DD: my response to: "No aquatic apes in Morris, Minnesota"
PZ is up in Morris, MN, which is just to the left of the famed big "C" of lakes (see map) that make up the majority of the "Land of 10,000+ lakes". Morris happens to be on a railroad line and at the intersection of a bunch of highways, so there's plenty of traffic, otherwise it'd be just another farm town (with a fabulous university).
Before the days of the locomotive and wheeled vehicles, and before the bow and arrow and atlatl were developed, and before horses were domesticated, humans could travel by foot or by dugout. Dugouts provided relatively safe access to remote inland areas where the big cats were kings and (waterways where) crocs and hippos resided. Before the development of the dugout, the most successful inland hominids were those that could climb above the cats and crocs, which is why the inland (apes)/apiths had curved phallanges and ancient Homo didn't.
Dugouts allowed easy access to extra weapons including slingstone pebbles used as ballast and spears used as push-poles, heavy cumbersome tools to carry by foot but easily by boat. Travel and trade eventually expanded from coastal settlements inland. Before dugouts, the inland was a dangerous place for a hominid that couldn't climb well or run fast and had only thrusting spears.
Dugouts, originally crafted by butted handaxes from waterside bent hollow tree trunks, were the first (cargo capable) "pickup trucks", and are still used worldwide in a more engineered form. A fisherman in one caught a coelecanth off the beach in Sulawesi in May. Ribbed watercraft (birchbark canoes, plank boats, umiaks) came later, partly due to the need for portaging.
Dugouts were the transitional technology enabling a coastal hominid (family) to move upstream and inland (w/o climbing adaptations), changing from daily diving and plucking sessile seafoods (where hydrodynamics were significant) to more terrestrial hunting and "dry" fishing using nets and spears.
I see no reason to think that acacia would have been chosen over other waterside trees for early dugout construction, though it may have been used later if others were unavailable, perhaps with fire to core it out.
(contributed by Lee Olsen at Sci.Anthro.Paleo)
A team of Spanish archaeologists, led by Dr. Manuel Dominguez-Rodrigo, from the Complutense University of Madrid, found residues of wood on the working edges of stone handaxes found in the region. The stone tools also show clear damage due to having been used in heavy-duty
activities. These important findings push the appearance of human woodworking back by 1 million years, and will be reported in the April/May issue of the Journal of Human Evolution. "This is the oldest evidence of woodworking in human evolution," said Dominguez-Rodrigo. "The remains belonging to Acacia trees are proof that early humans had wooden utensils, such as spears and digging sticks, which very likely enabled them to have the technology necessary to become successful hunters."
The area of Peninj contains some of the oldest archaeological sites in
the world with Acheulian tools. Most of the fossil fauna discovered by the Spanish team belong to animals that suggest a very open and dry savanna environment. Equids (like modern zebras), antilopini (like modern gazelles) and alcelaphini (like modern wildebeest) constitute most of the animals discovered. The fossil pollen discovered also indicates a very open landscape dominated by grasslands and a smaller number of trees among which Acacia is the best represented. Some plant residues discovered (called phytoliths) show that the type of grass most represented is a short grass that grows in very open and dry ecosystems."
DD: As might be expected, acacia for push-pole thrusting spears. Whether acacia was used for crafting (early) dugouts is much less certain. Cutting soft wood would presumably leave less traces than hard wood on handaxes. Push-pole thrusting spears would be a consumable disposable
item, easily replaced, a dugout less so. Thanks for the confirmation Lee!
Diving (My response to Seth's Human evolution post)
I agree with much of the AAT, but see it as part of life in a generalised coastal tropical habitat. Occupational specialization in later humans fits with my interpretation of butted hand axes as both butchering tools and woodcrafting tools used to construct the first dugout boats from hollow bent trees at waterside. These dugouts were the 'first cargo pickup trucks on the aquatic superhighway" that allowed trade and settlements upstream inland in areas formerly
dominated by the big cat predators, and allowed relatively safe easy transport of people including babies, with slingstone pebbles as ballast in the bottom for stability, and push-pole thrusting spears propelling and spare throwing spears bunched aside like arrows in a quiver. Further development of boats included thinner lighter dugouts and later portageable ribbed skin kayaks, birchbark canoes and plank sailboats on the sea of galilee 20,000 years ago.
The words Tectonic, Technical, Technology have the root Tek, which is Greek for carpenter or craftsman. I think it derived from the sound of stone "tick-ticking" against stone to make a hand axe and other simple tools. Other languages around the world have similar sounding words for crafting tools, which suggest great antiquity. (Chip or chop are other variations of it.)
The hand in primates (and even more in anthropoids) was selected for plucking loosely hanging fruits in angiosperm trees, which had previously been the long held domain of fruit bats and frugivorous birds. Plucking allowed the changes in the jaws and dental structure,
which allowed the brain to enlarge later.
This combined with greater vertical climbing and posture produced a more stable bipedal locomotion, as seen in the gibbon and spider monkey. Bipedal wading doesn't cause dry land bipedalism (see wetland apes which wade on 2 legs but walk on 4, while gibbons are bipedal on the ground but never wade), but it does reinforce an already bipedal habit.
Most likely the combination of fruit tree climbing, wading for molluscs in mangroves, shore cliff climbing for seabird eggs, coconut palm climbing, beachcombing for turtle eggs, vertical floating (with inflated laryngeal air sac) while plucking aquatic vegetation all combined to further the upright stance in hominoids and resulted in the complete loss of the tail. Later, the ancestors of the Great apes expanded inland along gallery forests staying arboreal and becoming more quadrupedal when on the ground, while ancient Homo erectus improved swimming and changed from vertical floating to horizontal backfloating (losing the lar. throat air sac but gaining a layer of skin fat) resulting in greater hydrodynamic linearity, thermoinsulation and oxygen breath holding abilities and becoming a more adept diver for shellfish and crustaceans.
I envision them diving as male-female pairs alternating dives, while the younger males acted as area patrol guards/gangs (also competing for deeper diving/spearfishing, tree climbing for coconuts and figs, and various small game hunting) and younger females as babysitters and
beachcombers at the shore. Later the use of hollow logs and driftwood as floats in waters with crocs or sharks began the emergence of the most primitive vehicular industry, shells pebbles and stone tools used to make simple dugouts.