Evolution: Not Only the Fittest Survive

[n2doc]

ScienceDaily (Mar. 27, 2011) — 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.

more

http://www.sciencedaily.com/releases/2011/03/110327191044.htm

[Deep13]

1. God did it!

What, they already have an explanation? Sorry, jumped the gun.

[robcon]

2. This is not news. Luck has had an enormous impact on survival.

Proto-humans and their descendants could easily have been wiped out in the most severe Ice Ages.

[mva92]

20. Nothing to do with luck

Most things aren't based on "luck", luck is just what we call unexplained events...

[fasttense]

3. It seems both the fit an unfit coexist.

They expected the unfit to die out and the fit to take over but that is not what happens.

[d_r]

4. Theres a story about a certain breed of salmon

I don't have all this correct, I'm going from memory.
But you all know the story of Salmon. They hatch way up in a small pool that is free of the predators that would eat the fry in the ocean. As they get bigger, they swim downstream, enter the ocean where there is much more food than back at that small pool, and spend years in the ocean getting bigger and getting stronger.

When the biological clock goes off, they migrate back up stream to those home pools to spawn. Only the strongest and smartest get there. You've seen the videos of swimming against the current, being eaten by bears and jumping up rock water falls, that sort of thing. When the strongest get back to the pool, the strongest males pick out the choicest rock outcroppings for their nests. They guard these nests from other males, and this signifies to the females who is the strongest. The males say "look at my beautiful rock outcropping that I defending from these other punk salmon, come lay your eggs here and let me fertilize them with my vibrant sperm so that your offspring will have only the best genes and can, in turn, produce progeny that will carry your genes forever."

But back in that same stream, there were a very few males that never swam out to the ocean in the fist place. The never got big, because all they had to eat was a poor diet in that little pool. They've been living up there waiting, while all the big guys went out to sea. And while the big strong males are facing off each other, guarding their nests from the other strong males to show their prowess, little homeboy is sneaking around the backside and fertilizing a few eggs. And in the next generation, some of those fry will carry those genes, and will stay in the pool and never grow big, and will sneak in a father a few more little guys in the future.

The point of that story is, there are many avenues for successfully passing along your genes. What is "obvious" in terms of being the "fittest" isn't always apparent. Evolution allows for possibilities of passing on traits that aren't obviously the "fittest," but fit with a niche that allows them to be passed on.

[GKirk]

6. I could learn a thing or two

about pick up lines from those salmon.

The males say "look at my beautiful rock outcropping that I defending from these other punk salmon, come lay your eggs here and let me fertilize them with my vibrant sperm so that your offspring will have only the best genes and can, in turn, produce progeny that will carry your genes forever."

[GeorgeGist]

8. That could explain Republicans and ...

Dinos.

[GKirk]

5. It seems to make sense...

...the fittest tend to protect the weakest.
i.e. babies (I'd say women too but I suspect I'd get my butt kicked for saying that) :)

[ladjf]

7. IMO the key to survival is the match up between a species' attributes

and the nature of the environmental circumstances.

[LiberalFighter]

9. Absolutely

Besides, the fittest doesn't necessarily mean smart enough to survive either. I can see the weakest surviving if they were cunning and smart enough. Say like out in the wild an animal that thinks it is strong and invincible or nearly so always being reckless and being the first to attack. While a weaker animal letting the stupid strong animal take the lead and if the strong one doesn't meet up with an enemy then the weaker one knows it is safe.

[ladjf]

16. Yes, it is the matchups that matter. nt

[Ready4Change]

10. Multiple routes to success.

Success on one route does not necessarily rule out simultaneous success on other routes.

Further, if resources are plentiful, multiple approaches to the same route can co-exist for a while. The strongest on a particular route only eliminates competitors if the route exists, unchanged, for an extended period of time. If the route changes before one species totally dominates, surviving 'inferior' species have a renewed chance to compete.

In reference to salmon streams, if a human dam closed off access to the ocean, then genetic lines that depend on ocean access would lose to the smaller, stay at home types. Perhaps that is how the smaller types got numerous enough to be noticed in the first place?

[qazplm]

11. I'd guess it should be amended to

survival of the fit enough.

[mzteris]

13. saw this after my post

yes - I had long discussions about this concept back in the 80's.

Being "fit enough" for a particular set of conditions doesn't necessarily mean you are the "most fit".

[mzteris]

12. it's not the "fittest"

it's the "fit enough" . . . and a bit of luck.

[bananas]

14. Survival of what fits.

I didn't realize there were any biologists left who believed in survival of the fittest.

[laconicsax]

15. "Survival of the fittest" wasn't coined by Darwin, and Darwin didn't mean it as "best species"

He used it as a metaphor, not a literal description.

Science journalism FAIL.

[Jim__]

17. "If there's a low mutation rate, survival of the fittest rules ..."

Dr Ivana Gudelj, also from the University of Exeter, said: "The fit use food well but they aren't resilient to mutations, whereas the less efficient, unfit consumers are maintained by their resilience to mutation. If there's a low mutation rate, survival of the fittest rules, but if not, lots of diversity can be maintained.

"Rather nicely, the numbers needed for the principle to work accord with those enigmatic experiments on bacteria. Their mutation rate seems to be high enough for both fit and unfit to be maintained."

I would have expected that for similar strains of bacteria, the mutation rate would be close to constant. What determines the mutation rate? The environment?

[hunter]

18. "Mutation" rates are also evolved traits.

Many species have a lot of unused stuff tucked away in their genes that is re-exposed when the environment changes.

When something is not working, the deck gets shuffled a bit, cards that were hidden are revealed, and cards that were exposed are hidden.

Since the earth is always changing life that doesn't evolve doesn't last. What's fit today may be deadly tomorrow.

[sofa king]

19. My favorite example is the tranny-sunfish.

Sunfish are like a lot of other fish, in that the male is usually big, mean, and takes over nest-guarding duties after fertilization.

But there's a second kind of male that superficially looks like a female and exhibits female behavior during mating, pretending to be another interested female during the ritual. A third kind hovers around while the Fabio-sunfish is busy doing his mating ritual with the female. Then once she lays her eggs, the cross-dressers and satellites swoop in, deliver their payloads, and leave the eggs for Fabio to take care of them.

In heavily fished ponds, all the sunfish begin to resemble females, because the fishermen take out the desirable males and leave the sneaky ones behind. The population then begins to suffer, because the sneaky ones don't protect the nests as well (or at all).

http://beheco.oxfordjournals.org/content/14/5/634.short

I don't think it's fair to call it a non-evolutionary trait, though, because the ultimate objective is to survive and reproduce. The sneaky ones are simply pursuing a secondary strategy that relies upon other males to do the heavy lifting, which I'm sure we have all seen in the workplace by now. That guy who calls in every day a shipment comes in? He's the tranny sunfish.

[eppur_se_muova]

21. News flash -- evolution is more subtle than journalists (and many scientists) can realize.

How many times has this lesson been repeated in the past several decades?

[guitar man]

22. Hell I figured that out a long time ago

Sitting on the porch on the farm watching june bugs, if they could survive, so could a lot of things :P