# Diversity of Human Gene Pool - Are we more immune to epidemics? **URL:** \ **Category:** Factual Questions\ **Created:** [December 3, 2011, 8:49am UTC](https://boards.straightdope.com/t/diversity-of-human-gene-pool-are-we-more-immune-to-epidemics/604933 "2011-12-03T08:49:21Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Dirty0ldman](https://avatars.discourse-cdn.com/v4/letter/d/d2c977/32.png) [@Dirty0ldman](https://boards.straightdope.com/u/Dirty0ldman)\ **Post date:** [December 3, 2011, 8:49am UTC](https://boards.straightdope.com/t/diversity-of-human-gene-pool-are-we-more-immune-to-epidemics/604933/1 "2011-12-03T08:49:21Z")
Due to medical advances, people who would normally have died continue to live and reproduce - it is therefore my belief that as a race we have the most diverse gene pool compared to other animals Now consider historical epidemics like flu, influenza and plagues that wiped out whole populations of ancient civilization If we exempt current medical technology (and hygiene maybe?) and exposed ourselves to epidemics - would more of our population survive due to a more diverse gene pool? **Bonus Question:** as in H. G. Wells ‘Time Machine’ when will our gene pool become so diverse that the human race forks off into different species? ---
**Author:** ![Blake](https://avatars.discourse-cdn.com/v4/letter/b/a9a28c/32.png) [@Blake](https://boards.straightdope.com/u/Blake)\ **Post date:** [December 3, 2011, 9:03am UTC](https://boards.straightdope.com/t/diversity-of-human-gene-pool-are-we-more-immune-to-epidemics/604933/2 "2011-12-03T09:03:16Z")
> [@Dirty0ldman](#): > > Due to medical advances, people who would normally have died continue to live and reproduce - it is therefore my belief that as a race we have the most diverse gene pool compared to other animals Sorry, but your belief is factually wrong. Humans in fact have one of the lowest levels of genetic diversity of all the animals we know of. There is less genetic difference within the entire human species than there is between two tribes if chimps living 200 yards apart on opposite banks of a river. There is less diversity in our entire species than there is between wolves on opposite sides of a mountain range. The only mammal species I know of with a less diverse gene pool than humans are all endangered. [quote[Now consider historical epidemics like flu, influenza and plagues that wiped out whole populations of ancient civilization[/quote] None of those diseases ever wiped out whole populations. Severely reduced them, sure, but not wiped them out. > [@](#): > > If we exempt current medical technology (and hygiene maybe?) and exposed ourselves to epidemics - would more of our population survive due to a more diverse gene pool? More than what? More than survived in the past? No, fewer would be survive. More than other species would? That depends on what other species. > [@](#): > > **Bonus Question:** as in H. G. Wells ‘Time Machine’ when will our gene pool become so diverse that the human race forks off into different species? Currently being discussed in [this thread.](http://boards.straightdope.com/sdmb/showthread.php?t=633473). The answer is " almost certainly never", barring interplanetary colonisation and subsequent tens of millions of years of physical isolation. ---
**Author:** ![Der\_Trihs](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/der_trihs/32/233_2.png) [@Der\_Trihs](https://boards.straightdope.com/u/Der_Trihs)\ **Post date:** [December 3, 2011, 11:43am UTC](https://boards.straightdope.com/t/diversity-of-human-gene-pool-are-we-more-immune-to-epidemics/604933/3 "2011-12-03T11:43:50Z")
> [@Blake](#): > > Currently being discussed in [this thread.](http://boards.straightdope.com/sdmb/showthread.php?t=633473). The answer is " almost certainly never", barring interplanetary colonisation and subsequent tens of millions of years of physical isolation. Barring genetic engineering, which of course could produce a new species in a single generation. ---
**Author:** ![Alka\_Seltzer](https://avatars.discourse-cdn.com/v4/letter/a/c89c15/32.png) [@Alka\_Seltzer](https://boards.straightdope.com/u/Alka_Seltzer)\ **Post date:** [December 3, 2011, 1:03pm UTC](https://boards.straightdope.com/t/diversity-of-human-gene-pool-are-we-more-immune-to-epidemics/604933/4 "2011-12-03T13:03:59Z")
> [@Blake](#): > > Sorry, but your belief is factually wrong. Humans in fact have one of the lowest levels of genetic diversity of all the animals we know of. There is less genetic difference within the entire human species than there is between two tribes if chimps living 200 yards apart on opposite banks of a river. There is less diversity in our entire species than there is between wolves on opposite sides of a mountain range. The reason for this is that the human population went through an extreme bottleneck event within the last few thousand years (I can’t find the figures right now). We are all descended from a small number of people, thought to be a few thousand. We came quite close to going extinct. Most of the human genetic diversity that does exist resides in people of African descent. ---
**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:** [December 3, 2011, 1:52pm UTC](https://boards.straightdope.com/t/diversity-of-human-gene-pool-are-we-more-immune-to-epidemics/604933/5 "2011-12-03T13:52:13Z")
> [@Alka\_Seltzer](#): > > The reason for this is that the human population went through an extreme bottleneck event within the last few thousand years (I can’t find the figures right now). We are all descended from a small number of people, thought to be a few thousand. We came quite close to going extinct. > > Most of the human genetic diversity that does exist resides in people of African descent. More like 60k -70k years ago, not just a “few”. There may have been as few as 2,000 -10,000 of us then. ---
**Author:** ![md2000](https://avatars.discourse-cdn.com/v4/letter/m/73ab20/32.png) [@md2000](https://boards.straightdope.com/u/md2000)\ **Post date:** [December 3, 2011, 4:10pm UTC](https://boards.straightdope.com/t/diversity-of-human-gene-pool-are-we-more-immune-to-epidemics/604933/6 "2011-12-03T16:10:36Z")
Plus, using medicine to keep people alive is counterproductive to the OP premise. We are keep people alive who have weak or erratic immune systems. The entire history of human populations was that a significant number of children died within 5 years, usually from childhood diseases. Today, almost all survive thanks to cleanliness and antibiotics. One of the biggest issues with childhood is diseases like asthma, where it seems the immune system attacks the body. I think the answer is the opposite. Diseases get weaker as they get older. The first bubonic plague killed (estimates vary) about 1/3 of europe. Subsequent waves were more of a nuisance than a disaster. The disease killed off those least able to fight it, and the disease agents survived and spread when they had a weaker effect on the host. The most lethal were burioed or burned before they could easily spread. We see the same effectwith AIDS. People used to drop off within a year or so of infection. Now, we have a lot of people living decades with the infection. Which version of the disease do you think spreads to more victims? ---
**Author:** ![Alka\_Seltzer](https://avatars.discourse-cdn.com/v4/letter/a/c89c15/32.png) [@Alka\_Seltzer](https://boards.straightdope.com/u/Alka_Seltzer)\ **Post date:** [December 3, 2011, 4:35pm UTC](https://boards.straightdope.com/t/diversity-of-human-gene-pool-are-we-more-immune-to-epidemics/604933/7 "2011-12-03T16:35:18Z")
> [@John\_Mace](#): > > More like 60k -70k years ago, not just a “few”. There may have been as few as 2,000 -10,000 of us then. Thanks, I couldn’t find a cite quickly, and was mis-remembering. The bottleneck has been tentatively linked to the [Toba eruption](http://en.wikipedia.org/wiki/Toba_eruption). In evolutionary terms, 70,000 years is not a long time. ---
**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:** [December 3, 2011, 4:50pm UTC](https://boards.straightdope.com/t/diversity-of-human-gene-pool-are-we-more-immune-to-epidemics/604933/8 "2011-12-03T16:50:03Z")
> [@Alka\_Seltzer](#): > > Thanks, I couldn’t find a cite quickly, and was mis-remembering. The bottleneck has been tentatively linked to the [Toba eruption](http://en.wikipedia.org/wiki/Toba_eruption). > > In evolutionary terms, 70,000 years is not a long time. Yeah, it’s not much time at all. But it was enough for us to go from ~.000002B to 7B worldwide! 🙂 I’m not sure how much the Toba link is scientific consensus at this point, or just one probable hypothesis. It gets popularize as established fact, but I don’t think we’re quite there yet. ---
**Author:** ![Alka\_Seltzer](https://avatars.discourse-cdn.com/v4/letter/a/c89c15/32.png) [@Alka\_Seltzer](https://boards.straightdope.com/u/Alka_Seltzer)\ **Post date:** [December 3, 2011, 5:13pm UTC](https://boards.straightdope.com/t/diversity-of-human-gene-pool-are-we-more-immune-to-epidemics/604933/9 "2011-12-03T17:13:00Z")
> [@John\_Mace](#): > > Yeah, it’s not much time at all. But it was enough for us to go from ~.000002B to 7B worldwide! 🙂 I think of it as a burp in geological terms, a belch to evolution and several eternities for pop culture. > [@John\_Mace](#): > > I’m not sure how much the Toba link is scientific consensus at this point, or just one probable hypothesis. It gets popularize as established fact, but I don’t think we’re quite there yet. I get the impression it’s a fairly strong hypothesis, but given the sparseness of the fossil record it might never make the leap to probable cause. ---
**Author:** ![Dirty0ldman](https://avatars.discourse-cdn.com/v4/letter/d/d2c977/32.png) [@Dirty0ldman](https://boards.straightdope.com/u/Dirty0ldman)\ **Post date:** [December 4, 2011, 3:03pm UTC](https://boards.straightdope.com/t/diversity-of-human-gene-pool-are-we-more-immune-to-epidemics/604933/10 "2011-12-04T15:03:52Z")
> [@Blake](#): > > Sorry, but your belief is factually wrong. Humans in fact have one of the lowest levels of genetic diversity of all the animals we know of. There is less genetic difference within the entire human species than there is between two tribes if chimps living 200 yards apart on opposite banks of a river. Can you provide a source for that? Everyone is talking about how the Human gene pool isn’t diverse but I find that hard to believe. I read articles about it deteriorating in terms of quality but not diversity. Take Sickle-cell anemia and how it protects against malaria - sickle-cell is the epitome of ‘bad genes’ that modern medicine can alleviate to some degree and allow carriers to promulgate. I am just asking how the spread of negative genes can actually make our species more diverse and increase our inherent immunity to future epidemics - just like sickle cell and malaria go together. ---
**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:** [December 4, 2011, 4:21pm UTC](https://boards.straightdope.com/t/diversity-of-human-gene-pool-are-we-more-immune-to-epidemics/604933/11 "2011-12-04T16:21:28Z")
> [@Dirty0ldman](#): > > Can you provide a source for that? > > Everyone is talking about how the Human gene pool isn’t diverse but I find that hard to believe. I read articles about it deteriorating in terms of quality but not diversity. > > Take Sickle-cell anemia and how it protects against malaria - sickle-cell is the epitome of ‘bad genes’ that modern medicine can alleviate to some degree and allow carriers to promulgate. > > I am just asking how the spread of negative genes can actually make our species more diverse and increase our inherent immunity to future epidemics - just like sickle cell and malaria go together. Gene diversity is never “deteriorating”. That’s a value judgement not applicable to evolution. [Here’s a nice picture](http://dnalc.org/view/15619-Human-Chimp-mtDNA-tree-comparison.html) showing what Blake was talking about. I think he is using “tribe” as in subspecies. ---
**Author:** ![Dirty0ldman](https://avatars.discourse-cdn.com/v4/letter/d/d2c977/32.png) [@Dirty0ldman](https://boards.straightdope.com/u/Dirty0ldman)\ **Post date:** [December 5, 2011, 3:07am UTC](https://boards.straightdope.com/t/diversity-of-human-gene-pool-are-we-more-immune-to-epidemics/604933/12 "2011-12-05T03:07:28Z")
> [@](#): > > Gene diversity is never “deteriorating”. That’s a value judgement not applicable to evolution. I concede that it may be an arbitrary judgement but it is applicable to evolution in the context of natural selection. [Check this link](http://www.livescience.com/445-darwin-natural-selection-work-humans.html) about how “13 percent of the genes examined in the study showed evidence for negative selection, whereby harmful mutations are weeded out of the population. These included some genes implicated in hereditary diseases” 13% looks like a large figure but we have no comparative data to benchmark it on. What I want to know is if medical advances have mitigated negative selection and to what extent? Lowering the impact of negative selection permits varied diversification - So as in the connection between **Sickle Cell Anemia & Malaria** would it boost our inherent immunity as a species against unknown future epidemics? ---
**Author:** ![Dirty0ldman](https://avatars.discourse-cdn.com/v4/letter/d/d2c977/32.png) [@Dirty0ldman](https://boards.straightdope.com/u/Dirty0ldman)\ **Post date:** [December 5, 2011, 3:16am UTC](https://boards.straightdope.com/t/diversity-of-human-gene-pool-are-we-more-immune-to-epidemics/604933/13 "2011-12-05T03:16:23Z")
A lot of talk goes on about racial purity and good genes. Lots of dystopian stories are based on genetic policing and regulation I am trying to find a **positive perspective** to retaining negative genes and all that rises to mind is the potential this diversity may have in immunity to incurable diseases. If anyone thinks of other positive arguments for retaining bad hereditary genes (as opposed to wiping them out) feel free to private message me ---
**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:** [December 5, 2011, 4:21am UTC](https://boards.straightdope.com/t/diversity-of-human-gene-pool-are-we-more-immune-to-epidemics/604933/14 "2011-12-05T04:21:32Z")
> [@Dirty0ldman](#): > > I concede that it may be an arbitrary judgement but it is applicable to evolution in the context of natural selection. > > [Check this link](http://www.livescience.com/445-darwin-natural-selection-work-humans.html) about how “13 percent of the genes examined in the study showed evidence for negative selection, whereby harmful mutations are weeded out of the population. These included some genes implicated in hereditary diseases” > 13% looks like a large figure but we have no comparative data to benchmark it on. What I want to know is if medical advances have mitigated negative selection and to what extent? > Lowering the impact of negative selection permits varied diversification - So as in the connection between **Sickle Cell Anemia & Malaria** would it boost our inherent immunity as a species against unknown future epidemics? I know you’re new here, so you don’t have the perspective of all the threads we’ve had on this MB to address this topic. There is no difference between “medical advances” that help some live and the first human ancestor who made a stone tool that allowed his clan to butcher a carcass and eat it whereas the other clan without stone tools couldn’t do so. We are a tool making species. That is the niche we have perfected _par excellence_. Those tools involve things that allow individuals to survive who would not do so absent such tools. That is who we are. From the first flint knife to the most sophisticated laser. If you want to decry the latest medical advance as “degrading the genome”, you will need to do the same for every discovery from stone tools to fire to agriculture to the wheel to modern medicine. ---
**Author:** ![SantaMan](https://avatars.discourse-cdn.com/v4/letter/s/da6949/32.png) [@SantaMan](https://boards.straightdope.com/u/SantaMan)\ **Post date:** [December 5, 2011, 6:01am UTC](https://boards.straightdope.com/t/diversity-of-human-gene-pool-are-we-more-immune-to-epidemics/604933/15 "2011-12-05T06:01:38Z")
This discussion got me to wondering just how often genetic makeup affects susceptibility to a particular disease. I understand that heart disease, diabetes, plague and sickle cell anemia (and for a few, HIV) would be included, but I have no idea how many others. Any thoughts? ---
**Author:** ![Dirty0ldman](https://avatars.discourse-cdn.com/v4/letter/d/d2c977/32.png) [@Dirty0ldman](https://boards.straightdope.com/u/Dirty0ldman)\ **Post date:** [December 5, 2011, 6:11pm UTC](https://boards.straightdope.com/t/diversity-of-human-gene-pool-are-we-more-immune-to-epidemics/604933/16 "2011-12-05T18:11:59Z")
> [@John\_Mace](#): > > I know you’re new here, so you don’t have the perspective of all the threads we’ve had on this MB to address this topic. There is no difference between “medical advances” that help some live and the first human ancestor who made a stone tool that allowed his clan to butcher a carcass and eat it whereas the other clan without stone tools couldn’t do so. We are a tool making species. That is the niche we have perfected _par excellence_. Those tools involve things that allow individuals to survive who would not do so absent such tools. That is who we are. From the first flint knife to the most sophisticated laser. If you want to decry the latest medical advance as “degrading the genome”, you will need to do the same for every discovery from stone tools to fire to agriculture to the wheel to modern medicine. That is very insightful, but not helpful. All you have done is expand the boundaries of my already complicated question when we need to be focusing on a specific factor. If you have any experience answering questions you would know that focusing and defining the scope as #2 poster (Blake) did is more important than introducing vague generalizations. > [@](#): > > This discussion got me to wondering just how often genetic makeup affects susceptibility to a particular disease. I understand that heart disease, diabetes, plague and sickle cell anemia (and for a few, HIV) would be included, but I have no idea how many others. Any thoughts? I think you have the correct approach to the problem SantaMan that would be the best place to start an enquiry and approach the subject matter ---
**Author:** ![Surreal](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@Surreal](https://boards.straightdope.com/u/Surreal)\ **Post date:** [December 5, 2011, 7:52pm UTC](https://boards.straightdope.com/t/diversity-of-human-gene-pool-are-we-more-immune-to-epidemics/604933/17 "2011-12-05T19:52:07Z")
> [@Alka\_Seltzer](#): > > The reason for this is that the human population went through an extreme bottleneck event within the last few thousand years (I can’t find the figures right now). We are all descended from a small number of people, thought to be a few thousand. Pleistocene human groups had very low genetic variation as well. ---
**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:** [December 5, 2011, 8:21pm UTC](https://boards.straightdope.com/t/diversity-of-human-gene-pool-are-we-more-immune-to-epidemics/604933/18 "2011-12-05T20:21:38Z")
> [@Surreal](#): > > Pleistocene human groups had very low genetic variation as well. The Pleistocene covers a timeframe from 2.5M years ago up until the end of the last ice age (about 10,000 BC). That includes the entire span of the genus _Homo_ (except for the last 12k years), so I’m not sure what you mean by that statement. I already corrected **Alka’s** dates in an earlier post, if that is what you were referring to. ---
**Author:** ![Surreal](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@Surreal](https://boards.straightdope.com/u/Surreal)\ **Post date:** [December 5, 2011, 8:36pm UTC](https://boards.straightdope.com/t/diversity-of-human-gene-pool-are-we-more-immune-to-epidemics/604933/19 "2011-12-05T20:36:54Z")
> [@John\_Mace](#): > > The Pleistocene covers a timeframe from 2.5M years ago up until the end of the last ice age (about 10,000 BC). That includes the entire span of the genus _Homo_ (except for the last 12k years), so I’m not sure what you mean by that statement. I meant to say that Pleistocene _hominins_ had very low genetic variation as well, so a recent bottleneck doesn’t appear to be sufficient to explain our lack of genetic variation. ---
**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:** [December 5, 2011, 8:42pm UTC](https://boards.straightdope.com/t/diversity-of-human-gene-pool-are-we-more-immune-to-epidemics/604933/20 "2011-12-05T20:42:36Z")
> [@Surreal](#): > > I meant to say that Pleistocene _hominins_ had very low genetic variation as well, so a recent bottleneck doesn’t appear to be sufficient to explain our lack of genetic variation. What definition of “hominin” are you using, and what data are you referring to? “Hominin” can mean different things depending on the context. These days, you see _Homininae_ meaning humans, chimps and gorillas and our ancestors back to the common one. _Hominini_ means the same, except excluding gorillas. [Next page](https://boards.straightdope.com/t/diversity-of-human-gene-pool-are-we-more-immune-to-epidemics/604933.md?page=2)