Women living in the 17th to 19th centuries had a slightly lower life expectancy if they gave birth to multiple sons, rather than to daughters.
Women living in the 17th to 19th centuries had a slightly lower life expectancy if they gave birth to multiple sons, rather than to daughters.
As the human population expands, the number of rare genetic variants has dramatically increased.
Sometime today, Earth’s 7 billionth person was born.
US border policy and fences threaten wildlife across the continent.
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