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I wonder if anyone has done an experiment like the one I'm about to describe. Let me know if you have heard of it.

The experiment would involve one set of slightly underfed mice that are not tall enough when on their hind legs to reach some extra food on a ledge in the cage. They'd smell it and want it, but they couldn't reach. The food would always be there, day after day, just out of reach.

You'd need a control group of mice who are similarly underfed but have no shelf of food that is frustratingly beyond their reach.

I'm curious if the mice that have the shelf of food just above their reach would produce taller offspring, on average, than the control group.

If so, I would call that Aspirational Evolution. My hypothesis is that creatures with brains have evolved in a way that allows one generation to influence the genes of the next based on what the parents imagine they need to better survive.

I do know that if one generation of humans lifts weights, for example, it doesn't automatically make their kids have bigger muscles. But going to the gym has no immediate survival advantage in the way that extra food has to a hungry mouse. Exercise registers to us as more of a rational decision that might pay off over the years. Hunger is right now, and emotional.

When humans get stressed, their bodies automatically produce one set of chemicals, and if they fall in love they produce another. There's a lot going on in our bodies, chemistry-wise. It wouldn't surprise me to learn that our minds - and specifically our aspirations - positively influence the design of the sperm and eggs that are formed by our bodily juices.

Has anyone done that experiment?

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Dec 5, 2013
Just read this today and thought of you and this post Scott

Sep 3, 2013
Just to agree with Code Jammer - Scott very deliberately said he WASN'T looking at Lamarkian evolution, but at whether chemical/hormonal changes in a subject, brought on by the reaction to the environment, would have an effect on offspring.

I agree it would be an intriguing experiment. I suspect it would fail, as I doubt that the hormonal changes would be pronounced enough to affect foetal deelopment, but might be worth doing.

Scott, you're a wealthy man. Employ an intern (or the stepkids) and get cracking!
Aug 31, 2013
"Has anyone done that experiment?"

Yes. The Soviet Union. It failed.
+4 Rank Up Rank Down
Aug 30, 2013
Three points:

1) Lamarckian evolution, in which the physical efforts of parents affect children (e.g., mice straining to reach will have taller offspring, body builders will have ripped kids, etc.) is basically false. Physical activity does not affect your genes or which genes you pass on.

2) However, the activation of various genes can be altered. What your parents do will affect which of your genes are activated and to which degree, even if it doesn't affect your genes directly. So it's possible that any genes relating to height might be more strongly activated.

3) Short mice might view the shortest of their lot as undesirable mating partners. So they would self-select for height and maybe produce taller offspring with time.
Aug 29, 2013
Late to the game, I know...

The answer is Yes!

To the extent that mice choose their breeding partners according to their own aspirations, longer mice will be more desirable and will breed with other longer mice. If all the mice in the experiment are the same size, this may not manifest until the 2nd generation starts breeding since you would expect this generation to have variations in size.

Evolution isn't just about survival advantages. It's also about mating advantages. For an animal to avoid becoming an evolutionary doorstop, it must survive, yes, but it must also breed. The more prolific breeders pass more of their DNA into the gene pool. If the survival and mating advantages are passed on genetically, that offspring will distribute the DNA into an even larger gene pool over time.

In any case - wishing won't work, but selecting a mate that shows desirable qualities does work. Naturally.
Aug 28, 2013
I wonder how a creature would distinguish between 'things I need to survive' versus 'things I really want'. If aspirational evolution worked, and not strictly for survival-related things, we would all have baseball bat sized penises by now.
Aug 28, 2013
Basically, evolution is about survival. If (a strong if) such a mechanism ("aspriational evolution") did exist, it would probably be a survival advantage in the long run.

On the other hand, evolution is about efficiency. The resources of any organism are limited and have to be used in the most efficient way to produce the biggest survival advantage. Implementing a hypothetical mechanism to transform wishes into future genes sounds rather complicated and might be less efficient than other, more direct ways to success (like leg training for better jumping abilities, learning to use tools for getting at the food, or simply looking for food elsewhere - the world out there has many more alternatives to offer than your simplistic experimental setup).

But in the first place, I think your concept would require a certain degree of intelligence in the respective species. In order to make a wish (I wish I'd be taller so I could get at the food) you have to be able to understand the nature of the problem first. I don't think mice' minds work that way. You need to be smart for expressing the wish, and if you are smart, you might as well devise ways to get at the food without waiting for your children's genes to evolve.
Aug 28, 2013
Not an expert in mice intelligence, but if a mouse figured how to jump or climb high enough, could that behavior be learned by other mice and offspring by example? And could something that is taught throughout the species, the way cats teach their young to hunt, be counted as evolution?
Aug 27, 2013
An awful lot of posters are talking about how this is similar to Lamarckism. I would argue that Scott is talking about something totally different. Lamarckism revolves around a parent "acquiring" a physical attribute i.e. a giraffe stretching its neck to be longer or a bodybuilder building above-normal muscle matter and then passing them on to their children (indicating that the genetic make-up of the parent has changed).

What Scott seems to be asking is can a parent actively alter the genetics of the offspring by wanting a specific attribute to be altered (kind of a wishful thinking sort of deal).

I don't think it is entirely unimaginable that this might be a possibility. Larmarckism is generally accepted as non-existent, but I don't think it has anything to do with Scott's idea of an aspirational change in familial genetics.

[I was just coming to post a message saying exactly what you said. I find it fascinating that this topic (evolution) causes people to lose their reading comprehension skills two words into any paragraph on the topic. I've never seen anything quite like it. Apparently you are immune to whatever blinded the others. I appreciate you doing the clarifying because if I had done it myself the Internet would say I was "backpedaling." -- Scott]
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Aug 27, 2013
Greetings to all;

Scott, interesting proposal. But not correct if you utilize the LaMarkian approach and expect rapid (within one or two generations) results. Consider the giraffe. Eons ago it started out as a short bodied animal. As its food source was from trees that grew progressively higher, only those giraffe ancestors with genes for longer necks and legs survived. Their shorter kin died off. That took any thousands of generations and helps demonstrate that genetic modification, i.e. messing with the DNA drives evolution.

There is an alternative. You could do the Wally, "no work" thing. That is. let radiation and/or DNA altering chemicals do the work and speed things up. That would still take several generations before you got your taller animals. Wishing all have a grand day.

Aug 27, 2013
We know now that environment does have some strange and unexpected effects on gene expression but if our minds could shape genetics to any large degree there would be much more variation in phenotype than there is - and it simply doesn't exist. It would be nice if it did - but it doesn't.

It is wrong to discount environment for human improvement, however. I saw a somewhat convincing study showing a correlation between 1st month nutrition and adult IQ. The world-changing suggestion is we could live in a world with somewhat smarter people if we focused some effort on that critical first month.
Aug 27, 2013
@Dilbro, well said, but i disagree.

"I keep reading your full comment, and I don't understand why even you don't think those are examples of what Scott is asking."
1. I think the examples are relevant because of the point you observed, that they are examples of environment potentially altering genes.

2. I did not complete my thought in my post, and I should have. In the case of alcoholism and PTSD potentially altering genes, the results in future generations tended to be NEGATIVE, i.e. higher correlations of the bad thing in future generations rather that lower correlations. This would be the reverse result from what Scott is proposing.

3. admit it, you liked the modernism dub.
+7 Rank Up Rank Down
Aug 27, 2013
Most likely the mice would just climb onto each-other to reach the food on day one.
+12 Rank Up Rank Down
Aug 27, 2013
Won't work.

If it did then we'd all have wings (man has dreamed of flying since forever).
+1 Rank Up Rank Down
Aug 27, 2013
Epigenetic theory, anyone? If it turns out to be true, and we and our genes are susceptible to it - why wouldn't mice and their genes be susceptible too?


Otherwise, it's still evolution without need for adjective like "aspirational"...
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Aug 26, 2013
Sorry, mistook a "slightly" for a "highly" on my mobile.
So, no starving involved.

Still, as long as the (additional) food source is so far up as to be out if reach ti all mice and their likely offspring, I don't think you'll get far because a slight size increase won't give an advantage. And mice surely aren't intelligent enough to think "One foot up is food, we need one foot mice, let's start a breeding programme".
+5 Rank Up Rank Down
Aug 26, 2013
Normally, the offspring of staving families tends to be smaller and mentally retarded. At least in humans.

I guess, for your experiment to work, you'd have to raise the food source gradually, over several generations, so that the longest mice survive. However, this is no longer lamarckian, but purely darwinian.
+4 Rank Up Rank Down
Aug 26, 2013
The answer will cost you the price of the grant I will need to conduct the experiment for you.

Surely someone with your resources can afford to support science?
+1 Rank Up Rank Down
Aug 26, 2013
Nobody has challenged what you said...

"i have heard of two different areas where genes have shown to be effected by experience. First, alcoholism has been shown to alter the genes of offspring in some cases. Second, extreme PTSD has been shown to alter the genes of offspring in some cases."

...and that seems like environment directly driving evolution in your two examples.
I keep reading your full comment, and I don't understand why even you don't think those are examples of what Scott is asking.

I see lots of comments where people think this is a question of "wishing" or "hyper-wishing".
But isn't the lifelong stress underfed mice experience, endlessly seeking the additional food, similar to PTSD.

If this was only a question of wishing producing results in the next generation, guys would no longer be able to walk, due to the "third leg" dragging painfully along behind them.
Aug 26, 2013
[With food continually out of reach can you explain why the mice wouldn't die before they produced any offspring?]

That same thought occurred to me as well, but it then occurred to me that underfed humans produce offspring all the time so....
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