Darwin re-visited

[Michaelangelica]

Originally Posted by KickAssClown

Dude, I am not sure you quite understand how the whole Darwin thing works.

if 70% of a populus is wiped
Survival is absolute, the subject lives and is capable of breeding. Adaptation is relative.

I know exactly what it says.
I say it is an inadequte explanation. It is too pat, too easy. It does not account for what happens in 20C, or what we are learning about DNA.
How does extiction of genetic lines help diversity? Diversity which in turn should help survival of a species?
I will argue more when I have my BIG THINK. I feel a bit under siege at the moment.

[Kayra]

Originally Posted by Michaelangelica

It is too pat, too easy. It does not account for what happens in 20C, or what we are learning about DNA.

20C is a pretty special time for humanity, that is for certain.

Originally Posted by Michaelangelica

How does extinction of genetic lines help diversity? Diversity which in turn should help survival of a species?

Extinction does not help diversity. Diversity helps prevent extinction. (Not a guarantee by any means, just the best method evolution has)

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.

Originally Posted by Michaelangelica

I will argue more when I have my BIG THINK. I feel a bit under siege at the moment.

You ask questions and force readers to think and justify their position. PLEASE do not think of us as attacking you, as that is not the intent.

By all means, have your BIG THINK, but please continue to ask the questions.

[hallenrm]

Go Ahesd, No objection Whatsoever!!

[Michaelangelica]

My problems with Darwin
1 The language used.
The value laden nature of it and the circular nature of the argument.
Lets try to define natural

nat·u·ral Listen: [ nchr-l, nchrl ]
adj.
http://www.yourdictionary.com

1. Present in or produced by nature: a natural pearl.

2. Of, relating to, or concerning nature: a natural environment.

3. Conforming to the usual or ordinary course of nature: a natural death.

4. a. Not acquired; inherent: Love of power is natural to some people. b. Having a particular character by nature: a natural leader. c. Biology Not produced or changed artificially; not conditioned: natural immunity; a natural reflex.
# Produced by nature; not artificial or manmade:

organic, unadulterated.
Idiom: pure as the driven snow.
# In a primitive state; not domesticated or cultivated; produced by nature:

native, rough, uncultivated, undomesticated, untamed, wild.
See wild.

Now how is Genetic engineering, IVF, immunisation, atomic bombs, bacterial warfare, new man-made tetrogenic & cancinogenic compounds/chemicals,machine-guns, surgery, pesticides, The Terminator Gene, hybridisation,heart transplants "natural".( I will leave "war" & terrorism off the list because sociobiologists will probably argue that it is natural.)

-- selection
noun

The act of choosing:

choice, election, option, preference.
See choice.
se·lec·tion Listen: [ s-lkshn ]
n.


1. a. The act or an instance of selecting or the fact of having been selected. b. One that is selected.

2. A carefully chosen or representative collection of people or things. See Synonyms at choice.

3. A literary or musical text chosen for reading or performance.

4. Biology A natural or artificial process that favors or induces survival and perpetuation of one kind of organism over others that die or fail to produce offspring.

(That last one is nasty but i will bravely include it and push on.)
Here the language is really "loaded'. "Selection" implies that a choice is made. when I buy apples from the supermarket I choose one over another. One apple I think is better than another. (marketers will tell me i choose the shiniest reddest plumpest apple. Organic farmers tell me I should be choosing the one with blemishes as this means I will be poisioning myself with less pesticide)
Now my argument is real choices are not being made. (Especially if you throw in the even more emotionally loaded word "fittest" as in survival of).
It is just a lottery. Lady Luck running wild. It is blind chance that favours one individual species or individual over another.
To use tems like natural selection "removes the chaff and allows the wheat though " is emotionally loaded.
NS does no such thing. What we have left of life is not the 'best" we can even use words like 'best'

(Genetic engineering
Genetic engineering i always thought a very precise careful accurate, 'engineering ed process after reading David Suzuki and Holy dressel's "Naked Ape to Super species" i realise it shoul be be called something like "Genetic Buckshot"there are many more problems with Genetic engineering than I thought possible. The near release of the bacterium Klebsiella planticula is a chilling story.)
They say

Is "survival of the fittest" a tautology?(Wikapedia)

The phrase "survival of the fittest" is sometimes claimed to be a tautology (i.e. it is a statement which is true by its own definition, and is therefore intrinsically uninformative). Unfortunately, although in evolutionary biology the word "fitness" has nothing to do with being "fit" since it quantifies potential or realized reproductive success (as in "realized fitness"), the noun's etymological connection with the adjective "fit" leads many to charge the phrase "survival of the fittest" is equivalent to saying "those who survive best are those who survive best" or "those who reproduce most are those who reproduce most", i.e., that it is a tautology. The reasoning is that if we take the word "fit" to mean "fitness" then "survival of the fittest" means "highest fitness of those with highest fitness".

However, Darwin and Spencer used "survival" as a proxy for "fitness" in the modern sense and "fittest" to refer to those individuals that are functionally most capable to tackle life challenges, i.e. to individuals endowed with phenotypic characteristics which improve most strongly one's probability of survival and reproduction. Therefore "survival of the fittest" intends to be a short version of the statement "those who are best at surviving and reproducing will have higher fitness" and this is not a circular statement since the sentence indicates that fitness is the consequence of one's ability to tackle life challenges.

Sure as long as you are also lucky
Cataclysms such as Volcanic eruption etc. obviously don't "select" unless you are immune to hot Lava of course, they simply wipe out.

The full cause-and-effect picture of how natural selection generates fitness differences is that those individuals which end up reproducing more do it because they differed from others in biologically relevant traits that affected their probability of surviving and/or reaching reproduction in better condition.

No they just happened to be in the right place at the right time in history

For instance, a gazelle that for some biomechanical reason runs faster than average will be more likely to escape predators and will therefore be more likely to produce more offspring than slower ones since the latter would get to reproduce during fewer breeding seasons. The faster gazelle would therefore be "selected", i.e., it would have higher relative fitness than slower ones, etc, but not "because it is selected" but rather because it can run faster and thus can escape better from predators so that ultimately it will go through more breeding seasons than average gazelles and thus will reproduce more (will have higher fitness).

Are you going to tell me that the 99.99% of life now extinct had a 'lower relative fitness'. Nonsense. they just happened to be in the way of a passing meteor.

2 the Question of diversity
The more diversity the more chance of survival. So why does natural selection reduce diversity?
99.99% of all life that has lived on earth is now extinct. (leaving us with a mere c1.5 million species)
How can this be an efficient sytem? It is a mind-numbingly profligately wasteful system. How can reducing diversity help survival?
To quote Suzuki and Dressel

"It is the differences that maximise the chance that there will be survivors under new conditions or different circumstances. Homogencity and monoculture run counter to this basic principle, making us vulnerable to sudden changes.. . .What if there is a mistake?"

and again they quote Tewolde Egziather

"If you were to go back to the time of the dinosaurs, and you were to see a little mammal running about, you would never think that this mammal would succeed the dinosaurs. who can tell which is the dinosaur and which is the mammal in our time, in this era of really frightening possibilities?. . .what is successful now and what will be successful in the future. . . is not something linear that proceeds from what we know at the moment (places) have destroyed many of the bridges they would of had into other possibilities.

As you say

Extinction does not help diversity. diversity helps prevent extinction

Sure the invention of sex gives us diversity but overall diversity is selected against. Why? What part of Darwin explains this phenomenon?

3 Socio-biology.
The inheritance of acquired behaviours.
I have many problems here. OK you can have altruism but if we have been selected for that behavior what selects for homosexuality? How does that removal of some of our brightest and best from the gene pool help diversity and any sort of individual or species survival?

I need to stop now but
What if natural selection has made a major mistake with man?
Edward Wilson professor of Biology at Harvard notes that If man were to become extinct this would benefit the ecology of the planet enormously.
If ants went extinct the results would be catastrophic. There would be major extinctions and ecosystem collapse.

Gaia anyone?

[KickAssClown]

Who said that this was the most efficent system? Took god only knows how many eons to get to this point.

However, it's merely statistical odds. It's like playing the lottery in vegas. You win some, you lose some, but the house always wins.

[Eclogite]

Originally Posted by Michaelangelica

What if natural selection has made a major mistake with man?
Edward Wilson professor of Biology at Harvard notes that If man were to become extinct this would benefit the ecology of the planet enormously.
If ants went extinct the results would be catastrophic. There would be major extinctions and ecosystem collapse.

Mankind is a single species. How many species of ants are there? What is the total number of ants? What is the total biomass of ants?

You are not comparing apples and oranges.

[Michaelangelica]

Originally Posted by Eclogite

Mankind is a single species. How many species of ants are there? What is the total number of ants? What is the total biomass of ants?

You are not comparing apples and oranges.

Yes I am. Check out the meaning of species.

How does Darwin account for death?

Not all life decides to pass on genes.
Some virus and bacteria just spontaneously die out. Usually because the are too efficient (No 'survival of the fittest' here)

Homosexuals do not tend to pass on their genes.
(We need to assume here that homosexuality is a sociobiological trait like altrusism)

How does Darwin account for the fact that 80% of the life on this planet
(Bacteria) can swap genetic material with any other bacteria, no sex involved. They just do it. How do they select which bits to swap?

[CraigD]

Originally Posted by Michaelangelica

Homosexuals do not pass on their genes.

This is a logical conclusion only if one assumes that all homosexuals never have heterosexual sex. This assumption is not supported by my experience – Of the roughly 20 males I personally know who have acknowledged to me that they are homosexual, 4 of them have fathered at least 1 child. I only know 10 women who have acknowledged to me that they are homosexual, 4 of whom have born at least one child.

I’ve discussed the details of parenthood with only a few homosexuals, most of them male. Several had children while in heterosexual relationships, before “coming out” and adopting a nearly or fully homosexual life style. One had a child as the result of a single sexual encounter with a female friend. A male homosexual couple and a female homosexual couple I know had child by way of a complicated agreement. None had children via artificial inseminated “surrogacy”, though I understand that this is sometimes done.

None of the children of homosexuals who I know are, to my knowledge, homosexuals.

It appears to me that, while homosexuality may reduce the probability of passing on one’s genes, it doesn’t reduce it to nearly zero. Conversely, being heterosexual doesn’t increase the probability to nearly 100%.

[Michaelangelica]

Originally Posted by CraigD

None of the children of homosexuals who I know are, to my knowledge, homosexuals.

It appears to me that, while homosexuality may reduce the probability of passing on one’s genes, it doesn’t reduce it to nearly zero. Conversely, being heterosexual doesn’t increase the probability to nearly 100%.

OK You win
You can have homosexual behaviour.
It is a matter for conjecture if it is an inherited trait anyway(I am not fond of socio-psycho-biology either)

What about the very promiscuous bacteria? (most of this planet's life)
How do they choose which bits of another's geonome to appropriate?
The "Natural Selection" model just does not work here.

Why do some species (in all senses of the word) decide to die?

[Michaelangelica]

This article has helped me understand that there is more at work than "Natural Selection". which is the point I started to make.
Darwin alone does not account for the 20C events or expansions of biological knowledge.
http://www.talkorigins.org/faqs/faq-...o-biology.html
My problem is fitting what I know into that one model
(I am still not convinced we have all the answers especially with bacteria)
But this goes some way to helping. Especially the anthropomorphizing of the word "selection"

When selection is spoken of as a force, it often seems that it is has a mind of its own; or as if it was nature personified.
This most often occurs when biologists are waxing poetic about selection. This has no place in scientific discussions of evolution.
Selection is not a guided or cognizant entity; it is simply an effect.

A related pitfall in discussing selection is anthropomorphizing on behalf of living things.
Often conscious motives are seemingly imputed to organisms, or even genes, when discussing evolution.
This happens most frequently when discussing animal behavior. Animals are often said to perform some behavior because selection will favor it.
This could more accurately worded as "animals that, due to their genetic composition, perform this behavior tend to be favored by natural selection relative to those who, due to their genetic composition, don't."
Such wording is cumbersome.
To avoid this, biologists often anthropomorphize. This is unfortunate because it often makes evolutionary arguments sound silly.
Keep in mind this is only for convenience of expression.

The phrase "survival of the fittest" is often used synonymously with natural selection. The phrase is both incomplete and misleading.
For one thing, survival is only one component of selection -- and perhaps one of the less important ones in many populations.
For example, in polygynous species, a number of males survive to reproductive age, but only a few ever mate.
Males may differ little in their ability to survive, but greatly in their ability to attract mates -- the difference in reproductive success stems mainly from the latter consideration.
Also, the word fit is often confused with physically fit.
Fitness, in an evolutionary sense, is the average reproductive output of a class of genetic variants in a gene pool. Fit does not necessarily mean biggest, fastest or strongest.

the genetics of these populations is consistant with drift models.

Thus, it is wrong to consider natural selection as the ONLY mechanism of evolution and it is also wrong to claim that natural selection is the predominant mechanism. This point is made in many genetics and evolution textbooks, for example;

"In any population, some proportion of loci are fixed at a selectively unfavorable allele because the intensity of selection is insufficient to overcome the random drift to fixation.
Very great skepticism should be maintained toward naive theories about evolution that assume that populations always or nearly always reach an optimal constitution under selection.
The existence of multiple adaptive peaks and the random fixation of less fit alleles are integral features of the evolutionary process.
Natural selection cannot be relied on to produce the best of all possible worlds." (Suzuki, D.T., Griffiths, A.J.F., Miller, J.H. and Lewontin, R.C. in An Introduction to Genetic Analysis 4th ed., W.H. Freeman, New York 1989)

And:

"One of the most important and controversial issues in population genetics is concerned with the relative importance of genetic drift and natural selection in determining evolutionary change.
The key question at stake is whether the immense genetic variety which is observable in populations of all species is inconsequential to survival and reproduction (ie. is neutral), in which case drift will be the main determinant, or whether most gene substitutions do affect fitness, in which case natural selection is the main driving force.
The arguments over this issue have been intense during the past half- century and are little nearer resolution though some would say that the drift case has become progressively stronger.
Drift by its very nature cannot be positively demonstrated. To do this it would be necessary to show that selection has definitely NOT operated, which is impossible.
Much indirect evidence has been obtained, however, which purports to favour the drift position. Firstly, and in many ways most persuasively is the molecular and biochemical evidence..." (Harrison, G.A., Tanner, J.M., Pilbeam, D.R. and Baker, P.T. in Human Biology 3rd ed. Oxford University Press 1988 pp 214-215)

The book by Harrison et al. is quite interesting because it goes on for several pages discussing the controversy.
The authors point out that it is very difficult to find clear evidence of selection in humans (the sickle cell allele is a notable exception).
In fact, it is difficult to find good evidence for selection in most organisms - most of the arguments are after the fact