# Are there any evolutionary pressures at work on Homo Sapiens today? How? **URL:** \ **Category:** Factual Questions\ **Created:** [February 14, 2012, 6:26am UTC](https://boards.straightdope.com/t/are-there-any-evolutionary-pressures-at-work-on-homo-sapiens-today-how/612796 "2012-02-14T06:26:51Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [February 15, 2012, 11:42am UTC](https://boards.straightdope.com/t/are-there-any-evolutionary-pressures-at-work-on-homo-sapiens-today-how/612796/41 "2012-02-15T11:42:04Z")
> [@Blake](#): > > So you can’t provide any evidence, it just stands to reason. Except in the case of humans, where it doesn’t stand to reason. And that proves the point you are trying to make. Which is that it doesn’t apply to humans. > Gotcha. :dubious: Blake, you’ve given me nothing to respond to, again. No argument and no counter-examples. Do you even dispute the claim? > [@](#): > > No, it doesn’t confirm what you are saying. What you are saying is that humans are unique in adapting their behaviour and technology to the environment. No, I said _knowledge_ and technology. All organisms adapt their _behaviour_ to their environment: a bee will behave differently if near to a flower. I’m talking about spreading know-how, which happens in only a very rudimentary form in a few organisms, except for humans. > [@](#): > > The fact that other species also have physiological adaptations _in addition_ to behavioural and technological adaptations doesn’t refute the fact that they \*have \* behavioural and technological adaptations. No, but it supports the point I was making. I said “…changes to a species’ habitat will often lead to changes in the species [physiology]”. You’ve simply given an example supporting this. As for the claim that non-human organisms also exhibit “technological adaptations”. Well, a handful of animals can use simple tools. But to imply that there is not a clear dividing line here would be absurd. Generally speaking we adapt using technology, other species on earth do not. ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [February 15, 2012, 11:43am UTC](https://boards.straightdope.com/t/are-there-any-evolutionary-pressures-at-work-on-homo-sapiens-today-how/612796/42 "2012-02-15T11:43:28Z")
> [@Blake](#): > > So you acknowledge that there are sound reasons why playing COD aids in our survival, but you can’t extrapolate form that that humans playing CoD aids in our survival. Playing CoD doesn’t aid in our survival, and I acknowledged no such thing. 😕 ---
**Author:** ![Darwins\_Finch](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darwins_finch/32/20304_2.png) [@Darwins\_Finch](https://boards.straightdope.com/u/Darwins_Finch)\ **Post date:** [February 15, 2012, 3:03pm UTC](https://boards.straightdope.com/t/are-there-any-evolutionary-pressures-at-work-on-homo-sapiens-today-how/612796/43 "2012-02-15T15:03:06Z")
> [@Mijin](#): > > The response still makes no sense in that context. Read your post #22; I think perhaps you’ve quoted the wrong part of what I said. I’m not really seeing the confusion. What you wrote: > [@Mijin](#): > > If we see an organism consistently expending energy on an activity, it’s a pretty safe bet that it contributes to their survival or reproduction (or the survival or reproduction of the group). Alternatively if it’s something redundant or harmful, we’d expect it to get selected out over time. This rule of thumb won’t work in studying modern humans. What I wrote (with correction): > [@](#): > > Of course [it] will. For one thing, not all humans live in the same environment. For another, all the fancy technology we’ve created only serves to change our environment - it does not change the fact that selection is still occurs. And for a third, what is considered ‘harmful’ is dependent on either the viability of a living organism in general, or on the environment in which the organism finds itself. Your “rule of thumb” absolutely applies to humans. Why wouldn’t it? Natural selection is still at work on us. ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [February 15, 2012, 3:10pm UTC](https://boards.straightdope.com/t/are-there-any-evolutionary-pressures-at-work-on-homo-sapiens-today-how/612796/44 "2012-02-15T15:10:05Z")
I’m not sure anyone has proper reading comprehension the last bunch of posts. Mijin says if an organism expends energy on an activity, it probably is for a purpose that supports evolutionary advantage. Blake says you don’t say anything that proves it so he doubts the assertion. I say that most activites are designed to enhance prestige ( equals, attract chicks) I give several examples why Mijin is right based on what people spend effort on. Blake says I gave counterexamples why he’s right. (??) The examples supported the opposite. Mijin seems to think I was agreeing with Blake when I was agreeing with him. The question was poorly worded, but this: “Blake - do you have any counterexamples to Mijin, of large expenditures of activity that do not seem for the purpose of enhancing the life quality of an orgnaism and its offspring, chances of reproduction, etc. ?” You stated he was wrong, but without significant numbers of counterexamples. Mijin also says humans use technology to adapt so we don’t have to physically adapt to our environment. I said the same - we use techonolgy so that, i.e. we don’t need to grow or shed fur coats, we have clothes and central heating and air conditioning. I’m not sure where the wolves come in, except to prove the point; animals adapt through the process of selection to their environment. We adapt our environment to us instead, using technology, so we don’t die off if our fur is too short or too long. Thus, evolutionary pressures - especially recently, especially in the first world - are less due to nature environmental factors. As for World of Warcraft - a lot of these activities are male domination games; guys do things that give them an edge over other guys, to appear the top dog or alpha male. Unfortunately, the pool of women impressed by guys’ WoW credentials is remarkably small, but the underlying concept is there. Guys show off for girls… ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [February 15, 2012, 3:27pm UTC](https://boards.straightdope.com/t/are-there-any-evolutionary-pressures-at-work-on-homo-sapiens-today-how/612796/45 "2012-02-15T15:27:27Z")
> [@Darwins\_Finch](#): > > I’m not really seeing the confusion. Fine, whatever, I’ll respond to your non sequiturs then. > [@](#): > > For one thing, not all humans live in the same environment. Of course not. And I have not suggested otherwise. In fact, this basically illustrates my other point. > [@](#): > > For another, all the fancy technology we’ve created only serves to change our environment - it does not change the fact that selection is still occurs. Yep, so selection is still happening (this was almost the first thing I said on joining this thread) but our technology certainly has had an effect on what gets selected. > [@](#): > > And for a third, what is considered ‘harmful’ is dependent on either the viability of a living organism in general, or on the environment in which the organism finds itself Not sure what you mean by this. I’m taking “harmful” to mean something which inhibits the survival or reproduction of the individual (or the colony, in the case of drones). And of course it’s relative: having lots of faeces around is harmful for me, but good for a dung beetle. > [@](#): > > Your “rule of thumb” absolutely applies to humans. Why wouldn’t it? Natural selection is still at work on us. _None of your points touched my argument at all_ Which was again: > [@Mijin](#): > > If we see an organism consistently expending energy on an activity, it’s a pretty safe bet that it contributes to their survival or reproduction (or the survival or reproduction of the group). Alternatively if it’s something redundant or harmful, we’d expect it to get selected out over time. This rule of thumb won’t work in studying modern humans. ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [February 15, 2012, 3:40pm UTC](https://boards.straightdope.com/t/are-there-any-evolutionary-pressures-at-work-on-homo-sapiens-today-how/612796/46 "2012-02-15T15:40:25Z")
> [@md2000](#): > > I’m not sure anyone has proper reading comprehension the last bunch of posts. > … > I say that most activites are designed to enhance prestige ( equals, attract chicks) > I give several examples why Mijin is right based on what people spend effort on. You’ve misunderstood my point, and your examples could be seen as counter to my point. I’m saying if you see a species consistently doing some action, say climbing a tree, it’s very likely that action aids their survival or reproduction. Perhaps it helps them avoid predation. Or perhaps it’s to find food. If the behaviour were useless we’d expect it to get selected out over time, as individuals that don’t waste energy climbing trees would gradually out-compete the tree climbers. Now with humans, that logic doesn’t work. Someone may spend hundreds of hours playing WoW, but it doesn’t contribute to their survival or reproduction. > [@](#): > > As for World of Warcraft - a lot of these activities are male domination games; guys do things that give them an edge over other guys, to appear the top dog or alpha male. Unfortunately, the pool of women impressed by guys’ WoW credentials is remarkably small, but the underlying concept is there. Guys show off for girls… So why do women play WoW? I think you’re reaching. In any case the psychology of the situation is irrelevant to my point. Obviously our brains were moulded by evolution, but I’m talking about whether _the activity_ is beneficial or not. Notice I didn’t talk about the psychology of the tree-climbers. If _the activity_ is not beneficial, it will get selected out. It’s irrelevant whether it evolved because it _was once_ beneficial. So, again: different to the situation with humans. ---
**Author:** ![Bozuit](https://avatars.discourse-cdn.com/v4/letter/b/edb3f5/32.png) [@Bozuit](https://boards.straightdope.com/u/Bozuit)\ **Post date:** [February 15, 2012, 3:53pm UTC](https://boards.straightdope.com/t/are-there-any-evolutionary-pressures-at-work-on-homo-sapiens-today-how/612796/47 "2012-02-15T15:53:29Z")
[Here’s one theory](http://www.youtube.com/watch?v=BXRjmyJFzrU) on the future progress of human evolution from the opening of the film Idiocracy. If anyone can point out why it’s wrong feel free to brighten my outlook for humanity. ---
**Author:** ![Darwins\_Finch](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darwins_finch/32/20304_2.png) [@Darwins\_Finch](https://boards.straightdope.com/u/Darwins_Finch)\ **Post date:** [February 15, 2012, 4:13pm UTC](https://boards.straightdope.com/t/are-there-any-evolutionary-pressures-at-work-on-homo-sapiens-today-how/612796/48 "2012-02-15T16:13:53Z")
> [@Mijin](#): > > _None of your points touched my argument at all_ _sigh_ A) Lots of organisms exhibit behaviors that do not directly relate to survival or reproduction. Just because a fair number of humans tend to have a lot of free time, thanks to technology, we are not exempt from procuring food or mates. Thus, your first point is largely irrelevant. B) “Harmful” traits are still selected against in humans. But, because of our societal structure and our technology, traits which at one time, or in another environment, might be considered harmful are no longer considered as such. Just because folks with poor eyesight tend to live longer and reproduce does not mean that harmful traits are no longer being selected against; it means that trait _is not considered harmful in the environment we have created_. Nothing you have said supports the idea that natural selection (or the “implications” thereof, whatever that means) no longer applies to us. Your “rule of thumb”, to the extent that such exists at all, still applies when studying humans. ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [February 15, 2012, 4:15pm UTC](https://boards.straightdope.com/t/are-there-any-evolutionary-pressures-at-work-on-homo-sapiens-today-how/612796/49 "2012-02-15T16:15:21Z")
Most leisure activities are basically social competition. Who usually “gets the girl”? The star quarterback, or the guy on the second line who as ofen as not drops the ball? (Not being a WoW fan, what proportion of WoW are women?) ---
**Author:** ![Pleonast](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/pleonast/32/1183_2.png) [@Pleonast](https://boards.straightdope.com/u/Pleonast)\ **Post date:** [February 15, 2012, 4:27pm UTC](https://boards.straightdope.com/t/are-there-any-evolutionary-pressures-at-work-on-homo-sapiens-today-how/612796/50 "2012-02-15T16:27:50Z")
> [@Smeghead](#): > > No organism will ever stop evolving as long as the basic fundamentals are in place: genetic variation and insufficient resources for all offspring to survive equally well. Evolution is an automatic, inevitable consequence of those conditions. Your post was excellent, **Smeghead** , except for this last bit (as noticed by **bldysabba** as well). The evolution requires only heritable variation in reproductive success (hmm, maybe that’s more of a definition of evolution). Genetic variation is, of course, the primary source of heritable variation, but it’s possible for other mechanisms to exist. For example, tags on the DNA (like methylation), or protein foldings directly inherited from the gametes. We wouldn’t say no evolution is happening simply because the genes aren’t changing. And while insufficient resources is a common cause for lack of reproductive success (along with predation), even a scenario where resources are effectively infinite (along with no predation) can result in evolution. Simply because some individuals will have more reproduction success in that environment than others will. ---
**Author:** ![The\_Other\_Waldo\_Pepper](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/the_other_waldo_pepper/32/12370_2.png) [@The\_Other\_Waldo\_Pepper](https://boards.straightdope.com/u/The_Other_Waldo_Pepper)\ **Post date:** [February 15, 2012, 4:35pm UTC](https://boards.straightdope.com/t/are-there-any-evolutionary-pressures-at-work-on-homo-sapiens-today-how/612796/51 "2012-02-15T16:35:28Z")
> [@Bozuit](#): > > [Here’s one theory](http://www.youtube.com/watch?v=BXRjmyJFzrU) on the future progress of human evolution from the opening of the film Idiocracy. > > If anyone can point out why it’s wrong feel free to brighten my outlook for humanity. We only need enough brainy folks – made the old-fashioned way – to do their thing until we can easily use tech to modify the genes of upcoming kids; so long as designer babies become available before the idiocracy scenario plays out, the idiocracy scenario won’t play out. ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [February 15, 2012, 4:40pm UTC](https://boards.straightdope.com/t/are-there-any-evolutionary-pressures-at-work-on-homo-sapiens-today-how/612796/52 "2012-02-15T16:40:36Z")
> [@Pleonast](#): > > … > > And while insufficient resources is a common cause for lack of reproductive success (along with predation), even a scenario where resources are effectively infinite (along with no predation) can result in evolution. Simply because some individuals will have more reproduction success in that environment than others will. I guess you could consider internal competition as the equivalent of predation. Of course, willing females may be considered a scarce resource too in almost any situation. The theory goes that with unlimited resources, the evolutionary pressure is for larger size, while with very limited resources, the pressure is for smaller size. When the only competition is against each other, the bigger tend to win. When the problem is frequent famine, those with larger bodies to feed are at risk. So with unlimited resources, the competition will be for what knocks off the competition or attracts the opposite sex for breeding. An interesting side note, with modern society we are reaching the point where restrained appetite will be a survival factor, as you read about more and more people dying of obesity problems earlier and earlier. ---
**Author:** ![John\_Mace](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/john_mace/32/185_2.png) [@John\_Mace](https://boards.straightdope.com/u/John_Mace)\ **Post date:** [February 15, 2012, 4:46pm UTC](https://boards.straightdope.com/t/are-there-any-evolutionary-pressures-at-work-on-homo-sapiens-today-how/612796/53 "2012-02-15T16:46:37Z")
We need a sticky on this. If the OP spends a little time searching, he’ll see that this has been done many, many times before on this MB. ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [February 15, 2012, 4:57pm UTC](https://boards.straightdope.com/t/are-there-any-evolutionary-pressures-at-work-on-homo-sapiens-today-how/612796/54 "2012-02-15T16:57:34Z")
> [@Darwins\_Finch](#): > > A) Lots of organisms exhibit behaviors that do not directly relate to survival or reproduction. Such as…? (And btw, I never said “directly”) > [@](#): > > “Harmful” traits are still selected against in humans. Of course. Defining harmful trait as one which affects our survival or reproduction, _of course_ they will be selected against. The point was about what we can extrapolate about an organism, based on our understanding of natural selection. Watching a species frequently climb trees we can say that the behaviour is either beneficial to their survival or reproduction, or it’s something that _was_ useful, and will now get selected out. Watching a human watching a movie, we can’t make such extrapolations. It’s not beneficial, nor has it ever been, but it’s not getting selected out either. > [@](#): > > Your “rule of thumb”, to the extent that such exists at all, still applies when studying humans. (so your conclusion is still false) ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [February 15, 2012, 5:04pm UTC](https://boards.straightdope.com/t/are-there-any-evolutionary-pressures-at-work-on-homo-sapiens-today-how/612796/55 "2012-02-15T17:04:19Z")
> [@md2000](#): > > Most leisure activities are basically social competition. Who usually “gets the girl”? The star quarterback, or the guy on the second line who as ofen as not drops the ball? Again, we’re going into EP territory here, and it’s irrelevant to my point. Let’s say all human behaviours are 100% motivated by surviving and reproducing. My point stands just fine because I was talking about whether _the behaviour is beneficial_, and you’ve already conceded that things like playing WoW are not. > [@](#): > > (Not being a WoW fan, what proportion of WoW are women?) I suspected you’d say this, but the question again was _Why do women play WoW?_ If it’s all about male dominance why do any women play? ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [February 15, 2012, 5:26pm UTC](https://boards.straightdope.com/t/are-there-any-evolutionary-pressures-at-work-on-homo-sapiens-today-how/612796/56 "2012-02-15T17:26:57Z")
> [@Mijin](#): > > I suspected you’d say this, but the question again was _Why do women play WoW?_ > If it’s all about male dominance why do any women play? It was an honest question… I have no clue what the proportion is… justs a suspicion, unsupported by facts, that very few women are interested; mostly because the theme, primitive warefare with blood and guts everywhere, I imagine appeals more to men. I may be mistaken. Women also play their own competition games to get men to notice them. Sometimes these games are physical, often they are more social or display. Why do women play hockey or basketball? (Other than confused sexual roles…) Fitness as it relates to body morphology is an attractor factor for women. I suppose when we have designer babies, it’s not the end of evolution so much as a whole different type of evolution. We are still creating differentiated hereditary beings who then play out their life to determine whether they too succeed and have more or less offspring using their genes, plus some variations. The selection and variability is simply done through labwork. For a clue what this might produce, look to purebred domestic animals. ---
**Author:** ![Bozuit](https://avatars.discourse-cdn.com/v4/letter/b/edb3f5/32.png) [@Bozuit](https://boards.straightdope.com/u/Bozuit)\ **Post date:** [February 15, 2012, 6:16pm UTC](https://boards.straightdope.com/t/are-there-any-evolutionary-pressures-at-work-on-homo-sapiens-today-how/612796/57 "2012-02-15T18:16:06Z")
> [@Mijin](#): > > Watching a species frequently climb trees we can say that the behaviour is either beneficial to their survival or reproduction, or it’s something that _was_ useful, and will now get selected out. Presumably in order for useful behaviours to appear, some individuals must start doing seemingly random things. Some behaviours can seem very bizarre to us (there is a tree frog that drops out of trees to avoid predators). Those behaviours must have evolved because some individuals started to do it. It makes me wonder how often individual animals do things like deliberately drop out of trees (or something more mundane) _without_ it serving an evolutionary purpose. > [@md2000](#): > > It was an honest question… I have no clue what the proportion is… justs a suspicion, unsupported by facts, that very few women are interested; mostly because the theme, primitive warefare with blood and guts everywhere, I imagine appeals more to men. I may be mistaken. I’m not a WoW player either, but I believe the game is more fantasy-based, with little to no blood or guts and things like elves. Girls like elves, right? ---
**Author:** ![Mijin](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/mijin/32/9369_2.png) [@Mijin](https://boards.straightdope.com/u/Mijin)\ **Post date:** [February 15, 2012, 8:03pm UTC](https://boards.straightdope.com/t/are-there-any-evolutionary-pressures-at-work-on-homo-sapiens-today-how/612796/58 "2012-02-15T20:03:56Z")
> [@Bozuit](#): > > Presumably in order for useful behaviours to appear, some individuals must start doing seemingly random things. Some behaviours can seem very bizarre to us (there is a tree frog that drops out of trees to avoid predators). Those behaviours must have evolved because some individuals started to do it. It makes me wonder how often individual animals do things like deliberately drop out of trees (or something more mundane) _without_ it serving an evolutionary purpose. Yes, I think that does happen. Also you may chance upon a diseased animal, say, and the pathology might make them do things that don’t benefit them. I know this isn’t your intention **Bozuit** , but some people might consider these as counter-examples. But I did say “Watching a _species_ frequently climb trees…”. ---
**Author:** ![Bytegeist](https://avatars.discourse-cdn.com/v4/letter/b/9dc877/32.png) [@Bytegeist](https://boards.straightdope.com/u/Bytegeist)\ **Post date:** [February 15, 2012, 8:16pm UTC](https://boards.straightdope.com/t/are-there-any-evolutionary-pressures-at-work-on-homo-sapiens-today-how/612796/59 "2012-02-15T20:16:17Z")
> [@md2000](#): > > I suppose when we have designer babies, it’s not the end of evolution so much as a whole different type of evolution. We are still creating differentiated hereditary beings who then play out their life to determine whether they too succeed and have more or less offspring using their genes, plus some variations. The selection and variability is simply done through labwork. For a clue what this might produce, look to purebred domestic animals. I’m also reminded of _Brave New World_, by Aldous Huxley. In that society, natural human reproduction no longer occurs.\* It’s all managed by the state. Seems to me that in such a world (assuming it could function as described), human evolution would come to an end. (\*) … in the setting where most of the novel takes place, that is. There are still “wild” societies elsewhere. ---
**Author:** ![Darwins\_Finch](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/darwins_finch/32/20304_2.png) [@Darwins\_Finch](https://boards.straightdope.com/u/Darwins_Finch)\ **Post date:** [February 15, 2012, 8:41pm UTC](https://boards.straightdope.com/t/are-there-any-evolutionary-pressures-at-work-on-homo-sapiens-today-how/612796/60 "2012-02-15T20:41:03Z")
> [@Mijin](#): > > Such as…? > (And btw, I never said “directly”) > > Of course. Defining harmful trait as one which affects our survival or reproduction, _of course_ they will be selected against. > > The point was about what we can extrapolate about an organism, based on our understanding of natural selection. > > Watching a species frequently climb trees we can say that the behaviour is either beneficial to their survival or reproduction, or it’s something that _was_ useful, and will now get selected out. > > Watching a human watching a movie, we can’t make such extrapolations. It’s not beneficial, nor has it ever been, but it’s not getting selected out either. > > (so your conclusion is still false) I’m not even sure what you’re arguing for or against at this point. How about you restate your supposed rule of thumb, because I’ve already mentioned how the second (“Alternatively…”) part absolutely applies to humans, and you just agreed to it! So how the heck is my conclusion false? 😕 As for the first part, there are all manner of learned behaviors which are not heritable, and thus play no part in biological evolution. Just because we see a population exhibiting a behavior does not make it evolutionarily meaningful; this is true whether we are looking at humans or any other species. [Previous page](https://boards.straightdope.com/t/are-there-any-evolutionary-pressures-at-work-on-homo-sapiens-today-how/612796.md?page=2) [Next page](https://boards.straightdope.com/t/are-there-any-evolutionary-pressures-at-work-on-homo-sapiens-today-how/612796.md?page=4)