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Thread: geographical isolation

  1. #1 geographical isolation 
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    geographical isolation happend when a physical barrier ( like floods) divides a population of species, this with natural selection causes reproductive isolation. As the two groups became different species!!

    but humans are geograhphically isolated , but they can still mate with each other. how come??


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  3. #2  
    Forum Freshman CrimsonViper's Avatar
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    Humans are not geographically isolated. If I wanted to, I could hop on a plane and be any where in the world within 24 hours. Isolation means that there can be absolutely no contact (and thus interbreeding) with the other population.


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  4. #3  
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    yes they are!
    and are you saying if so, the humans are geographically isolated that they can't breed together??? they still can!!!
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  5. #4  
    Moderator Moderator TheBiologista's Avatar
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    Quote Originally Posted by fatooma
    yes they are!
    and are you saying if so, the humans are geographically isolated that they can't breed together??? they still can!!!
    They can only be said to be isolated with respect to evolution if they can't mate. Humans are an example of a species for whom geographical separation has a much reduced impact on breeding, though it is of course still influential.
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    really? in what way it can be still influential?
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    there are asian people and black people and white people also hispanic people thats how it can have an impact. :P
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    Forum Masters Degree Twit of wit's Avatar
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    Quote Originally Posted by Topalk
    there are asian people and black people and white people also hispanic people thats how it can have an impact. :P
    "Hispanic" is not a race.
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    whatever! :x
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  10. #9  
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    Quote Originally Posted by Twit of wit
    Quote Originally Posted by Topalk
    there are asian people and black people and white people also hispanic people thats how it can have an impact. :P
    "Hispanic" is not a race.
    Topalk did not say that Hispanic was a race. Asians are not a race, you did not comment on that. Blacks are not a race, you did not comment on that. Topalk made note of some of the gross phenotypical and simplistic variants we see in homo sapiens that tend to particular geographical areas, as a way of illustrating Bio's point. It was a sound illustration.
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  11. #10  
    Forum Masters Degree Twit of wit's Avatar
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    Quote Originally Posted by Ophiolite
    Quote Originally Posted by Twit of wit
    Quote Originally Posted by Topalk
    there are asian people and black people and white people also hispanic people thats how it can have an impact. :P
    "Hispanic" is not a race.
    Topalk did not say that Hispanic was a race. Asians are not a race, you did not comment on that. Blacks are not a race, you did not comment on that. Topalk made note of some of the gross phenotypical and simplistic variants we see in homo sapiens that tend to particular geographical areas, as a way of illustrating Bio's point. It was a sound illustration.
    I'm not sure what you mean. Do you disagree with the word "race" or something else?
    OK, "hispanic" is not a phenotypical variant.
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  12. #11  
    WYSIWYG Moderator marnixR's Avatar
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    the trouble is that the concept of "race" has become tainted with cultural connotations when it comes to humans, therefore doesn't always refer to purely phenotypical differences
    in fact, cultural differences have often led people to exaggerate phenotypical differences beyond what they really there
    "Reality is that which, when you stop believing in it, doesn't go away." (Philip K. Dick)
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  13. #12  
    Moderator Moderator TheBiologista's Avatar
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    Quote Originally Posted by Twit of wit
    Quote Originally Posted by Ophiolite
    Quote Originally Posted by Twit of wit
    Quote Originally Posted by Topalk
    there are asian people and black people and white people also hispanic people thats how it can have an impact. :P
    "Hispanic" is not a race.
    Topalk did not say that Hispanic was a race. Asians are not a race, you did not comment on that. Blacks are not a race, you did not comment on that. Topalk made note of some of the gross phenotypical and simplistic variants we see in homo sapiens that tend to particular geographical areas, as a way of illustrating Bio's point. It was a sound illustration.
    I'm not sure what you mean. Do you disagree with the word "race" or something else?
    OK, "hispanic" is not a phenotypical variant.
    Ginger is a variation, and I think we can agree that hispanics are more genetically distinct than the gingers. We're getting kinda silly here.
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  14. #13  
    Forum Masters Degree Twit of wit's Avatar
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    Quote Originally Posted by TheBiologista
    Ginger is a variation, and I think we can agree that hispanics are more genetically distinct than the gingers. We're getting kinda silly here.
    Now this is geting ridiculous. Can you tell if someone is hispanic or not just by looking at him? No. Can you tell from his genes? Very unlikely.
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  15. #14  
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    actually you probaly could hispanics are sort of brown natrually meaning not from tanning on the beach while europeans are white and africans are black and asians are the same as hispanic according to skin coloor.
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  16. #15  
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    Quote Originally Posted by Topalk
    actually you probaly could hispanics are sort of brown natrually meaning not from tanning on the beach while europeans are white and africans are black and asians are the same as hispanic according to skin coloor.
    Most (I guess it could be around 80%-90%) of hispanics are of european origin.

    Edit: Just to explain little more. As you should notice, skin color in europe is not uniform, it is usually divided to four types. The lighter skin types are more common in northern europe. Most non-hispanic americans are from more northern parts of europe than hispanics, so they are more likely to have the pinkish skin types that don't tan easily, while hispanics are likely to have the quickly tanning types. So yes, there is some variation, but hardly any geographical isolation. And yes, hispanic americans are on average darker than non-hispanics, but same thing is true for southern/northern europeans in general.
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  17. #16  
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    Quote Originally Posted by Twit of wit
    Quote Originally Posted by Topalk
    actually you probaly could hispanics are sort of brown natrually meaning not from tanning on the beach while europeans are white and africans are black and asians are the same as hispanic according to skin coloor.
    Most (I guess it could be around 80%-90%) of hispanics are of european origin.

    Edit: Just to explain little more. As you should notice, skin color in europe is not uniform, it is usually divided to four types. The lighter skin types are more common in northern europe. Most non-hispanic americans are from more northern parts of europe than hispanics, so they are more likely to have the pinkish skin types that don't tan easily, while hispanics are likely to have the quickly tanning types. So yes, there is some variation, but hardly any geographical isolation. And yes, hispanic americans are on average darker than non-hispanics, but same thing is true for southern/northern europeans in general.
    We're just pointing out the existence of discrete varieties, not claiming they're caused by geographical isolation. I'd say it has a role, but culturally influenced sexual selection seems like the more likely main factor.
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  18. #17  
    Forum Masters Degree Twit of wit's Avatar
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    Quote Originally Posted by TheBiologista

    We're just pointing out the existence of discrete varieties, not claiming they're caused by geographical isolation. I'd say it has a role, but culturally influenced sexual selection seems like the more likely main factor.
    OK, but the point is that "hispanic" is not any specific variety.
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  19. #18  
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    Quote Originally Posted by Twit of wit
    Quote Originally Posted by TheBiologista

    We're just pointing out the existence of discrete varieties, not claiming they're caused by geographical isolation. I'd say it has a role, but culturally influenced sexual selection seems like the more likely main factor.
    OK, but the point is that "hispanic" is not any specific variety.
    No, 'the point' had to do with the persistence of heterogeneity in the human species despite diminishing physical and geographical barriers to breeding. That point has now been dwarfed by this side argument. Hispanic is not a variety to the extent that 'African' is, but it is still a variety characterised by numerous common traits such as dark hair, sallow skin and dark eyes- we might take it to be partially or wholly synonymous with 'Mediterranean', if that sits better with you. The key characters and borders of these varieties, whether we call them races or ethnicities, are nebulous. They're loose, a shorthand way of describing difference. Tolpak was very clearly talking in such broad terms. Can we return to the original topic?
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