Posted on 03/28/2016 6:19:00 AM PDT by SunkenCiv
One whole endogenous retrovirus genome -- and bits of 17 others -- were spotted in a study of 2,500 human genomes...
Nineteen new pieces of DNA -- left by viruses that first infected our ancestors hundreds of thousands of years ago -- have just been found, lurking between our own genes.
And one stretch of newfound DNA, found in about 50 of the 2,500 people studied, contains an intact, full genetic recipe for an entire virus, say the scientists who published their findings today in the Proceedings of the National Academy of Sciences.
Whether or not it can replicate, or reproduce, it isn't yet known. But other studies of ancient virus DNA have shown it can affect the humans who carry it.
In addition to finding these new stretches, the scientists also confirmed 17 other pieces of virus DNA found in human genomes by other scientists in recent years.
The study looked at the entire span of DNA, or genome, from people from around the world, including a large number from Africa -- where the ancestors of modern humans originated before migrating around the world. The team used sophisticated techniques to compare key areas of each person's genome to the "reference" human genome.
...about 8 percent of what we think of as our "human" DNA actually came from viruses. In some cases, HERV sequences have been adopted by the human body to serve a useful purpose, such as one that helps pregnant women's bodies build a cell layer around a developing fetus to protect it from toxins in the mother's blood.
(Excerpt) Read more at uofmhealth.org ...
Infectious Evolution: Ancient Virus Hit Apes, Not Our Ancestors, In The Genes
http://www.freerepublic.com/focus/news/1376168/posts
http://www.freerepublic.com/focus/news/1376168/posts?page=34#34
100,000 year-old DNA sequence allows new look at Neandertal’s genetic diversity
http://www.freerepublic.com/focus/news/1643837/posts
from the FRchives:The Scars of Evolution:"The most remarkable aspect of Todaro's discovery emerged when he examined Homo Sapiens for the 'baboon marker'. It was not there... Todaro drew one firm conclusion. 'The ancestors of man did not develop in a geographical area where they would have been in contact with the baboon. I would argue that the data we are presenting imply a non-African origin of man millions of years ago.'"
What Our Bodies Tell Us
About Human Origins
by Elaine Morgan
This article states that there our DNA has adopted viruses that are helpful. Do anti-viral medicines mess with them?
Whoa! You mean...We’re the ET’s we’ve been expecting visits from?
And we didn’t even need a UFO!
In some people it's a lot more than 8 percent.
Mulder and Scully wouldn’t find this surprising in the least.
The bit about adopting DNA that is helpful is just nonsense — the virus didn’t ask permission, it hacked its way in, then stayed put. Each gene “word” consists of three consecutive base pairs, such that former working sequences or future potentially working sequences are basically inert series of base pairs with a one or two-basepair intro rendering them useless.
LOL
GENOMEThe different kind blood group you have determines your susceptibility to certain diseases. For example, people with A blood are less likely to get diarrhoea than people with B blood. People with O blood are more susceptible to getting diarrhoea than anybody else. People with AB blood are virtually immune to diarrhoea because of their resistance. Nobody really yet knows how AB genotype protects them from this disease. "Since people with the O blood are the most susceptible to the disease, shouldn't they die out according to natural selection?' you are probably asking. That is true but there are a couple of things that keep the O group alive and one of them is malaria. People with O blood are more resistant to malaria than other groups. Another thing is that the O group is less likely to get certain cancers. These benefits cancel out the negative effect that the O blood group has on the diarrhoea disease so, this balance has kept the group from disappearing.
the autobiography of
a species in 23 chapters
by Matt Ridley
(from chap 9)
"For thirty years, nobody disputed this 'fact'. One group of scientists abandoned their experiments on human liver cells because they could only find twenty-three pairs of chromosomes in each cell. Another researcher invented a method of separating the chromosomes, but still he thought he saw twenty-four pairs. It was not until 1955, when an Indonesian named Joe-Hin Tjio travelled from Spain to Sweden to work with Albert Levan, that the truth dawned. Tjio and Levan, using better techniques, plainly saw twenty-three pairs. They even went back and counted twenty-three pairs in photographs in books where the caption stated that there were twenty-four pairs. There are none so blind as do not wish to see."
thank you for the explanation
According to the Virology Blog -
"About eight percent of human DNA is viral: it consists of retroviral genomes produced by infections that occurred many years ago. These endogenous retroviruses are passed from parent to child in our DNA. Some of these viral genomes are activated for a brief time during human embryogenesis, suggesting that they may play a role in development.
There are over 500,000 endogenous retroviruses in the human genome, about 20 times more than human genes. They were acquired millions of years ago after retroviral infection. In this process, viral RNA is converted to DNA, which then integrates into cell DNA. If the retroviral infection takes place in the germ line, the integrated DNA may be passed on to offspring."
It should be noted that the common cold is a retrovirus.
I think ancient viruses are to blame for the proliferation of species using calcium carbonate skeletons that is known as the Cambrian explosion.
Thanks! That helps, or at least adds complexity, when trying to put the human DNA percentage comparisons with other species into sharp perspective.
“This article states that there our DNA has adopted viruses that are helpful. Do anti-viral medicines mess with them?”
No. They aren’t active as viruses any more.
It is DNA integration in to the genome that affected chromosomal regulation or creation of novel genes which are now integrated in to the genome.
Ewww! Get it out!
That is one of the most interesting things I’ve read recently. Thanks. And thanks for the ping list. It is one of the reasons I keep returning to Free Republic.
My pleasure, and thanks for the kind remarks.
Disclaimer: Opinions posted on Free Republic are those of the individual posters and do not necessarily represent the opinion of Free Republic or its management. All materials posted herein are protected by copyright law and the exemption for fair use of copyrighted works.
