Slashdot Mirror
Opposable Thumbs and Upright Walking Caused By "Junk DNA"
quinnlynn writes "A group of research scientists at Yale discovered that the evolution of opposable thumbs and upright walking in humans is due to changes in the genome in the areas still classified as "junk DNA." Quoting: 'Results from a comparative analysis of the human, chimpanzee, rhesus macaque and other genomes reported in the journal Science suggest our evolution may have been driven not only by sequence changes in genes, but by changes in areas of the genome once thought of as "junk DNA." ... Researchers have long suspected changes in gene expression contributed to human evolution, but this had been difficult to study until recently because most of the sequences that control genes had not been identified. In the last several years, scientists have discovered that non-coding regions of the genome, far from being junk, contain thousands of regulatory elements that act as genetic "switches" to turn genes on or off.'"
Yale has also recently completed sequencing the Trichoplax genome. Trichoplax has the simplest known animal genome, and it shares 80 percent of its genes (comprised of 98 million base pairs) with humanity. Professor Stephen Dellaporta was quoted saying, "We are [excited] to find that Trichoplax contains shared pathways and defined regulatory sequences that link these most primitive ancestors to higher animal species. The Trichoplax genome will serve as a type of 'Rosetta Stone' for understanding the origins of animal-specific pathways."
When shall we welcome our furry, opposable thumbed overlords. Could Douglas Adams had been right all along?
Faster! Faster! Faster would be better!
Junk DNA doesn't exist. It's just DNA we don't understand.
RS
Shoes for Industry. Shoes for the Dead.
In defense of DNA fingerprinting it is often stated that the databases only store non-coding DNA, so there is no risk that someone might be able to centrally deduce possible health problems and other traits which could negatively affect the individual. How does that argument hold up now?
I have always found it irksome when biologists claim that a high percentage of our DNA is just junk (do-nothing) DNA. It's as though they were saying "we of course know what it does: It does not do anything". Why not say "we don't know what it does, if anything at all"?
Most of them do, "Junk DNA" is a handy phrase and one that's been picked up by the media, the majority of Biologists are quite open minded on the subject. The fact that a lot of it is translated in to RNA even lends wait to the argument that it is of functional value. Aside from that things like telomeres (the ends of DNA that get eaten away as the replicates) and centomeres would be labelled as "junk" even though they have obvious functional value. Most scientists just use "junk" as a synonym for "non-protein coding" as a kind of shorthand.
In the last several years, scientists have discovered that non-coding regions of the genome, far from being junk, contain thousands of regulatory elements that act as genetic "switches" to turn genes on or off.
...Biologists discover "flags". Seriously, these guys should just bring a programmer on-staff — preferably assembly, as decoding the arcane secrets of all Earth life should be a breeze for anyone whose day job involves the x86 instruction set.
How can I believe you when you tell me what I don't want to hear?
I probably should have clarified in the post but "Junk" DNA is a misnomer though still the most commonly used term for the part of the human genome (over 90% of it) that we don't know the uses for. The word "junk" isn't used in the sense that the DNA there is worthless and should be discarded. More like a junk drawer. There's a bunch of stuff over there that doesn't seem to belong to anything but we know that a lot of it probably does, so scientists keep testing around in there to see what goes where.
Actually its been widely known that 'junk DNA' does have an active role for a long time. The big problem is identifying which bits of it are responsible for regulation/transcription.
The main problem with the public's perception, and indeed that of some scientists, is the continued use of the term 'junk DNA' when the concept it embodies has been thoroughly discredited.
For the moment a lot of work does discount area's of DNA for which there isn't enough background information, but that's more to do with the need to make progress on the bits we understand, rather than to avoid looking at the junk.
This is likely why so many people still think that Junk DNA is a thing that we actively avoid. It isn't.
A learning experience is one of those things that say, 'You know that thing you just did? Don't do that.' - D. Adams
I don't understand it therefor it must be junk! Perfectly scientific.
Most scientists do not actually do this. Most reporters, on the other hand, do.
I'm a minority race. Save your vitriol for white people.
You found out what 10% of the brain does (the sensory/motor areas)? The other 90% must not be used for anything.
This old myth actually never had its origin in science, but was created and then spread through popular media. Please don't help it survive - it's time to let it die.
We'll eventually discover that DNA is just instruction tape for a type of turing machine which generates our entire body as its output. As we all know, Turing machines require lots of repetitive instructions to operate because they're so limited in their actions.
I'm glad I can now scientifically justify why I like a little junk in the trunk.
Don't worry if you're a kleptomaniac, you can always take something for it.
Our DNA has a goddamn registry.
This is hardly new. It has been recognised for some time that so-called "junk" DNA is nothing of the sort, but is almost certainly associated with gene expression to some degree.
The cool thing here (and what, I hope, will keep me in a job for a while) is trying to work out how.
(The fun aspect of molecular biology is that so much changes even over the course of a 4-year degree course... - and to think I nearly went into maths, where I wouldn't be doing anything remotely cutting-edge until PhD level...)
Charles Darwin was amazingly right on the broader picture of speciation and evolution. Not surprisingly, he got some stuff wrong. But nowhere does ol' Charley - or any other serious tract on evolution - require the perfection that your statement implies.
Many people (biologists included) look at highly evolved structures (and by this I am specifically not including television producers) and wonder about the complexity and intricacy of it all and use these concepts as some sort of metric for perfection. Evolution doesn't require this at all. All you have to do to be successful is to produce more of you than dies off for whatever reason. If you carry large quantities of DNA (or adipose tissue or whatever) that doesn't do anything useful but doesn't do anything harmful, then that's OK. If said stuff is a selective disadvantage, then it's not so OK but it might not be a problem in terms of the ability to create progeny. Stuff doesn't have to be there for a "reason". It can be neutral or only mildly deleterious and the critter survives.
That said, it may be that these piles of repetitive sequences interspersed with sequences that used to code for something but currently don't create a gene product or are used as a control sequence, serve as evolutionary reservoir to get spliced and diced by random processes and eventually create something that does help the organism survive.
Evolution only requires that the organism muddle through better than some other organisms. It doesn't require perfection and grace.
Faster! Faster! Faster would be better!