Darwin re-visited

[Ben]

freeztar: Split away if you think it appropriate. There is a lot more to be said on the subject if anyone is interested in a rational discussion.

 

Pyrotex: I have obviously offended you, for which I am truly sorry; that had not been my intention, and I hope you can forgive my "debating" style. Know what? I am rather fond of you (you bastard)

 

Let me set out my stall:

 

a) geneticists study the pattern of inheritance of particular phenotypes, regardless of the mechanism by which these phenotypes arise;

 

:cup: the unit of heredity is called a gene, and is now known to comprise a relatively short stretch of DNA (in most, not all, organisms)

 

c) potential genes (called Open Reading Frames - ORFs) comprise around 10% of the total DNA in your average mammalian cell; the remaining 90% has no known function (by and large)

 

d) every cell in a specialized organism - say a mammal - has exactly the same DNA content - amount and sequence - as far as is known

 

e) specialized here means the organism is a "colony" of cell groups, each of which has a different phenotype - skin, liver, blood, lung, blah, blah

 

d) of the 10% of the total DNA in each of these specialized cells which I called the ORFs, only a fraction of these find expression in phenotype of these different groups

 

Can you all now see why I bridle at the conflation of "gene" with "DNA"?

 

Anyway, dark o'clock tomorrow morning I'm off camping.

 

So later

[Pyrotex]

Hi, Ben. Love you, too. :cup:

 

Yes, I can easily see why one might criticize my post #711 above. Especially if you were expecting precise, literal and techical genetic explanations. And often, I DO use precise, literal and technical language when talking about genetics and evolution and "fitness" and all that.

 

And sometimes, I climb way to the top of the Ladder of Abstraction, and talk in (what amounts to) genetic metaphor and evolution metaphor. Kind of like Dawkins does in his books. In fact the titles of his books, "River Out of Eden", and "Climbing Mount Impossible" are themselves excellent and powerful metaphors. But for the details, you have to climb down the Ladder of Abstraction to the "rung" where the appropriate levels of technical detail are discussed, where the appropriate levels of distinction are made, say, between "DNA" and "genes".

 

One could, in principle, climb down the Ladder even further, and describe genetics entirely from the viewpoint of atomic mass, molecular stability, electric fields, bonding strength, charge distribution, resonance and valence. But it would be a vast exercise in futility!

 

Anyway, I would like to learn more about those "Open Reading Frames" you spoke of, and the various distinctions of the word "gene". Thanks.

[Michaelangelica]

Mendel’s understanding was incomplete. It is true that children inherit 23 chromosomes from their mother and 23 complementary chromosomes from their father. But it turns out that genes from Mom and Dad do not always exert the same level of influence on the developing fetus. Sometimes it matters which parent you inherit a gene from—the genes in these cases, called imprinted genes because they carry an extra molecule like a stamp, add a whole new level of complexity to Mendelian inheritance.

These molecular imprints silence genes; certain imprinted genes are silenced by the mother, whereas others are silenced by the father, and the result is the delicate balance of gene activation that usually produces a healthy baby.

, , ,

To understand the implications of imprinting, it helps to know a few basics. Imprinting is an epigenetic (meaning “beyond genetic”) mechanism, a molecular change that can happen within a cell that affects the degree to which genes are activated, without changing the underlying genetic code.

The type of imprinting that happens in egg and sperm cells is known as “genomic imprinting,” a reference to its fundamental heritable nature. Other types of imprinting can happen as a result of environmental influences, such as parental nurturing or abuse. [For more on epigenetics, see “The New Genetics of Mental Illness,” by Edmund S. Higgins; Scientific American Mind, June/July 2008.]

A Patchwork Mind: How Your Parents' Genes Shape Your Brain: Scientific American

[Larv]

A Patchwork Mind: How Your Parents' Genes Shape Your Brain: Scientific American

Michaelangelica, in the article you cite there is this statement:

 

To understand the implications of imprinting, it helps to know a few basics. Imprinting is an epigenetic (meaning “beyond genetic”) mechanism, a molecular change that can happen within a cell that affects the degree to which genes are activated, without changing the underlying genetic code.

I’m OK with that, so long as it is understood that there is indeed an “underlying genetic code.” What Higgins says here is not remarkable. Even being cold can engage a body’s genes to respond appropriately to hypothermia, such as shivering. And no one here is suggesting that hypothermia alters the “underlying genetic code.” A horse’s genes will induce it to grow more hair in the winter “without changing the underlying genetic code.”

 

This is partly why I have issues with the evo-devo folks. They too often, IMO, chose to ignore the “underlying genetic code” in favor of non-digital (i.e., analog) explanations for the underlying causes of evolution. Lamarck must be smiling in his grave.

[Michaelangelica]

Humans are the way that DNA makes copies of itself.

My brain and bum hurts

 

Fire=evolution(social?) hmmm. . . interesting idea.

I read recently one biologist (dietitian?) who said cooking food gave humans the greatest 'fillip' to development as the cooking partly digests and enables man to get much more calorific and other value from the food.

Also I read somewhere that charcoal on BBQ food could be tetrogenic.(not in spell check) Which, by inference, suggests it could have caused a viable mutation.

 

Seems to me we have at least three arguments going here now, -a bit hard to follow.

Is part of the problem the relative importance we each ascribe to epigenetic (not in spell check) inheritance?

[Michaelangelica]

Using Darwin's theories to help understand aging, depression, pain, medicine, diagnosis, the impefect/badly/non-sensical designed body (appendix,eye, ?l nerve,vas deferns' wanderings).

What are the benefits of depression?

What are the benefits of pessimism?

What are the benefits of pain?

What are the benefits of stress?

What are the benefits of anxiety?

What are the benefits of negative emotions/feelings?

How come the USA is the most depressed country? The American Dream?

SYNOPSIS: Why do diseases exist, and why hasn't the body evolved to be so much better? This program on Darwinian medicine features Professor Randolph Nesse in conversation with Natasha Mitchell, host of ABC Radio National's, All in the Mind.

Look in your doctor's kitbag, and you'll probably find a stethoscope, a thermometer, a first-aid kit. But a copy of Charles Darwin's Origin of Species too?

 

'Darwinian Medicine' asks: why do we get sick, and why didn't the body evolve to be better? Psychiatrist Randolph Nesse argues physicians ignore evolutionary theories at the peril of their patients.

m?

http://mpegmedia.abc.net.au/rn/podcast/2009/03/aim_20090321.mp3

[Larv]

How come the USA is the most depressed country? The American Dream?

When you combine greed with a gun-toting frontier mentality, and throw in self-righteous indignation along with a penchant for world domination, then it is easy to understand why the American dream is too often a worldwide nightmare.

 

Many philosophers and historians agree that Western capitalism is as Darwinian as you can get, even during these times of nanny state.

[Michaelangelica]

NOVA What Darwin Never Knew

 

 

One hundred and fifty years later, scientists decode nature's greatest mysteries—a two-hour special. Airs December 29, 2009 on PBS.

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Airs December 29, 2009 on PBS.

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Program Description

 

Earth teems with a staggering variety of animals, including 9,000 kinds of birds, 28,000 types of fish, and more than 350,000 species of beetles. What explains this explosion of living creatures—1.4 million different species discovered so far, with perhaps another 50 million to go? The source of life's endless forms was a profound mystery until Charles Darwin brought forth his revolutionary idea of natural selection. But Darwin's radical insights raised as many questions as they answered. What actually drives evolution and turns one species into another? To what degree do different animals rely on the same genetic toolkit? And how did we evolve?

 

 

What Darwin Never Knew

Tuesday, December 29 at 8 pm ET/PT on NOVA

 

Check your local listings as dates and times may vary.

 

"What Darwin Never Knew" offers answers to riddles that Darwin couldn't explain. Breakthroughs in a brand-new science—nicknamed "evo devo"—are linking the enigmas of evolution to another of nature's great mysteries, the development of the embryo. NOVA takes viewers on a journey from the Galapagos Islands to the Arctic, and from the explosion of animal forms half a billion years ago to the research labs of today. Scientists are finally beginning to crack nature's biggest secrets at the genetic level. The results are confirming the brilliance of Darwin's insights while revealing clues to life's breathtaking diversity in ways the great naturalist could scarcely have imagined.

 

See how closely parts of your body match those in other animals, from sharks to fruit flies, find out what the science of "evo devo" is all about, and more on the program's companion website.

NOVA | What Darwin Never Knew

 

Watch the program online beginning December 30.

[Essay]

Thanks again ...for that reminder/notice about NOVA!!!!!!!!

[nevaeh.aaric]

Remember that the simple (and astounding) act of procreation adds to the diversity of the species. Before, during, and after any environmental event that stresses the species and reduced diversity, procreation continues it's inexorable increase in that same diversity. Evolution demands that these two forces work in concert.

[paigetheoracle]

As someone who was recently attacked for suggesting that evolution is mental* (as in of the mind, not crazy), can someone list Evolution's weak points and possibly suggest ways they could be relevant, even if there is no scientific (consensus) proof for these ideas?

 

As an aside I once wrote to Sir David Attenborough, suggesting that how could anybody deny evolution when the body changed and adapted to circumstances throughout its life, from birth, through childhood, adolescence, the middle years and old age - not to mention the mind as old ideas i.e. prejudices (See my paper under Members Articles forum, 'Prejudice or Progress?) are continually discarded by us as individuals and societies as we mature and learn new things (As a child I picked my nose but stopped that as an adolescent - got into short lived relationships in my youth and have now settled into middle age, with less drive but no less concern for the world, in fact more).

 

* 'I was never trying to change anyone's mind exactly. I was always writing on the assumption that we were of the same mind and had the same values.' (Jonathan Safran Foer - a man after my own heart and as it is broken he can have it!). It seems to me it is like the question of matter and anti-matter - never the twain shall meet or can, just like the future will always be ahead of you like a carrot and the past sliding behind you as a trail of regrets ( Once you reach the future physically, it becomes the present and a way station, not the real future which is always out there).

[Pyrotex]

...can someone list Evolution's weak points ...?

Generally speaking, a "weak point" of any theory is generally either: a piece of hard evidence that the theory cannot explain -- or another (successful) theory that does not appear to be compatible with the first theory. For example, the photoelectric effect, which any college freshman could observe in the laboratory, could not be explained with classical electromagnetic theory; and quantum mechanics, though highly successful, appears incompatible with gravitational theory (also highly successful).

 

As far as I know, there is no evidence (evolutionary evidence, such as fossils) that Evolution hasn't explained. As far as I know, there is no other theory (Genetics would be where I would look first) that is clearly incompatible with Evolution. Quite the opposite, Evolution and Genetics are amazingly compatible.

 

As an aside I once wrote to Sir David Attenborough, suggesting that how could anybody deny evolution when the body changed and adapted to circumstances throughout its life, from birth, through childhood, adolescence, the middle years and old age - not to mention the mind as old ideas....

I have to stop you right here. Once again, you are confusing The Theory of Biological Evolution with ordinary, every-day, instances of "change". Body changes (maturation) have NOTHING to do with Evolution. Mind changes, attitude changes have NOTHING to do with Evolution.

 

Having a profound (weighty) idea has nothing to do with Gravity.

Being the "life" of the party has nothing to do with Biology.

Hitting it off with your new girlfriend (chemistry) has nothing to do with Chemistry.

Counting on your friends has nothing to do with Arithmetic.

Driving your point home has nothing to do with Automotive Engineering.

Getting hot under the collar has nothing to do with Thermodynamics.

Weathering a crisis has nothing to do with Meteorology.

Being the star of a Hollywood movie has nothing to do with Astronomy.

 

And changing your mind has nothing to do with Evolution. :doh: :doh: :doh:

[paigetheoracle]

Generally speaking, a "weak point" of any theory is generally either: a piece of hard evidence that the theory cannot explain -- or another (successful) theory that does not appear to be compatible with the first theory. For example, the photoelectric effect, which any college freshman could observe in the laboratory, could not be explained with classical electromagnetic theory; and quantum mechanics, though highly successful, appears incompatible with gravitational theory (also highly successful).

 

As far as I know, there is no evidence (evolutionary evidence, such as fossils) that Evolution hasn't explained. As far as I know, there is no other theory (Genetics would be where I would look first) that is clearly incompatible with Evolution. Quite the opposite, Evolution and Genetics are amazingly compatible.

 

I have to stop you right here. Once again, you are confusing The Theory of Biological Evolution with ordinary, every-day, instances of "change". Body changes (maturation) have NOTHING to do with Evolution. Mind changes, attitude changes have NOTHING to do with Evolution.

 

Having a profound (weighty) idea has nothing to do with Gravity.

Being the "life" of the party has nothing to do with Biology.

Hitting it off with your new girlfriend (chemistry) has nothing to do with Chemistry.

Counting on your friends has nothing to do with Arithmetic.

Driving your point home has nothing to do with Automotive Engineering.

Getting hot under the collar has nothing to do with Thermodynamics.

Weathering a crisis has nothing to do with Meteorology.

Being the star of a Hollywood movie has nothing to do with Astronomy.

 

And changing your mind has nothing to do with Evolution. :doh: :doh: :doh:

 

Forgive me for opening my mouth again and putting my size 11 foot in it - not literally of course because I am not double jointed or a gymnast.;)

[Michaelangelica]

It is very hard to see a better model when looking at any living organism

Dawin's Law of Natural Selection explains so much and is the cornerstone of most biological sciences

 

Perhaps even some physical sciences.I remember vaguely the story of a company that needed a better design for a hose nozzle. All the engineering firms they gave the brief to failed.

They could not design a better nozzle . A new company was asked. They gave ten new nozzles and asked 'Which is best?'. One was a little better so they made that change and gave the firm ten more nossles. One of those was better so on again for about 5 generations until a perfect nozzle was made.

An amazing problem solving strategy.

[lawcat]

Here is an interesting animal that seems to have evolved into immortanility:

The world's only immortal animal | Yahoo! Green

[Michaelangelica]

If humans could do this we would be in trouble.

[maikeru]

If humans could do this we would be in trouble.

 

How many of us would willingly volunteer to revert back to embryos or zygotes? :hihi: