full transcript

From the Ted Talk by Angela Koine Flynn: The science of skin color

Unscramble the Blue Letters

For hnaums whose dark skin effectively blocked whatever sunlight there was, vitamin D deficiency would have posed a serious tehrat in the north. But some of them hppnaeed to produce less melanin. They were exposed to small enough amounts of light that melanoma was less likely, and their lighter skin better asoerbbd the UV light. So they benefited from vitamin D, developed strong bones, and survived well enough to pdrocue healthy offspring. Over many gineetnoars of selection, skin color in those regions gradually lightened.

Open Cloze

For ______ whose dark skin effectively blocked whatever sunlight there was, vitamin D deficiency would have posed a serious ______ in the north. But some of them ________ to produce less melanin. They were exposed to small enough amounts of light that melanoma was less likely, and their lighter skin better ________ the UV light. So they benefited from vitamin D, developed strong bones, and survived well enough to _______ healthy offspring. Over many ___________ of selection, skin color in those regions gradually lightened.

Solution

  1. threat
  2. generations
  3. absorbed
  4. happened
  5. humans
  6. produce

Original Text

For humans whose dark skin effectively blocked whatever sunlight there was, vitamin D deficiency would have posed a serious threat in the north. But some of them happened to produce less melanin. They were exposed to small enough amounts of light that melanoma was less likely, and their lighter skin better absorbed the UV light. So they benefited from vitamin D, developed strong bones, and survived well enough to produce healthy offspring. Over many generations of selection, skin color in those regions gradually lightened.

Frequently Occurring Word Combinations

ngrams of length 2

collocation frequency
uv light 3
ancestors migrated 2
skin color 2

Important Words

  1. absorbed
  2. amounts
  3. benefited
  4. blocked
  5. bones
  6. color
  7. dark
  8. deficiency
  9. developed
  10. effectively
  11. exposed
  12. generations
  13. gradually
  14. happened
  15. healthy
  16. humans
  17. light
  18. lightened
  19. lighter
  20. melanin
  21. melanoma
  22. north
  23. offspring
  24. posed
  25. produce
  26. regions
  27. selection
  28. skin
  29. small
  30. strong
  31. sunlight
  32. survived
  33. threat
  34. uv
  35. vitamin