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My science textbook says this,

Evolution should not be equated with progress. In fact, there is no real 'progress' in the idea of evolution. Evolution is simply the generation of diversity and the shaping of the diversity by environmental factors. The only progressive trend in evolution seems to be that more and more complex body designs have emerged over time. However, again it is not as if older designs are inefficient! So many of the older and simpler designs still survive [..] In other words, human beings are not the pinnacle of evolution, but simply yet another species in the teeming spectrum of life.

I am not sure if I agree with this, after all humans do seem to be more advanced than dogs. Many people have asked me why I thought this was true, so here is my answer. Today, humans could wipe out dogs from Earth if they wanted, but you can hardly imagine a scenario in which dogs would do the same to humans.

What am I missing here?

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    $\begingroup$ Humans more advanced than dogs? When you consider that dogs have better hearing, a far better sense of smell, often (depending on breed) much greater endurance, a digestive system able to accept a wider variety of food... $\endgroup$ – jamesqf Mar 16 '17 at 18:00
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    $\begingroup$ And if you still think humans are more advanced than dogs, I'd ;like to see YOU catch a frisbee in your mouth :-) $\endgroup$ – jamesqf Mar 17 '17 at 4:04
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    $\begingroup$ humans are the products of 4 billions years of evolution, just like every other living organisms, so either you and e-coli are equally advanced or advancement/progress is not equal to evolution. Evolution is also quite happy to have organisms evolve in a direction that will eventually drive them extinct, as long individual selective entity does better than its competitors. Evolution is less marching in a direction and more the drunkard's walk. Any advancement is due only to chance. $\endgroup$ – John Mar 17 '17 at 9:59
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    $\begingroup$ @Prashant Gokhale: Well, if that's your definition of "advanced". And strictly speaking, humans haven't reached either Mars or Pluto, machines have :-) $\endgroup$ – jamesqf Mar 17 '17 at 18:02
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    $\begingroup$ Actually we try hard to wipe some pests out of one square mile, and usually cannot. When we do, we wipe out a significant part of biodiversity together. Is this to be advanced? $\endgroup$ – Rodrigo Mar 18 '17 at 0:51
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I'm glad you've asked the question as it is a common layman misunderstanding.

Dog vs Human

Your example comparing humans and dogs is actually very central to the logical flaw that yields many to equate evolution with progress.

There are several issues when you say

humans do seem to be more advanced than dogs

  1. Humans are not more evolved than dogs

    • Humans, dogs, jellyfish, oak tree, fungi, bacteria, .... we have all evolved during about 3.5 billion years. None of the extant lineages is more evolved than any other at least in terms of the number of years of evolution. Note, however, that what matters most when considering evolutionary time is the number of generations. Humans having a rather long generation time, it tends to make fewer generations. In this regard, one could expect a dog to have been through more generations than humans and could eventually be called more evolved but even there it is not that easy. See also Are we “more evolved” than present-day bacteria?
  2. You are a human, be aware of your biases

    • As @Jamesqf rightly said in the comments, you did not feel like considering the dog's extraordinary sense of smell, better hearing, higher jumps, stronger jaws or protective fur. Not to mention, dogs can typically raise way more offsprings than humans can. Not to become personal but my 8 months old, 9 kg Cocker Spaniel runs 300 meters at the same time Usain Bolt runs 200 meters! You seem to have only considered things that make you human such as opposable thumbs and high cognitive abilities. Coming to cognitive abilities you will note that a puppy learns by association faster than a baby human. Dogs just plateau much quicker than humans.
    • Make sure that you understand that high cognitive abilities are not a goal or a direction of evolution. While it is hard to measure the evolution of intelligence for both a question of definition and question of measurement tools, it is very very likely that many lineages (incl. eventually the Homo lineage) have evolved toward reducing intelligence at some point (see this post).
    • You say humans could wipe out dogs from Earth however again it feels very human (and awkwardly combative and hostile) to consider the ability to kill as a measure of progress.
  3. The illusion of considering two variables

    • You consider a correlation between two variables 1) how evolved a lineage is and 2) how advanced a lineage is. (As discussed in the first point, there is actually no variance in how evolved lineages are if we consider evolutionary time). You are determining those that are more evolved by how "advanced" you visualize the lineage. Your explanatory and response variables are therefore the same and you do not explain anything by saying 'humans are both more advanced and more evolved than dogs so evolution should equate progress'

Definition of progress

A big issue in your question is the definition of progress. For example, if you define progress as an increase of mean fitness (the concept of fitness in biology has nothing to do with bodybuilding, see here) over time, then yes evolution is in part to be equated with progress as increase in mean fitness over time is exactly what natural selection is doing (see the so-called Fundamental Theorem of Natural Selection).

Evolution ≠ Natural Selection

So, let's assume we define progress as an increase in mean fitness over time. As stated in the previous section, this is exactly what natural selection is doing. So, instead of saying Evolution should not be equated with progress, one could say Natural selection is to be equated with progress (as a reminder this assumes a very specific definition of progress)

You will note that I replace the term evolution with natural selection. It is often unclear to laymen but these two terms, while related, are different.

Evolution is a change of allele (loosely speaking, an allele is a variant of a gene) frequency over time. There are a number of mechanisms that can cause evolution, one of which is natural selection (which itself is caused by a fitness differential associated with genetic variance). But there is way more to evolution than just natural selection. Genetic drift, mutations, migration and other demographic elements are all important factors causing the evolution of populations.

You should have a look at Understanding Evolution by UC Berkeley. It is a very introductory online course on evolutionary biology that will teach you about the basic forces that cause evolution.

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    $\begingroup$ Well said, though I'd argue one point. Evolutionary time should not be measured in years, but in generations. Which means that bacteria, which can produce a new generation every few hours, are far more evolutionarily advanced than us primitive chordates ;-) $\endgroup$ – jamesqf Mar 20 '17 at 3:16
  • $\begingroup$ It would be misleading also to consider number of generations as the quantity of evolution but I agree with your point. I try not to get into complications but I edited my post. Feel free to edit it yourself if you would think of a better way of phrasing it. Thanks. $\endgroup$ – Remi.b Mar 20 '17 at 5:06
  • $\begingroup$ I always thought that what you propose here as other elements are categorically different and are not the alternative to natural selection. Without mutations or migration or etc. there would not be selection, as there would not be change. And selection then would work like a filter of that change, not the component of change itself. $\endgroup$ – rus9384 Jul 12 '18 at 21:13
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    $\begingroup$ I always enjoy and appreciate your answers. This is another good one. I do wonder, though, about equating natural selection with progress. You define it specifically, which helps, but over time, as well as the very word progress suggests an ongoing march over many generations in a constant environment. I wouldn't expect Darwin's finches to be any more fit now than they were in 1836, or in 1831, for that matter. Environments change. Sometimes selective pressures favor large beaks, other times small. You're more knowledgable here, but I wondered what your thoughts were. $\endgroup$ – De Novo Jul 12 '18 at 21:25
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There are two issues here; defining "progress" and equating evolution with it. I'll take the second one first.

When we "equate evolution with progress" we are typically making specific claims (sometimes without thinking about it). We mean that progress is an important priority of evolution or even its goal. We mean that evolution always leads to progress. And when we say "don't equate evolution with progress" we're saying that neither of those things is implied in the Theory of Evolution, and in fact, there isn't much evidence for either.

Humans are more advanced than dogs (again, skipping the question of defining "progress" for now), but humans and dogs aren't the only organisms around. E.coli is as much the outcome of 4 billion years of evolution as we are, yet we didn't "progress" in the same way at all.

One way of looking at it is thinking of diffusion. When I release a dot of dye into the water, it expands outward. Is there a specific force pushing it outward? Are any of the molecules trying to go outward? No, and no; all the molecules are moving randomly, and it is statistics that make it so their overall movement is outward; there simply is more space to move outside of the dot than inside.

And if I put that dye on the right edge of a water container, it would expand leftward. Again, is there a leftward force? Do all the molecules want to go left? No, and no: all the molecules are moving randomly, they just can't go further right than they already are, so for a molecule by the edge any random movement right keeps them where they are and any random movement left takes them left. And the overall average of the molecule's positions will move leftward, even though no specific molecule has a leftward bent (if they did we might expect molecules to disappear from the right edge, and in a diffusion situation they don't). Moreover, if we took the leftmost molecule at a certain point and looked at its trajectory over time, it would sure look like it's deliberately moving leftward... But that deliberateness would be an illusion; out of trillions of molecules moving randomly the odds are good that one of them would have made only or mostly leftward movements, and obviously that's the kind of molecule that would end up being leftmost in the first place. That doesn't mean it is being pushed left, or that its next movement will be leftward.

So applied to evolution, for almost all measures of "progress" we can come up with - size, intelligence, behavioral complexity, structural complexity, whatever - if evolution was pushing any lineage randomly along those variables we would still expect the maximum and even average size/intelligence/complexity to increase over time, because it would be very hard for life to become smaller, dumber or simpler than E.coli (harder but not impossible ! And we see examples of such trajectories, in parasites especially).

Now, you will tell me, evolution isn't random! Through natural selection, it leads to adaptation. True; it leads to adaptation to the environment. Change the environment, you change the direction that evolution will "push" a given lineage. And in the case of things like complexity or intelligence (the usual markers for "progress" in evolution), those traits can be adaptive or not depending on the environment; complexity allows more variety in responding to the environment, intelligence allows more productive interactions with said environment, but both have a cost, in risks of errors, in energy consumption, and so on. And so while you might say this lineage over this time period (in this environment) shows a definite trend towards complexity or intelligence (or gaining flight, or losing sight...), it is impossible to say the same of Evolution as a whole.

One point of evidence that the increase in maximum "progress level" is the result of diffusion and not a specific progress-ward force, is that as the right side of the container that still contained dye, the biosphere still contains tons of (a majority of in fact!) "un-progressed" organisms. This would not be true if Evolution as a whole were pushing toward progress. (in fact, you might note that I am not quite correct here! In a naturalistic view of abiogenesis, living things (or not-technically-living ancestors to living things) must have existed that were themselves outcomes of evolution but were incredibly simple compared to today's amazing bacteria, and those could be thought to be the lower bound in complexity, and Evolution did move life as a whole away from it! So we could argue that Evolution does move towards a minimal level of "progress" (the amount sufficient to compete against a bacterium). It's just that we reached that level over 3 billion years ago).

And to get back to the first point about defining "progress", once you dig down into what that means it can become all the clearer that evolution doesn't push one way or another. Bacteria have more metabolic diversity than Eukaryotes could hope for. Humans are more intelligent than dogs but worse at smelling. It can be argued that from a Müller's Ratchet perspective, "complexity" in Eukaryotes is pretty much constant, and any progress in one domain is the result of tradeoffs in another domain. This doesn't mean humans aren't more "advanced" than dogs, but it does demonstrate you need to be more specific about what "advanced" means for that to be true.

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  • $\begingroup$ It is also worth mentioning one result from the long term E. Coli experiment, sample are periodically taken and frozen, and when older samples are pitted against newer ones, sometimes the older ones outcompete the younger ones. ncbi.nlm.nih.gov/pmc/articles/PMC5788700 $\endgroup$ – John Mar 9 at 19:49
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When you say, humans are more advanced than dogs, from what perspective are you saying that from? Is it in the capacity to use intelligence, to build and create, to do the math, to climb trees? If it is any of these, you are right: humans are better at using intelligence to build and create, at doing the math and at climbing trees than dogs do. However, from the perspective of, say, hunting down a rabbit or detecting by smell some chemical component at very low concentrations in a suitcase, dogs are indubitably better.

So which is actually more advanced? The answer is none, they are just differently adapted to be better at some things - the things they needed to be better at to survive, and which evolution created and preserved. So evolution here simply means the constant modification of living organisms and the perseverance of those who become better adapted to the conditions they live in - this means that a bacteria today is as evolved as a human being, his dog or the tree that dog is peeing on. Now when we talk about progress, we're talking about something which function or capacity improves over a continuum. Evolution does make progress sometimes, such as the progression from initial photoreceptors to the organs of vision we have today (called eyes), and the increasing capacity of some bacteria strains to resist antibiotics - both are signs of progress, and both are made possible through the process of evolution.

At a larger level, we see that life, though evolution, has been progressively more able to create more and more complex organisms (complexity here meaning the amount of information necessary to describe the organism), through the principle of "complexity allows for the creation of more complexity". Today, there are indubitably more complex organisms that there was in the beginnings of life, and yes, we can say humans are one of the most (if not the most, because of brain complexity) complex beings alive, and also complex things in the universe. So we can say that evolution is a process which made possible the progress towards more and more complex things.

What I hope to have helped understand is that evolution and progress are correlated and interdependent, but not the same thing. Evolution is a process which allows for progress, but not always and not necessarily.

I am not including any sources or background because this question relates more to etymology and meaning than scientific research.

EDIT: interesting things you may like to watch about the progress and evolution of complexity:

https://www.youtube.com/watch?v=MTFY0H4EZx4

https://school.bighistoryproject.com/bhplive

https://www.ted.com/talks/david_christian_big_history

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  • $\begingroup$ Okay so Ill answer the questions you asked me at the beggining of the answer. $\endgroup$ – Agile_Eagle Mar 17 '17 at 4:19
  • $\begingroup$ 1.For hunting a rabbit, humans are undoubtedly better, we have sophisticated equipment for that. $\endgroup$ – Agile_Eagle Mar 17 '17 at 4:19
  • $\begingroup$ 2. Moreover for smelling etc, we simply use the dogs for our own use. We can control dogs and use them for our work, but dogs simply cant control us. $\endgroup$ – Agile_Eagle Mar 17 '17 at 4:20
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    $\begingroup$ @Prashant Gokhale: Really? You obviously haven't met my dogs, have you? You might think about who goes out to work all day, and who gets to lounge around the house :-) $\endgroup$ – jamesqf Mar 17 '17 at 18:11
  • $\begingroup$ @jamesqf and we're not even talking about cats yet! :p $\endgroup$ – Filipe Rocha Mar 17 '17 at 19:24
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  1. There is no real progress behind the idea of evolution.

  2. Evolution is simply the generation of diversity and shaping of diversity by environmental selection.

  3. The only progressive trend in evolution seems to be that more and more complex body designs has emerged over time. It doesn't means that the older designs are inefficient.

  4. However, one of the simplest form of life (Bacteria) can even survive in harsh conditions such as hot springs or ice of Antarctica.

  5. Therefore, Human beings aren't the pinnacle of evolution, but simply yet another species in teeming spectrum of evolving life.

SOURCE: NCERT Class 10 science textbook

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  • $\begingroup$ priyanshu, I've downvoted your answer because it is a late answer that doesn't add to the information already present in other answers. We welcome contributions from new users, though. You might try some unanswered questions. It's best if you avoid posting answers to a previously answered question unless your answer adds something to the post. $\endgroup$ – De Novo Mar 9 at 20:36

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