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Evolving yeah, but toward what? We completely screwed natural selection, so I guess bad genes will be creeping into the population for a long time, things like

by cfontes 11y ago

Evolving yeah, but toward what? We completely screwed natural selection, so I guess bad genes will be creeping into the population for a long time, things like cancer, malformations and genetic related diseases will be blooming like crazy in the next centuries. Let's hope medicine keeps up with it.

bakhy 11y ago
you could say we "evolved" medicine. it's too simple to regard evolution as something that happens merely on an individual level. e.g. it was always possible that the strongest and smartest human will get killed by a group of physically and intellectually weaker people. does that mean we stopped evolving back then? no, we evolved social behavior, like many animals before us, i guess...
openasocket 11y ago
Our current evolutionary situation is not completely without precedent. A somewhat similar case is the birds of paradise. These birds have virtually no natural predators and need to only forage a few hours a day for food. With few other forms of natural selection at play, their evolution has been guided almost entirely by sexual selection, resulting in some dramatic examples of sexual dimorphism. I predict something similar may happen in humans.
jegutman 11y ago
Evolution doesn't have a direction, it's an explanation of a thing that happens. Diversity in the gene pool is almost certainly a plus for the long-term survival of the species, but it's marginal, must like everything that would determine the long-term survival of the species. Almost all diseases that happen after a species' reproductive age is very difficult to select out either in a positive or negative way unless it happens to be strongly genetically linked (either through sharing genes or being very close on a chromosome) to a different positive or negative trait. Even then in the long run the survival of that trait will be dominated by its independent characteristics. The way to flip this around is that you could also look at the "survival" of the disease, disorder, etc. Not that we WANT these to survive, but they either will or won't. If a disease causes death 100% of the time at age 2 and provides no other benefits in the carrier / recessive trait it tends not to last in the gene pool for very long.
- liamconnell 11y ago
  > Almost all diseases that happen after a species' reproductive age is very difficult to select out either in a positive or negative way unless it happens to be strongly genetically linked (either through sharing genes or being very close on a chromosome) to a different positive or negative trait. Well that's not entirely true. I think humans evolved (and still evolve) on a tribal level. So an individual's traits that strengthen the tribe are also good for the survival of the tribe since one's entire gene pool would be wiped if the neighboring tribe killed all of you, even if the individual is post-reproductive age. I find that most people never talk about evolution on a tribal level like this.
jameshart 11y ago
If a variation doesn't have an impact on reproductive success, then by evolution's terms, it is not a bad variation, it's just a variation. Variation in general - genetic diversity - is good in that it insulates the species as a whole against specific shocks.
im3w1l 11y ago
Genetic drift is a slow force, and medicine will easily be able to outpace it.
jo909 11y ago
I think genetic diseases (aka "runs in the familiy") will stay as a selection factor. Would you prefer to have offspring with someone who has a family history of severe cancer or some autoimmune disease? I wouldn't. So once genetic desease reaches a problematic threshold (where medicine can not offset it), I'm pretty sure people will begin to talk about their families health history earlier in the mating ritual. Or test (and select) their embryos if the bad trait was passed on. Or at some point modify them. Which both will lower the spread of bad genes.

by cfontes 11y ago

bakhy 11y ago

you could say we "evolved" medicine. it's too simple to regard evolution as something that happens merely on an individual level. e.g. it was always possible that the strongest and smartest human will get killed by a group of physically and intellectually weaker people. does that mean we stopped evolving back then? no, we evolved social behavior, like many animals before us, i guess...

openasocket 11y ago

Our current evolutionary situation is not completely without precedent. A somewhat similar case is the birds of paradise. These birds have virtually no natural predators and need to only forage a few hours a day for food. With few other forms of natural selection at play, their evolution has been guided almost entirely by sexual selection, resulting in some dramatic examples of sexual dimorphism. I predict something similar may happen in humans.

jegutman 11y ago

Evolution doesn't have a direction, it's an explanation of a thing that happens. Diversity in the gene pool is almost certainly a plus for the long-term survival of the species, but it's marginal, must like everything that would determine the long-term survival of the species. Almost all diseases that happen after a species' reproductive age is very difficult to select out either in a positive or negative way unless it happens to be strongly genetically linked (either through sharing genes or being very close on a chromosome) to a different positive or negative trait. Even then in the long run the survival of that trait will be dominated by its independent characteristics. The way to flip this around is that you could also look at the "survival" of the disease, disorder, etc. Not that we WANT these to survive, but they either will or won't. If a disease causes death 100% of the time at age 2 and provides no other benefits in the carrier / recessive trait it tends not to last in the gene pool for very long.

liamconnell 11y ago
> Almost all diseases that happen after a species' reproductive age is very difficult to select out either in a positive or negative way unless it happens to be strongly genetically linked (either through sharing genes or being very close on a chromosome) to a different positive or negative trait. Well that's not entirely true. I think humans evolved (and still evolve) on a tribal level. So an individual's traits that strengthen the tribe are also good for the survival of the tribe since one's entire gene pool would be wiped if the neighboring tribe killed all of you, even if the individual is post-reproductive age. I find that most people never talk about evolution on a tribal level like this.

jameshart 11y ago

If a variation doesn't have an impact on reproductive success, then by evolution's terms, it is not a bad variation, it's just a variation. Variation in general - genetic diversity - is good in that it insulates the species as a whole against specific shocks.

im3w1l 11y ago

Genetic drift is a slow force, and medicine will easily be able to outpace it.

jo909 11y ago

I think genetic diseases (aka "runs in the familiy") will stay as a selection factor. Would you prefer to have offspring with someone who has a family history of severe cancer or some autoimmune disease? I wouldn't. So once genetic desease reaches a problematic threshold (where medicine can not offset it), I'm pretty sure people will begin to talk about their families health history earlier in the mating ritual. Or test (and select) their embryos if the bad trait was passed on. Or at some point modify them. Which both will lower the spread of bad genes.