"Evolution: Not Only the Fittest Survive"

[Skwim]

"Darwin's notion that only the fittest survive has been called into question by new research published in the journal Nature. A collaboration between the Universities of Exeter and Bath in the UK, with a group from San Diego State University in the US, challenges our current understanding of evolution by showing that biodiversity may evolve where previously thought impossible.

The work represents a new approach to studying evolution that may eventually lead to a better understanding of the diversity of bacteria that cause human diseases.

Conventional wisdom has it that for any given niche there should be a best species, the fittest, that will eventually dominate to exclude all others.

This is the principle of survival of the fittest. Ecologists often call this idea the `competitive exclusion principle' and it predicts that complex environments are needed to support complex, diverse populations.

Professor Robert Beardmore, from the University of Exeter, said: "Microbiologists have tested this principle by constructing very simple environments in the lab to see what happens after hundreds of generations of bacterial evolution, about 3,000 years in human terms. It had been believed that the genome of only the fittest bacteria would be left, but that wasn't their finding. The experiments generated lots of unexpected genetic diversity."

This test tube biodiversity proved controversial when first observed and had been explained away with claims that insufficient time had been allowed to pass for a clear winner to emerge.

The new research shows the experiments were not anomalies."

source and more
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And it's stuff like this that gives science such credibility: it's willingness to change in the face of new evidence, something one will never see in creation "science."

 

[Jose Fly]

Professor Robert Beardmore, from the University of Exeter, said: "Microbiologists have tested this principle by constructing very simple environments in the lab to see what happens after hundreds of generations of bacterial evolution, about 3,000 years in human terms. It had been believed that the genome of only the fittest bacteria would be left, but that wasn't their finding. The experiments generated lots of unexpected genetic diversity."

I'm a little surprised that this is considered controversial. That a population will carry deleterious alleles and traits through time rather than evolve towards some sort of optimum has been, I thought, established for years. Just ask salmon biologists.

 

[McBell]

Seems to me that the fact that they survived makes them the fittest...

Perhaps the article is using a different definition of fittest?

 

[Where Is God]

If anything humans defy this rule. Think about all the chickens we farm. The chicken population is the same as the human population.... They have no reason to flourish without us. (Not saying chicken farming is good) chickens are not natural predators, and are only good breeders.

 

[tumbleweed41]

"Darwin's notion that only the fittest survive has been called into question .......

...Conventional wisdom has it that for any given niche there should be a best species, the fittest, that will eventually dominate to exclude all others...​

​

Darwin used the term "survival of the fittest" in his Fifth edition of On the Origin of Species as a metaphor for "better adapted for immediate, local environment". Not as a scientific term that insinuates only the strong survive.
It was Herbert Spencer who coined the phrase in Principles of Biology after reading earlier editions of Darwins book. Spencer was also a Lamarckian Evolutionist.

Source

 

[painted wolf]

Fitness is reproductive success... at least in evolutionary biology. From reading the abstract of the actual paper, this is the definition they use as well.

Genetic diversity is a benefit to a population and population dynamics are pretty complex... so I'm not surprised by this finding.. that doesn't stop it from being very cool!

I find the fact they talk about metabolic management more interesting and that metabolic balancing act goes a long way to explaining the diversity in these experiments. It's also very cool that they managed such diversity in a very limited system!

But I agree with your conclusion... that one of the joys of science is that old ideas are challenged and tested and if lacking discarded or modified to better reflect reality.

wa:do

 

[Skwim]

[/indent]Darwin used the term "survival of the fittest" in his Fifth edition of On the Origin of Species as a metaphor for "better adapted for immediate, local environment".

Your source says "better designed for immediate, local environment." is in reference to his use of the term "improved."

"To Darwin, improved meant only 'better designed for immediate, local environment.' "
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Not a the object of the "metaphor," "survival of the fittest."

Your source also says.

"Natural selection is the central concept of Darwinian theory—the fittest survive and spread their favored traits through populations. Natural selection is defined by Spencer's phrase "survival of the fittest,"
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So regardless if Darwin used the phrase or not, the notion behind it, "the fittest survive and spread their favored traits through populations" was always there.
That some have taken "survival of the fittest," to mean only the fittest survive is unfortunate. My understanding has always been that if any single form can survive it would be the fittest form.

 

[painted wolf]

I think the real problem is what people think "fitness" means.

Fitness is simply the ability to reproduce successfully. This is not the way people generally think of the term... much like the difference between the scientific and common definition of the word "theory".

wa:do

 

[tumbleweed41]

Your source says "better designed for immediate, local environment." is in reference to his use of the term "improved."

"To Darwin, improved meant only 'better designed for immediate, local environment.' "
​

Not a the object of the "metaphor," "survival of the fittest."

Your source also says.

"Natural selection is the central concept of Darwinian theory—the fittest survive and spread their favored traits through populations. Natural selection is defined by Spencer's phrase "survival of the fittest,"
​

So regardless if Darwin used the phrase or not, the notion behind it, "the fittest survive and spread their favored traits through populations" was always there.
That some have taken "survival of the fittest," to mean only the fittest survive is unfortunate. My understanding has always been that if any single form can survive it would be the fittest form.

Well thats what I get for using a secondary source....