On 27/08/2013 10:28 PM, Warp wrote:
> When you really start to study how genes work, you start seeing that
> there is, in fact, no intelligent design behind it. No intelligent
> designer, no matter how incompetent, would be so sloppy and so lazy.
> A mindless process that's simply the by-product of natural laws is.
>
> On the positive side, genes are a marvelous example of emergent behavior
> in nature. Complexity arising from simple rules.

I'm sure a lot of people actually think that somewhere in your DNA is an 
encoded number that says how long your femur should be, what speed your 
heart should beat at, and various other technical data - you know, like 
a man-made blueprint would have on it. If only scientists could work out 
how do "decode" this information, we would then know everything there is 
to know about the human body. (Or, indeed, any other organism...)

What *actually* happens is that DNA encodes the instructions for 
building various different proteins, which - by a MIND-NUMBINGLY 
INDIRECT series of steps - results in something that has a recognisable 
form.

I guess it's a bit like an IFS. Take, for example, this famous example:

w 	a 	b 	c 	d 	e 	f 	p
ƒ1 	0 	0 	0 	0.16 	0 	0 	0.01
ƒ2 	0.85 	0.04 	−0.04 	0.85 	0 	1.6 	0.85
ƒ3 	0.2 	−0.26 	0.23 	0.22 	0 	1.6 	0.07
ƒ4 	−0.15 	0.28 	0.26 	0.24 	0 	0.44 	0.07

This doesn't describe any geometric shapes at all. It merely defines 
four spatial transformations. And yet, iteratively applying these 
transforms yields a strange attractor which looks strikingly like a fern 
leaf... even though there's no fern coordinates here.

It seems likely that an *actual* fern probably works the same way...

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On 27/08/2013 10:28 PM, Warp wrote:
> Genes are, ultimately, rather inefficient at "optimizing" an organism
> Evolution is all about compromises. The genetic code is very slow to
> change in the right way to do something efficiently.

I love the suggestion some people are making that maybe humans will 
"evolve" to be less fat.

This makes it sound as if "evolution" is some magical process whereby 
each time we reproduce, our DNA gets optimised to our situation, so that 
as generations pass, everybody slowly improves...

No, this is not how evolution works. When you say "humans will evolve to 
be less fat", what you're actually saying is "all the fat people will 
die". Because THAT has how evolution changes stuff.

Of course, we have all sorts of government institutions set up 
explicitly to PREVENT this mass death happening. Thus, humans will NOT 
in fact "evolve to be less fat". Because there's no selection pressure. 
Organisms only evolve to avoid stuff that kills them. If it's not fatal, 
it doesn't get fixed. And since humans no longer live in an environment 
where the weak perish and only the strong survive, evolution has little 
or nothing to do with it.

(OK, correction: It doesn't matter if it kills you or not. It matters if 
it stops you reproducing. Killing you is just the most obvious way to do 
that...)

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Orchid Win7 v1 <voi### [at] devnull> wrote:
> I love the suggestion some people are making that maybe humans will 
> "evolve" to be less fat.

> This makes it sound as if "evolution" is some magical process whereby 
> each time we reproduce, our DNA gets optimised to our situation, so that 
> as generations pass, everybody slowly improves...

Indeed, genes do not "try" to do anything. They just change slightly with
each individual that's born. Whether those changes will be retained and
widespread throughout the population (during the next few thousands of
generations) depends on lots of things, but mostly on whether it helps the
individuals with that particular change to have a slight edge over those
who don't. (Although sometimes a change can be retained even if it's not
particularly beneficial, as long as it doesn't decrease survival rates.)

Another thing that many people don't understand is that a change in a
gene can have several consequences. The one and same mutation can cause
several effects, some of them can be beneficial and others neutral or
even detrimental. However, it sometimes happens that the benefit is greater
than the harm, in which case the change may get preserved and spread to
future generations. This is often the source of genetic mutations that
seem detrimental and hinder survival rates. On their own they may seem
contrary to natural selection, but more often than not, it's simply a case
of the same mutation causing both beneficial and detrimental changes at
the same time.

I have been thinking that humans have evolved to a point where rather
than becoming better, we may in fact be becoming worse. Because of
progress in healthcare, nutrition, and all other kinds of things that
help people survive, all kinds of detrimental changes to our genes are
not being removed from the gene pool, which means that over time our
genes will become more and more trash. I'm expecting that as further
thousands and thousands of generations pass, the number of genetic
disorders and diseases will only increase in prevalence, simply because
there's nothing removing them from the gene pool.

Basically the only hope we have is if medical science advances to the
point that we can fix those genetic disorders, and our moral philosophy
advances to the point where we allow ourselves to do so.

> No, this is not how evolution works. When you say "humans will evolve to 
> be less fat", what you're actually saying is "all the fat people will 
> die". Because THAT has how evolution changes stuff.

Actually, for humans to evolve to be less fat would require

1) for obesity to be an inherited trait (that can change without causing
   ancillary side-effects that are worse), and
2) for people with this trait to never reach a reproductive age.

Not very likely to happen.

-- 
                                                          - Warp

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>> This makes it sound as if "evolution" is some magical process whereby
>> each time we reproduce, our DNA gets optimised to our situation, so that
>> as generations pass, everybody slowly improves...
>
> Indeed, genes do not "try" to do anything. They just change slightly with
> each individual that's born.

If anything, the only thing "deciding" what genes will go into the next 
generation is YOU - when you decide who to **** with. ;-)

> Another thing that many people don't understand is that a change in a
> gene can have several consequences.

Again, just like a fractal. But then, if you look at molecular biology, 
you discover that cortisol is a hormone, and also just happens to be a 
neurotransmitter too - how random is that? That's like making a 
telephone that's also a video camera - oh, wait...

> I have been thinking that humans have evolved to a point where rather
> than becoming better, we may in fact be becoming worse. Because of
> progress in healthcare, nutrition, and all other kinds of things that
> help people survive, all kinds of detrimental changes to our genes are
> not being removed from the gene pool, which means that over time our
> genes will become more and more trash. I'm expecting that as further
> thousands and thousands of generations pass, the number of genetic
> disorders and diseases will only increase in prevalence, simply because
> there's nothing removing them from the gene pool.

That's the idea I get too.

> Actually, for humans to evolve to be less fat would require
>
> 1) for obesity to be an inherited trait (that can change without causing
>     ancillary side-effects that are worse), and

I think it already is.

It is obvious that how fat you are depends on what you eat. But it is 
equally obvious that some people have more of a tendency to retain fat 
than others, or more of a drive to eat more. As with most things, it's 
partly genetic and partly environmental.

> 2) for people with this trait to never reach a reproductive age.

Well, technically we just need them to not reproduce - either by dying, 
or by failing to find a mate, or whatever.

But yes, I share your conclusion. Not likely.

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> (OK, correction: It doesn't matter if it kills you or not. It matters if
> it stops you reproducing. Killing you is just the most obvious way to do
> that...)

It isn't beyond the realms of possibility that fat people have fewer 
babies (for medical and social reasons).

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> It is obvious that how fat you are depends on what you eat.

And how active you are. Which both probably are linked to how your 
parents behave. Does an "inherited behaviour" count as evolution of the 
mind?

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On Thu, 29 Aug 2013 08:21:50 +0100, scott wrote:

>> It is obvious that how fat you are depends on what you eat.
> 
> And how active you are. Which both probably are linked to how your
> parents behave. Does an "inherited behaviour" count as evolution of the
> mind?

There also is, from what I've read, a genetic component to it.  How the 
body processes nutrients can vary from person to person - otherwise 
there'd be a "perfect" diet that everyone could use (beyond "be 
sensible", that is).

Jim

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>>> It is obvious that how fat you are depends on what you eat.
>>
>> And how active you are. Which both probably are linked to how your
>> parents behave. Does an "inherited behaviour" count as evolution of the
>> mind?
>
> There also is, from what I've read, a genetic component to it.  How the
> body processes nutrients can vary from person to person - otherwise
> there'd be a "perfect" diet that everyone could use (beyond "be
> sensible", that is).

I've read stories about how lab rats injected with certain hormones 
gorge themselves on fat, while if you inject them with different ones 
they prefer to feast on protein. It's entirely possible that there's a 
genetic component to your dietary preferences - and maybe even your 
level of physical activity. Like I said, I'm not suggesting that it's 
ALL genetics; the environmental factors are obvious for all to see. But 
I think there's certainly a genetic component to all of this.

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Orchid Win7 v1 <voi### [at] devnull> wrote:
> I've read stories about how lab rats injected with certain hormones 
> gorge themselves on fat, while if you inject them with different ones 
> they prefer to feast on protein. It's entirely possible that there's a 
> genetic component to your dietary preferences - and maybe even your 
> level of physical activity. Like I said, I'm not suggesting that it's 
> ALL genetics; the environmental factors are obvious for all to see. But 
> I think there's certainly a genetic component to all of this.

And let's not forget, once again, that genes very seldom affect only one
thing. Most often they affect several things. People tend to think that
genes encode individual aspects of the human biology, and that you can
just "fine-tune" each individual aspect by tinkering with its correspondent
gene. But that's not how it usually works.

It's not impossible that the fact that our bodies tend to store all the
extra fat they can get rather than being "moderate" about it may be the
result of a gene that, if modified, would affect something else much more
negatively.

(Although it's also not impossible that "fixing" the obesity problem by
tinkering with the necessary gene could also have other beneficial
ancillary consequences. However, I would guess this to be unlikely
because if it were the case, it would have probably happened on its own
a long time ago.)

-- 
                                                          - Warp

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On 8/28/2013 12:35 AM, Thomas de Groot wrote:
> On 27-8-2013 23:09, Patrick Elliott wrote:
>> On 8/27/2013 10:20 AM, Orchid Win7 v1 wrote:
>>> I was thinking more like if there was one member of the frog family
>>> which has five legs instead of the usual four, or something. THAT would
>>> be weird...
>> Yeah, well.. That isn't likely to happen, six maybe, since you have the
>> whole bi-lateral symmetry thing going on, but then, you would find that,
>> much like "missing" ones, the extras are either a) caused by
>> environmental toxins (common issue with frogs in fact), or b) a copying
>> on the genes needed to produce the limbs. Whether or not, without other
>> regulatory changes, you can get "functional" ones is another matter.
>
> During evolution, Nature does it the other way round. During the
> Devonian when lobe-finned bony fishes appeared and evolved into
> amphibians, Nature experimented with different possibilities. There were
> animals with 7 or more numbers of digits on their legs. Eventually, only
> the animals with 5 digits made it. All the others became extinct.
>
> Search for Acanthostega, Ventastega and Tiktaalik.
>
> Thomas
>
Think I covered that. You are talking about "digits", not "limbs". And, 
yeah, you can change the number of digits trivially, due to, as I said, 
them being coded so that you get, starting with the "thumb" as 0: build 
1, then 2, then 3, then 4, then... either stop and build 0, or keep 
adding on digits, until the "kill point", when the process stops making 
new digits, and goes back to finish with what, for us, is the "fifth", 
i.e., the thumb. The same code that allowed for 7 or more back then, 
still works the same now. It just hits the "stop" point in the cycle 
sooner. But, you can see from, for example, some cats, a case where you 
get 6 toes. Same thing, it start with 1, then goes up to 5, before going 
back to make '0', i.e., the analogous "thumb".

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