Question about Evolution and Efficiency

[throwaway1]

Hello everyone!

 

I had an argument about evolution with someone I know and they claimed that efficiency is a criteria of evolution (as in evolution drifts towards more efficiency).

 

I then pointed out that our very first ancestors (single-celled organisms) were technically already the most efficient organisms and evolution doesn't drift towards more efficiency or less efficiency, it's all about survivability, efficiency really doesn't matter. I mean if efficiency truly was a criteria wouldn't we have to be able to set a minimum standard for how efficient an organism has to be in order to survive? Can we even quantify efficiency in organisms?

 

ps: I'm not a biologist obviously

[Ringer]

No, making babies that make babies is the only criteria for evolution. If your babies make more baby making babies than the other guys babies, then, baby, your babies are moving the process of evolution along.

 

But really, efficiency would be a criteria of ID/Creationism not evolution. Evolution works with a blindfolded buckshot method, if enough stuff comes out of the barrel somethings going to hit the target. It's not efficient, but you still hit the target.

[throwaway1]

Thanks for your reply.

 

The person I am having this argument with had this to say:

 

"Again, you've stated that my argument was an arbitrary amount of efficiency is required
for survival but that's not my argument. If you asked them whether
evolution resulted in capabilities or practices that can be considered
efficient in for example our species that may have helped us survive,
you'd get an answer relevant to this argument."

 

I told him that it can result in capabilities or practises that can be considered efficient, but it can also result in capabilities or practises that could be considered inefficient, it goes both ways. Who is right? Is efficiency a criteria?

Edited February 19, 2013 by throwaway1

[CharonY]

As Ringer stated, the core criterion is the ability to reproduce viable offspring. Even survival is only secondary to that. If the death of one organisms enables its offspring to survive, it may be a viable strategy (and there are many examples for species in which one or both parent die some time after successful reproduction).

So the focus on survival is maybe a bit misleading.

[Arete]

Another issue is that the "efficiency" of an individual organism to pass its genes on to the next generation is relative to:

 

a) The other organisms in the population. The old adage that you don't need to run faster than the lion, you just have to run faster than the guy next to you applies. If the average contribution of genetic material of an individual to the next generation (fecundity) is F, any value greater than F is going to increase the ratio of your genetic material (and thus you evolutionary potential) relative to the population.

 

As an extreme example, a giant panda will only have 5-8 offspring in its lifetime. Thus, though 8 offspring is relatively extremely low fecundity in comparison with other organisms, it is the level of fecundity that will make you a relatively successful (in evolutionary terms) panda. http://www.wwfchina.org/english/pandacentral/htm/learn_about_giant_panda/panda_q_a/reproduction%20.htm

 

b) The environment. Specialization generally comes at the expense of general application. Becoming extremely efficient in a particular environment generally comes at the expense of being less efficient in other environments - rendering extremely specialized organisms highly vulnerable to environmental changes - and environments constantly change. Thus generalized function, even if it's not optimally adapted to a particular environment is often an extremely successful evolutionary strategy. Specialization and increased adaptation towards a fixed peak fitness or efficiency is only effective if you can be very certain that peak is not currently shifting and will not shift in the future - as once it does a specialized strategy may become highly inefficient.

 

An example is if you're a plant who can highly specialized to live above the treeline on mountains - and thus highly efficient compared to your competitors in such an extreme environment - as the climate warms and the environment changes, the habitat you are optimally efficient in shifts above the top of the mountain, and you are out-competed by less specialized plants in a changed environment - thus going locally extinct. http://www.jstor.org/stable/4096792

Edited February 19, 2013 by Arete

[Delta1212]

Of course, as the slow ones get eaten by the lions, the average speed of the population is going to inch up over the generations.

 

Evolution does tend toward increased efficiency because being wasteful with resources is not an effective strategy (unless you're showing off your fitness by demonstrating how wasteful you can afford to be, but that's not truly being wasteful).

 

In a changing environment, though, you're never going to reach maximal efficiency because the definition of what is efficient keeps shifting, often faster than many species can keep up with.

 

Evolution doesn't so much maximize efficiency as slowly peel away inefficiency. Over time that has similar results, but it does take a lot of time, often turns out less than optimal strategies and never quite reaches the peak, because evolution isn't concerned with the best way of doing things, only a way that is "good enough." The most it can do is raise the bar on what qualifies as good enough.

[Ringer]

"Again, you've stated that my argument was an arbitrary amount of efficiency is required

for survival but that's not my argument. If you asked them whether

evolution resulted in capabilities or practices that can be considered

efficient in for example our species that may have helped us survive,

you'd get an answer relevant to this argument."

His question is a using a weird definition of efficient. If something that helped us survive is efficient, anything that allows for survival can be efficient. Our metabolism helps us survive so in that definition it could be considered efficient, but it only uses about 25% of the energy intake so it's not really very efficient. It sounds like a set up to make a convoluted, and ultimately pointless, point.

 

Personally, I'd want him to strictly define efficiency before continuing.

[jp255]

I agree with ringer here. Efficiency needs to be defined and should have been, but I will add some comments to the discussion. When I read the topic title I thought you were going to discuss whether or not the process of evolution in general is efficient.

 

It seems to me the OP and his friend are not on the same page. The friend is arguing that evolution tends towards greater efficiency (for example, new allele compared to the previous allele of origin), so no arbitary level of efficiency is needed to call something efficient.

 

An important point that has been raised already. Efficiency with regards to what? reproduction, survival, fitness, a combination of them?

 

If anything efficiency should be an outcome of evolution, not a criterion of it. The efficiency your friend is arguing for is only possible because of the conditions required for evolution which is "individuals reproduce with variation which causes differential survival/reproduction" and "traits are heritable". So his argument should be "the outcome of evolution always leads to greater efficiency", or something similar to that.

 

Although, it is possible for average fitness levels to fall over generations so I don't agree.

 

Another way of looking at it is when you consider evolution as a heuristic search algorithm, which attempts to discover the highest fitness solution in the fitness landscape. Of course, this is purely theoretical and can't really be applied to nature as we do not know the shapes of the fitness landscapes. Consider it this way and efficiency could occur on two levels, the first is the speed at which it can find the optimum solution and the second is efficiency in terms of fitness gains. For the formor, the process of evolution is not constant and new evolutionary mechanisms have evolved over time so it is a possibility evolution has become more efficient in this aspect (hard to test). To the latter, it is possible that fitness levels can fall over generation (short term at least, and it is common for sexual selection to be involved).

[Ophiolite]

It seems to me that the OP's friend is equating fitness with efficiency. Thus an organism that is more efficient will make better use of its resources and be more likely to survive and procreate. If this is what he means he is correct, but by replacing fitness with efficiency he has merely obscured the basic principle.

[Consistency]

http://en.wikipedia.org/wiki/Efficiency

 

http://en.wikipedia.org/wiki/Alpha_%28ethology%29

[overtone]

Efficiency at what?

[Consistency]

Efficiency at what?

 

Mating, eating, gathering non-poisonous foods, migrating for food, defending themselves from predators, etc...