From the contemporary fossil hominin record we see
evidence for three or four major transitions in the emergence
of modern human life history related to encephelization and
sexual maturation (Table 2).
Although this evidence suggests that longer lifespan
emerged in punctuated equilibrium bursts, the bone
and dental evidence suggests that the main push towards
later sexual maturation came with the emergence of postHomo
erectus hominids. We know that the australopithecines
had a life history pattern similar to extant
great apes (i.e. "live fast and die young"). Early
Homo as well as Homo erectus/ergaster forms were unlike
either extant hominoids or modern humans. Both
dental evidence and cranial size evidence suggests that
they were exhibiting the early stages of what would eventually
become the modern human life history, as they
were aging slower, reproducing later, and living longer
than their australopithecine predecessors. There
are currently some difficulties understanding exactly
when the modern life history pattern evolved post-Homo
erectus but it is present in the Upper Paleolithic.
However, understanding when our life history evolved is
not the same as understanding how our life history evolved.
And for that we will need to explore Life History Theory
(LHT).