Study Guides (238,069)
Canada (114,906)
Biology (441)

Biology 1M03 notes for Test #2.docx

11 Pages
Unlock Document

McMaster University
Richard B Day

Biology notes for Test #2 Chapter 10- From Hominoid to Hominin  6 million years ago, climate, geographic change led to the evolution of hominins: cooling, less rain, rain seasonality, woodland and savanna spread  Hominae- clade containing gorillas, chimps and humans  What it takes to be a Biped: skull (position of foramen magnum determines if something walks on 2 or 4 legs), spine (lumbar lordosis), pelvis is short and stout, pelvis abductor mechanism (balance), femur (long femoral neck and cortical bone distribution (nonuniformly), bicondylar angle of the knee (balance), foot and ankle have a none grasping big toe and arches.  Between 7 to 5 mya, the common ancestor of chimps and humans roamed the Earth  At the Beginning, some of the ancestors of humans: 1. Sahelanthropus was found in Chad, Africa and was dated at about 6-7 million years old. Features: foramen magnum suggests bipedality, chimpanzee-sized brain, small canines, flat face and large browridge. 2. Orrorin was found in Kenya, Africa and was dated to be about 6 million years old. Mix of woodland and savanna habitat, femur suggests bipedality and teeth are chimpanzeelike. 3. Ardipithecus kadabba was found in Ethiopa, Africa and was dated to be about 5.2-5.8 million years old. Features: toe bone suggests bipedality, canine sharpens against lower premolar. 4. Ardipithecus ramidus was found in Ethiopa, Africa and was dated to be about 4.4 million years old. Woodland habitat, bipedal based on the features of his skull, pelvis and foot. Climbing is based on hand, feet and pelvis; as well as a small brain and small canines.  Many different hypotheses as to why hominines have evolved to walk on two legs  Additional species of human decent: 1. Australopithecus anamensis- Found in Kenya and Ethiopia of Africa and was dated to be about 3.9-4.2 million years old. Habitat in a grassy woodland environment, bipedal (tibia bone) and canines are smaller than modern apes. 2. Australopithecus afarensis- Found in Ethiopia, Tanzania and was dated to be about 3-3.6 million years old. Habitat in a woody grassland; contained smaller canines, larger molars than Au. anamensis, bipedal, partial skeleton of Lucy (actual specimen) and the body size is of dimorphism. 3. Australopithecus africanus- Found in South Africa, cave deposits; was dated to be about 2.2-3 million years old. Habitat was in the woody grassland and some of its bony features were: cranially similar to Au. afarensis, bigger molars and smaller canines. Also was bipedal and had rapid tooth development. 4. Australopithecus garhi- Found in East Africa, was dated to about 2.5 mya and its bony features were: a small brain, sagittal crest, large teeth, possibly longer legs and possibly had stone tools. 5. Australopithecus sediba- found in the Malapa Cave in South Africa, being dated from about 1.8-2 mya; bony features are: small brain, small teeth, long arms, primitive foot as well as derived pelvis and hands. 6. Paranthropus boisei- The Robust Australopiths- cranial adaptations= enormous back teeth, sagittal crests, large temporalis muscles, huge cheek bones (zygomatic arches) and was bipedal. Was dated to be from about 2.5 mya in Kenya, Tanzania and Ethiopia. Also they ate seeds, tubers and roots. 7. Paranthropus robustus- found in South Africa from about 1-1.8 mya; contained cranial and dental adaptations for heavy chewing, bipedal and extended growth in males. 8. Paranthropus aethiopicus- found in Kenya from about 2.5 mya 9. Kenyanthropus- found in Kenya from about 3.2-3.5 mya and contained many features such as: small bones, flat face and small molars.  What are the differences from phylogenetic trees that we have encountered before? Answer: scale, a lot of question marks, dashed lines, Homo heidelbergensis (usually marked with a node= common ancestor is unknown). Chapter 11- Oldowan Toolmakers and the Origins of Human Life History  The Origins of Tool Use- tools found within the environment, using tools is ancient in our lineage (many modes of tool use)  The Oldowan Toolmakers- flakes, hammer stones and cores used to create tools (mostly made by a right handed individual). Earliest evidence of this is from Dikika from about 3.4 mya as well as Gona (first tool made) from 2.5 mya.  Complex Foraging Strategies in Humans- food resources= collection of food such as fruit and leaves; extracted food such as termites, honey and tubers; hunted food such as vertebrate prey.  Methods of food acquisition: Figure 12-3  Human Foraging- hunting, tuber extraction, hard to acquire food which acquires hard to learn skills (promotes a long juvenile period).  Division of Labor- men: hunting, women: extractive foraging  Food Sharing: Chimpanzees- mothers with infants, meat sharing (small prey usually not shared, large prey shared with other members of group).  Human Food Sharing- food sharing and division of labor in humans: juveniles are consumers, middle aged men and postmenopausal women are producers.  Extractive foraging and hunting require intelligence and learning= large brain, long juvenile period, increased longevity, paternal investment and reduced dimorphism (less competition).  Meat eating favours food sharing  Archeological Evidence for Food Procurement- tools being used for a variety of tasks, including large game butchery; wear patterns on bone tools were used to evacuate termite mounds.  Tool Modes: Mode 1- carcass butchering, digging sticks; South Africa used bone tools for termite extractive foraging. Evidence for meat eating is the concentrations of butchered bones and tools. Stone tool versus teeth markings on bone (determine what they used to take the meat off of bone to eat= hunting: tooth marks on top of cut marks and Scavenging: cut marks on top of carnivore tooth marks).  Scavenging- is just as difficult and dangerous as hunting is; most of the large mammalian carnivores practice hunting and scavenging (humans may have stolen kills from carnivores).  Oldowan toolmakers had home bases; modern foraging societies (also a butchering site; safe and away from predators) Chapter 12- From Hominin to Homo  Origins of Homo- approximately 2.3 mya, Africa, larger brains, smaller teeth, Australopithecus limb proportions and rapid development.  Early Homo- Homo habilis: about 1.4-2.3 mya, East and South Africa  Homo ergaster- evolved from early Homo (after coolings in temperature), about 0.6-1.8 mya  Homo eragster Morphology- skull, Ancestral: postorbital constriction, no or less pronounced chin, receding forehead; Derived: less proganthic, larger brain, smaller jaws and teeth; Unique: brow ridge, occipital torus, long legs, narrow hips, barrel chest, modern human body proportions, reduced sexual dimorphism, terrestrial biped and has less of a diaphragm= limited speech.  Note the importance in the differences in genus between the Homo ergasters and the Homo sapiens.  Between 1.6 and 1.4 mya, H. ergaster improved on Oldowan tools and added the Mode 2 of tools (technological innovation)= the first standardized tools  Mode 2 tools- biface (hand ax), specifically designed, unchanged for 1 million years  Evidence that H. ergaster ate meat includes the abnormality of the bones of the women; the ubiquity of hand axes, cut marks in animal bones from stone tools, the dental morphology and intestinal parasites (didn’t cook the meat they ate). Hunting or scavenging the meat? Unknown  Vitamin A poisoning- by digesting the liver of a prey (rich in Vit. A) and cause abnormal bone growth  H. ergaster- could likely control fire  Between 1.8-1.2 mya H. ergaster started to leave Africa and migrated as far as the Caucasus Mountains; they were the first taxa to leave Africa.  H. ergaster was related to H. heidelbergensis  Homo erectus- discovered in the late 1800s, first fossil evidence for an ape-human transitional species  Found in Java, Indonesia, dating to between 1.8 and 1.6 mya  Cranial differences: thicker skull, more massive face, more pronounced occipital torus and brow ridge and sagittal keel.  Mode 1: in most localities; mode 2: present in rare circumstances (possibly bamboo tools)  Homo ergaster in Africa and western Eurasia was related to Homo heidelbergensis= large brain, large brow ridge, , no chin and prognathic face.  Homo heidelbergensis Tool kit- large game hunting= spears, butchered animal bones; diversity of food resources; mode 3 technology= prepared core technique.  Homo florensiensis (the “hobbits”)- found in Flores, Indonesia about 16- 74 kya, small bodied (3 ft tall), small brained and used sophisticated stone tools  Neanderthal World- fluctuating environment, cooling trend, Eurasia, frigid grassland and many large mammals  Anatomy- large brain (larger than Homo sapiens), oblong skulls (occipital bun, thin- walled bones), unique teeth (taurodont roots= more pulp in tooth and heavily worn incisors= used for more than just eating), short, stocky, more robust limbs with better developed muscle attachments, wide torso, short arms and legs.  Mode 3 tools- Mousterian (flint stone tools), large game hunters  Intelligence- caves as home bases but no shelters, burial of dead, personal ornaments (cultural evolution)  Life of Neanderthal- short life span, difficult lives (arthritis, gum disease, injuries and caring for the injured).  Homo heidelbergensis is related to Homo sapiens in Africa about 200,000 years ago (some overlap with living Neanderthals)  Replacement of one hominin species by another; rests on the ideas of climate change and adaptive radiation  Hominins split into several new species as they migrated out of Africa during the Pleistocene  1-4% DNA in Europeans and Asians is shared with Neanderthals= mtDNA is unshared between Neanderthals and m
More Less

Related notes for BIOLOGY 1M03

Log In


Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.