60,000 years ago, there were something like a quarter of a million modern humans. 3,000 years ago, thanks to the higher food yields allowed by agriculture, there were 60 million humans. A larger population means there’s more genetic variance: mutations that had previously occurred every 10,000 years or so were now showing up every 400 years. The changed living conditions also began to select for different genes. A “gene sweep” is a process where beneficial alleles increase in frequency, “sweeping through” the population until everyone has them. Hundreds of these are still ongoing today. For European and Chinese samples, the sweeps’ rate of origination peaked at about 5,000 years ago and at 8,500 years ago for one African sample. While the full functions of these alleles are still not known, it is known that most involve changes in metabolism and digestion, defenses against infectious disease, reproduction, DNA repair, or in the central nervous system.
The development of agriculture led, among other things, to a different mix of foods, frequently less healthy than the one enjoyed by hunter-gatherers. For instance, vitamin D was poorly available in the new diet. However, it is also created by ultraviolet radiation from the sun interacting with our skin. After the development of agriculture, several new mutations showed up that led to people in the areas more distant from the equator having lighter skins. There is also evidence of genes that reduce the negative effects associated with e.g. carbohydrates and alcohol. Today, people descending from populations that haven’t farmed as long, like Australian Aborigines and many Amerindians, have a distinctive track record of health problems when exposed to Western diets. DNA retrieved from skeletons indicates that 7,000 to 8,000 years ago, no-one in central and northern Europe had the gene for lactose tolerance. 3,000 years, about 25 percent of people in central Europe had it. Today, about 80 percent of the central and northern European population carries the gene. [...]
People in certain areas have more mutations giving them a resistance to malaria than people in others. The human skeleton has become more lightly built, more so in some populations. Skull volume has decreased apparently in all populations: in Europeans it is down 10 percent from the hight point about 20,000 years ago. For some reason, Europeans also have a lot of variety in eye and hair color, whereas most of the rest of the world has dark eyes and dark hair, implying some Europe-specific selective pressure that happened to also affect those.
As for cognitive changes: there are new versions of neurotransmitter receptors and transporters. Several of the alleles have effects on serotonin. There are new, mostly regional, versions of genes that affect brain development: axon growth, synapse formation, formation of the layers of the cerebral cortex, and overall brain growth. Evidence from genes affecting both brain development and muscular strength, as well as our knowledge of the fact that humans in 100,000 BC had stronger muscles than we do have today, suggests that we may have traded off muscle strength for higher intelligence. There are also new versions of genes affecting the inner ear, implying that our hearing may still be adapting to the development of language—or that specific human populations might even be adapting to characteristics of their local languages or language families.
Allele variation that generates different heights or melanin within various races, point mutations like sickle cell, the mutations that generate lactose tolerance in adults, or that affect our ability to process alcohol, are micro-evolution. They do not extrapolate to new tissues and proteins that define different species. I accept that polar bears descended from a brown bear, that the short-limb, heat-conserving body of an Eskimo was the result of the standard evolutionary scenario. I have no reason to doubt the Earth existed for billions of years.
Humans have hundreds of orphan genes unique among mammals. To say this is just an extension of micro-evolution relies on the possibility it could happen, but you need 50MM new nucleotides that work to arise within 500k generations. Genetic drift could generate that many mutations, but the chance these would be functional assumes proteins are extremely promiscuous. When you look at what it takes to make a functioning protein within the state-space of all amino acid sequences, and how proteins work in concert with promoter genes, RNA editing, and connecting to other proteins, the probability this happened via mutation and selection is like a monkey typing a couple pages of Shakespeare: possible, but not probable.
This all argues for a Creator, who could be an alien, or an adolescent Sim City programmer in a different dimension, or a really smart and powerful guy that looks like Charlton Heston. The argument for a Christian God relies on issues outside of argument by design
micro-evolution. They do not extrapolate to new tissues and proteins that define different species.
You claimed that evolution in humans seems to have stopped. Kaj_Sotala gave you evidence that it hasn’t. Of course the examples he gave were of “micro-evolution”; what else would you expect when the question is about what’s happened in recent evolution, within a particular species?
Humans have hundreds of orphan genes unique among mammals.
There’s some reason to think that most human “orphan genes” are actually just, so to speak, random noise. Do you have good evidence for hundreds of actually useful orphan genes?
I’m curious what you think the earth looked like during those billions of years. Scientists have pretty concrete ideas of what things were like over time: where the continents were, which species existed at which times, and so on. Do you think they are right about these things, or is it all just guesswork?
When I was younger I thought that evolution was false, but I started to change my mind once I started to think about that kind of concrete question. If the dating methods are generally accurate (and I am very sure that they are), it follows that most of that scientific picture is going to be true.
This wouldn’t be inconsistent with the kind of design that you are talking about, but it strongly suggests that if you had watched the world from an external, large scale, point of view, it would look pretty much like evolution, even if on a micro level God was inserting genes etc.
The 10,000 Year Explosion disagrees; to quote my own earlier summary of it:
Allele variation that generates different heights or melanin within various races, point mutations like sickle cell, the mutations that generate lactose tolerance in adults, or that affect our ability to process alcohol, are micro-evolution. They do not extrapolate to new tissues and proteins that define different species. I accept that polar bears descended from a brown bear, that the short-limb, heat-conserving body of an Eskimo was the result of the standard evolutionary scenario. I have no reason to doubt the Earth existed for billions of years.
Humans have hundreds of orphan genes unique among mammals. To say this is just an extension of micro-evolution relies on the possibility it could happen, but you need 50MM new nucleotides that work to arise within 500k generations. Genetic drift could generate that many mutations, but the chance these would be functional assumes proteins are extremely promiscuous. When you look at what it takes to make a functioning protein within the state-space of all amino acid sequences, and how proteins work in concert with promoter genes, RNA editing, and connecting to other proteins, the probability this happened via mutation and selection is like a monkey typing a couple pages of Shakespeare: possible, but not probable.
This all argues for a Creator, who could be an alien, or an adolescent Sim City programmer in a different dimension, or a really smart and powerful guy that looks like Charlton Heston. The argument for a Christian God relies on issues outside of argument by design
You claimed that evolution in humans seems to have stopped. Kaj_Sotala gave you evidence that it hasn’t. Of course the examples he gave were of “micro-evolution”; what else would you expect when the question is about what’s happened in recent evolution, within a particular species?
There’s some reason to think that most human “orphan genes” are actually just, so to speak, random noise. Do you have good evidence for hundreds of actually useful orphan genes?
I’m curious what you think the earth looked like during those billions of years. Scientists have pretty concrete ideas of what things were like over time: where the continents were, which species existed at which times, and so on. Do you think they are right about these things, or is it all just guesswork?
When I was younger I thought that evolution was false, but I started to change my mind once I started to think about that kind of concrete question. If the dating methods are generally accurate (and I am very sure that they are), it follows that most of that scientific picture is going to be true.
This wouldn’t be inconsistent with the kind of design that you are talking about, but it strongly suggests that if you had watched the world from an external, large scale, point of view, it would look pretty much like evolution, even if on a micro level God was inserting genes etc.