Are selected for mutations simply random occurences?

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Discussion Overview

The discussion centers on the nature of mutations that are "selected for" in evolutionary biology, specifically whether these mutations are purely random occurrences or if there is some directed mechanism involved. The scope includes theoretical considerations of evolution and natural selection, as well as implications of human intervention in genetic traits.

Discussion Character

  • Debate/contested
  • Conceptual clarification

Main Points Raised

  • One participant questions whether the evolution of traits, such as a tanish color for camouflage, is due to random mutations or if there is a directed mechanism in DNA that influences survival strategies.
  • Another participant asserts that while mutations are random, the selection process is not, as it is influenced by environmental factors that favor certain traits.
  • A different viewpoint introduces the concept of human intervention in evolution, citing examples like engineered frost resistance in tomatoes.
  • One participant suggests that while random mutations are common, the selection process may also involve genes that control mutation rates and repair mechanisms, indicating that not all aspects of mutation are random.
  • A recommendation is made for Richard Dawkins' "Extended Phenotype" as a resource for further understanding these concepts.

Areas of Agreement / Disagreement

Participants express differing views on whether mutations are purely random or if there are directed mechanisms involved. There is no consensus on the nature of mutations and selection processes, indicating an ongoing debate.

Contextual Notes

Participants reference specific examples and theoretical frameworks, but the discussion remains open-ended with various assumptions about the mechanisms of mutation and selection not fully resolved.

Sundu
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Are "selected for" mutations simply random occurences?

I just read Carl Sagan's and Ann Druyan's Shadows of Forgotten Ancestors and there is something that I am not fully clear about. I will give an example:

Let us suppose that there is a zebra-like creature. Over time, the zebra-like creature evolves into a mammal that is much harder for predators to detect; it loses its contrasting black and white stripes and takes on a tanish color, letting it camoflauge easier in the African savanah.

How did this tanish color evolve? Was it simply a completely random mutation that one or two animals were born with, passing the mutation on to future generations and having the mutation being "selected for" throughout the species because many other of these creatures simply die due to being easy prey, thus being unable to pass THEIR genes on? Or does something in the DNA say "Look, we need to develop a new survival strategy"? I tend to think that it is the former, as the latter does not make much sense to me, but I just want to be sure.

Thanks.
 
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The mutation is random, but the selection is not, the selection is "natural", i.e., preferred by the environment such that it will be of aid to the organism long enough that it has an advantage until it breeds.
 
There is one exception to that: human intervention. Many survival traits such as frost resistance in tomatoes are deliberately engineered these days.
 
Danger said:
There is one exception to that: human intervention. Many survival traits such as frost resistance in tomatoes are deliberately engineered these days.

Too bad they didn't have GModification for humans during WWII. My uncle lost all his toes to frost bite after crashing his bomber in Greenland and waiting for rescue.:rolleyes: (Actually I think he'd rather have no toes than the genes of an Artic krill to pass on to his descendents. :wink:
 
Sundu said:
Was it simply a completely random mutation that one or two animals were born with, passing the mutation on to future generations and having the mutation being "selected for" throughout the species because many other of these creatures simply die due to being easy prey, thus being unable to pass THEIR genes on? Or does something in the DNA say "Look, we need to develop a new survival strategy"?
Thanks.

In most cases it is the random mutation - directed selection process.

But... Imagine that the selection is not between genes that decide the colour of the stripes but mutations and selection of genes controlling the rate of - controlling and repair of mutations. Or the meiosis process. In other words - genes that control the mechanisms of replication.
In such cases it may be that the selection process may affect the mutation. The very fact that cells do contain mechanisms for repairing the `easy errors' of DNA replication is a proof that not everything is random.

I recommend old, but very illuminating Extended Phenotype by Richard Dawkins.
 
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