Science and Exploration

[dreadgeek]

Originally Posted by Hollylane

I haven't been on much lately, and I just saw this. I'm prone to being succinct in my answers Aj, even more so when I've just arrived home from work. So, I hope that my short answer helps.

Basically, I think that necessary evolution of plants and animals happens in its own time. It is probably my Native American side that recoils from tampering with plants and animals, and changing them by inserting proteins or anything else into them, that would not be possible through a natural evolutionary process or through selective processes.

If I can ask you one other follow-up, does that same feeling (I don't know what to call it when you say your Native American side) apply to editing *out* genes? I ask that in the context of the Huntington's chorea example I gave a few days ago. Since we know that any number of repeats above 35 is where things start to go badly and there is *no* benefit to having 39+ repeats of the CAG motif on chromosome 4, editing out all repeats above 35 would prevent people from a rather horrible disease. Are you saying that just as you don't think we should be changing genes except in the long, blind process (which, in my mind, is pretty wasteful) of selection that we shouldn't edit out genes even if doing so would save lives? I'm trying to understand where the line would get drawn.

If inserting genes in is, for lack of any better term, against nature isn't editing genes out also against nature? If we apply the standard consistently (i.e. don't insert anything and don't remove anything) then aren't we condemning people who could otherwise be saved? Admittedly, it is perfectly natural to die of Huntington's. I will not argue that somehow it is unnatural. There are lots of fates that are perfectly natural but that I am glad we can overrule. I'm not ready to condemn people to a horrible disease starting at 27 just because they have 50 repeats of a gene on chromosome 4. There's no evolutionary benefit to Huntington's disease. It is simply one of those things where nothing nature says it *can't* happen so it *does* happen.

So why on Earth does the motif continue to show up in a small portion of the population? Why hasn't it been selected out? Because by the time you reach your late 20s, in the environments in which we evolved, you've already likely had children. Any gene for a disease that can, if you'll excuse the term, hold its horses until *after* you've had at least one child will tend to be able to ride along with the rest of your genome. After you've passed your genes on at least once, nature really doesn't have much use for you. Another way of putting it is that genes that cause diseases that kill you before you have a chance to reproduce are selected out. So all of the low-hanging fruit, from the gene's point of view, was selected out hundreds of thousands or millions of years ago. The genes for diseases that we see tend to strike after your early twenties which, in the EEA (Environment of Evolutionary Adaptation) was well into the average person's reproductive career. So diseases like Alzheimer's and Huntington's and heart disease and high blood pressure are all back-loaded toward the end of one's reproductive career. A bunch of fifteen year old people dying is a net-loss from the gene's point of view, particularly in the EEA. A bunch of 45 year old people dying is zero-sum from the gene's point of view. By 45 you've already reproduced a few times, your oldest surviving children are, at that point, adults. From the point of view of nature, you're now superfluous. Thanks for playing. Nice of you to leave some genes around. You're expendable, your genes are not. That's nature for you.

So unless we intervene using technology (selective breeding in humans, needless to say, is a road we should not even contemplate going down) then we're pretty much signing the death warrants of any person unlucky enough to have 39+ repeats of the CAG motif on C-4. That's the natural way. I think we should veto nature because I think it is wrong vis a vis Huntington's.

Cheers
Aj

[Hollylane]

Originally Posted by dreadgeek

If I can ask you one other follow-up, does that same feeling (I don't know what to call it when you say your Native American side) apply to editing *out* genes? I ask that in the context of the Huntington's chorea example I gave a few days ago. Since we know that any number of repeats above 35 is where things start to go badly and there is *no* benefit to having 39+ repeats of the CAG motif on chromosome 4, editing out all repeats above 35 would prevent people from a rather horrible disease. Are you saying that just as you don't think we should be changing genes except in the long, blind process (which, in my mind, is pretty wasteful) of selection that we shouldn't edit out genes even if doing so would save lives? I'm trying to understand where the line would get drawn.

If inserting genes in is, for lack of any better term, against nature isn't editing genes out also against nature? If we apply the standard consistently (i.e. don't insert anything and don't remove anything) then aren't we condemning people who could otherwise be saved? Admittedly, it is perfectly natural to die of Huntington's. I will not argue that somehow it is unnatural. There are lots of fates that are perfectly natural but that I am glad we can overrule. I'm not ready to condemn people to a horrible disease starting at 27 just because they have 50 repeats of a gene on chromosome 4. There's no evolutionary benefit to Huntington's disease. It is simply one of those things where nothing nature says it *can't* happen so it *does* happen.

So why on Earth does the motif continue to show up in a small portion of the population? Why hasn't it been selected out? Because by the time you reach your late 20s, in the environments in which we evolved, you've already likely had children. Any gene for a disease that can, if you'll excuse the term, hold its horses until *after* you've had at least one child will tend to be able to ride along with the rest of your genome. After you've passed your genes on at least once, nature really doesn't have much use for you. Another way of putting it is that genes that cause diseases that kill you before you have a chance to reproduce are selected out. So all of the low-hanging fruit, from the gene's point of view, was selected out hundreds of thousands or millions of years ago. The genes for diseases that we see tend to strike after your early twenties which, in the EEA (Environment of Evolutionary Adaptation) was well into the average person's reproductive career. So diseases like Alzheimer's and Huntington's and heart disease and high blood pressure are all back-loaded toward the end of one's reproductive career. A bunch of fifteen year old people dying is a net-loss from the gene's point of view, particularly in the EEA. A bunch of 45 year old people dying is zero-sum from the gene's point of view. By 45 you've already reproduced a few times, your oldest surviving children are, at that point, adults. From the point of view of nature, you're now superfluous. Thanks for playing. Nice of you to leave some genes around. You're expendable, your genes are not. That's nature for you.

So unless we intervene using technology (selective breeding in humans, needless to say, is a road we should not even contemplate going down) then we're pretty much signing the death warrants of any person unlucky enough to have 39+ repeats of the CAG motif on C-4. That's the natural way. I think we should veto nature because I think it is wrong vis a vis Huntington's.

Cheers
Aj

No, I am not applying that to intervening with technology where humans are concerned. Humans can make choices about their bodies, and about the health and well-being of their children, animals and plants cannot.

Additionally, there is a lot of information available that suggests, that many problems in humans(and in animals and plants) exist, because of the things that humans do to this planet (with science & technology), and what they choose to put into their bodies (food, medication, chemicals..etc).

When I refer to my Native American side, I am referring to how I feel about taking care of this planet, with the belief that everything is connected, and that every thing that we do has an effect on something else. Despite all of the information available, despite the existence of amazing science and technology, I cannot agree with changing plants or animals by inserting anything, or removing anything, in a manner that would not occur naturally. I also adamantly refuse to accept that torturing animals in the name of science, is our right as coinhabitants of this planet.

A simple example of where this has gone wrong, is corn production. The majority of corn produced in the US at this time has very little nutritional value in comparison to the original crop native to this continent, maize. Corn grown today, could not have existed as a wild plant, in its present form. A great film that illustrates perfectly the reasons why I used corn as an example, is the documentary, King Corn.

[Toughy]

I posted this in the Zombie thread....however it does belong here:

from HuffPo

Bats' Oral Sex Helps Prolong Copulation, Scientists Say (VIDEO)

http://www.huffingtonpost.com/2013/0...een&ref=topbar

[Corkey]

http://news.yahoo.com/scientists-pos...205206362.html


Looking for dark matter.

[dreadgeek]

Originally Posted by Corkey

http://news.yahoo.com/scientists-pos...205206362.html


Looking for dark matter.

You beat me to the punch on this the other day, Corkey. I started working on an explanation and it became a bit more complex. So, I wanted to ask would people find it helpful if I put together a short primer on dark matter, what it is and why it matters?

Cheers
Aj

[Corkey]

Originally Posted by dreadgeek

You beat me to the punch on this the other day, Corkey. I started working on an explanation and it became a bit more complex. So, I wanted to ask would people find it helpful if I put together a short primer on dark matter, what it is and why it matters?

Cheers
Aj

Great idea Aj, go for it!

[dreadgeek]

So, I said I'd do this a few days ago. I apologize for the delay:

Science advances not when someone exclaims "Eureka!" but when someone cocks their head and says, "well now, that's unexpected". There are a number of issues that caused astronomers, astrophysicists and cosmologists to say "well, I wasn't expecting that". I'll only take two because they are the easiest to explain and require no math to get to an understanding.

The first is the concept of gravity lensing. Gravity lensing is caused when the light of a very distant object is warped around an intervening mass like, say, a galaxy. As everyone knows, light moves from point A to point B and, as everyone is aware of from the idea of black holes, light can be affected by gravity. When this happens at astronomical distances what happens is that the object either appears as either a ring (known as an Einstein ring) or it'll appear slightly offset from where the object actually is. Now, if we know the approximate mass of a galaxy (which can be estimated from its size and density of stars) then we can know about how much refraction there should be. The problem then is that astronomers see more lensing than can strictly speaking inferred from the masses in between them and some distant light source. This begs the question of *why* this is happening.

The second concept is the spin of a galaxy. This is a bit more complicated. Think of a spiral galaxy like a solar system writ large. In the center of the galaxy is a hugely massive orbit (a supermassive black hole) and most of the mass of the galaxy is in that bulge in the center. Then there's the spiral arms. Calculating the rotational speed of a galaxy of a given size *should* be a pretty straightforward application of Newton's and Kepler's laws that work very well when applied to solar systems. The basic idea here is that the closer to the gravitational center an object is, the faster it rotates and the farther out it is, the slower it rotates. Except that's *not* what we see. Instead we see a near uniform rotational speed even at the outer extremities of the galaxy--for instance where our solar system is in relation to the rest of the Milky Way. Again, this begs the question of *why*.

Now, the proposed answer is that there is some 'missing' matter that we can't directly observe. This missing matter is called 'dark matter'. Why dark? Because it does not interact strongly with the electromagnetic force (light in all its form and splendor). Ordinary matter (the kind of stuff we and everything we can see) will interact with the electromagnetic force. For instance, someone walking into the room where you currently sit reading this can see you because all of the matter that makes you you is reflecting electromagnetism in the visible portion of the spectrum. Dark matter doesn't do that. Instead if it interacts with light at all it does so very weakly and all evidence, so far, is that it does not interact with it at all.

If this were all that there was to dark matter it would be almost impossible to find but fortunately this isn't the case. Dark matter *does* interact with itself and when it does it splits off into exotic particles that were predicted by physicists who started working on the problem. The experiment aboard the ISS (International Space Station) detected the kinds of particles that the theory predicted which is usually a sign that we're on the right track.

Dark matter and dark energy are *not* the same thing and shouldn't be confused with one another.

Cheers
Aj