Notices
Results 1 to 53 of 53

Thread: Evolution of agriculture

  1. #1 Evolution of agriculture 
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    Definition of agriculture (Wikipedia): Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life.[1] Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the development of civilization.
    There are many questions I want to ask.
    How could hunter gatherer human, domesticate food creating plants? It seems unnatural in those days.
    Prior to domestication, were those plants creating the food? Then for whom?
    When did human learn agriculture or say farming?
    Because according to me: Agriculture is to understand the role of a single seed in a life cycle of a particular plant. It was impossible for hunters and gatherers.


    Reply With Quote  
     

  2.  
     

  3. #2  
    Forum Masters Degree
    Join Date
    Jan 2011
    Posts
    500
    Understanding the life cycles of plants is essential for hunter-gatherer societies. If one doesn't know where there are nutrients, then one can't go there to gather them. It takes a lot of calories to go out to gather, so one cannot really do it at random and hope to get something.

    Given that hunter-gatherers already understand something about the life cycles of plants, it's not that hard to learn the relationship between seeds and plants. It becomes pretty obvious because seeds of many kind begin to grow on the surface of the ground.

    It then becomes in the best interets of h-g societies to manage their wildlife. Many h-g societies performed controlled burns in order to ensure that certain corridors would be available for game and for certain kinds of plants. Many h-g societies groomed certain areas in other ways for the growth and concentration of certain plants.

    Once this behaviour becomes established, if a plant can be found that is regular enough, that has enough nutrient value, and that can be stored, more-or-less sedentary agriculture is viable. This is especially the case in areas where some sort of trade can be maintained with other groups that continue to hunt and gather.


    Reply With Quote  
     

  4. #3  
    Forum Radioactive Isotope skeptic's Avatar
    Join Date
    Nov 2008
    Location
    New Zealand
    Posts
    4,840
    Personally I believe that a simple form of agriculture has been practised for a very long time by our ancestors, including hunter/gatherer tribal societies.

    The thing is that, ever since the evolution of Homo sapiens, some 200,000 years ago, the emergence of highly intelligent individuals, even genius, will happen periodically. These special individuals will initiate change in their societies. Some of those changes might be simply a new way of knapping stone tools. But some are likely to have involved agriculture.

    The best example I can think of is growing cassava. This tropical food plant produces a mass of roots able to be cooked and eaten. To replant it, all you need to do is stick the stem back in the ground. If you first break the stem into several pieces, and stick each piece in the ground, you end up with a bunch of cassava plants growing and producing edible roots. This would be simple agriculture, and could even be practised by nomadic tribes who pass the same place again.

    The big break through into a more modern system of living came about 10,000 years ago. However, it seems to have been characterised by the cultivation of grains, such as wheat. Grains have the great benefit that they can be stored dry almost indefinitely. Thus, a seasonal crop can supply a tribe all year round. With this more secure food supply, the development of settled communities such as villages and towns can occur, and also the development of specialised trades, such as tool makers, who will swap their products for food.

    However, there are many societies where cultivation of grains never happened, and instead, growing other crops predominated. Since many of these other crops could easily have been cultivated in ways similar to cassava as described above, I strongly suspect that this simplified agriculture was widely practised long before the cultivation of grains.
    Reply With Quote  
     

  5. #4  
    Veracity Vigilante inow's Avatar
    Join Date
    Oct 2009
    Location
    Austin, TX
    Posts
    3,499
    ^ +1

    Couldn't agree with you more. Well writ.
    Reply With Quote  
     

  6. #5  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    Quote Originally Posted by skeptic
    The big break through into a more modern system of living came about 10,000 years ago. However, it seems to have been characterised by the cultivation of grains, such as wheat. Grains have the great benefit that they can be stored dry almost indefinitely. Thus, a seasonal crop can supply a tribe all year round. With this more secure food supply, the development of settled communities such as villages and towns can occur, and also the development of specialised trades, such as tool makers, who will swap their products for food.
    If the evolution of Homo sapiens happened some 200,000 years ago and If cultivation of grains happened 10000 years ago, then one can easily argue that there was little chance for evolution of human civilization to start prior to evolution of agriculture and hence humanís civilization is 10000 years old only.
    Reply With Quote  
     

  7. #6  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    What I want to say is our civilization is at least 60 to 70 thousand years old. We didnít know farming then but for that long period (60 to 70 thousand years) we coevolved with weedy species which started to grow bigger seeds for humans diet.
    Reply With Quote  
     

  8. #7  
    Forum Radioactive Isotope skeptic's Avatar
    Join Date
    Nov 2008
    Location
    New Zealand
    Posts
    4,840
    uday

    do you have evidence for this idea?
    Reply With Quote  
     

  9. #8  
    Iuvenis ducis Darkhorse's Avatar
    Join Date
    Mar 2011
    Posts
    105
    Plants don't grow food for us they grow them to propagate. So before we domesticated them they still produced food, some of it would be eaten by animals, some would be eaten by H-G and some would rot on the ground.

    H-G would have certain types of preferred food, and would attempt to locate the "best" type of that food. This causes a virtuous cycle since their like of a food usually will help propagate the food through waste products, spoilage, and spills. As time passes the food that they like appears more often closer to their camping locations which starts an informal farming process at camp locations.

    With planet growing closer to the camps they can be protected from animals. Again the best plants are chosen first which leads to further refinements in the plants around the camps.

    All this can happen without the H-G having any idea about farming and why planets grow. When the penny drops and they link seeds (or other forms of propagation) to plants, it is a small step to move to slash and burn farming.
    Reply With Quote  
     

  10. #9  
    Forum Freshman
    Join Date
    Apr 2011
    Posts
    17
    The best example I can think of is growing cassava. This tropical food plant produces a mass of roots able to be cooked and eaten. To replant it, all you need to do is stick the stem back in the ground. If you first break the stem into several pieces, and stick each piece in the ground, you end up with a bunch of cassava plants growing and producing edible roots. This would be simple agriculture, and could even be practised by nomadic tribes who pass the same place again.
    Yes, this makes so much sense.

    All it would take to make this observation is to note that scraps tossed on the midden lead to new plants being sprouted. Surely it's not a big leap to conclude that pieces of the plant can put in a different place for planned cultivation.
    Reply With Quote  
     

  11. #10  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    Quote Originally Posted by skeptic
    uday

    do you have evidence for this idea?

    YES. I do have as much evidence for my hypothesis as the other hypothesis of human evolution have.
    Does one have evidence for bipedalism, hairlessness and other human evolution hypothesis?
    According to Darkhorse: "Plants don't grow food for us they grow them to propagate."
    So if for propagation plants have to grow food, their main interest lies in who eats it. Plants canít carry their seeds but they can certainly choose their seed carriers by growing the food to the liking of their preferred carriers. This is what co evolution is.
    Coevolution theory of David Rindos, proposes that proximity of humans and a plant would set in motion a process by which humans would modify environment of that plant favoring genetic changes in it. These same changes would make plant more attractive as human resource.
    My hypothesis suggests that weedy species living in the vicinity of human band started to grow bigger seeds (grains) for human diet and stopped his wandering.
    Weedy species were low ranked species of the habitat and hence had great genetic plasticity, favoring rapid co evolutionary response to supreme human band influence.
    Human supremacy, established on the lands of perennial rivers and a process of coevolution between weedy species and humans, might have taken place at the same time.
    Reply With Quote  
     

  12. #11  
    Iuvenis ducis Darkhorse's Avatar
    Join Date
    Mar 2011
    Posts
    105
    Plants know nothing about how their seeds get propagated, they have no "interests". Please explain where plants would do this reasoning. In their leaves, stalks, or maybe their roots? You have been watching too many Disney movies, plants do not think, move or sound like Eddy Murphy.

    Did humans change the plants environment? Yes. Did the plants know anything about this? No. In order to know something you have to be able to think and plants don't think.

    My mistake was using your word food. Plants do not create food they create a package for their seeds that maximises its chances to survive. It provides nutrients to get it started and that is it. The fact that we eat those packages and call them fruit, or food or mana means nothing to the plant.

    Everything you are claiming can be explained by the existing theories and it does not require any plant thinking. Show me scientific proof that plants can think and I will listen to you.
    Reply With Quote  
     

  13. #12  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    Quote Originally Posted by Darkhorse

    Everything you are claiming can be explained by the existing theories and it does not require any plant thinking. Show me scientific proof that plants can think and I will listen to you.
    I know that plants donít think. That is for sure. What I meant to say is there in my last post yet I repeat it in other form.
    Genetic changes take place in plants and animals and all living objects (thinking or non-thinking) when their environment is modified. Living objects go on living; changes take place at their genesí level.
    It is for their (genesíown) survival. I know little about it but the diversity of life and yet the inter dependence of living objects for survival is astonishing.
    I request you to read carefully what David Rindos proposes in his Co evolution Theory: ďProximity of humans and a plant would set in motion a process by which humans would modify environment of that plant favoring genetic changes in it. These same changes would make plant more attractive as human resource.Ē
    Before human band started to live on the banks of perennial rivers, weedy species had very small seeds, which were supposed to be flown away by wind and in case if consumed by animals they would come out unharmed and thus propagate far away.
    Reply With Quote  
     

  14. #13  
    Moderator Moderator TheBiologista's Avatar
    Join Date
    Aug 2008
    Posts
    2,564
    Quote Originally Posted by uday yadav
    Genetic changes take place in plants and animals and all living objects (thinking or non-thinking) when their environment is modified. Living objects go on living; changes take place at their genesí level.
    Genetic changes don't really take place within an organism during it's lifetime, regardless of environmental changes. We pick up some mutations as we go through life, but the vast majority of these can't be passed on to our children. Inheritable genetic changes take place when our gamete cells undergo reassortment, or more rarely when our gamete cells are genetically modified by mutagenic agents. These sorts of genetic changes in populations are taking place constantly. For example, each new human is born with several hundred new variations in their DNA. However, the environment has little to do with those changes. The environment determines which of these variations will survive longest and reproduce the most. The environment changes the frequency of this gene and that gene, but it is not the origin of variation.

    That's a potted version of evolution. Mutation causes the changes, selection determines which changes become common and which ones do not. Other species form a part of natural selection, along with the environment. So it's correct to say that species co-evolve, but your understanding of evolution seems to be a bit wooly.
    Reply With Quote  
     

  15. #14  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    [quote="TheBiologista"]
    "That's a potted version of evolution. Mutation causes the changes, selection determines which changes become common and which ones do not. Other species form a part of natural selection, along with the environment. So it's correct to say that species co-evolve, but your understanding of evolution seems to be a bit wooly."


    Thanks. That is master stroke. I had tried to understand the subject (genetics) but could not go beyond my last post. It takes hundreds of births for remarkable changes to take place in an organism that we would call evolution.
    I hope it doesnít come in my way of constructing a faultless and most probable human evolution hypothesis that I am eager to post here.
    It includes : human shoulders,
    perennial rivers,
    bigger seeds : long lasting food stock
    bipedalism,
    menstruation,
    hairlessness,
    shelters, colonization,
    long lasting food stock becomes perennial food stock,
    rise of civilization on the banks of perennial rivers,
    understanding the role of a single seed in life cycle of a plant 10000 years ago,
    rush to grab immeasurable land on the earth for agriculture.
    Reply With Quote  
     

  16. #15  
    Universal Mind John Galt's Avatar
    Join Date
    Jul 2005
    Posts
    14,168
    Darkhorse,
    you appear to be denying that the evolution of many fruits are specifically to encourage comsumption by animals that will then deposit the seeds in arich bed of natural manure. If you are not denying this then you are, effectively, agreeing with uday's rather metaphorical description of the process.

    Uday,
    I'm not sure you are saying anything especially new or surprising. We domesticated plants and animals. They also domesticated us.
    Reply With Quote  
     

  17. #16  
    Iuvenis ducis Darkhorse's Avatar
    Join Date
    Mar 2011
    Posts
    105
    Ophiolite, the point I am trying to make is that plants do not make decisions about what happens to their seeds. Plants grow and produce seeds. Through natural selection plants that are more edible are propagated more freely. The encouragement of consumption is a by product of natural selection not of purposeful design.
    Reply With Quote  
     

  18. #17  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    Quote Originally Posted by Ophiolite
    Uday,
    I'm not sure you are saying anything especially new or surprising. We domesticated plants and animals. They also domesticated us.
    my hypothesis is totally different and will definitelly surprise you. It is an answer to all human mysteries.
    Reply With Quote  
     

  19. #18  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    80,000 to 100,000 years ago, human was living in bands of 20 to 30 members in many places on the earth like many other animal bands. He had body fur and like every other animal he kept distance from fire.
    Humanís shoulder joints, allowed his shoulders to move through a tremendous range of motion, making it the most mobile joint in the human body. The shoulder can abduct, adduct, rotate, be raised in front of and behind the torso and move through a full circle in the sagittal plane. See Wikipedia.
    Using both palms and fingers, he could grip a thing less firmly than that of other primates but unlike them he could strike a thing with force and much speed. Hence, by gripping long and heavy sticks human band was able to hit and kill animals without getting injured.
    Furthermore, the human band could throw stones at animals from safe distance with a frightening speed that animals had to run away or get injured. Above this, the band always carried sharp sticks with them which they could pierce into the body of animal of any size, bringing instant death.
    For throwing, hard-hitting, forcing the penetration and striking, humans developed peculiar shoulder joints unlike other primates that made all the animals, keep safe distance from human band. For fear of injury or death, every other animal had to leave its habitat on arrival of human band.
    Though supreme human bands wandered from place to place in search of food [fruits, edible plants, roots and animals], they preferred, as any other animal band would, to spend most of their time in the vicinity of perennial rivers and perennial water streams. During their stay, other animals stayed away from them.
    CONCLUSION: Peculiar shoulder joints was a single cause of human supremacy.
    Long durations of their stay near perennial rivers, influenced nearby fields of weedy species greatly. In the durations of human band stay, all the vegetation including weedy species experienced complete protection from herbivorous animals. In absence of herbivorous and carnivorous animals, their habitat was being affected only by human supremacy, his food wastes and his excrements. His food wastes and his excrements were nutritionally richer than other powerful and big animals as occasionally all powerful animals were part of his diet. Weedy species were low ranked species of the habitat and hence had great genetic plasticity, favoring rapid co evolutionary response to supreme human influence.
    Coevolution theory of David Rindos, proposes that proximity of humans and a plant would set in motion a process by which humans would modify environment of that plant favoring genetic changes in it. These same changes would make plant more attractive as human resource.
    In the presence of human band and in the absence of grazers; weeds and shrubs lived through an undisturbed life span which made Davidís theory possible. On the most fertile lands of perennial rivers, weedy species, under unintentional protection of human bands, started to produce bigger seeds for them.
    Within no time human band became attracted to bigger seeds. This was a long lasting and durable food stock that presented itself on his land of choice. I admit, this total process of co evolution might have taken thousands of years.
    Human supremacy was the cause of Davidís theory of co evolution and perennial rivers; its location.
    Human bands living by perennial rivers thus came in possession of abundant food stock (bigger seeds retaining on stalks). This food was not like large animal meat that if not consumed, decomposes in few days. This food was not only a big food stock but also a durable and non decaying and non decomposing food stock till coming monsoon.
    On the arrival of monsoon, these seeds got deformed into edible vegetables and then got lost into flourishing jungle of the plants that would eventually again start the process of growing heavy stock of seeds on their stalks but meanwhile human band had to wander in the vicinity in search of food.
    Human band became heavily dependent on weedy species for their durable food stock of bigger seeds. Herbivorous animals, lured by bigger seeds, entering these fields were easily brought into diet of human band. So they intentionally started protection of fields of growing seeds which were increasing year by year. Protection of growing seeds became self rewarding engagement.
    CONCLUSION: ďAs grains evolved to be long lasting food for humans, the hairy human bands started to stay near all perennial rivers, nearly 70 to 80 thousand years ago.Ē
    Want me to go further with my hypothesis?
    Reply With Quote  
     

  20. #19  
    Universal Mind John Galt's Avatar
    Join Date
    Jul 2005
    Posts
    14,168
    Quote Originally Posted by uday yadav
    80,000 to 100,000 years ago, human was living in bands of 20 to 30 members in many places on the earth like many other animal bands. He had body fur and like every other animal he kept distance from fire.
    1. We had already lost our significant body hair 100,000 years ago.
    2. We had been using fire since before we were homo sapiens - over one million years ago.

    I don't need to proceed any further with your idea. It is wrong.
    Reply With Quote  
     

  21. #20  
    Forum Cosmic Wizard SkinWalker's Avatar
    Join Date
    Apr 2005
    Location
    Grand Prairie, TX
    Posts
    2,376
    2. We had been using fire since before we were homo sapiens - over one million years ago.
    Earliest evidence of control of fire is at around 780 ka at a site in modern Israel called Gesher Benot Ya'aqov. It was probably a Homo ergaster or H. erectus site.

    That's not to say that fire wasn't invented elsewhere at a much earlier time, this is just the single oldest site that presents inarguable evidence that fire was under the full control of early humans.

    It was probably invented several times by different hominid groups.
    Reply With Quote  
     

  22. #21  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    Quote Originally Posted by Ophiolite

    I don't need to proceed any further with your idea. It is wrong.
    Does it mean that hereon you wonít allow my ideas all contradictory to existing ones, be posted here?
    Reply With Quote  
     

  23. #22  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    If human was hairless 100ka, was he confined to the warmer part of the earth? Why on earth did he loose his fur and started using othersí furs? When did he reach colder places and why? Many of archeological findings are being exploited as ďevidenceĒ by the senior experts to support their otherwise senseless theories.
    One savanna theory proposes human lost hair 7mya. There is one theory population bottleneck that says only 1000 humans remained in some part of Africa some mya and that time human lost his fur, he became erect and then spread all over the earth. And to prove such theories they have stamped these archeological findings as ĎEVIDENCEí.
    One most senseless theory says menstruation happened 7mya. What an insult to women.
    Reply With Quote  
     

  24. #23  
    Suspended
    Join Date
    Apr 2007
    Location
    Pennsylvania
    Posts
    8,795
    Quote Originally Posted by uday yadav
    In the durations of human band stay, all the vegetation including weedy species experienced complete protection from herbivorous animals.
    Hah! Did you ever try growing a garden?
    Reply With Quote  
     

  25. #24  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    Quote Originally Posted by Harold14370
    Hah! Did you ever try growing a garden?
    Start killing and eating the intruders, garden plants will grow rapidly.
    Reply With Quote  
     

  26. #25  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    Quote Originally Posted by Ophiolite
    1. We had already lost our significant body hair 100,000 years ago.
    2. We had been using fire since before we were homo sapiens - over one million years ago.

    I don't need to proceed any further with your idea. It is wrong.
    To,
    OPHIOLITE,
    Ok. I agree. There is a convincing theory of hairlessness and control of fire some mya. You are convinced of their viability. And you are devoted to that theory.

    But are you not curious about my rather foolish and wrong idea of human hairlessness a little? Just out of curiosity, donít you want to know the monkey tricks I am going to play while proposing human hairlessness long after human co evolution with grain plants?
    Reply With Quote  
     

  27. #26  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    Since my last post some 40 visitors read this topic. Evolution of agriculture. So I am encouraged to write further.
    Human is hairless and uses clothes or animal skin for protection from cold and extreme heat. So I concluded that some time back human became so powerful that when he killed some animal for his diet, other predators dared not come near him for their share. So he could keep the prey as well its skin too. Again it is very simple to see that alone he could not have killed the animal because compared to other predators human body is very vulnerable. So I obviously concluded that human lived in groups. Further I concluded that he lived in a band of 25 to 30 members and so could kill every available animal for diet and animal skin.
    This led me to think that human had lost his fur only after he became capable of protecting animalís fur. But then he might protect many things along with animalís fur. Powerful human taking care of his belongings in the hungry world was a big thing and might have shaped the environment in the vicinity which again might have helped him for his further development.
    Power leads to development. Humanís power driven social development canít be older than 100 thousand years. That is why time span of my story is 100 thousand years. But in no way power would have helped him loose his hair. Why should he carry animal skins when he had his own fur? Why should he loose his hair when other animals of the world have not done so?
    Further, human lives everywhere on the earth. Though he lives in Iceland, he does not have body fur for protection from freezing temperatures. When in history, did human reach Iceland or say North Pole and South Pole? It is sure thing that if he had reached the poles with his body fur on, he would not have lost it in that extreme cold conditions. So when he reached the extremely cold poles, he was hairless. Powerful human band always must have lived on the land of its own choice and colder poles were definitely not its chosen habitat.
    So I concluded that extremely overpowering conditions must have made humanís hairlessness a small issue for him and have compelled him to leave his chosen land and go further and further ahead until he found some kind of secured land to stay on.
    Above mystery has compelled most of the thinkers to surrender themselves to the idea of population bottlenecks.
    Human has spread himself everywhere on the earth. Animals (deer, lion, rhino, tiger, elephant, zecbra etc) live together but donít live where human lives. Every species wants to populate the whole world by their offspring. Then why did all the animals including primates stay away from human habitats? Staying away has brought them to the stage of extinction.
    Then comes agriculture. Thinkers simply say Ďwhen human started agriculture, he stayed near rivers.í But when you define the word agriculture you will know how difficult it was for human to start agriculture.
    Agriculture is to understand the role of a single seed in a life cycle of a particular plant.
    Hunter gatherer human stayed in one place to learn agriculture is only foolish.
    Isnít it an unsolved mystery? Bipedalism, hairlessness, agriculture? Do you have an answer?
    I have. My next post is about evolution of bipedalism and menstruation.
    Reply With Quote  
     

  28. #27  
    Moderator Moderator TheBiologista's Avatar
    Join Date
    Aug 2008
    Posts
    2,564
    Quote Originally Posted by uday yadav
    Since my last post some 40 visitors read this topic. Evolution of agriculture. So I am encouraged to write further.
    Unless they post responses, I request that you please do not make additional posts. Unless a thread is genuinely popular, it should not be bumped up the list.
    Reply With Quote  
     

  29. #28  
    Time Lord
    Join Date
    Apr 2008
    Posts
    5,328
    Quote Originally Posted by uday yadav
    by gripping long and heavy sticks human band was able to hit and kill animals without getting injured.
    Furthermore, the human band could throw stones at animals from safe distance with a frightening speed.
    We also see chimpanzees drive off threats and nuisances by mobbing targets with sticks and thrown stones. The chimps aren't very dexterous, but it works.

    Quote Originally Posted by uday yadav
    Why should (man) loose his hair when other animals of the world have not done so?
    I argue that we lost our hair partially because other animals had not. We're more easily identifiable as a unique species. This saves everybody a lot of hassle.

    Weapons provide a "sting", so harassing us - as with bees or porcupines - becomes more trouble than we're worth. Predatory mammals learn to avoid such species. They'd bully another primate... if they can tell us apart. I think it no coincidence that our markings, displays, and vocalizations set us apart: markings like our unique hair pattern, displays like passive bipedalism & arm waving when distressed, vocalizations like our incessant babbling that alerts animals (who know man) to leave the area. These are warning traits of we got on account of our stingers.

    I think we lost our hair for many reasons. Identification to other species is one.

    There is good reason to believe humans were once less hairy than today. Our lice (body lice not head lice) had gone extinct, then later we had sufficient hair to reacquire lice from gorillas. Those gorilla lice evolved into our modern human lice.

    Perhaps the resurgence of body hair had something to do with our migration to cooler regions and wearing clothes? Clothes become the new species marking, so there'd be no advantage in maintaining hairlessness for looks. Also, primitive clothes are painfully rough and chafing to bare skin, but body hair helps a lot in this case. Can we correlate a people's traditional clothing (or lack of) with their body hair?

    Quote Originally Posted by Harold14370
    Did you ever try growing a garden?
    Deer only forage in suburbs and cities now that we've stopped teaching them to avoid us. How often do you see modern man brain a deer at 20 meters with a pop bottle and follow up with a roar and a thrown crowbar? Since chimps do it, and our earliest art depicts it, safe to assume this was normal behaviour.


    Quote Originally Posted by uday yadav
    For fear of injury or death, every other animal had to leave its habitat on arrival of human band.

    In the durations of human band stay, all the vegetation including weedy species experienced complete protection from herbivorous animals.
    Or, good protection. That's enough isn't it?

    ***

    You might get evidence from the food plants of relatively modern pre-agricultural people. For example there are meadows around settlements on the British Columbian coast that have been occupied since the last ice age, not exactly farmlands but certainly picked over and rooted up by humans year after year.

    The "crops" include camas lily bulbs, intriguing because they always grow intermixed with the (deadly) death-camas, distinguishable by the flower's colour. Our long practice of loosening the soil, harvesting bulbs from flowering plants, leaving and dispersing undersized and death-camas bulbs, may have influenced these plants' co-evolution.

    ***

    I really like your thesis, uday yadav, that humans blindly adapted into agriculture rather than "invented" it.
    A pong by any other name is still a pong. -williampinn
    Reply With Quote  
     

  30. #29  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    Quote Originally Posted by Pong
    I think it no coincidence that our markings, displays, and vocalizations set us apart: markings like our unique hair pattern, displays like passive bipedalism & arm waving when distressed, vocalizations like our incessant babbling that alerts animals (who know man) to leave the area. These are warning traits of we got on account of our stingers.

    I think we lost our hair for many reasons. Identification to other species is one.



    ***

    I really like your thesis, uday yadav, that humans blindly adapted into agriculture rather than "invented" it.
    I thank you a lot. Your timely response saved this thread being stifled. I am grateful to you.
    Your opinion about loss of hair is worthy. Once the natural compulsion gone, you gain special identity with hair gone. Yes I agree with you completely.
    Prior to co evolution, when a growing band went on wandering for days in search of food, individuals always found themselves divided in couple of groups, according to food availability. Whenever a group had enough individuals to establish its supremacy over land of its choice, dominant males of the group always avoided reassembling and formed a separate band.
    Thus always staying in the band of 20 to 30 members, an individual of the human band retained his body fur and yet avoided parasites. Human didnít dream of hairlessness then.
    After co evolution human bands living by perennial rivers came in possession of abundant food stock (bigger seeds retaining on stalks).


    Every member of the band had direct access to this long lasting and durable food stock. No other animal had dared disturb this arrangement yet.
    But long lasting, durable food stock of seeds lured not only herbivorous animals. It attracted the other human band.
    The other human band, that did not live in the vicinity of perennial rivers but lived by other water resources, came to know of this miracle, that took place on the most fertile lands of perennial rivers. The other human band was going to challenge this arrangement.
    Supreme human bands were comprised of 20 to 30 vulnerable individuals, males and females. Individual human was vulnerable to the outside world, but united in the band; he was the cause and possessor of human supremacy over this world. Hence dominant males had less scope for aggression.
    Due to peculiar shoulder joints, killing the animals had become a job of skill hence in spite of males being stronger, females equally participated in it.
    They were equal in number. Mating urge of a female was connected with her reproductive program that was designed by nature for her. Individuals, females and their newborns lived under protection of their united supremacy. In this situation dominant natured males had fewer reasons to attract every female for copulation. Their aggression also was not compulsive enough for female submission. On the occasion, female freely chose her mate to satisfy her desire of copulation that was inseparable part of her reproductive program.
    When the other band saw the fields of durable food stock they had no option but to posses it. They attacked the land holder band and both bands fought the cruelest battle on the earth. For human female, this was the time when she started emptying her womb.
    They had to kill every member of the opposing band. No one was to escape. If they escape, they will come back well prepared. Whoever wins had to kill and whoever loses had to escape. Band had no place for outsider male.
    Both supreme bands fought bitter battle. The attackers won. The possessors were unprepared and lost the battle and had to escape with whatever number of remaining members.
    Both bands lost number of members. Not all the females of the loser band could escape as they were target of the winner band males. They wanted them alive. Not all the females of the loser band could escape as they were target of the winner band females also and winner females wanted them dead.
    For fear of being stoned to death, many of them did not run away.
    To avoid death in cruelest manner by winner females, loser females had only one opportunity. Seek protection of winner males. Offer her body to winner males for copulation and save it from cruel injuries and consequent death.
    But that was not enough. Copulation was inseparable part of her reproductive program. Many of them were already pregnant from loser males. If they were not aborting (removal or expulsion of an embryo or fetus from the uterus: Wikipedia), they were definitely going to be killed afterwards to kill growing seed of enemy in their uteri.
    Growing seed of enemy was a thing to destroy.
    Fear of death emptied their wombs within no time. Heavily pregnant females could not abort and were brutally killed.
    Above battle between two supreme human bands took place on the most fertile lands of perennial rivers, across the earth at some time in human history.
    Human band structure had no place for outsider male. Till then no two human bands had ever shared same land because they had many options regarding land of choice in the vicinity of perennial rivers and perennial water streams.
    But now their land of choice was narrowed to fields of bigger seeds only. Every human band struggled to hold maximum portion of the fields in its possession.
    Human bands went on attacking each others for exclusive possession of fields of growing seeds. Possession never was long lasting. They lost and won for immeasurable period in human history but they never stayed away from this long lasting food stock till every monsoon when seeds got deformed into edible vegetables and then got lost into flourishing jungle of the plants.
    Due to this, fields of weedy species acquired rapid growth and occupied most of the fertile land along perennial rivers. Food stock of fighting bands increased many folds.
    For thousands of years, fighting human lived mainly on seeds of weedy species. Seeds were high in food energy (Calories) and carbohydrates and were tasty. His jaws and teeth shaped accordingly.
    Though human bands fought hundreds of battles, a battle was always brief. Except for those brief periods of battles and aftermath, human lived through thousands of years readying for a next battle.
    Reply With Quote  
     

  31. #30  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    Battles and preparations of next battle brought in him many changes. He stood erect. He acquired more skill and accuracy in throwing, hard hitting, forcing penetration and striking.
    His body and mind developed to fight and win the cruelest battle.
    He fought the enemy face to face, he stood his ground and he did not back away. These things made him totally erect.
    Fighting the growing danger with even more growing courage became most valued in the band.
    Increasing fields of seeds had become liability for the winner band. Band could not possess and protect fast spreading fields of growing seeds all the time. Loser band had already encroached the invisible boundary established by previous battle and was looking for an opportunity to win back.
    Human band had to hide its long lasting food stock. He learnt to use his palms and fingers according to his purpose.
    He learnt new job of collecting ears of seeds and carrying them at one place to make a food stock that he wanted to keep hidden from enemies. He used grass, big leaves, and creepers to hide the stock.
    He weaved the creepers. He invented a knot. By this, he could give his weaving a basket type shape. He prepared a net. This invention made carrying of ears easy. It saved time.
    Next he prepared a covering to hide food stock. This covering hid food stock. But he discovered that on arrival of monsoon, the covering also saved much of the food stock that till then used to get deformed into edible vegetables.
    He prepared such coverings that kept food stock dry in the monsoon. His wanderings stopped. He settled permanently on the banks of perennial rivers.
    Because of coverings, long lasting food stock became perennial food stock. Every human band on the earth reached nearby fields of bigger seeds, fought battles and somehow grabbed a portion of these fields and settled there permanently. Weedy species grew rapidly.
    Human started to understand value of surrounding nature. He made coverings of many kinds. He covered himself. He prepared a shelter for himself. He saved himself from sun and cold and rains.
    He used creepers to bind sharp stones firmly to long sticks. He made weapons to use in battles and hunting.
    He made walls of mud in the beginning. But afterwards he learnt to build protection walls of stones using mud as a mortar. He made pots from the mud.
    Perennial food stock made human a colonist. Colonies expanded. Growing population of humans influenced the vicinity tremendously. Weedy species grew and populated to its maximum ability on the land, influenced by human colonization.
    Weedy species attached their growth to the growth of humans.
    Throughout the monsoon, human lived among weedy species. He observed weedy species growing into fields. He sensed other shrubs growing as an obstacle to growing of weedy species. He engaged himself in plucking the unwanted shrubs growing nearby the weedy species. Weedy species grew rapidly.
    That was the time when most of the plants tried their best to get included into the human diet. Many could change themselves to the liking of human. Thus on the banks of perennial rivers, human was presented with an unending food stock that was rich in life energy and had a range of taste. Nourishing and regular food supply made human healthy. Most of the fruits, roots and vegetables evolved by this time for human diet.
    Growing size of colonies brought diseases. But total control over fields of bigger seeds and vegetables had become a single motive of human. He would not go away from long lasting food stock. Instead he grew wise and followed self employed rules of sanitation and cleanliness. Human occasionally ate meat. Hence he escaped diseases of the carnivorous animals which come with thick population.
    Thick population aggravates diseases. To minimize this aggravation and because disease could not kill total human population, nature took away his body fur. Food giving plants improvised the food quality to help human change from hairy human to hairless human. This is how human lost his body fur.
    Reply With Quote  
     

  32. #31  
    Forum Radioactive Isotope skeptic's Avatar
    Join Date
    Nov 2008
    Location
    New Zealand
    Posts
    4,840
    uday

    You spin a very long and involved tale with little or no supporting empirical evidence.

    For example : if you want to know the 'natural' size of a human tribe, then look to recent hunter/gatherer human tribes, such as in the Amazon. You will find that the 'natural' grouping is not 20 to 30, but 50 to 200 per tribe. This number is seen in modern humans as the normal number of friends, family, colleagues etc that each of us has reasonably regular contact with.

    Other characteristics can be derived from the fossil record. For example, we know that our ape predecessors achieved an upright stance many millions of years ago. Homo sapiens, according to the fossil record, is approximately 200,000 years old - a newcomer, and has changed little physically, as shown by fossils, in that time. Even neanderthal man is substantially older than that.

    The fossil record shows that fire was first used by (probably) Homo erectus, more than a million years ago. Chipped stone tools even earlier.

    There is no shortage of information from scientific discoveries even in Wiki. It would make your ideas a lot more credible if you were to refer to proper scientific discoveries, instead of simply telling a story derived from your own imagination, as if that was scientific truth.
    Reply With Quote  
     

  33. #32  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    Quote Originally Posted by skeptic
    uday

    You spin a very long and involved tale with little or no supporting empirical evidence.
    Your main objection is to physical evolution and my main object is co evolution of plant and human. You argue that loss of hair, erectness, and menstruation already existing and had nothing to do with long lasting food stock.
    My human evolution theory itself contains evidence.
    If plant and human co evolved, most appropriate place was hundreds of banks of Perennial Rivers across the earth.
    And if co evolved with plant, humans thereon must have stayed together (fought, won, lost; fought, lost, won) near food plant.
    If stayed together forever, he must have evolved physically and then socially and culturally.
    Once you accept co evolution, you have to add a new chapter in human evolution history. That chapter started with co evolution and ended with knowledge of agriculture.
    I divide this chapter into 2 phases.
    1) From long lasting food stock to perennial food stock. This phase mainly must have caused physical evolution and must have laid foundation for social and cultural evolution. In this phase primate human was transformed in modern human who was on the verge of civilization. And hence this phase must have lasted for not less than 40k to 50 k years.
    2) From perennial food stock to agriculture. This is second phase when human colonized and populated and was of vital importance in humanís social and cultural evolution though it differed from place to place across the earth. It must have lasted 4k to 5k years when human learnt the idea of agriculture.
    You mention about Amazon tribes grouped in 50 to 200 members. But see that they are hairless. Their women menstruate.
    My theory says that tribals across the world were not tribals but lived with us from co evolution to agriculture. They themselves are the evidence. They have evolved physically, socially and culturally like us.
    They have some rituals to perform. They believe in ghosts. Their gods exist in some form. Most important social evolution they lived through is marriage. Some kind of marriage bond exists in tribals across the world. Their devotion to their leader and tribe, their hierarchy and their ingenious weapons all things are evident that they stayed with us until we all came to know agriculture. How we separated is last part of my story yet untold but very obvious.
    Reply With Quote  
     

  34. #33  
    Forum Radioactive Isotope skeptic's Avatar
    Join Date
    Nov 2008
    Location
    New Zealand
    Posts
    4,840
    Uday

    You are still not presenting empirical evidence. What you are saying appears to be mere hypothesizing from few or no facts.

    Such evidence that paleoanthropologists and archaeologists have gleaned would suggest that large scale agriculture, with cultivation of grains such as wheat, began about 10,000 years ago. There is no real evidence of agriculture before that, though some may have occurred. From 10,000 BCE to the present, there is an increasing wealth of artifacts and remains to be dug up and analysed by archaeologists, giving a good picture of life over that period.

    Your ideas are presented without backing evidence.

    Look at other data. Take erect posture for example.

    The oldest evidence of this is more than 4 million years, with the fossil remains of Ardipithecus. http://en.wikipedia.org/wiki/Ardipithecus

    On hairlessness
    Studies of genetic diversification in human lice indicate that humans first wore clothes about 170,000 years ago - necessary only if they were hairless. http://lepidoptera.newsvine.com/_new...0000-years-ago

    So, Uday, why not do a little research, and present ideas with backing by suitable references?
    Reply With Quote  
     

  35. #34  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    Quote Originally Posted by skeptic
    The oldest evidence of this is more than 4 million years, with the fossil remains of Ardipithecus. http://en.wikipedia.org/wiki/Ardipithecus
    You wanted me to read this for bipedalism:
    ďA. ramidus existed more recently than the most recent common ancestor of humans and chimpanzees (CLCA or Pan-Homo LCA), and thus is not fully representative of that common ancestor. Nevertheless, it is in some ways unlike chimpanzees, suggesting that the common ancestor differs from the modern chimpanzee. After the chimpanzee and human lineages diverged, both underwent substantial evolutionary change. Chimp feet are specialized for grasping trees; A. ramidus feet are better suited for walking.
    ramidus had a more primitive walking ability than later hominids, and could not walk or run for long distances.[13] The teeth suggest omnivory, and are more generalised than those of modern apes.Ē


    There is no need to go beyond co evolution. If he was hairless and bipedal many many millions of years ago, let him be. I never said that human was quadruped at the time of co evolution. By a little bend I meant to say almost erect but not as erect as todayís human. Incessant and unavoidable fights with the enemy who was by no means a little weaker, had to affect human bodily in some way.
    The research is going my way and in coming time theory of co evolution will have sufficient evidence. I will name some archaeobotanists,Schultes, Hofmann, Vavilov that I read just now, are working on cannabis and hemp. Their research will prove my theory of co evolution.

    Now the hairlessness.
    I read the article. Principal investigator David Reed, associate curator of mammals at the Florida Museum of Natural History, is in reality a salesman of ďOut of Africa TheoryĒ. Donors have funded National Science Foundation.

    Actually no one knows how to move our ancester out of Africa hairless. This problem is eating all the money funded by truth seekers. Once he comes out of Africa with his fur on everything collapses and funds go down the drain. So every scientist of whatever field is determined to take the poor fellow (our ancestor) to the barber shop to shave his body forever before moving him out of Africa and introducing him to the world.
    Reply With Quote  
     

  36. #35  
    Forum Radioactive Isotope skeptic's Avatar
    Join Date
    Nov 2008
    Location
    New Zealand
    Posts
    4,840
    Uday

    I think you missed my point.

    If you wnat to present ideas on human evolution, or anything else, that is fine. But you need to provide backing. Merely stating that something is so, according to your ideas, is meaningless without backing evidence.
    Reply With Quote  
     

  37. #36  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    Quote Originally Posted by skeptic
    Uday

    I think you missed my point.

    If you wnat to present ideas on human evolution, or anything else, that is fine. But you need to provide backing. Merely stating that something is so, according to your ideas, is meaningless without backing evidence.
    Thank you for response.
    No. I did not miss anything.
    You asked for evidence because you could not find a single flaw in my story. Other theorists bring their ideas with immeasurable possibilities to repair them so the debate goes on and on.
    New idea doesnít come easy. Ideas do have their credentials. Putting forth new ideas cannot be called as meaningless. One should be good hearted to appreciate good ideas that are hard to make a hole into.
    I read the previous threads about aquatic ape hypothesis and bipedalism. It was amazing to see the response they received. No one enquired about evidence. And then I saw the reason. You enjoy so much making holes in the ideas; you donít give a hoot to the evidence.
    What I miss is a single word of appreciation for my idea.
    1. Good idea but lacks evidence.
    2. Most probable and logical with a single fault. No evidence.
    3. Superior to existing ones but without evidence.
    Donít you think such remarks appropriate?
    I thank PONG who openly appeciates my idea of co evolution and calls it a thesis.
    Reply With Quote  
     

  38. #37  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    It should have occured to me much earlier.
    Evidence for co evolution.
    At the start agriculture was, not consuming all the bigger seeds but keeping some to sow in the soil. If human sowed bigger seeds is an evidence for agriculture, bigger seeds are evidence of co evolution.
    Reply With Quote  
     

  39. #38  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    Evidence of co evolution.

    In Israel, seeds of wild pulses and other food plants, found to be 60,000-50,000 years old, from Kebara Cave on the western slope of Mt. Carmel.

    http://gby.huji.ac.il/centers/botan/...le_kislev.html
    Reply With Quote  
     

  40. #39  
    Forum Radioactive Isotope skeptic's Avatar
    Join Date
    Nov 2008
    Location
    New Zealand
    Posts
    4,840
    Sorry Uday

    Your reference does not constitute such evidence. Read it again.
    Reply With Quote  
     

  41. #40  
    Forum Sophomore MiguelSR1's Avatar
    Join Date
    Mar 2010
    Location
    San Diego C.A. United States
    Posts
    141
    Agriculture has come long ways, from the hand alone to genetic modified foods. Yeah that's a hella long way all right
    Imagination is key to the logic of thought, a greatest eternal truth.

    ME
    Reply With Quote  
     

  42. #41  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    Quote Originally Posted by skeptic
    Sorry Uday

    Your reference does not constitute such evidence. Read it again.
    You must be kidding. YOU and not me READ this.

    SMALL-GRAINED WILD GRASSES AS STAPLE FOOD AT THE 23000 YEAR OLD SITE OF OHALO II, ISREAL . --- by Ehud Weiss, Mordechai E. KIsley, Orit Somchoni, and dani Nadel

    "The plant assemblage of the Upper Palaeolithic site Ohalo 2, Israel, contains large quantities of charred Gramineae (Poaceae) grains. Wild barley (2503 grains) and wild emmer wheat (102 grains) indicate these cereals were an important staple food of the human inhabitantsí diet. An additional 16000 grains 0f five other Gramineae were found at the site. These include alkaligrass, brome and bladder/creeping foxtail. In light of the quantities of these grains at Ohalo2, and the fact that these finds are unknown from other sites of this and later periods, this article addresses the question of the significance of these cereals in the inhabitantsí diet.

    More than 16 000 grains of small-grained grasses were retrieved at Ohalo II, a submerged 23 000-year-old site on the shore of the Sea of Galilee, Israel. The grains were part of a very large archaeobotanical assemblage, unique for its period and region, as well as its exceptionally good preservation. This paper proposes that these grains were a staple food at Ohalo II, based on several lines of evidence: 1. the large number of grains found; 2. the fact that all grains were fully mature; and 3. ethnographic parallels for the use of small-grained grasses in hunter-gatherers' societies as well as among present-day agriculturalists."


    Now I will tell you what this means.

    human ate grains 23000 years ago but could sow only 10000 years ago.

    Please admit your mistake good heartedly.
    Reply With Quote  
     

  43. #42  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    Quote Originally Posted by MiguelSR1
    Agriculture has come long ways, from the hand alone to genetic modified foods. Yeah that's a hella long way all right
    A good quote. But agriculture is only 10000 years old whereas the grains, we have been eating, are 50000 years old. How is that?
    Reply With Quote  
     

  44. #43  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    Quote Originally Posted by skeptic
    The big break through into a more modern system of living came about 10,000 years ago. However, it seems to have been characterised by the cultivation of grains, such as wheat. Grains have the great benefit that they can be stored dry almost indefinitely. Thus, a seasonal crop can supply a tribe all year round. With this more secure food supply, the development of settled communities such as villages and towns can occur, and also the development of specialised trades, such as tool makers, who will swap their products for food.
    What else have I told in my story?
    Except that grains were already there for human diet.
    Reply With Quote  
     

  45. #44  
    Forum Radioactive Isotope skeptic's Avatar
    Join Date
    Nov 2008
    Location
    New Zealand
    Posts
    4,840
    Uday

    I have never said that grains were not human food.

    However, you have been claiming co-evolution, and that is not demonstrated in your quote.
    Reply With Quote  
     

  46. #45  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    Quote Originally Posted by skeptic
    Uday

    I have never said that grains were not human food.

    However, you have been claiming co-evolution, and that is not demonstrated in your quote.

    Seeds of weedy species are so small and get easily separated from their stalk that they are usually blown away by wind for propagation. And if eaten, tiny seeds escape being chewed, come out unharmed and get propagated. Thus weedy species donít have to invest more than one percent of their biological weight in seeds for propagation.

    The fact is this that some weedy species started investing more than 15 to 20 percent of their biological weight on seeds to make them big. Now wind couldnít blow them away and if eaten by grazers they were surely to be chewed and if harmed, useless for propagation. Weedy species invested 20 percent of capital on propagation. It was 20 times more than previous investment so it cannot be without some kind of returns. It must be some give and take formula hence must be long and long dependable security. But it proved to be a right decision on their part because along with humans they propagated the whole world.

    Though everything I mentioned above must have happened genetically, it must have happened between supreme human bands and vulnerable weedy species. There was no animal of this capacity on the earth.

    Skeptic, so the co evolution.
    Reply With Quote  
     

  47. #46  
    Forum Radioactive Isotope skeptic's Avatar
    Join Date
    Nov 2008
    Location
    New Zealand
    Posts
    4,840
    Fine Uday

    Now show me the evidence that this happened.
    Reply With Quote  
     

  48. #47  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    YES. Skeptic.
    I will have to provide evidence that supports my thesis. I am searching for it.
    Reply With Quote  
     

  49. #48  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    Quote Originally Posted by TheBiologista

    Genetic changes don't really take place within an organism during it's lifetime, regardless of environmental changes. We pick up some mutations as we go through life, but the vast majority of these can't be passed on to our children. Inheritable genetic changes take place when our gamete cells undergo reassortment, or more rarely when our gamete cells are genetically modified by mutagenic agents. These sorts of genetic changes in populations are taking place constantly. For example, each new human is born with several hundred new variations in their DNA. However, the environment has little to do with those changes. The environment determines which of these variations will survive longest and reproduce the most. The environment changes the frequency of this gene and that gene, but it is not the origin of variation.

    I have some contradictory info.
    http://www.necn.com/Boston/Health/Li...213641802.html
    Will you please explain?
    Reply With Quote  
     

  50. #49  
    Moderator Moderator TheBiologista's Avatar
    Join Date
    Aug 2008
    Posts
    2,564
    Quote Originally Posted by uday yadav
    Quote Originally Posted by TheBiologista

    Genetic changes don't really take place within an organism during it's lifetime, regardless of environmental changes. We pick up some mutations as we go through life, but the vast majority of these can't be passed on to our children. Inheritable genetic changes take place when our gamete cells undergo reassortment, or more rarely when our gamete cells are genetically modified by mutagenic agents. These sorts of genetic changes in populations are taking place constantly. For example, each new human is born with several hundred new variations in their DNA. However, the environment has little to do with those changes. The environment determines which of these variations will survive longest and reproduce the most. The environment changes the frequency of this gene and that gene, but it is not the origin of variation.

    I have some contradictory info.
    http://www.necn.com/Boston/Health/Li...213641802.html
    Will you please explain?
    Certainly. The journalist who wrote that piece is not a biologist. She misunderstood the PMRI's findings. That, or the PMRI released an inaccurate press release. It's possible that both things happened. If you take only one thing from your discussions here on The Science Forum, it should be that mainstream press coverage of science stories is usually inaccurate and often completely wrong.

    If you're interested, here's the research paper that the story was based on:
    Changes in prostate gene expression in men undergoing an intensive nutrition and lifestyle intervention
    D Ornish et al. PNAS 2008 vol. 105, no. 24, p8369 Ė 8374

    The key phrase is gene expression. The genome, the DNA, remains unaltered. Furthermore, if it were altered, it would not automatically follow that this would be a change that could be passed on to our offspring.
    Reply With Quote  
     

  51. #50  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    [quote="TheBiologista"]
    Quote Originally Posted by uday yadav
    Quote Originally Posted by TheBiologista

    Genetic changes don't really take place within an organism during it's lifetime, regardless of environmental changes. We pick up some mutations as we go through life, but the vast majority of these can't be passed on to our children. Inheritable genetic changes take place when our gamete cells undergo reassortment, or more rarely when our gamete cells are genetically modified by mutagenic agents. These sorts of genetic changes in populations are taking place constantly. For example, each new human is born with several hundred new variations in their DNA. However, the environment has little to do with those changes. The environment determines which of these variations will survive longest and reproduce the most. The environment changes the frequency of this gene and that gene, but it is not the origin of variation.
    The key phrase is gene expression. The genome, the DNA, remains unaltered. Furthermore, if it were altered, it would not automatically follow that this would be a change that could be passed on to our offspring.
    Very much interested. Studying the subject (least bothered until now).
    Reply With Quote  
     

  52. #51  
    Time Lord
    Join Date
    Mar 2007
    Posts
    8,035
    I find it really hard to believe that plant agriculture would have preceded animal husbandry, especially when you consider the various vestigial traits left over in our bodies that indicate a primarily meat based diet for our distant ancestors.

    Probably it starts like this:

    1) - Hunters realize one day that they can take an animal "prisoner" instead of killing it outright, which makes it a hell of a lot easier to transport back to their village (since it's walking under its own power), and allows them to store the meat by keeping the animal alive until they're hungry enough to eat it.

    2) - Those same hunters observe that an animal stored long enough can become impregnated and bear offspring in captivity..

    3) - These hunters start looking for ways to keep their flocks fed. Probably it starts out as a nomadic thing.

    4) - These hunters observe that if they gather large amounts of the kind of food their flocks are eating, they can keep them fed when foraging is scarce.

    5) - During a particularly hungry time, some of the hunters decide to try eating the grain they've been storing for their flocks.

    6) - Grain agriculture should arrive not long after that.

    The reason I'd object to a direct jump from gathering to farming is because most of the kinds of vegetation a gatherer might come across are not viable sources of baseline nutrition. Agriculture can't get it's start from apple orchards, or berry fields. Those are supplemental nutrition. They don't work as a basic diet. Before any plant agriculture can get under way, first humanity must get a taste for grains.
    Some clocks are only right twice a day, but they are still right when they are right.
    Reply With Quote  
     

  53. #52  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    Quote Originally Posted by kojax
    I find it really hard to believe that plant agriculture would have preceded animal husbandry, especially when you consider the various vestigial traits left over in our bodies that indicate a primarily meat based diet for our distant ancestors.

    Probably it starts like this:

    1) - Hunters realize one day that they can take an animal "prisoner" instead of killing it outright, which makes it a hell of a lot easier to transport back to their village (since it's walking under its own power), and allows them to store the meat by keeping the animal alive until they're hungry enough to eat it.

    5) - During a particularly hungry time, some of the hunters decide to try eating the grain they've been storing for their flocks.

    6) - Grain agriculture should arrive not long after that.

    The reason I'd object to a direct jump from gathering to farming is because most of the kinds of vegetation a gatherer might come across are not viable sources of baseline nutrition. Agriculture can't get it's start from apple orchards, or berry fields. Those are supplemental nutrition. They don't work as a basic diet. Before any plant agriculture can get under way, first humanity must get a taste for grains.
    Exactly. I totally agree with you. Agriculture came long after human tasted the grains and started living near such grains giving weedy plants.
    Animal husbandry indicates sedentary life style. I think when human settled; (according to me near perennial rivers) he tamed animals. Most probably first was sheep and goats. They could survive only in the mountains. Human band chased them down and on the plains. Once brought down on the plains, sheep and goats were helpless because human band would not let them go back to the mountain and they dared not run away in the jungle for the fear of predators.
    Human band provided them protection and they obeyed. As grains were viable source of baseline nutrition, humans collected grains from the weedy plants, plants still offered fodder for the domestics (sheep and goats). Domestics gave milk and meat.
    Reply With Quote  
     

  54. #53  
    Forum Bachelors Degree
    Join Date
    Apr 2011
    Location
    mumbai
    Posts
    412
    Here are two theories which I claim as a support to my human evolution theory on human hairlessness and fire control just 40000 to 70000 i.e. 40k to 70k years ago.
    1] According to the research, by Professor Mark Stoneking and collegues at the Max Planck Institute of Evolutionery Anthropology in Leipzig, Germany, humans might have first worn clothes around 42000 to 72000 years ago.
    Since fur and fabrics do not fossilise, anthropologists have long wondered when human started wearing clothes.
    The new approach focused on the subtle genetic differences between the head louse (Pediculus humanus capitis) and the body louse (p. Humanus corporis) these human actoparasites differ mainly in their habitat on the host: head lice live in the hair and scalp, while body lice feed on hairless parts of the body but lay their eggs only in clothes.
    Thus the researchers concluded that an indirect measure of when our ancestors first wore clothes would have emerged by figuring out when body lice first appeared.
    DNA analysis of the human head lice and body lice sent from around the world revealed the modern genetic variation in the parasites.
    Assuming that mutations occur at a given rate, Stonekingís team came to the estimate that ďbody lice originated not more than about 72000 to 42000 years ago.Ē
    http://amser.org/index.php?P=FullIma...eenshot&edit=0
    2] British scientists Professor Mark Pagel of the University of Reading and Sir Walter Bodmer of the University of Oxford, propose that humans lost their hair because it reduced the number of biting and disease-causing parasites, and made them more sexually attractive, according to a new theory.
    This theory claims that because humans could respond flexibly and effectively to their environment - by producing fire, shelter and clothing - hairlessness was both possible and desirable. Clothes and shelter can be changed or cleaned better than a permanent layer of fur which can be infested with parasites.
    http://amser.org/index.php?P=AMSER--...esourceId=4963
    Reply With Quote  
     

Bookmarks
Bookmarks
Posting Permissions
  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •