PBS GENETIC DIVERSITY QUIZ, What differences make a difference

Along with many other writers and commentators I’ve written more than once about Donald Trump’s abysmal  ignorance,

in regard to so many things, in regard to this country’s and the world’s past history, in regard to the present, to what’s happening right now, and in regard to where his ignorance is perhaps most pronounced, and most frightening if he ever were to win the presidency, in regard to the physical and biological, as well as the political sciences. In short,  he is mostly ignorant regarding just about everything you’d assume he should know having been chosen as the presidential candidate of one of our two major political parties.

Trump’s ignorance was especially noticeable for me during the Presidential Debates, when at so many moments during those debates, when I would have wanted him to say something interesting and thoughtful, perhaps revealing his own up until then still hidden but perhaps (?) intelligent take on things? But he was a disappointment. No matter what the question from the moderator, Trump seemed only capable of repeating the shallow and superficial and “nasty”, although colorful  words and expressions of the “Trump rallies,” intended to arouse among his no less ignorant listeners their devotion to his cause  as well as their anger against “crooked Hillary.”

In these debates the most he would ever say regarding the policies of the other party, was that their policies were failures and that he, Donald Trump, while making America great again, would scrap them all, the tax code, the excessive regulations on business and entrepreneurship, the Obama immigration and trade measures, as well as the affordable care Act, put into effect also by President Obama. And other than to say he would scrap the measures of his predecessor he said little or nothing of what he would do to replace them, only such things as that he would deport the illegals and build an impenetrable wall between us and our neighbors to the South.

Then just the other day I happened to see the following Genetic Diversity Quiz on the PBS.org web site, exploring the question, what differences make a difference. A great question. What if Donald Trump were to take the quiz? Well he probably never would because he hates to be exposed, as not being better, more knowledgeable than everyone else.

Take the quiz  yourself and see how you would do with the differences that make a difference. If the Donald were ever to take it how do you think he would do, not only in this quiz but in other comparable quizzes, say on U.S.History, economics, the Political and natural sciences, the great books, the great works of art and music, all the knowledge that represents the great and real achievements of man living in a free and open society.

I wonder if Trump even understands what that means, to live in a free and open society, especially given his oft stated opposition to free trade, in a society where the free movement of people and goods is the norm. Especially given his authoritarian and bullying stances on so many things.

Anyway, here’s the quiz (a cure for racism?). Let me know how you do.

What differences make a difference?

  1. Approximately how old are modern humans?
    1. 170,000 years
    2. 40,000 years
    3. 70,000 years
    4. 1.2 million years
    5. 5 million years
  2. Which group has the most genetic variation?
    1. Humans
    2. Chimpanzees
    3. Penguins
    4. Fruit flies
    5. Elephants
  3. What is the source of genetic variation in humans?
    1. mutation
    2. genetic drift
    3. natural selection
    4. sexual selection
    5. environment
  4. Which two present-day populations are most likely to be genetically similar?
    1. Italians and Ethiopians
    2. Senegalese and Kenyans
    3. Italians and Swedes
    4. Chinese and Lakota (Sioux)
    5. Saudi Arabians and Ethiopians
  5. What caused differences in skin color to evolve?
    1. The environment
    2. Natural selection
    3. Sexual selection
    4. Tanning oil
    5. We don’t know
  6. If you know a person’s skin color, what can you predict about them?
    1. their blood type
    2. their height
    3. the likelihood they will get certain inherited diseases
    4. whether or not they have musical talent
    5. none of the above
  7. An individual from which country is most likely to carry the sickle cell trait?
    1. Ireland
    2. Greece
    3. South Africa
    4. Samoa
    5. Mexico
  8. Your ancestors are likely to include:
    1. Nefertiti
    2. Julius Caesar
    3. Qin Shi Huang – first emperor of China
    4. All of the above
    5. None of the above
  9. Which continent has the greatest human genetic diversity?
    1. Europe
    2. Asia
    3. North America
    4. South America
    5. Africa
  10. If a catastrophe wiped out everyone except people in Europe, how much of the total genetic variation in our species would be left?
    1. 50%
    2. 38%
    3. 94%
    4. 21%
    5. 74%


  1. A. 170,000 years
    The earliest hominids evolved from apes about 5 million years ago, but modern humans (Homo sapien sapiens) didn’t emerge until about 150,000 to 200,000 years ago in eastern Africa. Our species first left Africa only around 70,000 years ago and quickly spread across the entire world. All of us are descended from these African ancestors.
  2. D. Fruit flies
    Fruit flies have existed for a very long time and they also have a short life span, so lots of genetic mutations have accumulated over many generations. Modern humans are a relatively young species, and we have always moved, mixed and mated, so we are one of the most genetically similar of all species.
  3. A. Mutation
    Genetic drift, natural selection and sexual selection act to distribute traits, but new genetic variants arise only through mutation – copying errors during reproduction. We all have the same 35,000 or so genes, but some genes come in different forms, called alleles. For instance, the gene that governs blood group proteins comes in three variants, resulting in A, B or O blood type. Some mutations are harmful, leading to stillbirth or deadly diseases like spinal bifida. Those that are neutral or create an evolutionary advantage are passed on and spread through successive generations.
  4. E. Saudi Arabians and Ethiopians
    Populations that live near each other geographically tend to be more alike than populations that live far apart. We tend to think of Saudi Arabians and Ethiopians as different races, but they are most similar because there has been more recent “gene flow” – intermixing between these two groups. Often when variation seems to follow “racial” lines, it is more accurately explained by geographic proximity.
  5. E. We don’t know
    People in tropical areas tend to be darker, while northern and southern populations tend to be lighter. Some scientists attribute this to natural selection in response to ultraviolet (UV) light. Dark skin blocks some UV radiation. Other scientists believe that superficial physical differences arose from cultural preferences, an evolutionary force known as sexual selection.
  6. E. None of the above
    Most traits are governed by different genes, so they are inherited independently. The presence of one trait doesn’t necessarily signal the presence of another trait. We think people come packaged into groups, even – as anthropologist Jon Marks jokes, “color-coded for our convenience” – but it turns out they don’t. Visual traits – skin color, for example – tell us nothing about deeper internal differences or abilities.
  7. B. Greece
    We often think of sickle cell as a “racial” disease that affects people of African descent, but it evolved as a trait that confers resistance to malaria. It occurs in people whose ancestors came from regions where malaria was once common, like the Mediterranean, Arabia, Turkey, southern Asia and western and central Africa, but not in areas such as southern Africa. Ancestry, not race, is a better indicator of whether or not one carries the markers for sickle cell, Tay Sachs, porphyria and other genetic diseases.
  8. D. All of the above
    We each have 2 parents, 4 grandparents, 8 great-grandparents. Steve Olson and Joseph Chang point out that if we go far enough back in time, only about 30 generations, we each have a billion potential ancestors, more than the population of the earth at the time. This means that any historical person living 1,600 years ago whose children had children is likely to be among our ancestors. Olson writes that because of human migrations and mating, “the DNA now in our cells consists of bits and pieces of the DNA that was in thousands of people’s cells a millennia ago.”
  9. E. Africa
    All modern humans originated in Africa, and we spent most of our evolution as a species together there. All the other populations of the world can be seen as a subset of Africans. Every human trait found elsewhere can also be found in Africa, with the exception of a few recent variations favored by the environment, sexual selection, or drift – such as light skin.
  10. C. About 94% of our total human genetic variation would remain
    If only the Swedes or Poles survived, we would still retain about 85% of our genetic variation. This is because most variation is within, rather than between, races. On average, any local population contains 85% of all human genetic variation, and any continent contains 94%. This is because humans have always migrated and mixed their genes. Two random Swedes, for example, are likely to be as different as a Swede and a Senegalese.

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