ANTH 1013 1st Edition Lecture 21Outline of Last Lecture I. Ostodontokeratic cultureII. Homo habillisIII. Homo rudolfensisIV. Stone toolsV. ParanthropusVI. Homo erectusOutline of Current Lecture I. Homo erectus/ergasterII. Acheulean toolsIII. The Savanna hypothesisIV. Why is Homo erectus/ergaster the first out of Africa?V. What happened between 1.8 mya and today?VI. AnatomyCurrent LectureI. Homo erectus/ergasteri. Found outside Africa!ii. If the division between H. ergaster and H. erectus is real, then H. ergaster is slightly earlier and more primitive anatomicallyiii. Its not a simple geographic split (see Dmanisi specimens)a. Dmanisi – Republic of Georgiaiv. Why is H. ergaster/erectus the first out of Africa?a. Technology? Anatomical changes? Subsistence?II. Acheulean toolsi. Acheulean stone tools – used for a very long timeii. Found in Africa, none in Asiaa. Hand axe – tear-dropped shaped iconic tool of the acheuleanb. Core-based – made from a core, not a flakec. Bifacial – has 2 distinct sides1. Bifaces are new addition to the stone tool kitiii. Acheulean tools don’t appear until 1.7 mya, which is after the migration out of Africaa. Technological changes in stone tools cant be the explanation for H. erectus/ergaster expansion out of AfricaThese notes represent a detailed interpretation of the professor’s lecture. GradeBuddy is best used as a supplement to your own notes, not as a substitute.1. The earliest populations out of Africa have Oldowon stone tools2. The Acheulean never made it to Southeast Asiaiv. Increased reliance on animal protein?a. Need tools to eat more meatIII. The Savanna hypothesisa. Early idea that the shift to bipedalism was a response to living in an open habitatb. This hypothesis cannot be correct, savannas didn’t really exist in the early Pliocene or late Miocenec. Cannot be correct because the earliest hominins were living in and exploiting woodland habitatsd. So, hypotheses for the origin of bipedalism that require a savanna environment are rejectede. However, adaptation to savanna habitats may play an important role in nichediversification of hominins <2 million years old1. Paranthropus boisei (C4 rich diet)2. Homo erectus/ergaster (large body size, lean body form, tool use, meat eating, range expansionii. H. erectus and the Savanna hypothesisa. Studies have shown that human bipedalism is more energetically efficient than quadrupedalism or bent-hip, bent-knee bipedalismb. Bipedal posture reduces exposure to the sunc. Large animals have larger home ranges and lower population densities (more spread out)d. Carnivorous animals tend to have larger home ranges1. Resources are not clumped like fruits in a treee. Homo erectus/ergaster was not a pure carnivore, but certainly ate meatiii. How did they acquire meat?a. If they were hunting, there’s a big problem1. No claws or big canines to kill with2. Can’t outrun a quadruped anyway3. They didn’t have stone-tipped projectile weaponsa. No bows and arrowsb. No spears with stone tips4. Maybe they had wooden spears?5. How do they get close enough to an animal to kill it?b. Endurance running1. Homo erectus/ergaster would have been the first hominin capable of endurance running2. Permits a type of hunting known as persistence huntingiv. Sweating and hair lossa. Humans are “naked sweaty apes.” Why? 1. Losing body hair allows you to effectively use evaporative coolingv. H. erectus/ergaster footprintsa. Like you would expect from the postcranial skeleton of the “Turkana Boy,” they are like modern humansb. Stride length and foot size indicate a walking speed and stature like modern humansvi. The savanna hypothesis is a good fit for homo erectusa. Selective pressure on the savanna favor large body size and obligate bipedalism1. Exposure to the sun2. More predators3. Larger home range4. Persistence huntingIV. Why is H. ergaster/erectus the first out of Africa?i. For over 4 million years hominin evolution was confined to Africaii. What changed?a. Likely has to do with the niche of homo erectus/ergasterb. Development of the hunter/gatherer, or at least a scavenger/gatherer, lifestyleiii. H. erectus/ergaster was not tied to any particular dietary item, it had a broad dietary nicheiv. Big Picturea. Human-like in so many ways1. Anatomically2. Behaviorally (hunter/gather or scavenger/gatherer)b. First hominin to have a “global” distribution: an ecological generalistc. Now we need to focus on its phylogenetic roleV. What happened between 1.8 mya and today?i. H. erectus/ergaster was the first to colonize Europe and Asiaii. Theres evidence for continuous occupation since that colonization occurrediii. Between H. erectus/ergaster and us there is a profusion of types of Homoa. Referred to as the “Muddle in the middle”iv. Homo heidelbergensisa. Found in Zimbabwe, Ethiopia, Greece, France, Spainb. “Denisovans” – different from anything we’ve seenc. Are all the things regional populations of a single widely dispersed species?1. It all comes down to gene flowv. Gene flow and the muddle in the middlea. With a road distribution over the Old World for nearly 1.7 million years, populations could become isolated, cutting off gene flowb. The situation is perfect for local populations to form and diverge from one another phenotypicallyc. Was one, all, or some of those regional populations our ancestor?vi. Multiregionalisma. Migration and interbreeding between:1. Europeans + Africans2. Africans + Asians3. Asians + Australasiansb. Gene flow has been occurring between populations of Homo for the last 2 million yearsvii. Replacement/ Out of Africaa. Homo sapien species migrates out of Africa and replaces all prior Homo speciesb. Modern humans originate in Africa as one of the regional descendants of H. erectusc. This replacement occurred without interbreedingd. Geographical variation is a recent developmentviii.Multiregionalism vs. Replacementa. Both scenarios acknowledge that modern human populations are phenotypically variableb. Multiregionalism predicts that variation has a deep origin in timec. Replacement suggests that variation is recent and that all populations should indicate an origin in Africaix. How do we know which model is correct?a. To figure out who’s right, were going to use 2 sources of information:1. Anatomy: If Multiregionalism is right then we should see features of the “archaic” populations in people living in the same places today (Neandertal