DNA sequences from the Middle Pleistocene reveal that the extinct Eurasian straight-tusked elephants were closely related to today's African forest elephants (Loxodonta cyclotis) in Africa.
The evolutionary loss of the main enzyme required for ketone body biosynthesis suggests that alternative strategies to provide energy for large brains during fasting evolved repeatedly in mammals.
Elephants and fruit bats have evolved large brains even though they have lost a gene that is fundamental to the supply of energy to the brain when glucose is not available.
As new technology makes it possible to perform experiments that were unimaginable a decade ago, Eve Marder argues that we can still learn from the past.