On Natural Selection

Originally posted by KazetNagorra
Evolution does not lead to "improvement" of species, it leads to change. Whether or not such change is an improvement depends on what you think is an improvement, nature does not judge.

Evolution is not "random" but requires a random element. If you only have the random element, but no reproducing agents or no interaction with the environment, there ...[text shortened]... Man developed a complex brain because this improved the reproductive success of individuals.

For any living being to have a reproductive ability, it has to have a survival ability first ! But you say that Evolution does not select survival ability. Strange !
By the way it may be better to exclude words such as Nature or Environment. These two words have no denotation. Let us say that some external( external only ?) factors cause some variants to be destroyed and some to survive. As per living evidence the evolution is biased towards survival and biased towards improvement -at least within Humanoid apes- don't you think?

Originally posted by rvsakhadeo
For any living being to have a reproductive ability, it has to have a survival ability first ! But you say that Evolution does not select survival ability. Strange !
By the way it may be better to exclude words such as Nature or Environment. These two words have no denotation. Let us say that some external( external only ?) factors cause some variants to ...[text shortened]... owards survival and biased towards improvement -at least within Humanoid apes- don't you think?

Natural selection selects survival ability if, and only if, this improves reproductive success. This will be often the case but it would be wrong to say natural selection selects survival ability.

Whether or not an adaptation is an "improvement" is dependent on the context. Something which helps reproductive success today might be a disadvantage several generations later, if circumstances have changed. So a static view in which evolution keeps "improving" living beings is false.

Originally posted by KazetNagorra
Natural selection selects survival ability if, and only if, this improves reproductive success. This will be often the case but it would be wrong to say natural selection selects survival ability.

Whether or not an adaptation is an "improvement" is dependent on the context. Something which helps reproductive success today might be a disadvantage seve ...[text shortened]... have changed. So a static view in which evolution keeps "improving" living beings is false.

well said.

And an example of natural selection selection NOT selecting survival ability but improved reproductive success would be the evolution of peacock feathers.
Clearly such feathers are a significant burden on survival of the individual as such feathers make the peacock more easily seen and attacked by predators.

Originally posted by rvsakhadeo
Please cite proof that all the species continue to improve in the design of body and brain.

And in a later post

I don't see why you have included water, earth,atmosphere et. unless according to avid evolutionists,these inanimate things also evolve.

You do not know what you are talking about.

Seriously. Get a basic education on what the modern notion of evolution actually is, before coming here and arguing against windmills.
What you're doing now is similar to arguing against chess because the king can only move one square diagonally and is therefore trapped in the centre: a combination of outdated and completely wrong, the result being both daft and irrelevant.

Richard

Agree. Pure nonsense.

rvsakhadeo

this is a simple way you can understand evolution without misunderstanding it providing you know how artificial selective breading works to create significant change in the characteristics over many generations to produce the many breads of dogs etc:

natural evolution is just like artificial selective breading except one critical difference;
the conscious intelligent human breeder with intent on selecting for particular characteristics in each generation is replaced with the unintelligent mindless environment that unintentionally and mindlessly selects particular characteristics in each generation.

Evolution is simply natural selective breading as opposed to artificial selective breading.
Evolution is nature's selective breeder.

Originally posted by rvsakhadeo
Darwin stated that Nature selects the species best fitted for survival. Naturally this presupposes "Nature" as an agency engaged consciously in an activity
of " Selection" of the species best fitted for survival. Since this amounted to bringing in God by back door,Darwin added the words to the effect that this activity goes on automatically or by chance. ...[text shortened]... t in all living things
to live and to procreate ? Where does
this instinct comes from?

Those organisms that didn't eat or procreate are all gone. The ones that eat and procreate are the ones that survive as a species.

Originally posted by rvsakhadeo
For any living being to have a reproductive ability, it has to have a survival ability first ! But you say that Evolution does not select survival ability. Strange !
By the way it may be better to exclude words such as Nature or Environment. These two words have no denotation. Let us say that some external( external only ?) factors cause some variants to ...[text shortened]... owards survival and biased towards improvement -at least within Humanoid apes- don't you think?

How about this:

The 'thing' that does the selecting is the competition between individuals for limited resources and the constant battle between predator and prey.

Competition between individuals is not intelligent or conscious.
Battle between predator and prey is not intelligent or conscious.

If a random mutation gives an individual a better facility for obtaining a scarce resource / catching prey / evading capture then that individual is more likely to survive long enough to reproduce, thereby passing on this mutation to its offspring. Over time, those individuals with the mutation will reproduce more than those without. That mutation will eventually become the norm and the species has 'evolved'.

Conversely, an individual with a mutation giving it a worse facility for the above is less likely to survive long enough to reproduce and pass on the mutation. That mutation will then tend to die out and the species will not therefore evolve in that direction.

One of the things that makes an individual more likely to reproduce is a tendency to seek out the opposite sex when they are receptive. This is an example of a component of your 'drive to survive etc'. Those that are not bothered with mating will be less likely to mate and pass on that disinterest.

No intelligent, conscious or purposeful agency is involved in any of the above.

Does that help?

--- Penguin.

Ps, the advice to read a more modern book is good advice. I have read Origin of Species and it is very dry and plodding. Dawkins is far more readable. I've not tried the Selfish Gene but the Blind Watchmaker is very good.

Originally posted by Penguin


Competition between individuals is not intelligent or conscious.
Battle between predator and prey is not intelligent or conscious.

What's so intelligent about being conscious?

Originally posted by rvsakhadeo
Has any improvement been seen in species other than humans to the extent you are describing?Has evolution stopped in cockroaches for the last millions of years but has continued at a terrific pace for humanoid apes so that Homo Erectus developed into Homo Sapiens in far less time, and so that today Homo Sapiens thinks of nothing about travelling to othe ...[text shortened]... ?
Please cite proof that all the species continue to improve in the design of body and brain.

“....Has any improvement been seen in species other than humans to the extent you are describing?...”

if you are talking about toolmaking and language intelligence, no. We are unique in that respect just as elephants are unique in having such long trunks.

“...Has evolution stopped in cockroaches for the last millions of years but has continued at a terrific pace for humanoid apes so that Homo Erectus developed into Homo Sapiens in far less time, and so that today Homo Sapiens thinks of nothing about travelling to other planets and developing clones of sheep and the like ? ...”

Yes. Significant evolution occurs only when there is a significant change in the environment or some other evolutionary impetus such as, in the case of human evolution, dramatic cultural and technological advances (such as the invention of stone tools and fire etc and the culture of cooking meat) which would have resulted in an increase in brain size to take better advantage of that (brainier people would be better able to work out how they can use fire to their advantage than stupid people and also make more effective tools etc).

“...Please cite proof that all the species continue to improve in the design of body and brain. ...”

who suggested that improvements are occurring all the time in every species? They do not and the theory of evolution doesn't imply that they do. Significant change only occurs during a cladogenesis.
Have you heard of punctuated evolution? If not, read this for it explains that evolution occurs in bursts followed by long lulls;

http://en.wikipedia.org/wiki/Punctuated_equilibrium

Originally posted by rvsakhadeo
I am asking about the process. Not about the Theory. It is not a chemical or physical reaction but a process purporting to select the fittest species. Why does it take place ?

Natural selection is pretty easy. Dumb, sickly, or clumsy animals often die and are removed from the gene pool. Attractive,fast, and strong animals get mates while the rest have a smaller chance of reproducing.

Only with humans do we circumnavigate this natural selection with modern technology to keep the weak and sickly alive to pass their genes onto others.

It's selection by an animal's choice and available selections in mates, not someone saying who should or should not live.

P-

Originally posted by Phlabibit
Attractive,fast, and strong animals get mates

And when they've got enough mates, they all head on down to the pub for a nice evening together.

Beer is the evolutioniser.

Originally posted by Andrew Hamilton
“....Has any improvement been seen in species other than humans to the extent you are describing?...”

if you are talking about toolmaking and language intelligence, no. We are unique in that respect just as elephants are unique in having such long trunks.

“...Has evolution stopped in cockroaches for the last millions of years but has continued ...[text shortened]... occurs in bursts followed by long lulls;

http://en.wikipedia.org/wiki/Punctuated_equilibrium

I invite your attention to a recent news item about reduction in human brain size for the last few thousand years. Also a news item in significant reduction in Sperm Count in humans over the last few dozens of years. An evolution in reverse? A development towards Extinction of human species ?

Originally posted by rvsakhadeo
I invite your attention to a recent news item about reduction in human brain size for the last few thousand years. Also a news item in significant reduction in Sperm Count in humans over the last few dozens of years. An evolution in reverse? A development towards Extinction of human species ?

“...An evolution in reverse? ...”

No. If natural selection selects for a smaller brain then there must be a recent change in our environment or culture that gives a net advantage in having a slighter smaller brain. There are significant biological costs in having such a large brain such as greater energy consumption and greater risk of heat stroke etc. Also, as any good neurologist will tell you, a smaller brain does not necessary mean less intelligence! The brain can be made smaller simply by being more efficiently wired, not stupider!

As for the significant reduction in Sperm Count in humans over the last few dozens of years, that obviously must be caused by environmental factor (such as pollution and unhealthy life style etc) and NOT evolutionary factors because a “few dozens of years” is simply not enough time for as humans to undergo significant evolutionary change.

“...A development towards Extinction of human species ? ...”

Evolution works on the genetic variants level within the species and not on the species as-a-whole level.
There is nothing in evolutionary theory that says there is no possibility that a species as a whole can evolve characteristics that make it more susceptible to extinction as a whole although I don't see the slightest bit of evidence that this is happening to the human species. Also, living things evolve to be more adapted, not ever less!

Dinosaurs evolved very large and, no doubt, that made them more susceptible to extinction in the event of a global natural disaster. But the fact remains, they didn't evolve large in order to become extinct! They evolved large because that was the best adaptation at the time before any global natural disaster.

Originally posted by rvsakhadeo
I invite your attention to a recent news item about reduction in human brain size for the last few thousand years. Also a news item in significant reduction in Sperm Count in humans over the last few dozens of years. An evolution in reverse? A development towards Extinction of human species ?

Again this is not what evolution means!

Again (again!) do your homework first, before you start opinionating.

Richard