Tag Archives: Research

Out Of Africa: Human DNA

dna_rgbDid anyone watch “The Human Family Tree” recently on the National Geographic channel? One of the most fascinating facts found out, after checking the DNA of 350,000 human beings from every corner of the planet, is we all come from the same area of Africa.

200,000 – 150,000 years ago: The genetic journey of everyone alive today began with one woman — “Scientific Eve” — who lived in Africa and passed along her DNA through special cell structures called mitochondria, which only women pass down to further generations. What that means is, we are all related: Black, White, Yellow, Brown . . . we’re all the same. Our DNA varies by 1/10 of 1%, and that small percentage is what gives us our individual identities.

The color of a humans skin comes not from DNA, but where our ancestors migrated to. European ancestors lived in cold climates, so skin pigmentation lightened over generations. Those living in warmer or hotter climates retained the darker characteristics. It makes it interesting, then, how much race (which actually doesn’t exist) plays the role it does in society.  I wonder how racists would actually feel if they knew they were hating their brothers and cousins?  My guess is they would not believe the evidence when presented to them. All one has to do is look to people like Linda Jenkins, Bill O’Reilly and their ilk to understand facts have little meaning to them.

So, readers, how do we change the minds of people bent on destroying race relations, when the evidence of DNA points to the non-existence of race? Is it even possible?



Filed under Celebration, Diversity, Evolution, hate groups, History, Life Lessons, racism, Research, Thinking/Considering

PTSD: An Interaction of Combat Stress and Hippocampal Volume

Animal studies demonstrated that repeated and prolonged stress for an animal can produce damage to the hippocampus.  The hippocampus is an area of the brain that has been implicated in declarative memory for humans.  Declarative memory include memories that were created from  our school learning as an example,  and those personal memories such as what our 12th birthday was like.

Given the intriguing findings about the effects of extreme stress on  the hippocampus in animals, MRI researchers looked into the structural aspects of the hippocampus in humans who suffered chronic unremitting forms of posttraumatic stress disorder (PTSD).  They found that those persons who had been diagnosed with PTSD had smaller hippocampal volume.  Given these findings, 2 questions  remained:  was smaller hippocampal volume a neurotoxic effect of combat stress, or 2) was smaller hypocampal volume a pre-existing condition that rendered the person vulnerable to PTSD?

To address this question, Mark Gilbertson, of the Dept of Psychiatry at Harvard University, and colleagues obtained a sample of monozygotic (or identical) twins who were discordant for combat duty  (one twin had been in combat, the other had not).

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Filed under Healthcare, Psychological Disorders, Psychology Ramblings..., Research, WAR