Biological Energy Redistribution?

Discussion in 'Biology & Genetics' started by KUMAR5, Dec 21, 2017.

  1. Yazata Valued Senior Member

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    The environmental factors would seemingly have to have some impact on differential rates of reproduction.

    Imagine an organism that's very adapted to a particular mode of life (and only that mode of life). If environmental conditions change so dramatically as to destroy that ecological niche, then that organism might become extinct. While those kind of events probably explain a lot of the succession observed in the fossil record, it isn't really Darwinian evolution.

    Now imagine the environmental changes occurring gradually. Imagine that some organisms have heritable phenotypic qualities that make them better adapted to the slightly different conditions. If that adaptive difference makes a difference in their rates of reproduction compared to their old-model fellows, the new variant can be expected to be better represented in future generations. Actually it's more complicated than that, since my scenario imagines a gradualist scenario where tiny phenotypic changes accumulate over time. (That's how Darwin himself imagined it.) But even small genotypic changes can have dramatic and sudden phenotypic effects if they impact fetal development or something. (So we might see 'punctuated equilibrium' events.)

    Your example of cooking might arguably fail right out of the gate. The evolutionary advantage of cooking might be that it makes food easier to digest and hence more nutritious. Arguments have recently been advanced that this might be part of what fueled the explosive growth of hominin brains. (I think that's still hypothetical, but it seems plausible.)

    https://www.smithsonianmag.com/science-nature/why-fire-makes-us-human-72989884/

    https://www.amazon.com/Human-Advantage-Understanding-Became-Remarkable/dp/0262034255

    Ok, I guess that I can buy that. I just saw news the other day that large doses of ibuprophen can (reversibly) lower male sperm counts and testosterone production. I can imagine environmental conditions where that kind of thing happens. If that has an impact on comparative reproductive rates between populations, then there might be selection against populations where those conditions exist. We might be seeing something like that now in the Western world today where sperm counts are said to be dropping and with them reproduction rates. (The latter probably more for sociological reasons.) Reproductive rates have fallen below replacement in many countries and many of these are being flooded by migrants from high reproduction rate regions. But while that would indeed lead to the rapid change in the genetic makeup of a population inhabiting a particular region, it wouldn't be Darwinian evolution. If the cause of the selective difference isn't genetic and heritable, and is instead linked to particular places and modes of life, then new arrivals in those disfavored places and new recruits to those disfavored modes of life might fall prey to the selective disadvantages as well and the cycle repeats.
     
    Last edited: Jan 10, 2018
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  3. DaveC426913 Valued Senior Member

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    No. All pressures put stress on the individuals. Those that eat better reproduce more, passing along their traits. Full stop.
     
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  5. KUMAR5 Registered Senior Member

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    This is what I am thinking. "Survival of fittest" may cover only one part of evolution but depending on particular environment, natural selecion should cover both sides and may also lead to threat to any species.
     
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  7. KUMAR5 Registered Senior Member

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    Survival of fittest should cover only one side of evoluion but natural selection both sides depending on specific environment. We produce millions of sperms, how inherited and environmental factors can effect due to previous odd exposures and which one will be successful in different environment, fittest or weaker, we need to better understand.
     
  8. KUMAR5 Registered Senior Member

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    Odd can be on both side. Better than normal will also be an odd.
     
  9. KUMAR5 Registered Senior Member

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    Thanks. Good explanation. However I am just trying to check negative side of evolution due to constant exposure of negative, unnatural, unhealthful or destructive environment. Survival of fittest under any odd or even environment is just positive side of evolution but whether it can also be negative or not(somewhat survival of unfit) this we can check. Probably, all past consideration about evolution are subject to natural exposures--odd or even. But today, we are exposed to many odd exposures, which Darwin or other might had not even thought.



    Sorry, above can just be one side of cooking. We got it later so it is somewhat secondary natural to us. Other side or health affect from cooked foods is also indicated:
    Effects on nutritional content of food...
    https://en.wikipedia.org/wiki/Cooking

    Yes, this can indicate negative side of evolution which I thought in early part of this post. We can better understand it by recent sperms, egg & vagina quality & environment. I am not sure, whether inharent quality of these cause changes in evolution or just their environment(pH, mucus, thermodynamics etc.)
     
  10. Yazata Valued Senior Member

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    'Negative' how? 'Evolution' why?

    Environmental conditions obviously might influence the survival of organisms in the environment. That will certainly have an effect on the biota in a particular area where whose environmental conditions prevail.

    Organisms dying or reproducing less efficiently because of environmental conditions isn't 'negative evolution'. Biological evolution only becomes applicable if some organisms in your changed environment have a better ability to tolerate it and if that superior tolerance is heritable. That's because the more tolerant variant will be more numerous in the population as time goes on.

    Evolution is joined at the hip with ecology (in the scientific, not the political activist sense).

    I don't understand what you are trying to say there.

    Are you trying to argue that creating an unnatural environment causes human beings to devolve?

    If so, I don't agree with you. I don't believe that evolution has a single preferred direction of advance. (Those ascent of man diagrams create that impression.)

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    But what about the evolution of parasites? Parasitic lineages may end up with a great deal of their physiology reduced, compared to free-living relatives. Yet biologists would have to say that they are highly adapted, hence highly evolved for their new environments.

    https://en.wikipedia.org/wiki/Cestoda

    Evolution isn't about ascent or descent, it's about adapting to environments and lifestyles, in other words to ecological niches.

    I do agree that there are certain heritable qualities of human beings that human beings value. And changing our environmental conditions so that individuals who lack the heritable qualities we value have a reproductive advantage, will end up in humanity tending towards losing those qualities.

    Those subsequent individuals will still be highly adapted and highly evolved for their new conditions, even if they aren't as intelligent, strong or creative (or whatever our preferred qualities are) as we might like.
     
  11. origin In a democracy you deserve the leaders you elect. Valued Senior Member

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    I think that is your problem in a nutshell. Humans are natural. Building a shelter is therefore natural. Cooking food is therefore natural. How could it be anything but natural.
    Your 'negative side of evolution' is a construct of your own set of beliefs and values.
     
  12. KUMAR5 Registered Senior Member

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    If survival of fittest by natural selection is certain model of evolution then all who are concieved and take birth should be the equally fit. But we do see variations in survival and fitness even at same time. Unless medically intervened, many miscarriages can happen, many children can die before their reproductive age without reproduction, many fruit get early fall without fully ripened. Many such happening happen naturally without environmental effect. What does it suggest? Either non fit beings also come into model of natural selection or non genetic part i. e.future conditions after conception also come into picture of natural selection model.
     
  13. KUMAR5 Registered Senior Member

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    I think, all evolutionary changes should be at some cost. These should have both advantage and disadvantage. Eg cooking.
     
  14. origin In a democracy you deserve the leaders you elect. Valued Senior Member

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    I don't think so. It is simply a case that if a trait in a species means it is more likely to successfully reproduce the trait will be carried on. It has nothing to do with cost, or what we would consider an advantage or disadvantage.
     
  15. Write4U Valued Senior Member

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    Of course humans are not exempt from natural selection. Just trace the homonidae line, you can clearly see natural selection at work.

    Modern humans have devised ways to get around infirmity and extending age, but its very successful avoidance of the natural selection has created other problems, which will eventually be our demise.

    Global warming is one such result of human activity and last but not least, there is the exponential function which will cause crowding of large numbers in small habitable spaces and cause shortage of available resources. That's when natural selection will start culling the human population. It's a mathematical inevitability.
    Even at 1% steady growth the human population will exponentially double every 70 years!
     
  16. Write4U Valued Senior Member

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    This is why insects are so adaptable. Their exo-skeleton allows for more space inside as well as relative greater strength and protection. They can pull something 100x their weight, they can jump 50x their own body length.

    Compare it to donning your exo-skeleton of your car or a bulldozer. Relatively speaking insects live within such naturally developed portable vehicles and that gives them a great advantage. It allowed them to become functional hundreds of millions of years before more sophisticated organisms developed.
    https://en.wikipedia.org/wiki/Insect
     
  17. KUMAR5 Registered Senior Member

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    Yes true. We just need to see, how all recent unnatural odds created by humans will be adjusted in evolution and natural selection. Since, these are comparatively new, we need to check it in new style. If nature balance itself can hold some truth, all odds need to be anyway adjusted to bring nature to balance.
     
  18. KUMAR5 Registered Senior Member

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    459
    Yes that is one side of evolution but other side should also be possible bringing destruction, extinction, unhealth etc.
     
  19. Write4U Valued Senior Member

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    That is what The Hellstrom Chronicle warns against. There are only two mobile species which are on the increase. Man, because he can alter its environment, and the insect which can adapt to every alteration, manmade or natural. They have 600 million years of evolutionary refinement in physical adaption, not mental adaption. Man's extraordinary mental abilities is a double edged sword. As we develop our own environment, we are destroying the natural environmen for most all other species, except the insect.

    And then there is a class below the insect, which are practically indestructible, such as the mobile tardigrade, the water-bear and extremophiles which have adapted to extreme environments.
    https://oceanservice.noaa.gov/facts/extremophile.html
     
  20. KUMAR5 Registered Senior Member

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    Do you feel, we shall always progressively be better in survival and fitness?
     
  21. KUMAR5 Registered Senior Member

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    "Natural selection:
    Differential survival and reproduction of organisms as a consequence of the characteristics of the environment."
    How above definition need necessarily match with survival of fittest? I also doubt, if we are already not evolved to other or destructive side of evolution in view of our mass preferance of destructive nature.
     
  22. origin In a democracy you deserve the leaders you elect. Valued Senior Member

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    I am not sure what you are talking about, the definition is stating what survival of the fittest means. Do you think it is saying something else?
    What destructive side of evolution are you talking about?
    If for instance we end mankind with a nuclear war and the planet becomes radioactive so that only species of insects that are resistant to radiation and microbes survive, that will just be normal evolution as we know it.
     
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  23. KUMAR5 Registered Senior Member

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    That definition do not suggest only survival of fittest otherwise why there would had been a need to name it differently. I think following quote can indicate, what I am thinking, :
     

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