cretaceous Period, Ferns[wp] exploded in biological diversity. They did so at a time when angiosperms[wp] (or "flowering plants") were becoming more common and causing older families to become rarer like Seed Ferns[wp], Ginkgos[wp], Cycads[wp] (probably), and to a much lesser extant Conifers[wp]. Paleontologists were perplexed as to why ferns, which were practically living fossils by the Cretaceous, should undergo such a monumental surge in biological diversity at a time when the diversity of many major non-angiosperm clades was declining. At some point during the Cretaceous a fern somehow ended up with a gene called neochrome that helped it survive in dim light, it prospered and it's descendants prospered. The fern in question did not evolve its neochrome gene; it stole it.[4]
  • Homo Sapiens, aka Humans, have 145 genes that likely came from other species[5]. That's right, you are a freak created by SCIENCE! (cue dramatic music, lightening). Or really, nature just doesn't give a damn about your quaint ideas of "decency", and the definition of "human" isn't nearly as clear-cut as we like to pretend.

[edit] Footnotes

  1. Government to store E. coli with human DNA
  2. Yes that's his name
  3. Arstechnica. The Discovery Institute has quotes from Ford Doolittle already, and I ain't linking to them. Just search on Google.
  4. Darkened Forests, Ferns Stole Gene From an Unlikely Source — and Then From Each Other by Jennifer Frazer (May 6, 2014). Scientific American.
  5. Mar 14, The Economist
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