The position of the polar timberline in present-day Europe versus the position of the timberline at the most severe stage of the Würm Ice Age.

Ice Age conditions in Europe

A: The position of the polar timberline in present-day Europe 

B: The position of the timberline at the most severe stage of the Würm Ice Age. (~22,000 years ago)
C: The limits of glacial debris deposited during the Würm Ice Age.
D: The limits of glacial debris deposited during the Riss and Mindel Ice Age.

Source: http://donsmaps.com/icemaps.html (via JayMan)

"Natural" age-specific marital fertility, East Asia and Europe, ca. 1600-1800

Source:
One Quarter of Humanity
J. Z. Lee and W. Feng (1999)

Share of never married females, China & Europe, ca. 1800

-> By age 20-24 most Chinese females were already married, while the vast majority of European females were still single.

-> By age 30-34, virtually no Chinese females remained single, whereas 30 percent of their Western counterparts were still spinsters.

See also:
Share of never married males, China & Europe, ca. 1800

Source:
One Quarter of Humanity
J. Z. Lee & W. Feng (1999)