Lecture 9 1 How does childhood growth and age of sexual maturity differ between chimps and humans Chimps are born much smaller but their growth is more rapid than humans between 5 10yrs They are weaned at 5 yrs Reproduce at around 13yrs Live til 30 yrs Human are born larger but grow slower and for a longer period of time Weaned til 2 3 yrs Reproduce typically at 19 yrs Live til 55 yrs 2 What is mean expected adult lifespan after age 15 for chimps and humans After 15 yrs chimps have about 15 yrs left and humans have around 40 more years 3 Understand how to read a survival curve Proportion surviving vs age Chimps have a faster decline in comparison to humans 4 What is reproductive value at birth The total expected reproductive output of an individual over their lifetime given average survival and fertility rates through life 5 What is the probability of survival to age 70 for hunter gatherers Between 10 30 6 What is the typical difference between males and females in mortality rate What does testoterone have to do with this difference Males die at higher rates than females due to sexual selection Testosterone produces risky behavior which will in turn compromise the immune system 7 What is the main difference between male and female age specific fertility curves in humans Females show a 5 yr mean whereas males show a 20 yr mean Men can reproduce for a longer period of time because they don t give birth or have to breastfeed 8 What are 4 implications of the V equation 1 Anything affecting the future will be worth less in comparison to anything happening now 2 Anything that affects mortality early in the lifespan will have a large impact on fitness 3 Survival is not favored by NS near the end of a life 4 No future fertility means no selection pressure to survive 9 What is age specific reproductive value V x The expected reproductive total output from age x or the probability of surviving to each future age times the fertility expected at each of future age starting from age x 10 What are the two terms on the right side of the V equation that represent an evolutionary tradeoff for investment of energy Investment in current fertility and future reproductive value 11 Understand the 4 evolutionary implications of the age specific reproductive value 1 Evolve to value kin according to their reproductive value young adults mourn more severely 2 People should value themselves relative to other kin according to their own reproductive value adults should help children in places with high child mortality 3 Characteristics indicate low reproductive value should tend to lower one s value to kin abortion common 4 Females will be valued according to their Vx High Vx attractive to males 12 Know examples presented in class showing that fertility and survival represent an evolutionary tradeoff Humans who do not reproduce have longer lifespans Organisms with low predation rates have long lives 13 What is senescence The gradual deterioration of body function under optimal conditions all sexually reproducing organisms do this 14 Why do humans get old and die Because NS favors a life history that invests little in survival beyond a certain age x 0 Lecture 10 1 What is uniformitarianism The natural processes that take place now have always taken place in history 2 Know the difference between paleontology paleoanthropology archeology Paleontology remains of past life forms fossils skeletons etc Paleoanthropology studies of Hominins and primates environmental reconstruction Archeology material cultural products remains of human disturbance 3 What are artifacts ecofacts features sites and settlement systems Be able to recognize examples of each Artifacts objects produced by humans Ecofacts remains of human activity not intentionally produced fire ashes animal bones from food etc Features non portable evidence of human activity Sites collection of artifacts ecofacts and features 4 What are the three ways that living things and artifacts are preserved Sediments cover body and turn to stone natural preservation and carbonization 5 What is the chemical process of fossilization organic structures are partially dissolved and replaced by inorganic minerals fossils are rock not bone 6 What types of environments deter organic decay and lead to preservation of organic material After a volcanic eruption extremely cold summer hypoxic dry 7 Why do peat bogs preserve organic material Low amounts of oxygen which is used in most decaying processes 8 What 3 types of observations do archeologists use to make inferences about the past Morphology distribution in space distribution in time 9 What does level of sexual dimorphism tell us Social organization 10 What three types of points can be seen in the morphological progression of stone points in the Great Basin from the Paleolithic to the late pre historic Arrow Atlatl dart and spear Tools are getting smaller which indicates change in spear thrower to bow and arrow 11 What do we learn about hominin habitats from examining the distribution of known hominin fossils around the world Mainly lived in S and E Africa they are woodland savanna dwellers 12 What is taphonomy Study of animal remains at sites 13 Understand stratigraphy and the law of superposition Strat series of layers deposited by some geological processs Super objects on the bottom are older than objects on top closer in size means monogamy etc 14 What is the difference between absolute dating and relative associative dating Absolute fossil material is dated using physical and chemical rates Relative associations to provide a logical chain for dating 15 Know 5 types of absolute dating mentioned in class Radiometric decay isotopes change to other forms half life Fission track glassy materials contain amounts of uranium 238 this decays and releases which leave tracks Tracks can be counted to determine age Thermoluminescence substance is heated and electrons inside are released by measuring electrons they can determine the last time it was heated good for pottery or stone tools m Electron spin resonance measures number of trapped electrons mainly measures calcium limestone coral marine shells fossil teeth mollusks or egg shells Tree ring tooth enamel rings dendocronology counting rings on trees back a couple kya 16 Radiometric dating is based on what process What is an isotope 17 What is a half life What is the half life of C14 and K40 How long it will take half of an isotope to convert to another isotope C14 5730 years