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
- threat
- generations
- absorbed
- happened
- humans
- 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
- absorbed
- amounts
- benefited
- blocked
- bones
- color
- dark
- deficiency
- developed
- effectively
- exposed
- generations
- gradually
- happened
- healthy
- humans
- light
- lightened
- lighter
- melanin
- melanoma
- north
- offspring
- posed
- produce
- regions
- selection
- skin
- small
- strong
- sunlight
- survived
- threat
- uv
- vitamin