Fire use is generally described as beginning up to 1mya.  But I came across
a report in Science dated 30 April 1999 which may interest readers of
EvFit.

Quote begins.

Fireplaces have been found in Kenya dated to approximately 1.6mya.  The
relative thinness of the bone in the sides of the skull of Homo erectus
[which emerged at about this time] compared with that of earlier hominids,
along with smaller teeth, makes it clear that H. erectus was doing
something to make chewing easier [than it had been one or two hundred
thousand years earlier].  They clearly had the pyrotechnical ability to
cook tubers at least as far back as 1.6mya, even if further research must
determine what was cooking.

Quote ends.

Keith's comments: (1) If you look at the skulls of Australopithecus
aethiopithecus you will see the marked saggital crest which anchored the
huge jaw muscles this hominid used for ... what?  Most likely butchering
and chewing raw meat.  (2) 1.6mya is about 65,000 generations; I think we
can assume that this is long enough ago for our gut to have had time to
optimize for a cooked as well as an uncooked diet.  (3) Using fire is not
the same as having fire always on hand; for example, the Tasmanian
aborigines, living on the cold shores of the Southern Ocean at the same
latitude south as New York is north, had no fire for up to 10,000 years
through to the early 1800s.  (4) This is good news for those like me who
squeamishly shy away from facing up to the prospect of eating raw meat in
order to adopt the palaeolithic diet.

Keith