> Lucy would have been a very poor hunter. She had no tools...
Without more luck than we seem to have had, only stone tools are
likely to have survived in the archaeological record from Lucy's time.
Yet interesting non-stone tool sets have been observed in many animals
with smaller brains, and lower ratios of brain mass to body mass, than
hers, so it is perhaps a little risky to rule out all tool use by
_Australopithecus_afarensis_.
Use of found or fabricated woody tools for various purposes is
widely reported in apes, in old-world monkeys, and in new-world monkeys
(Fossey; Fragaszy and Adams-Curtis; Goodall; Westergard; Westergard and
Fragaszy; and Beck, who in turn cites many authors). Nest-building is
well-documented in such primates as _Pan_troglodytes_ and
_Gorilla_gorilla_ (Goodall; Schaller, p. 213; Fossey, p. 47
etc.). _Pan_troglodytes_ and _Pongo_pongo_ both create simple rain
shields from leaves and twigs (Beck cites diverse sources on p. 104, and
on p. 75 cites MacKinnon (1971, 1974), Galdikas (1975, 1978) and
Rijksen). _Pan_troglodytes_ beats noisily on things as part of display
(Goodall, p. 112). _Pongo_pongo_ has been observed to use ad-hoc rafts
(following observation of human use of boats), and even to paddle (Beck,
p. 132, citing then-unpublished work by Galdikas). Should we not expect
artifacts and artifact use at least this complex from the generally
better-encephalized and closely related hominid line? (I am reluctant
to use the word "encephalized", for it suggests phrenology with a PhD:
It may only obscure great ignorance of how brain structure relates to
cognition.)
> ...she was
> slow, she did not have sharp teeth and her claws were a joke.
It is thought-provoking to realize that hominids are probably the
wimpiest mammals of their size in the entire Pleistocene. How did our
ancestors keep from becoming a popular and soon-extinct fast-food
selection? Behavior is a likely explanation, and even such simple
ad-hoc tool use as throwing rocks might have made a difference.
> Erectus was originally dated to less than 1.5 mill years. Now hes as
> far back as 4-5 million. Sapiens was once thought to go back only
> 20,000-40,000 years, yet it is now thought to date as far back as 100k
> to 150k, maybe even more.
I haven't heard of an _Erectus_ date earlier than about 2 million
years ago (mya). Do you have a reference?
There is a problem here with how people use words. The essence of
"species" as used by most biologists is reproductive isolation -- the
boundary of a "species" is the limit to which genes can mix by mating
(with plenty of caveats). Lacking a time machine, one cannot always
decide whether two populations of creatures that lived at different
times are one species, or two. People like to use the word "lineage"
instead. To understand what it means, imagine that you had a complete
and correct phylogenetic family tree showing the evolution of the
populations of creatures in which you were interested. (Usually you
don't have any such thing.) Slice the tree horizontally, and the number
of distinct cut surfaces you produce is the number of extant species at
that time -- that is, the number of extant species is the number of
distinct branches of the tree that pass upward through the given time.
(More caveats about what happens if a cut intercepts a speciation
process.) A "lineage" is a maximal interval on a specific branch,
between nodes -- a segment of the evolution of a population within which
no speciation events took place. That's not the same as saying that no
evolution took place, of course
Thus, if you happen to believe that no speciation event took place
in the lineage leading to _Homo_sapiens_ in the last two million years
(a controversial subject), you would say that we and the creature
commonly known as _Homo_erectus_ are on the same lineage, and you would
probably use the first-published of the two species names --
_Homo_sapiens_ -- to label that lineage. In that view, one could say
that the lineage of _Homo_sapiens_ was extant two million years ago.
Yet even if so, no one doubts that there are substantial physiological
differences between the members of that lineage who lived then, and
those who live now.
-- Jay Freeman, First Extropian Squirrel
References:
Beck, Benjamin B., 1980. _Animal_Tool_Behavior_, Garland STPM
Press. (This work is in part a catalog of behavior, with copious
references. It is fascinating, thoughtful, and humbling. I
occasionally cite cataloged behavior as, e.g.: (Beck, 1980, p. 29,
citing Hess).)
Fossey, Dian, 1983. _Gorillas_in_the_Mist_, Houghton Mifflin.
Fragaszy, Dorothy M., and Leah E. Adams-Curtis, 1991. "Generative
Aspects of Manipulation in Tufted Capuchin Monkeys
(_Cebus_apella_)", _J._Comp._Psych._ 105, 387-397.
Goodall, Jane, 1988 (revised; original 1971). _In_the_Shadow_of_Man_,
Houghton Mifflin.
Schaller, George B., 1964. _The_Year_of_the_Gorilla_, Ballantine.
Westergard, Gregory Charles, 1988. "Lion-Tailed Macaques
(_Macaca_silenus_) Manufacture and Use Tools", _J._Comp._Psych._
102, 152-159.
Westergard, Gregory Charles, and Dorothy Munkenbeck Fragaszy,
1987. "The Manufacture and Use of Tools by Capuchin Monkeys
(_Cebus_apella_)", _J._Comp.__Psych._ 101, 159-168.