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The parent's question is pretty common and the answer given by scientists is always "Yes we're still evolving" but while it technically may be correct I think i

The parent's question is pretty common and the answer given by scientists is always "Yes we're still evolving" but while it technically may be correct I think it gives people the wrong impression - like we could possibly grow a tail in 500-1000 years. I'm no expert by any means, but my understanding is that usually there needs to be some event that causes one species to diverge significantly. For example, if some percent of the population of some land dwelling animal becomes trapped on an island due to some geological activity, those that are better jumpers may be more fit for that new environment to survive like you stated (either to obtain food or avoid the common predators on that island). And thus over a period of hundreds or thousands of years in which they are separated on that island from the rest of their species, they will slowly evolve to be categorized as a new species. But I can't see humans evolving to become a vastly different looking species (which is the layman's definition of an "evolved" species) since we are now a global population and our physical abilities do not determine our fitness to survive unless there was some global killer such as climate change which significantly changes civilization as we know it (e.g. we go back to being hunter/gatherers).

vidarh 10y ago
It can be something relatively small. The trait for blond hair in Northern Europe dates back only ca. 11,000 years, and the benefit is unclear (it may be related to vitamin D). Keep in mind that it only needs to benefit survival a bit more than it hinders it. If it provides a big adantage, it will spread rapidly, but as long as it provides some advantage it stands a chance of surviving long enough to get a foothold and keep spreading. Even if it doesn't provide any advantage, as long as it doesn't have a negative effect it still has a shot at spreading if it just happens to occur in a population that's otherwise successful. > since we are now a global population and our physical abilities do not determine our fitness to survive Our fitness also involves our ability to select a mate and have offspring, not just physical survival. It could very well be that our ability to select a mate will over long enough time scales be affected by appearance and changing cultural factors.
- Amezarak 10y ago
  As you allude later on, selection for environmental fitness is not the only form of selection. Blonde hair need not confer a survival advantage if at one point it conferred a reproductive advantage. That's sexual selection. In some cases, traits can be disadvantageous in terms of survival but immensely advantageous reproductively.
  - mannykannot 10y ago
    >In some cases, traits can be disadvantageous in terms of survival but immensely advantageous reproductively. This is a really important part of Darwin's and Wallace's theory - without taking it into account, many traits do not look beneficial, which would be quite a problem for the theory. More controversially (at least at the time), it illustrates that evolution is all about immediate advantage; there is no long-term plan or ladder of progress.

vidarh 10y ago

It can be something relatively small. The trait for blond hair in Northern Europe dates back only ca. 11,000 years, and the benefit is unclear (it may be related to vitamin D). Keep in mind that it only needs to benefit survival a bit more than it hinders it. If it provides a big adantage, it will spread rapidly, but as long as it provides some advantage it stands a chance of surviving long enough to get a foothold and keep spreading. Even if it doesn't provide any advantage, as long as it doesn't have a negative effect it still has a shot at spreading if it just happens to occur in a population that's otherwise successful. > since we are now a global population and our physical abilities do not determine our fitness to survive Our fitness also involves our ability to select a mate and have offspring, not just physical survival. It could very well be that our ability to select a mate will over long enough time scales be affected by appearance and changing cultural factors.

Amezarak 10y ago
As you allude later on, selection for environmental fitness is not the only form of selection. Blonde hair need not confer a survival advantage if at one point it conferred a reproductive advantage. That's sexual selection. In some cases, traits can be disadvantageous in terms of survival but immensely advantageous reproductively.
- mannykannot 10y ago
  >In some cases, traits can be disadvantageous in terms of survival but immensely advantageous reproductively. This is a really important part of Darwin's and Wallace's theory - without taking it into account, many traits do not look beneficial, which would be quite a problem for the theory. More controversially (at least at the time), it illustrates that evolution is all about immediate advantage; there is no long-term plan or ladder of progress.