anth 021 exam 3
What are the dental formulae generally for mammals, primates, strepsirrhines, New World monkeys, Old World monkeys, and apes?
2.1.3.3. - Lemurs 1.1.2.3. Toothcomb Incisors=1 Canine=2 Premolar=3 Molar=4 Homodontic- all teeth similar inform, sharp, and replaced continuously throughout life Heterodontic - different types of teeth present • Some specialized for chewing • One set of deciduous - baby or milk teeth are replaced by adult teeth as other mammal 1.Incisors - cuVng teeth in the front of the jaw 2. Canines - long sharp "dog-‐like" teeth 3.Premolars- more fla_ened teeth also called bicuspids 4.Molars - flat chewing teeth •Functional differences between teeth enable food to be processed before injection •Numbers and patterns of teeth are distinc>ve for different mammals. Primates are quite ancestral/primative compared to many other mammals.
How old is earth? Roughly how long did it take for multicellular life to evolve on earth? What are the relative timings of the major events in the evolution of animal life?
4.6 by life on earth occurred 3.5 by so it took 1.1 billion years to evolve Precambian (4.6-550 my) Paleozoic (570-230 my): Early life, origin of animals with complex body parts Mesozoic (230 my-66my): Middle Life, age of dinosaurs, first birds and mammals Cenozoic (66 my-present): New Life, age of mammals
What are the main groups of apes and how do we classify the great apes?
Guinness orangutan chimp human Grade: orangutan gorilla chimp human Genus and species for gorilla-gorilla Human - homosapians chimp - pan - genus 1) tryglo 2) panisus
How do differences in primate social grouping and reproductive behavior affect patterns of sexual dimorphism in the primate skeleton and teeth?
High sexual dimorphism suggests male-male competition for access to females
Compare and contrast the primate social systems discussed in lecture. Provide specific examples of primate groups that follow these systems. Make a table including the different systems, a description of each, and some examples of primate species that use each.
Primates are social primates
Explain the Principle of Faunal Succession and Law of Superposition. How are these ideas used in paleoanthropology?
Principle of Faunal Succession: (more ancient fossils tend to reside in the lower strata) different fossil species always appear and disappear in the same order and once a fossil species goes extinct, it disappears and cannot reappear in younger rocks Law of Superposition: the law states that strata that are younger will be deposited on top of older strata, given normal conditions of deposition (stratigraphy)
Where do the different major groups of primates live?
Prosimians and Anthropoids...
What do the differences in limb lengths tell us about primate locomotion?
Quadrupedal: fore and hind limb lengths comparable Bipedal: longer hind limbs VCL: longer hind limbs Brachiation: longer forelimbs
What are biostratigraphy and molecular dating? How does molecular dating work? What are the assumptions of each?
Relative method of dating that uses the associations of fossils in strata to determine approximate age Molecular clocks (dating) compare DNA sequences to judge evolutionary distance between groups, study mutation in mtDNA (genomic DNA) assumes mutation rate is constant
What is reproductive investment? Compare and contrast: the relative reproductive effort of male and female primates, in terms of mating effort and parental effort (pre- and post-birth), the general reproductive strategies of male and female primates, and male and female mate preferences.
Reproductive effort is defined as that proportion of the total energy budget of an organism that is devoted to reproductive processes. Reproductive effort at a given age within a species will be selected to maximize reproductive value at that age.
What is the theory of sexual selection? Know the two forces of sexual selection that Charles Darwin proposed? Compare and contrast contest competition (e.g., male-male competition) and mate choice (e.g., female choice). Be able to define sociobiology? How does sociobiology explain primate behaviors?
Sexual selection is a mode of natural selection in which some individuals out-reproduce others of a population because they are better at securing mates. The study of the biological determinants of social behavior, based on the theory that such behavior is often genetically transmitted and subject to evolutionary processes.
How do the characteristics of smell, vision, hands, fingernails, encephalization level (brain size and complexity), and locomotion pattern vary across primates?
Smell: reduced olfaction = Vision: increased Hands: grasping hands w/opposable thumbs Post orbital bar Post orbital closure Nails instead of claws Encephalization: Brain grows as it goes from lemur to human Locomotion: Ardo->Terr Lem->Hun/Quadru/Bipe (Non primates: divergent big toe - feet look like hands - climbing)
How does the tectonic drift impact world geography? What are the implications for primate evolution? For example, is the Atlantic Ocean presently getting bigger or smaller?
South America moved closer to africa, North America moved closer to Europe and Asia; ATLANTIC OCEAN GETTING BIGGER
What is the difference between phylogeny and taxonomy?
Taxonomy compares and illustrates similarities and differences whereas a phylogeny which shows the evolutionary relationships between organisms.
What is the basic structure of a long bone?
The diaphysis (shaft of the bone) grows from the center out toward the ends of the bone, epiphyses are separate bone growth areas on either end of the bone and fuse to the diaphysis to form one solid bone
What is the tooth comb, how many and which teeth are found in it, and which primates have one?
Together (dental comb): First incisor - Second incisor - Canine and Further back is called the Second Premolar Lemurs
What types of ecological information can be deciphered from the geological record? How do we know?
diets and habitats- known from chemical analysis of teeth and bones
What types of traits are used to construct phylogenetic trees?
Derived traits such as # of limbs or skull structure.
Know the seven geologic epochsof the Cenozoic. What is their order relative one another? What were the major event(s) in each epoch associated with primate evolution? For example: When was the first adaptive radiation of the first true primates? When was the initial adaptive radiation of anthropoids? What are the major climactic trends for each epoch?
7 Epochs of the Cenozoic Paleocene (66 Ma) - origin of primates, radiation of primate like mammals Eocene (56 Ma) - adaptive radiation of true primates and prosimians Oligocene (34 Ma) - adaptive radiation of anthropoids Miocene (23 Ma) - adaptive radiation of apes Pliocene (5 Ma) - adaptive radiation of bipedal hominoids Pleistocene (2.6 Ma) - Evolution of Genus Homo Holocene (10 Ka) - development of agriculture
What are clades and what are grades? What are the different ways species can be grouped on a cladogram?
A clade is a group of species with shared ancestral background and a grade is a group of species with shared derived traits.
What does a phylogenetic tree represent? What do the nodes represent?
A phylogenetic tree is a hypothesis that depicts the evolutionary relationships among groups of organisms; in detailed phylogenetic trees, nodes indicate when new species diverged from a common ancestor.
How do absolute and relative dating methods differ? Give examples of each. What are the respective advantages and limitations of these techniques? Explain Carbon14 radioisotope dating and how it differs from Potassium/Argon (K-Ar) dating methods. What is a half-life?
Absolute dating gives a specific date for the fossil (i.e. radioisotopes C14 dating) but relative dating just lets you know which fossil is older/newer relative to another fossil.
What is an adaptive radiation?
Adaptive radiation is a process in which organisms diversify rapidly from an ancestral species into a multitude of new forms, particularly when a change in the environment makes new resources available, creates new challenges, or opens new environmental niches.
What are the potential costs and benefits of group living (sociality)? What models have been proposed to explain the evolution of primate groups? Be able to explain the basic ideas of these models. What are some different strategies used to ameliorate conflict within groups?
Benefits to sociality include resource acquisition and defense and decreased vulnerability to predators. Costs to sociality include competition over food and mates, increased vulnerability to disease, and increased hazards from conspecifics (e.g., cannibalism, cuckoldry, incest, or infanticide). Primatologists are divided over whether between-group feeding competition or predation is the primary factor favoring sociality in primates.
Why are tarsiers difficult to classify taxonomically? Where do they live? Which is cuter a tarsier or an aye-aye? What ecological niche does the aye-aye fill?
Best living examples of what early primates were like -
What are fossils? What types of information can they preserve?
Bones that are replaced by rock or are mineralized. Impressions are of soft body parts i.e. brain, feathers. They can preserve skeletal and dating information.
How has our increasing brain size affected our skeleton with respect to bipedalism?
Brain size increased and body increased
What are the characteristics of haplorhines?
primates Haplorhines share a number of derived features that distinguish them from the strepsirrhine "wet-nosed" primates (whose Greek name means "curved nose"), the other suborder of primates from which they parted in evolution some 63 million years ago. The haplorhines, including tarsiers, have all lost the function of the terminal enzyme which manufactures vitamin C, while the strepsirrhine prosimians, like most other orders of mammals, have retained this enzyme and the ability to manufacture vitamin C. The haplorhine upper lip, which has replaced the ancestral rhinarium found in strepsirrhines, is not directly connected to their nose or gum, allowing a large range of facial expressions. Their brain to body ratio is significantly greater than the strepsirrhines, and their primary sense is vision. Haplorhines have a postorbital plate, unlike the postorbital bar found in strepsirhines. Most species are diurnal (the exceptions being the tarsiers and the night monkeys).
What are the characteristics of strepsirrhines?
primates Strepsirrhines are a suborder of primates that includes the lemuriform primates, which consist of the lemurs of Madagascar, galagos ("bushbabies") and pottos from Africa, and the lorises from India and southeast Asia
What are the characteristic features of mammals? What are the characteristic features of primates? What are the major adaptive trends of primates?
primates are mammals
What are the two major taxonomic divisions of primates?
primates include prosimians and simians
