http://online.wsj.com/article/SB1000142 ... 46478.html
So we're evolving as a species toward greater individual (rather than racial) genetic diversity. But this isn't what most people mean when they ask if evolution has stopped. Mainly they seem to mean: "Has brain size stopped increasing?" For a process that takes millions of years, any answer about a particular instant in time is close to meaningless. Nonetheless, the short answer is probably "yes." ...First, it's clear, from glancing around society, that clever people—who on average have slightly bigger brains—aren't having more babies than less-clever people. Second, the fossil record strongly suggests that our brain size peaked at 1,500 cubic centimeters around 20,000 years ago and has since shrunk to 1,350 cc
Human Evolution Isn't What It Used to Be
Brain size is not everything though. It is amount of surface area of the brain that makes much of a difference. Also the way the different areas of the brain are connected. Genetically we are pretty much still at stone age levels with very little changes since then. One big genetic change was the sustained production of lactase as adults. This was in response to the wide spread domestication of animals and thus the availability of milk products to adults as well (giving those with ability to digest them an advantage).
Currently we dont have much of an evolutionary pressure and thus evolution seems rather unlikely. In fact, thanks to the social systems almost everywhere, the opposite of evolution is likely to happen.
Currently we dont have much of an evolutionary pressure and thus evolution seems rather unlikely. In fact, thanks to the social systems almost everywhere, the opposite of evolution is likely to happen.
Artificial Womb
Given the negative effects of a large number of uncontrollable factors on the development of a fetus effecting both that fetus and subsequent generations at the genetic and epi-genetic levels I assert that the use of artificial wombs will not only become desireable but necessary for the development of truly mentally and physically healthy babies.
The challenge will be to replicate all of the benefits/positive processes of a natural womb and introducing their use into society without triggering huge societal backlashes. Probably by starting with couples that have fertility issues and/or repeated miscarriages.
An upside from a societal perspective is that this may provide a path for industrialized societies to avoid the negative growth rate spiral by removing 9 months of pregnancy as a disincentive to having children and taking advantage of those couples that decide later in life that they wish to have children without having to worry about the attendant downsides to them (presuming proper egg and sperm viability/genetic screening).
The challenge will be to replicate all of the benefits/positive processes of a natural womb and introducing their use into society without triggering huge societal backlashes. Probably by starting with couples that have fertility issues and/or repeated miscarriages.
An upside from a societal perspective is that this may provide a path for industrialized societies to avoid the negative growth rate spiral by removing 9 months of pregnancy as a disincentive to having children and taking advantage of those couples that decide later in life that they wish to have children without having to worry about the attendant downsides to them (presuming proper egg and sperm viability/genetic screening).
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palladin9479
- Posts: 388
- Joined: Mon Jan 31, 2011 5:22 am
It should be going in reverse
Evolution should be going backwards shortly. Smart well-educated people are not having many children. Stupid nearly useless people are having tons of children. From a pure genetics point of view, bad genetics are outnumbering good genetics, largely due to no social pressure to prevent bad genetics from spawning more bad genetics. This is of course an incredibly general statement.
Idiocracy paints a pretty decent if a bit humorist picture of the direction we're going in.
http://www.imdb.com/title/tt0387808/
Idiocracy paints a pretty decent if a bit humorist picture of the direction we're going in.
http://www.imdb.com/title/tt0387808/
Re: It should be going in reverse
The old "Marching Morons" scenario...trouble is the social welfare state is supported by the smart hard working productive people who aren't having so many babies. At some point this would presumably cause the system to collapse, long before our genes were "de-evolved" significantly. In the post collapse society, with all the mad scramble to survive, natural selection would re-assert itself in short order, and begin selecting for intelligence, industry, resourcefulness etc.palladin9479 wrote:Evolution should be going backwards shortly. Smart well-educated people are not having many children. Stupid nearly useless people are having tons of children. From a pure genetics point of view, bad genetics are outnumbering good genetics, largely due to no social pressure to prevent bad genetics from spawning more bad genetics. This is of course an incredibly general statement.
Idiocracy paints a pretty decent if a bit humorist picture of the direction we're going in.
http://www.imdb.com/title/tt0387808/
Re: It should be going in reverse
from a purely genetic point of view, "good genetics" is not being smarter or more productive, but reproducing more.palladin9479 wrote:Evolution should be going backwards shortly. Smart well-educated people are not having many children. Stupid nearly useless people are having tons of children. From a pure genetics point of view, bad genetics are outnumbering good genetics, largely due to no social pressure to prevent bad genetics from spawning more bad genetics. This is of course an incredibly general statement.
Idiocracy paints a pretty decent if a bit humorist picture of the direction we're going in.
http://www.imdb.com/title/tt0387808/
we didnt become intelligent because it is cool to be intelligent, but because it allowed us to survive more and thus reproduce more and pass our genes forward.
Last edited by AcesHigh on Tue Jun 05, 2012 6:21 am, edited 1 time in total.
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palladin9479
- Posts: 388
- Joined: Mon Jan 31, 2011 5:22 am
Re: It should be going in reverse
Yep, how long will this take to happen? How many centuries of development would be lost, how much work would it take to rebuild things again. Human adaptability has proven to be our greatest boon, we'll always make it to the top. It's going to be one helluva struggle for those after though. A good series to watch to get a feel for a semi-post-apocalyptic world would be Jeremiah.williatw wrote:The old "Marching Morons" scenario...trouble is the social welfare state is supported by the smart hard working productive people who aren't having so many babies. At some point this would presumably cause the system to collapse, long before our genes were "de-evolved" significantly. In the post collapse society, with all the mad scramble to survive, natural selection would re-assert itself in short order, and begin selecting for intelligence, industry, resourcefulness etc.palladin9479 wrote:Evolution should be going backwards shortly. Smart well-educated people are not having many children. Stupid nearly useless people are having tons of children. From a pure genetics point of view, bad genetics are outnumbering good genetics, largely due to no social pressure to prevent bad genetics from spawning more bad genetics. This is of course an incredibly general statement.
Idiocracy paints a pretty decent if a bit humorist picture of the direction we're going in.
http://www.imdb.com/title/tt0387808/
Short Description, deadly virus gets out and kills off everyone in the world who's already gone through puberty. It does this within a period of 6 months. With few exceptions the survivors are only children who are now forced to grow up and survive in a world that's been thrust back into the middle ages. It's not pretty.
are you all really discounting the fact we can manipulate our own evolution now?
moronic humanity?? Only if we want (and we may want it, after all, the more morons, the more the few intelligent people will be able to rule). If we feel goody, soon we can spread synthetic viruses that will implant genes unto every human on the planet, making them smarter.
not counting artificial synthetic improvements like neuroships, etc, etc.
moronic humanity?? Only if we want (and we may want it, after all, the more morons, the more the few intelligent people will be able to rule). If we feel goody, soon we can spread synthetic viruses that will implant genes unto every human on the planet, making them smarter.
not counting artificial synthetic improvements like neuroships, etc, etc.
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CaptainBeowulf
- Posts: 498
- Joined: Sat Nov 07, 2009 12:35 am
The social welfare state may be an extreme example of it, but I think that most societies/civilizations - even ones in early transition from stone age to iron age - function to reduce selection pressure. Difficult to say with the ones that conduct organized mass murder - the mass murder is likely indiscriminate at a genetic level (discriminate on tribal, religious, class or ethnic/racial levels).
Many societies have religious codes which suggest that you should help the needy etc. These are not always followed, but still, things like alms houses go right back through the middle ages. More generally, societies provided organized hunting and farming opportunities, which provided a lot more food. Perhaps the strongest kept the best food for themselves, but weaker people who would not have survived in a very primitive state now got enough to get by and possibly reproduce once or twice.
Also, fortified towns, organized military forces, clearing of land etc. etc. greatly reduced the populations of other large predatory animals which compete with and occasionally predate humans. This again allowed many more people to survive.
Beyond this, when you look at the scale and destruction of classical era battles such as Cannae, you realize that many of the fittest young males may have been marched off to war and slaughtered generation after generation before they had had much opportunity to reproduce (zero to one or two children), thereby actually working counter to the way that natural selection would have worked in a pure hunter-gatherer society.
I have read that some biologists think that humans have evolved fair bit on the genetic level in the last 2000 years - basically in terms of immunity to diseases. Urban societies were breeding grounds for plagues, and it stands to reason that the main selection pressure before the advent of modern antibiotics was for resistance to various classes of virus and bacteria. It could be - I don't know if there's anything conclusive on this topic.
Final thing - Aces, I don't think we're really at the point where we can manipulate our own evolution yet. You have to get modifications into the germline cells, placed consistently in the appropriate locations so that they match up in the cells of the fetus when people reproduce. Also, there's a lot that we don't understand yet about how the DNA sequence transcodes into the various proteins that make up the bulk of our tissue structures, and therefore what the implications of making changes are. If things keep going in the right direction, maybe in a few decades. If a disaster happens - coronal mass ejection fries all electronics, Yellowstone volcano explodes again, asteroid strike, pandemic - then possibly we'll be set back centuries.
Many societies have religious codes which suggest that you should help the needy etc. These are not always followed, but still, things like alms houses go right back through the middle ages. More generally, societies provided organized hunting and farming opportunities, which provided a lot more food. Perhaps the strongest kept the best food for themselves, but weaker people who would not have survived in a very primitive state now got enough to get by and possibly reproduce once or twice.
Also, fortified towns, organized military forces, clearing of land etc. etc. greatly reduced the populations of other large predatory animals which compete with and occasionally predate humans. This again allowed many more people to survive.
Beyond this, when you look at the scale and destruction of classical era battles such as Cannae, you realize that many of the fittest young males may have been marched off to war and slaughtered generation after generation before they had had much opportunity to reproduce (zero to one or two children), thereby actually working counter to the way that natural selection would have worked in a pure hunter-gatherer society.
I have read that some biologists think that humans have evolved fair bit on the genetic level in the last 2000 years - basically in terms of immunity to diseases. Urban societies were breeding grounds for plagues, and it stands to reason that the main selection pressure before the advent of modern antibiotics was for resistance to various classes of virus and bacteria. It could be - I don't know if there's anything conclusive on this topic.
Final thing - Aces, I don't think we're really at the point where we can manipulate our own evolution yet. You have to get modifications into the germline cells, placed consistently in the appropriate locations so that they match up in the cells of the fetus when people reproduce. Also, there's a lot that we don't understand yet about how the DNA sequence transcodes into the various proteins that make up the bulk of our tissue structures, and therefore what the implications of making changes are. If things keep going in the right direction, maybe in a few decades. If a disaster happens - coronal mass ejection fries all electronics, Yellowstone volcano explodes again, asteroid strike, pandemic - then possibly we'll be set back centuries.
We may not be able to directly manipulate germline cells to direct our own evolution but we certainly have other tools available to us to positively affect it.CaptainBeowulf wrote: Final thing - Aces, I don't think we're really at the point where we can manipulate our own evolution yet.
We have genetic sequencing which is rapidly reaching the cost point where it can be used on a regular basis to identify negative genetic traits.
We have in-vitro fertilization where with the right combination of techniques can equal the same implantation/success rates as natural methods, with the benefit that blastocysts with negative traits can be screened out.
We have cyrogenic suspension of fertilized eggs which would allow us to twin and save individuals by separating the trans-potent blastocyst cells to form multiple identical twins, implanting one developed blastocyst and freezing the rest. Wait x years to see how the child develops and decide on the benefits of bring the rest of the blastocysts to term.
We have IUDs which could be implanted at puberty (with mandated replacement as they have a 5-10 year life) and only removed permanently when the prospective parents have accumulated sufficient means to raise a child. That would help solve some social welfare issues as well as screen for people who have the desire and ability to have and support a child.
We can use the aforementioned sequencing to identify both positive and negative genetic traits and include that information in dating sites highlighting the genetic benefits and downsides to potential matches.
We can develop housing areas that are as free as possible from environmental factors that would negatively affect fetal development (Arsenic, mercury, benzenes, formaldehyde, flame retardants, PCBs, Dioxins...) specifically for child rearing families as well as ensuring their food supply is similarly untainted.
These methods are all well within the means of either organized groups or society as a whole to implement and would have a significant positive benefit on our evolution.