Simplify Evolution

[A_Nony_Mouse]

My theist girlfriend thinks its ridiculous that we evolved from apes.

We didn't. We and apes share a common ancestor. In turn monkeys and apes share a common ancestor further back.

Most of the problems with discussing evolution is that it is so simple in concept yet the "examples" are almost invariably misstated. Nothing personal. It is so simple that it is hard to grasp.

We were having a discussion about things while watching "The Bible" mini-series. She said she is open to the possibility that there is no god, but still thinks the evolution of apes to humans is a crock of shit. She said she learned about evolution in school, but didn't let me get into the discussion any further. (Typical believer. "I think I'm right, but I'm not going to let you say anything that makes logical sense, because it will make me look stupid") I'm not sure she really has an understanding of how it works or she would be able to see how humans could have evolved from apes.

So my question to you all is how would you simplify evolution so I don't have to just say "go read for yourself", because I know she won't. What would be the easiest way to explain how evolution takes place in layman's terms?

Also if you may have some answers to other related questions such as "how long it would take for humans to evolve from apes?", etc., I would love to hear those also. With enough logic I think I can show her what reality looks like.

I will tell you what evolution is very simply. It takes very little additional knowledge. Lots of people can not grasp it being this simple because the examples/results appear unrelated.

An allele is a variation in gene expression. It is the reason that children of the same sex of the same parents are not identical. That is the natural source of variation of ourselves and all species. It is these variations which drive evolution.

Evolution is the change of allele frequency within a population over time. That is all. It is that simple. When the allele frequency has limited variability you have a new species. Species do not continue to change when the range of allele expression does not result in more children. More children is the simple way of saying reproductive advantage.

When you get into the details of how this works it does get a bit more complicated although the basic concept remains exactly as simple as above. The next few paragraphs are only about how a new allele frequency becomes dominant. If you take the time to think about it the ideas almost as simple as the above.

But if you can get away with saying allele drift, aka evolution, aka speciation is faster when there are small groups in relative isolation you don't have to read any further.

Like a small group of finches isolated on the Galapagos. That is Darwin talking about finches adapting to different food supplies, filling some niches. There is no requirement that evolution will fill all niches or that evolution has to occur. There were no carnivorous finches to eat other finches, to fill the predator niche. In fact there is no requirement that the finches ever adapted to the different food supplies.

For a species, only alleles which result in having more children promote a specific set of allele frequency changes. Take for example opposable thumbs. IF more opposible means more food then it will lead to more offspring. Opposability will become more common. As all apes did not evolve opposable thumbs, only the ones on the human branch did, it would appear it has no value in itself. As our branch used tools that would suggest tools can be better used if there is an opposable thumb.

There is another thing that helps evolution, small separated groups. If there is a large population no matter what the advantage of a different gene expression like more opposable thumbs if it keeps being "averaged out" in a large population there is not going to be a change in frequency. American Indians arrived as a small group and their alleles resulted in distinct physical characteristics. They were separated from old world.

In the old world different races occur where there are physical barriers which slow interbreeding. Even though all are Indo-European northern Europe, southern Europe (separated by the east-west mountain chain across Europe) and north Africa (separated by the Med) have distinct physical characteristics. But in northern Europe from Ireland to the Urals the differences are much less. Any new allele frequency arising in the Urals can travel to Ireland (and vice versa) in only a thousand years which is not long enough for particular allele frequency to become dominant. But despite the mountains and distances the "white" Indo-Europeans, the pre-WWII Aryans, do not dilute from India to Ireland to Morocco.

Anyway speciation by reproduction in isolation is Dawkins' only claim to fame in the field. The rest is popular writing like Sagan.

One more point, the allele variation is random just like the believers claim. However the disappearance of variations which reduce reproductive success, that result in fewer children is deterministic and ruthless. The latter believers do not want to hear.