Are you saying that brine shrimp are ancestral to the fly?
Posted on 02/08/2002 5:40:18 AM PST by JediGirl
Scientists have discovered the first genetic evidence explaining how small mutations can cause big changes in an organism's body.
Until now there has been little proof that one genetic change can successfully lead to a whole new species.
A University of California study has shown how a mutation in a 'master gene' which controls others could lead to a major body change.
The study looked at a class of genes known as Hox, which switch on and off other genes during an organism's development as an embryo.
The San Diego team used brine shrimp to prove a simple mutation here suppressed 15% of the limb development in the animal's central body region.
This would have allowed its ancestors, which had limbs on every segment of its body to lose their hind legs and evolve into six-legged insects.
Professor William McGinnis, who led the study, claims it answers the question as to how evolution can introduce big changes into an animal's body shape and still generate a living animal.
He said: "Creationists have argued that any big jump would result in a dead animal that wouldn't be able to perpetuate itself.
"And until now, no one's been able to demonstrate how you could do that at the genetic level with specific instructions in the genome."
Story filed: 12:41 Friday 8th February 2002
Aren't the fly, mosquito, moth , and butterfly at the same level? In that case there is no "progression" to be shown.
Are you saying that brine shrimp are ancestral to the fly?
[Timmy] Mutations DO occur in nature. But they cause the creature to DIE, not survive.
Hehehe... This just posted here:
BALTIMORE — For years after he won two gold medals in the 1964 Winter Games, Eero Mantyranta was dogged by rumors of deceit: The Finnish cross-country skier had something in his blood, people whispered, something that had given him an edge.
He never failed a drug test, but the rumors turned out to be true.
Scientists eventually discovered Mantyranta harbored a rare mutation in his DNA, a quirk that caused his body to crank out more red blood cells than the average athlete. The extra cells bathed his laboring muscles in oxygen, providing the boost he needed to glide past competitors.
On the eve of the Winter Games in Salt Lake City, sports officials and scientists fear the day may not be far off when athletes born without such lucky genes could add them, cheating not with drugs but DNA. ...
Nebullis, I have a theory for why we don't hear about more beneficial mutations, at least in humans: It's harder for the average doctor to justify the cost of doing a DNA analysis on a patient who is "too healthy" in some respect. But finding a genetic cause for the patient having some congenital problem is quite justifiable. What do you think?
According to ThinkPlease who read "the paper itself", and summarized it to say the scientists "took this gene ... in the particular species of shrimp, and told it to activate itself in the thorax region..."
And also said "this is the first time that someone has actually manipulated a small bit of the genetic code..."
Scientists conducting genetic engineering by no means "answers the question as to how evolution can introduce big changes into an animal's body shape and still generate a living animal" as Professor William McGinnis states in the article.
You are right, RaceBannon, this is simply scientists conducting genetic engineering. No more, no less.
I appreciate your explanation even if some of it was over my head, and I agree with the first part of this statement.
However, to say that "such a large step isn't so hard for nature to achieve after all," strikes me as a little incautious.
NAME ONE MUTATION that has PROVEN to be beneficial. Show me the previous version of a creature that mutated, then show me the better version that had more complexity and became another species. You cannot use theory, either, you must use evidence.
I was just wondering if jennyp responded to you privately as I could not find a post from her or anyone that provided a beneficial mutation.
They're more like sister groups. However, in body plan, which is what we're discussing, the brine shrimp are ancestral to the fly.
It's the only one I know of off the top of my head. (Just came across it in the paper, in fact.)
Thanks. Of course I saw it right after I posted that question! As I asked in post 50, is that the only example? I'm no scientist, but I would think, from the certainty of what we hear of evolution, that there are additional examples of beneficial mutations besides something dated yesterday.
We keep posting at or near the same time! Is there anyplace I can read up on other beneficial mutations?
Race, now you're defending creationism by attacking the very concept of an experiment!
Any valid scientific experiment is a controlled subset of what we observe in nature - specifically designed to isolate the phenomena under study from those phenomena that are unrelated (noise). Your new complaint, if true, would render moot all experiments ever made about anything!
Why are you enthusiastically using such a destructive line of argument? Yet another thing that should bother you, IMO.
4.) What is the evidence this actually happened in time past? If this is a laboratory manufactured event, the mutation, how in the world does this prove the following: Brilliant people, working with the latest technologies, performed numerous planned and controlled events to manufacture a genetic mutation in a shrimp inside laboratory settings; proving it all happened by chance???
Ummm... yeahhhhh. Mutations have never occurred in nature, so this experiment couldn't possibly be valid.
Your answer was an evasion.
There is a way to answer the very valid question he asked. Why don't you do it?
I understand that brine shrimp are living fossils... I deal with them all the time. And I'm with you on the body plan discusiion, and the significance of turning off genes for extra limbs. OK there.
But I don't believe it's splitting hairs to say that your "ancestral" statement is equivalent to saying "In terms of primatology, the tree shrew is ancestral to the human." Despite our common lineage with prosimians, that's not a comment you'd make, is it?
I don't mean to be picky, but given how contentious this subject can be, shouldn't we be more careful in our phrasing?
I think this is true. But there are ongoing studies to determine why people are disposed to exceptional longevity, cancer resistance, why they can do with less sleep or run faster or have better cognitive function etc. These are considered genetic improvements from "normal", not simply absence of disease.
Remember the lactose intolerance mutation? Also, tetrochromats.
Is there anyplace I can read up on other beneficial mutations?
Let's see... Here's one relating to mosquitos, known to have occurred after 1984. Here are a few examples, including the bacteria that eat Nylon, something not found in nature. Here's an extended description of the evidence that the blood clotting mechanism in vertebrates evolved by several gene duplications & modifications from the common ancestor.
Some mutations are pretty obviously "beneficial" or "harmful", but the interesting thing is, beneficial is only meaningful in the context of the organism's environment. So there's no absolute measure of beneficial-ness, outside of actually putting the organisms into a specific environment.
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