Religion and Ethics Forum
General Category => Science and Technology => Topic started by: SusanDoris on June 05, 2021, 01:38:50 PM
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The (braile) book* I have started reading is, 'Origins: How The World Made Us' by Lewis Dartnell, who is a professor at Westminster University and part of his job is communicating science to a wider audience.
So far it is very interesting. I am hoping that somewhere he will explain how, since Homo sapienssapiens left Africa about 40,000 years ago and then spread throughout the world, why there is such variation in skin pigmentation, eye shape, etc that could have evolved by natural selection in such what seems like a comparatively short time; while at the same time we are all still one species, able to interbreed. I can understand (as he has already said, that homo erectus left Africa and spread very widely long before that, and that Neanderthals were settled and thriving in Europe and wider, also that for some reason when homo sapienssapiens came along they disappeared comparatively quickly, but that 40,000 years is a puzzle.
I've been trying to work out how many generations there must have been in 40,000 years. If I take 4 generations per 100 years and multiply by 10 for 1000 years, that makes400,000 generations, then by 40 to get to the 40,000 years ... well, I'm foundering because I can't really do that on a piece of paper!!
I wonder if any of that makes any sense and if anyone has any thoughts on this as I would be most interested to hear.
*The NLB have changed braille books. Instead of making this book into 7 volumes with a spiral at the centre, and each volume in its plastic, hard folder, they have a new machine which prints a book as requested (and if available of coursse) into double the number of books, stapled non-returnable and re-cyclable.
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I recall reading somewhere that it would take 40 generations of selective breeding to turn a wolf into a chihuahua. (And it's quite possible that my recollection is not accurate.) For natural selection to achieve the same result would certainly take rather longer.
I also recall reading somewhere that the European white skin/blue eyes formulation is possibly about 10,000 years old - that is 400 generations.
(This is not criticism but just an acceptance of the difficulties your visual problems cause, but you seem to have vastly over calculated the number of generations in 40,000 years - at 4 generations every century it would be 1,600 generations.)
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I recall reading somewhere that it would take 40 generations of selective breeding to turn a wolf into a chihuahua. (And it's quite possible that my recollection is not accurate.) For natural selection to achieve the same result would certainly take rather longer.
I also recall reading somewhere that the European white skin/blue eyes formulation is possibly about 10,000 years old - that is 400 generations.
(This is not criticism but just an acceptance of the difficulties your visual problems cause, but you seem to have vastly over calculated the number of generations in 40,000 years - at 4 generations every century it would be 1,600 generations.)
Thank youfor your reply- it is all very interesting. I tried putting a question into google, but the predictive text - which I can't see of course and although this is probablyk very useful to most people, it isn't to me! - meant that it kept coming up with answers which didn't help.
this book is going to take me quite a long while to read, and, while getting used to the way an author writes, it is often necessary to read a page a couple of times. It usually gets easier as I go along.
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I think your maths is a bit out: at four generations per century, there would be 1760 generations in 40,000 years.
Richard Dawkins once asked us to imagine a woman on Brighton beach, standing sideways-on to the sea, which is on her right. her left hand is holding the right hand of her mother, whose left hand is holding the right hand of her mother, and so on all the way up to the Scottish border, where the first woman's remote ancestor is holding in her left hand the right hand, not of her mother, but her sister, who is facing her, not alongside her. Her left hand is holding the right hand of her daughter, who is holding the right hand of her daughter, and so on, all the way back down to Brighton beach, where the woman we started with is face to face with a chimpanzee. (If memory serves, the illustration uses females throughout because the ancestry is traced through mitochondrial DNA, which is passed down on the female side.)
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I think your maths is a bit out: at four generations per century, there would be 1760 generations in 40,000 years.
Richard Dawkins once asked us to imagine a woman on Brighton beach, standing sideways-on to the sea, which is on her right. her left hand is holding the right hand of her mother, whose left hand is holding the right hand of her mother, and so on all the way up to the Scottish border, where the first woman's remote ancestor is holding in her left hand the right hand, not of her mother, but her sister, who is facing her, not alongside her. Her left hand is holding the right hand of her daughter, who is holding the right hand of her daughter, and so on, all the way back down to Brighton beach, where the woman we started with is face to face with a chimpanzee. (If memory serves, the illustration uses females throughout because the ancestry is traced through mitochondrial DNA, which is passed down on the female side.)
Thank you - much appreciated. I can just imagine that! However, I find it really difficult to get my head round the time scales, but hope to be better informed when I've read the book.
It seems too that the sites of major tectonic plate movements, mainy the Great Rift Valley inAfrica had a huge effect on homini* evolution.
* This is the word used as a general term it seems.
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My maths is out, as well. There'd be 1,600 generations in 40,000 years.
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Different genetic variations could have arisen due to interbreeding with other homo species such as Neanderthals and Denisovans.
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Different genetic variations could have arisen due to interbreeding with other homo species such as Neanderthals and Denisovans.
Yes, this makes sense I think.
Actually, I thought I knew quite a bit about geology, but I don't think I had realised vbefore reading the part I have read these last couple of days that ice ages came after the dinosaur age.
The fact that we, the human species, are here after the whole long run of evolution is stunningly amazing.
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I wonder if we will continue to evolve and what the species would be like in thousands of years time assuming our planet still exists?
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I wonder if we will continue to evolve and what the species would be like in thousands of years time assuming our planet still exists?
Sure, we are still evolving. Currently we are evolving a new (median) artery in the arm, for instance.
https://www.sciencefocus.com/news/humans-are-evolving-an-extra-artery-in-the-arm/ (https://www.sciencefocus.com/news/humans-are-evolving-an-extra-artery-in-the-arm/)
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Yes, this makes sense I think.
Actually, I thought I knew quite a bit about geology, but I don't think I had realised vbefore reading the part I have read these last couple of days that ice ages came after the dinosaur age.
The fact that we, the human species, are here after the whole long run of evolution is stunningly amazing.
There are regular and alternating glacial (period of glacial advancement) and interglacial (period of glacial retreat) periods. We entered an interglacial period about 10000 years ago.
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There are regular and alternating glacial (period of glacial advancement) and interglacial (period of glacial retreat) periods. We entered an interglacial period about 10000 years ago.
The latest pages I read yesterday explain why the world was so hot before that and how the tectonic plate movements changed things. It is all very interesting.
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There are regular and alternating glacial (period of glacial advancement) and interglacial (period of glacial retreat) periods. We entered an interglacial period about 10000 years ago.
Quite. The Pleistocene ice age was one of the worst periods for life in Earth history with extreme volatility in the climate, record lows in CO2 levels etc and yet it was this awful period in which humans evolved. The rather sudden onset of the Holocene ushered in a new climate, stable, warm with plentiful rainfall and higher CO2 levels making farming a viable means of making a living. Hence the exponential growth in human numbers, hence the rise in civilisations, hence the rise in energy consumption, resource depletion and ecosystems degradation all of which now threaten the benign stable conditions which allowed for our success in the first place.
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Quite. The Pleistocene ice age was one of the worst periods for life in Earth history with extreme volatility in the climate, record lows in CO2 levels etc and yet it was this awful period in which humans evolved. The rather sudden onset of the Holocene ushered in a new climate, stable, warm with plentiful rainfall and higher CO2 levels making farming a viable means of making a living. Hence the exponential growth in human numbers, hence the rise in civilisations, hence the rise in energy consumption, resource depletion and ecosystems degradation all of which now threaten the benign stable conditions which allowed for our success in the first place.
Yeah. And the glacial period allowed for many land bridges between different land masses. Bering strait, Palk strait, between Indonesian islands and so on, that allowed humans to settle around the world....from 40000 to 15000 years ago.... The warmer climate for the last 10000 years has enabled agriculture, urban settlements and civilization as we know it...
Meant to be...IMO ;)
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Sure, we are still evolving. Currently we are evolving a new (median) artery in the arm, for instance.
https://www.sciencefocus.com/news/humans-are-evolving-an-extra-artery-in-the-arm/ (https://www.sciencefocus.com/news/humans-are-evolving-an-extra-artery-in-the-arm/)
Another example of ongoing evolutionary change is the trait, predominantly present in the European population, of being able to digest lactose.
https://www.npr.org/sections/thesalt/2012/12/27/168144785/an-evolutionary-whodunit-how-did-humans-develop-lactose-tolerance?t=1623222222196 (https://www.npr.org/sections/thesalt/2012/12/27/168144785/an-evolutionary-whodunit-how-did-humans-develop-lactose-tolerance?t=1623222222196)
O.
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The book continues to be very interesting on every page. The thing that has always puzzled me, and which I hope supplies the answer to that puzzling, is how a population of a few thousand could have multiplied so quickly - well, comparatively quickly - and disperse throughout the world, plus becoming so different in outward appearance. One of the reason could be that if they interbred with the homo erectus (or other) hominis who had survived the Ice Age then those genes could have helped I suppose.
Edited to say: more likely Neanderthals though.
It is completely astonishing to me that there ar so many people who believe that ETs are either popping down here occasionally or actually are amongst us all the time who manipulate human genes. Why, oh why, when there is such far, far more fascinating science to learn about!
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Homo Erectus is way up the line.....one of the earliest of the Homo genus (emerged about 2 million years ago). It was probably the early ancestor of Homo sapiens as also Neanderthals and Denisovans.....and probably became extinct around the time Homo Sapiens were emerging.
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Homo Erectus is way up the line.....one of the earliest of the Homo genus (emerged about 2 million years ago). It was probably the early ancestor of Homo sapiens as also Neanderthals and Denisovans.....and probably became extinct around the time Homo Sapiens were emerging.
That seems to be the right chronology. Near the start of the book, the author appeared to say that adaptations or mutations could be developed rather than being random, so I sent an e-mail to ask. He has written an e-mail today, thanking me for my interest and explaining clearly what the position is
No, no organism can initiate particular mutations. All mutations are random errors that occur in the DNA, but through natural selection any mutations that act to enhance the survival or reproduction of an organism become more prevalent in the next generation – this is how over time (over many generations) organisms become better adapted to their environment.
So it is nice to have clarity.
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Another example of ongoing evolutionary change is the trait, predominantly present in the European population, of being able to digest lactose.
https://www.npr.org/sections/thesalt/2012/12/27/168144785/an-evolutionary-whodunit-how-did-humans-develop-lactose-tolerance?t=1623222222196 (https://www.npr.org/sections/thesalt/2012/12/27/168144785/an-evolutionary-whodunit-how-did-humans-develop-lactose-tolerance?t=1623222222196)
O.
What is driving this evolution do you think?
Surely, people that are lactose intolerant (in Europe) do not die before they have children?
I am surprised that humans are evolving so much as we work to avoid this, by making sure people survive as long as possible.
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That seems to be the right chronology. Near the start of the book, the author appeared to say that adaptations or mutations could be developed rather than being random, so I sent an e-mail to ask. He has written an e-mail today, thanking me for my interest and explaining clearly what the position isSo it is nice to have clarity.
Hey, that's nice. Write to the author and get a reply; it's not every author that would do that, well done. Lewis Dartnell has just gone up in my opinion, not that he was low before :D
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Another example of ongoing evolutionary change is the trait, predominantly present in the European population, of being able to digest lactose.
https://www.npr.org/sections/thesalt/2012/12/27/168144785/an-evolutionary-whodunit-how-did-humans-develop-lactose-tolerance?t=1623222222196 (https://www.npr.org/sections/thesalt/2012/12/27/168144785/an-evolutionary-whodunit-how-did-humans-develop-lactose-tolerance?t=1623222222196)
O.
Another one is the spread of a variant of the EPAS1 gene that confers enhanced oxygen transport, just what you need if you live at high altitude. The incidence of this allele is something like 90% in the population of modern Tibetans, compare that to 10% incidence in the population of Han Chinese, from whom Tibetans derive. This is maybe evidence of the harshest selection pressure on any population of humans in recent millennia, the mortality rate amongst the population of Han Chinese who migrated up into the Himalaya not carrying this mutation must have been awful.
https://en.wikipedia.org/wiki/EPAS1 (https://en.wikipedia.org/wiki/EPAS1)
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What is driving this evolution do you think?
Surely, people that are lactose intolerant (in Europe) do not die before they have children?
Not in large quantities, I should think, but to a small degree perhaps, so it's not run wildfire through the human population but it's gradually spready.
O.
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What is driving this evolution do you think?
Surely, people that are lactose intolerant (in Europe) do not die before they have children?
I am surprised that humans are evolving so much as we work to avoid this, by making sure people survive as long as possible.
I think the phrase 'driving evolution' is out of place. Evolution happens, it is not driven by anything. If mutations occur which happen to be beneficial and are passed on that is fortunate and happens by chance. I do not think it can be said to be 'driven' by anything.
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I think the phrase 'driving evolution' is out of place. Evolution happens, it is not driven by anything. If mutations occur which happen to be beneficial and are passed on that is fortunate and happens by chance. I do not think it can be said to be 'driven' by anything.
I agree to so e extent, but to be beneficial they have to be more efficient at passing on the gene. This would mean that others would not be as successful at passing on their genes.
We strive quite rightly to make sure people are not disadvantaged so I am not sure how this evolution is taking place. Unless there are losers there is nothing for evolution to grab onto. Is there?
Or am I missing it?
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Evolution has no purpose or goal. Mutations are random - those which are beneficial may take several generations to demonstrate their advantages. The benefit of a favourable mutation is that it may provide you with a marginal advantage over someone who does not possess it. It is possible that everyone, following conception, may have a genome in which several unplanned, totally random, copying errors, mutations, have taken place
For the most part these mutations are of no consequence but it is possible that one may give a particular advantage if a particular environmental situation occurs.
If the environmental circumstances which make the mutation advantageous persist, then those possessing the mutation are more likely to survive and pass their mutation onto their offspring. Those not possessing it may find it difficult to cope with the environmental conditions, possibly die early and fail to reproduce successfully. If they do reproduce then their offspring will be similarly disadvantaged.
Evolution works essentially by having a small number of winners and a large number of losers but eventually the winners will outnumber the losers.
but to be beneficial they have to be more efficient at passing on the gene. This would mean that others would not be as successful at passing on their genes.
It has nothing to do with efficiency, merely - by possessing a particular mutation - being better equipped ... fitness ... to survive. Those not so equipped are more likely not to survive.
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I agree to so e extent, but to be beneficial they have to be more efficient at passing on the gene. This would mean that others would not be as successful at passing on their genes.
We strive quite rightly to make sure people are not disadvantaged so I am not sure how this evolution is taking place. Unless there are losers there is nothing for evolution to grab onto. Is there?
Or am I missing it?
To the extent that people have access to modern health care, where we (rightly) endeavour to enable people survive and reproduce regardless of genetic problems (and also enable the healthy to limit their reproduction via contraception), you're correct and the potential for natural selection is limited.
However, even modern health care cannot cure all problems, is far from universally available even today, and has only been available for a tiny fraction of human history.
The future (natural) evolution of humans depends critically on whether technological society survives, continues to make progress in medicine, and to what extent it is made available to the entire world population.
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I agree to so e extent, but to be beneficial they have to be more efficient at passing on the gene.
But they cannot take any positive, active steps to become more efficient. That happens or it doesn't.This would mean that others would not be as successful at passing on their genes.
That's their bad luck , and why such huge percentages of species of life have become extinct. Nowadays medical help and care can help individuals cope with problems, but that's not evolution.We strive quite rightly to make sure people are not disadvantaged so I am not sure how this evolution is taking place. Unless there are losers there is nothing for evolution to grab onto. Is there?
Again, evolution is not active,, does not grab onto something; mutations are either fortunate for the species or not.
Just to think of the several billion years when the planet was forming life starting and, from then on, continuing in an unbroken line of life via the dinosaurs, smaller mammals, Ice Ages and then an ape species having mutations which were passed on and here we are, homo sapienssapiens ... ... well, it is far more amazing than any sci-fi story ever invented! :)
Or am I missing it?
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But they cannot take any positive, active steps to become more efficient. That happens or it doesn't.That's their bad luck , and why such huge percentages of species of life have become extinct. Nowadays medical help and care can help individuals cope with problems, but that's not evolution.Again, evolution is not active,, does not grab onto something; mutations are either fortunate for the species or not.
Just to think of the several billion years when the planet was forming life starting and, from then on, continuing in an unbroken line of life via the dinosaurs, smaller mammals, Ice Ages and then an ape species having mutations which were passed on and here we are, homo sapienssapiens ... ... well, it is far more amazing than any sci-fi story ever invented! :)
Or am I missing it?
I think I understand all that but if the unlucky ones still have children then evolution has no effect surely.
I cannot yet see how being lactose intolerant disadvantages individuals in respect of them having children. If that's the case how does evolution pass on this trait, when the trait of not have the gene replicates equally well?
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I think I understand all that but if the unlucky ones still have children then evolution has no effect surely.
The change doesn't happen instantly but over generations. The children of those who do not have the mutation - and their children - will find it harder to survive than the children of those who do. Don't forget, until relatively recently many children did not survive until adulthood. Medical intervention, as we understand it, is rather less than two hundred years old.
I cannot yet see how being lactose intolerant disadvantages individuals in respect of them having children. If that's the case how does evolution pass on this trait, when the trait of not have the gene replicates equally well?
My understanding (which may be incorrect) is that all babies are born able to digest lactose but that this ability fades away as the child develops in many ethnic groups. The European ability of adults to digest lactose is about 7,000 years old. Your comment suggests that the process was the other way round: the ability to digest lactose was universal but most of humanity lost it.
I'm not sure, however, whether the inability to digest lactose and lactose intolerance are necessarily the same thing. Perhaps someone can enlighten me.
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The change doesn't happen instantly but over generations. The children of those who do not have the mutation - and their children - will find it harder to survive than the children of those who do. Don't forget, until relatively recently many children did not survive until adulthood. Medical intervention, as we understand it, is rather less than two hundred years old.
My understanding (which may be incorrect) is that all babies are born able to digest lactose but that this ability fades away as the child develops in many ethnic groups. The European ability of adults to digest lactose is about 7,000 years old. Your comment suggests that the process was the other way round: the ability to digest lactose was universal but most of humanity lost it.
I'm not sure, however, whether the inability to digest lactose and lactose intolerance are necessarily the same thing. Perhaps someone can enlighten me.
Again I sort of agree, but NOW all people survive intolerant or not, so evolution has nothing to work with. Both sets of genes copy just as well, albeit we as a society intervene to make it happen.
In my limited understanding, if people with or without the gen survive long enough to have children, there can be no evolution in the direction of genes for tolerance.
I am not saying you are wrong, I am questioning my understanding of the mechanic of selection, when we get involved to stop selection happening.
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But they cannot take any positive, active steps to become more efficient. That happens or it doesn't.
That's their bad luck , and why such huge percentages of species of life have become extinct. Nowadays medical help and care can help individuals cope with problems, but that's not evolution.Again, evolution is not active,, does not grab onto something; mutations are either fortunate for the species or not.
Just to think of the several billion years when the planet was forming life starting and, from then on, continuing in an unbroken line of life via the dinosaurs, smaller mammals, Ice Ages and then an ape species having mutations which were passed on and here we are, homo sapienssapiens ... ... well, it is far more amazing than any sci-fi story ever invented! :)
Or am I missing it?
Well, I think that has been mostly true .. up to now. Of-course people could affect long term human development by simply having more children than everyone else. Now we have more effective tools to change which genes to pass on or not - tools which will inevitably be used - for good or bad. In addition, we are effectively in charge of much animal life too.
It is not really a question of survival - it is a statistical effect. Lactose intolerance is common in China, or was, but social and economic factors encourage people to consume milk products and, over time, the population becomes more lactose tolerant- just because those that are tolerant tend to rise in society, have more wealth and influence and their children tend to do better.
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The change doesn't happen instantly but over generations. The children of those who do not have the mutation - and their children - will find it harder to survive than the children of those who do. Don't forget, until relatively recently many children did not survive until adulthood. Medical intervention, as we understand it, is rather less than two hundred years old.
My understanding (which may be incorrect) is that all babies are born able to digest lactose but that this ability fades away as the child develops in many ethnic groups. The European ability of adults to digest lactose is about 7,000 years old. Your comment suggests that the process was the other way round: the ability to digest lactose was universal but most of humanity lost it.
I'm not sure, however, whether the inability to digest lactose and lactose intolerance are necessarily the same thing. Perhaps someone can enlighten me.
From the NHS website:
"Lactose intolerance is a common digestive problem where the body is unable to digest lactose, a type of sugar mainly found in milk and dairy products."
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Again I sort of agree, but NOW all people survive intolerant or not, so evolution has nothing to work with. Both sets of genes copy just as well, albeit we as a society intervene to make it happen.
In my limited understanding, if people with or without the gen survive long enough to have children, there can be no evolution in the direction of genes for tolerance.
I am not saying you are wrong, I am questioning my understanding of the mechanic of selection, when we get involved to stop selection happening.
You are right in that there will always be a proportion of the population that will be intolerant - the genes will be passed on. In every generation the parent's genes (along with ancestral genes carried) are shuffled - the phenome depends on which genes are dominant or expressed rather than the full content of the genome.
- But the size of that proportion also depends on many other factors - not only on whether children survive, but on how well they do relative to other groups.
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I think I understand all that but if the unlucky ones still have children then evolution has no effect surely.
I cannot yet see how being lactose intolerant disadvantages individuals in respect of them having children. If that's the case how does evolution pass on this trait, when the trait of not have the gene replicates equally well?
If they have children and the descendants of those children are alive today and carry the mutation, then whatever the mutation was, it did not prevent them from surviving, it was just a mutation that did nothing in particular!! They would have been able to adapt to changes in environment with or without it. To be lactose tolerant would appear to be one of those traits.
Evolution doesn't do anything, it is just a word to describe what has happened to living things.
Edited to add: Evolution does not have direction. It happens or it doesn't. With hindsight, we can see what we can label direction, but that doesn't change the facts.
Also, whatever medical changes can do to help the living, the chances of any such change just possibly being passed on to any more than just a single child or two is as near impossible as makes no difference. Just think of the billions of us there are!
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If they have children and the descendants of those children are alive today and carry the mutation, then whatever the mutation was, it did not prevent them from surviving, it was just a mutation that did nothing in particular!! They would have been able to adapt to changes in environment with or without it. To be lactose tolerant would appear to be one of those traits.
Evolution doesn't do anything, it is just a word to describe what has happened to living things.
Edited to add: Evolution does not have direction. It happens or it doesn't. With hindsight, we can see what we can label direction, but that doesn't change the facts.
Also, whatever medical changes can do to help the living, the chances of any such change just possibly being passed on to any more than just a single child or two is as near impossible as makes no difference. Just think of the billions of us there are!
I think you are missing my point. I agree that in the wild being lactose tolerant would be a useful evolutionary advantage. In the current climate though it does not give any advantage, so humans do not tend to evolve to be lactose tolerant for the simple reason that non lactose tolerant people also survive to have offspring. That as far as I understand it, is evolution.
Because of the way our civilisation currently is, we have effectively turned evolution off. Sure there will be mutations, but those mutations are mitigated by our efforts.
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I think you are missing my point. I agree that in the wild being lactose tolerant would be a useful evolutionary advantage. In the current climate though it does not give any advantage, so humans do not tend to evolve to be lactose tolerant for the simple reason that non lactose tolerant people also survive to have offspring. That as far as I understand it, is evolution.
It is simply an aspect of the unbroken line of life – that some mutations happen and don’t make a lot of difference. However, if they eventually cease to show, that would be caused by another random mutation.
Because of the way our civilisation currently is, we have effectively turned evolution off
absolutely disagree. Nothing can turn evolution off. The DNA is constantly split and rejoined as new cells are constantly being made and it is unbelievably fantastically marvellous that this system has continued for so long and still continues. No-one can take any action which will alter that procedure. . Sure there will be mutations, but those mutations are mitigated by our efforts.
Yes, I agree, but only for each individual as they are able to take advantage of those efforts. Random mutations can happen anywhere in the trillions of cell replications that occur in the billions of people alive today. Our efforts cannot change that.
and it causes extinction, it iis no-one' fault and
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I think you are missing my point. I agree that in the wild being lactose tolerant would be a useful evolutionary advantage. In the current climate though it does not give any advantage, so humans do not tend to evolve to be lactose tolerant for the simple reason that non lactose tolerant people also survive to have offspring. That as far as I understand it, is evolution.
Because of the way our civilisation currently is, we have effectively turned evolution off. Sure there will be mutations, but those mutations are mitigated by our efforts.
I don't think lactose tolerance confers no advantage. A lactose-intolerant person might take lactose by mistake (or wilfully, out of curiosity, in the case of a small child), and snuff it as a result.
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I agree that in the wild being lactose tolerant would be a useful evolutionary advantage.
That depends on what you mean by "in the wild". Obviously, for mammals, being lactose tolerant until weened is a must, but after that, producing the necessary enzymes to digest milk is a waste of time and developing lactose intolerance would be an evolutionary advantage.
In the current climate though it does not give any advantage, so humans do not tend to evolve to be lactose tolerant for the simple reason that non lactose tolerant people also survive to have offspring.
Certainly that is true if you are talking about modern civilisation, but if you lived in a prehistoric society that relied heavily on dairy farming, it would be life or death.
Because of the way our civilisation currently is, we have effectively turned evolution off. Sure there will be mutations, but those mutations are mitigated by our efforts.
I don't think that is the case. There will still be evolution, but we can't say in which direction it will go. For example, if there is a negative correlation between intelligence and family size (Not saying there is, I just made that up), maybe there would be evolutionary pressure towards humans getting more stupid.
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Maybe lactose tolerance can be turned on or off, depending on whether it's needed? No idea if that's the case but might make sense.
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Maybe lactose tolerance can be turned on or off, depending on whether it's needed? No idea if that's the case but might make sense.
No, I'm afraid it doesn't! Mutations either happen or they don't. They cannot be initiated by a species. Remember that:In the King James Version of the Bible the text reads: Which of you by taking thought can add one cubit unto his stature?
so I have to concede that the biblical quote makes sense!
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In the early years of this century, I visited Japan on four occasions. Among the things which I observed were differences between old and young people which were probably the consequence of different dietary practices.
Young Japanese people were taller than older. I guessed that this was possibly due to the arrival of McDonalds and the increased amount of protein that this had made available. But even more noticeable - and one which saddened me - was a significant number of elderly women bent almost double by apparent osteoporosis. This is something which we, in Europe, where we have adequate calcium supplies in the form of milk, see rarely. My expectation is that the ready availability of milk in Japanese supermarkets will ensure that this condition will become rare.
I do not know whether this milk has reduced levels of lactose. My assumption has been that in people who are not of European heritage that lactose passes through the gastro-intestinal tract without being digested. This suggests to me that they would be lactose tolerant. Were they lactose intolerant then they would suffer from some observable pathological reaction. Certainly there would have been insufficient time for mutation to have occurred.
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I do not know whether this milk has reduced levels of lactose. My assumption has been that in people who are not of European heritage that lactose passes through the gastro-intestinal tract without being digested. This suggests to me that they would be lactose tolerant. Were they lactose intolerant then they would suffer from some observable pathological reaction. Certainly there would have been insufficient time for mutation to have occurred.
Well ... it doesn't really work like that.
In populations where milk has not been part of the traditional diet, such that most people do not generate lactase after weaning (lactase helps digest the lactose in milk), consumption of milk products causes lactose to accumulate in the lower intestinal tract or bowel where it supports colonies of bacteria that cause the various symptoms of lactose intolerance.
So if the Japanese do not have the genetics to continue lactase production and start consuming milk (actually some forms of milk - eg some yogurts can mitigate the bad effects) they will suffer from lactose intolerance.
And why is it only the women suffering from osteoporosis? Could be that bearing children is heavily demanding of calcium from the mother? The fact is that calcium is available in plentiful supply in a variety of fruit and vegetables.
We all need to understand our genetics and thus the likely behaviour of our digestion system and biology - and optimise our nutrient intake to suit.
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In the early years of this century, I visited Japan on four occasions. Among the things which I observed were differences between old and young people which were probably the consequence of different dietary practices.
Young Japanese people were taller than older. I guessed that this was possibly due to the arrival of McDonalds and the increased amount of protein that this had made available. But even more noticeable - and one which saddened me - was a significant number of elderly women bent almost double by apparent osteoporosis. This is something which we, in Europe, where we have adequate calcium supplies in the form of milk, see rarely. My expectation is that the ready availability of milk in Japanese supermarkets will ensure that this condition will become rare.
I do not know whether this milk has reduced levels of lactose. My assumption has been that in people who are not of European heritage that lactose passes through the gastro-intestinal tract without being digested. This suggests to me that they would be lactose tolerant. Were they lactose intolerant then they would suffer from some observable pathological reaction. Certainly there would have been insufficient time for mutation to have occurred.
I am running a topic on 'our evolution' on the Science board of the GH forum, a forum where mis information about evolutionary biology is quite widespread unfortunately. Two of the posters started talking about an Anne McCaffrey and a Juan Enriquez, in relation to their alt views on evolution, so I looked them up. The former is a famous ci-fi writer but I have not looked up what she had to say about evolutionary biology. The second a well-known businessman who seems to be 'in' with the DNA discoveries people. I saw a link to a video so clicked on it. The intro mentioned a TED talk connection, but the first part of the video was quite enough for me. Juan Enriquez was giving a talk with a screen and, in rather supercilious tones, was talking about Darwin's finches as if Darwin was quite wrong about all that. So I checked out that too! And of course Darwin, when he first saw and collected some of those birds to bring back to England did not at that time consider why or how the birds not only had different beaks, but had become 18 different species.
The changes in the physical size and shape of Japanese people since the much closer links with the western world have been noticed for some time, havn't they. What I find one of the most interesting things about the human species is that, even though there are so many different sizes and shapes, all humans can still interbreed which, I suppose, proves how much communication there must have been since modern humans evolved. As a matter of irrelevant fact, both my nephews married Japanese girls and both have families.
The current chapter I am reading is about the 11,000 years ago start of agriculture.
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Well ... it doesn't really work like that.
In populations where milk has not been part of the traditional diet, such that most people do not generate lactase after weaning (lactase helps digest the lactose in milk), consumption of milk products causes lactose to accumulate in the lower intestinal tract or bowel where it supports colonies of bacteria that cause the various symptoms of lactose intolerance.
So if the Japanese do not have the genetics to continue lactase production and start consuming milk (actually some forms of milk - eg some yogurts can mitigate the bad effects) they will suffer from lactose intolerance.
And why is it only the women suffering from osteoporosis? Could be that bearing children is heavily demanding of calcium from the mother? The fact is that calcium is available in plentiful supply in a variety of fruit and vegetables.
We all need to understand our genetics and thus the likely behaviour of our digestion system and biology - and optimise our nutrient intake to suit.
We are all lucky that there is so much information available about nutritional values of food, and my contemporaries and I, wartime children, sometimes talk about our diets then and wonder why that has meant we are not all dead yet!! :)
With my familly history of heart attacks and strokes, I have, for a greater part of my life tried to follow a sensible middle way and I hope that, along with the heart surgery and pills of todays medical care, plus sensible exercising, will continue to keep me going for a year or two more!
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For the record, answersingenesis says that lactose intolerance is 'normal' and that the mutations for lactase persistence are not an increase in genetic information but a decrease, and so are not 'evolution'.
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For the record, answersingenesis says that lactose intolerance is 'normal' and that the mutations for lactase persistence are not an increase in genetic information but a decrease, and so are not 'evolution'.
For the record answersingenesis is dishonest ignorant bollocks
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For the record answersingenesis is dishonest ignorant bollocks
A stopped clock and all that.
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A stopped clock and all that.
Except evolution is not 'increase in genetic information' so not even that.
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Except evolution is not 'increase in genetic information' so not even that.
So it's decrease in genetic information?
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So it's decrease in genetic information?
Woo, and we have a winner in a false dichotomy contest. Misrepresenting evolution as answersingeneneis do doesn't mean the opposite is what it is. So if I say cheese is high tannins, and you say it isn't, it doesn't you are saying cheese is low tannins. It's irrelevant.
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So it's decrease in genetic information?
No. Evolution may increase or decrease information (and you also have to properly define what you mean by information - something creationists rarely even attempt). You really do need to understand that AiG is full of lies and/or astounding ignorance.
See Claim CB102 (http://www.talkorigins.org/indexcc/CB/CB102.html).
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Except evolution is not 'increase in genetic information' so not even that.
The sentence was plausibly true except for the very last bit.
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So it's decrease in genetic information?
It can be either.
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Woo, and we have a winner in a false dichotomy contest. Misrepresenting evolution as answersingeneneis do doesn't mean the opposite is what it is. So if I say cheese is high tannins, and you say it isn't, it doesn't you are saying cheese is low tannins. It's irrelevant.
Yes I get that AIG tend to define evolution in terms of increase in complexity, microbes to man, but that it fundamentally means change over time.
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Yes I get that AIG tend to define evolution in terms of increase in complexity, microbes to man, but that it fundamentally means change over time.
So why do you go back to a site that lies to you? They are not only lying about how evolution is defined, they are also lying about variation and selection not being able to increase information or complexity.
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So why do you go back to a site that lies to you? They are not only lying about how evolution is defined, they are also lying about variation and selection not being able to increase information or complexity.
Glad you used the word complexity.
In lactase persistence, genes are modified so that lactase persists through adulthood. This doesn't seem any more or less complex than if it didn't persist. Agreed, it may be beneficial, but is not adding any new processes or structures to the organism. So it can't be used to illustrate the theory that all life shares common ancestry.
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In lactase persistence, genes are modified so that lactase persists through adulthood. This doesn't seem any more or less complex than if it didn't persist. Agreed, it may be beneficial, but is not adding any new processes or structures to the organism. So it can't be used to illustrate the theory that all life shares common ancestry.
It illustrates one of the processes involved (the evidence as a whole is encyclopaedic) but that's not really the point. I was asking why you would refer to a site that lies. AiG lies about evolution being an increase in information and it lies when it says random variation and selection cannot increase information.
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So it's decrease in genetic information?
Sorry to be a pedant, but it's neither an increase or decrease in information, it's a change in the amount of data. It only becomes information when it's interpreted.
Simple patterns of data, when interpreted, can lead to inordinately complex expressions, and conversely very broad ranging datasets can be interpreted into tightly defined information bundles - that's the essence of statistics, after all.
O.
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Sorry to be a pedant, but it's neither an increase or decrease in information, it's a change in the amount of data.
If you really want to be pedantic, it might not even be that. It might just be a change in the data, not the amount of data.
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If you really want to be pedantic, it might not even be that. It might just be a change in the data, not the amount of data.
There is that instance, too, of course.
O.
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I wonder if Spud really, actually, deep down, thinks that God intervened in evolution somewhere and did a bit of gene manipulation or something. I wonder if he has really read anything that explains clearly the basics of our evolution. He could try 'The Ancestor's Tale' by Richard Dawkins, I suppos, but I doubt if even the clarity there would impress.
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For the record, answersingenesis says that lactose intolerance is 'normal' and that the mutations for lactase persistence are not an increase in genetic information but a decrease, and so are not 'evolution'.
Well, they would say that, wouldn't they?
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It illustrates one of the processes involved (the evidence as a whole is encyclopaedic) but that's not really the point. I was asking why you would refer to a site that lies. AiG lies about evolution being an increase in information and it lies when it says random variation and selection cannot increase information.
Which process involved in common descent does it illustrate?
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Which process involved in common descent does it illustrate?
Natural selection but, again, that wasn't the point. Why do you go back to a site that tells you lies?
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Natural selection but, again, that wasn't the point. Why do you go back to a site that tells you lies?
So does natural selection create new structures or processes then, because lactase persistence sure doesn't.
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So does natural selection create new structures or processes then, because lactase persistence sure doesn't.
Random mutation and natural selection together do. See the link I gave before (Claim CB102 (http://www.talkorigins.org/indexcc/CB/CB102.html)). Mutation provides novelty (new information to work on) and natural selection filters out the harmful and amplifies the useful.
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I wish I could navigate quickly and efficiently through the Talk Origins web site!
Anyway, today the pages I have been reading deal with a 55 million years ago warming period which was followed by a period of gradually cooling taking about 200,000 years. During the warm period - can't remember how long this lasted - and the following coolling period, the grasses and animals humans domesticated evolved, fortunately for humans. Once the domestication had started, it moved quickly which enabled rapid population growth. It's all very fascinating.
Apparently Eurasia had six of the grass species which were the cereals, north America, and some other regions had 4 and others, had only 2, so Eurasia had a distinct advangtage. The animals we domesticated had various sorts of cloven hoofs.
Regarding the lactose tolerance/intolerance question, I wonder whether, since large changes in the biology of species can only really be observed and analysed maybe thousands of years after they have become thoroughly established, I wonder whether that particular mutation is still in the process of being selected for or not.
What would have happened to human evolution if these facts had not beenin place, godness knows where we'd be!
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The warming period referred to is known as the Paleocene/Eocene thermal maximum, or PETM for short, when a massive injection of CO2 into the atmosphere over some tens of thousands of years raised global average temperatures by 5 to 8 degrees celsius, melting the ice caps and raising sea levels considerably. This warming period is used as a case model in climate science for what happens if you inject a vast amount of carbon dioxide into the atmosphere, as currently we are emitting a similar amount, only over a couple of centuries rather than over 20,000 years or so.
The proto-mammals liked the warmer conditions, it would seem, it resulted in a massive radiation of new mammal species across the globe; after 200 million years being predated and suppressed by the dinosaurs, the mammals were free and with all the ice gone, they had a whole new world of opportunities to explore and niches to adapt into. This massive mammalian radiation laid the ground work for the lineages that would eventually lead to us - primates, arboreal apes, genus homo, and then homo sapiens around 200,000 years back.
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Thank you, Torridon. The most difficult thing I find is to try and visualise, say, 20,000 years and then to think of how many mutations would have to have taken place over how many generations and places for new species to emerge.
The latest thing is about horses. I must look it up today, but apparently there were horses before the last Ice Age , but when humans crossed the Baring Strait landmass into the north American continent during the IceAge, they caused the extinction of the species and horses then were absent from America until the Spanish arrived in the 15th century.
I think the bibliography at the end of the book is going to be very long and I'd need another two lifetimes to read them all!! :)
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https://www.ndtv.com/science/nesher-ramla-homo-new-type-of-early-human-found-in-israel-2471919?pfrom=home-ndtv_trendingtrending
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https://www.ndtv.com/science/nesher-ramla-homo-new-type-of-early-human-found-in-israel-2471919?pfrom=home-ndtv_trendingtrending
I think they are probably wrong about the Neanderthals evolving in europe. Just because they have found evidence of Neanderthals there, does not mean they evolved there. They more likely evolved in East Africa and then migrated out.
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Hi everyone,
Dragon Man..... Perhaps closest ancestor...
https://www.ndtv.com/world-news/dragon-man-scientists-say-new-human-species-is-our-closest-ancestor-2472621?pfrom=home-ndtv_topscroll
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This is not directly associated with the book, but the article I am going to link to here could well have happened in similar fashion a billion or so years ago. I found it very interesting.
A friend was telling me about a programme she had listened to. It was about explosive cylindricrical craters in 'siberia. I googled it and the first link was to
this (https://www.bbc.com/future/article/20201130-climate-change-the-mystery-of-siberias-explosive-craters) extremely interesting article.
Anybody know anything more about this, or studied it at all?
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This is not directly associated with the book, but the article I am going to link to here could well have happened in similar fashion a billion or so years ago. I found it very interesting.
A friend was telling me about a programme she had listened to. It was about explosive cylindricrical craters in 'siberia. I googled it and the first link was to
this (https://www.bbc.com/future/article/20201130-climate-change-the-mystery-of-siberias-explosive-craters) extremely interesting article.
Anybody know anything more about this, or studied it at all?
There is a section on it n this edition of the Travel.Show that I watched yesterday
https://www.bbc.co.uk/iplayer/episode/m000ybmd/the-travel-show-30-tokyo-olympics
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There is a section on it n this edition of the Travel.Show that I watched yesterday
https://www.bbc.co.uk/iplayer/episode/m000ybmd/the-travel-show-30-tokyo-olympics
Sounds as if there are some interesting programmes to watch. Did the one you saw interview any of the people living in that area? I wonder how much their daily lives use modern technology.