Does anybody know the focal points of evolution by natural selection?

Question

biology 101

Answer 1

"Focal Points", as in the important concepts to get across?

Well - HEREDITY, MUTATION and SELECTION.

Heredity - that you inherit the characteristics of your parents.

Mutation - but that you can sometimes develop new characteristics, sometimes better, sometimes worse.

Selection - that characteristics that are better will provide an advantage, and will therefore become more common over time.

Answer 2

gribbling's answer is just about right. My only correction would be that instead of heredity, mutation, and selection ... I would say heredity, variation, and selection. In other words, mutation is ultimately the source of new variation, but sexual reproduction also *dramatically* increases variation in those organisms that use it. In other words, the important thing about mutation is that it produces variation.

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{Sorry about the following ... but this is a good illustration of why creationism is hurting science education in the U.S. Evolution is actually really easy to explain ... but not when we also have to clear up a lot of BAD misinformation spread by creationists ... no wonder people are confused.}

kdanley's answer is full of the usual creationist misinformation. Creationists would have you believe that they can point out simple and obvious "serious problems" with evolution, without any explanation of how tens of thousands of PhD's in biology, genetics, biochemistry, etc. ... for over 150 years ... have all overlooked these obvious "problems." In other words, creationists would have you believe that scientists are, by and large, idiots.

1. Yes, beneficial mutations are rarer than harmful or neutral ones ... but it doesn't matter. It's the beneficial ones that propagate, the harmful ones disappear fast. That is the point of the "Selection." It is not enough to just pull a number out of a hat like "trillions and trillions" ... you need to show how you arrived at that number other than just saying "a ridiculous big number" (might as well just say "bazillions").

2. Mutation is not just "scrambling or loss" of genetic information. Entire genes get duplicated. A single gene duplication followed (perhaps generations later) by a positive transcription error to one of the two copies now produces a brand new gene.

Or to put it another way ... every year we need a new flu shot. Why? Because the flu viruses have evolved imunity (in a single year) to last-year's flu shot. Where did these immunity genes come from if not mutation? How is that not "new information"?

3. It is mutation that creates variation. Natural selection filters that huge variation for the beneficial ones. Again, back to the flu virus example ... if the immunity was not "created" by new mutations, then creationists would have you believe that it was already there ... in other words, that God created flu viruses already containing the genes for immunity to all flu viruses that have been, *or ever will be* developed by man!

4. There is no evidence at all that long-term accumulation of old obsolete mutations (what we call junk DNA) makes the DNA any more unstable. In fact, the presence of *any* non-functional DNA is evidence of evolution ... and any junk DNA shared between two species is further evidence of common ancestry. The connection to the Jenga game is bizarre ... it makes a nice image, but there are no fundamental similarities at all that justify the comparison.

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{edit --- for Mannyd101}

Glad we crack you up ... but the consensus of the scientific community trumps Readers Digest ... especially when discussing *matters of science* ... especially when creationists show they are unqualified to really discuss the science because they display a basic, *FUNDAMENTAL* lack of understanding of how the theory works.

The entire *point* of Natural Selection is that it is NOT just accidents ... but accidents filtered by a *relentless* elimination of bad accidents and propagation of good accidents. *Four billion years* of that relentless process.

You are laboring under the unfounded creationist claim that science in general, which includes evolution, is an attack on, or denial of, God. It is not. Nobody here is attacking God. So your Readers Digest testimonials of God's intercession in people's lives are wonderful and inspiring (and I do not dispute them) ... but entirely irrelevant to a science forum, to evolution, and even moreso, to this asker's question!

>"There are no atheists in foxholes."

Stop equating scientists (and anyone else who supports evolution) with atheists.

The key problem with creationists is that they see atheists *everywhere*. I've had creationists tell me both of the last two Popes are atheists because the have both spoken out in support of evolution. The 10,800 Christian preachers, ministers, priests, deacons, etc. who signed the Clergy Letter Project (see source) ... all atheists.

Answer 3

The replication of life is not perfect. Mutations are introduced by a variety of means, and can add information (principally by gene duplication). The ones that reproduce pass on the genes. It the gene confers an advantage, more of the next generation of offspring will have the gene. If it creates a disadvantage, less will.

Answer 4

You guys and gals just crack me up. Your explanations are simply laughable. To seriously claim that there is one instance where a logical sequence of events accidentally occurred is ludicrous e.g. put a million monkeys on typewriters and you will not get even one logical sentence or a pour a million bottles of paint will not produce on letter. However, to claim that there were multiple trillion accidents that somehow produced this amazing world does not border on insanity, it is insanity. Darwin theory of evolution was never proven and is simply based on preconceived notions that are the results of wishful thinking.

I avid reader of the Reader’s Digest and recently noticed a pattern. Every month the Reader’s Digest writes a real life drama. The person who lives to tell the story 10 out of 10 times recalls his praying to GOD at the most precarious moments. I wonder what happens to all the people that believe the world is a jumble of accidents at the time of their moment of truth. I have two theories: One is that they do not budge even at the last moment and so GOD has no reason to save them and they die and do not live to tell their story. Or there was never a case that a person facing death should not admit that GOD created the world and that God is the omnipresent.

As the true saying goes: There are no atheists in fox holes!

Answer 5

According to evolutionists beneficial mutations allow a life form to take over the gene pool and improve the species. However, there are some serious problems with this logic.
1. Beneficial mutations are extremely rare. Real evolution would need trillions and trillions of these but we have observed only a handful.
2. Mutation is merely scrambling or loss of genetic information. Real evolution would require an increase in information, order, and complexity.
3. Natural Selection only selects. It doesn't create. Having birds with better beaks does not explain the origin of birds or beaks.
4. Natural Selection has limits. Too many mutations make the DNA unstable.

Next time you play a game like Jenga, think about mutations. You are not adding blocks. You are merely rearranging them. The more you do, the more unstable the tower becomes. Also, that process will not build anything but a taller tower. I hope I answered your question.

-secretsauce
Quit equating evolution with science. Scientists taught that heavy objects fell faster than lighter objects for 2,000 years even after Galileo (a creationist) proved them wrong on the tower of Pisa.
I know it is annoying when people point out flaws in your thinking, but don't kill the messenger if you cannot handle the message. Am I spreading misinformation and creating confusion just because I do not agree with you?
Flu shots are proof of evolution? I haven't had flu shots for years and have rarely gotten sick. Do you even know what they are injecting into you? Study that one out. Even if flu viruses mutate and become resistant to vaccines that is only proof of micro-evolution. Can a virus evolve into a vaccine?

*note to askers*
If you ask questions about evolution be prepared for responses from people like secretsauce and myself. This is a hotly debated topic and there are fundamentalists like secretsauce and me on both sides.

Answer 6

exactly what everyone else who answered this question just said.