Help
Options
Question
What are the five big Extinction events?
click to flip
Didn't know it?
click below
click below
Knew it?
click below
click below
Don't know
Question
How is extinction measured?
Remaining cards (74)
Know
retry
shuffle
restart
0:00
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.
Normal Size Small Size show me how
Normal Size Small Size show me how
Earth 150
Dino Extinction
| Question | Answer |
|---|---|
| What are the five big Extinction events? | End of the Triassic, end of the Permian, the late Devonian, and the end of the Ordovician. The come from Skarkovsky's data set. |
| How is extinction measured? | By how many fossils stop appearing after that point. |
| What is the most recent extinction and which is the largest? | The dinosaur extinction, or the Cretaceous, is the most recent and the end of Permian still stands as the largest. |
| Explain the fossil genera graph. | Graph answers questions about life on Earth and how long things live. It shows the distribution of geologic lifespans of genera. The graph is highly skewed--most genera have lifespans less than the mean. It is based on Seposki's work. |
| What is the avaerage lifespan of a genus? | Approx 20 million years |
| How often is life on Earth killed off? | Approx every 100 million years |
| What is life on Earth today the result of? How did mammals come to evolve? | Life on Earth is partly the result of natural selection and partly extinction filtering. Dino extinction paved the way for mammal evolution |
| Explain Gambler's Ruin and how it relates to extinction | It is a game simulation of normal gambling odds , which relates to extinction in that there is a hypothesis suggesting extinction could be related only to chance. The hypothesis was presented by David Raup (Good Genes, Bad Luck '92) |
| Which organisms have "broke the bank" and what does that mean? | There are so many species of insect and mammals that it is almost inconceivable that they will ever go extinct. |
| Explain the Kill Curve and where it is derived from | David Raup analyzed Seposki's data of fossil occurrences throughout geologic time and found that little extinctions (species kill of 5%) are common (approx every 1 million yrs) and big extinctions (species kill 65%) are rare (every 100 million yrs). |
| Who is Gene Shoemaker? | He related impact time (or spacing) to the size of craters |
| Explain the Impact Kill Curve, or Extinction-Impact Curve | David Raup used Shoemaker's data and combined crater impact data with the initial Kill curve. On the graph, the x axis changes from elapsed time to crater diameter. Graph statistically supports hypothesis that impact is responsible for extinction. |
| What kind of data would validate impact-extinction hypothesis? | Finding craters and precisely dating them so as to correlate with extinctions |
| Which extinction relates to an impact? | So far only the dino extinction is proven to relate to asteroid impact |
| Explain correlation vs. causality | Correlation may not indicated causality. With correlation, there is a mutual relationship between two or more things. With causality, one event is the consequence of another. Just because 2 things grow/decline @ similar rates, doesn't mean they're related |
| What is "First Strike"? | An event that lowers the population size below the minimum viable population making them vulnerable to extinction. Passenger Pigeon: A species doesn't have to be killed off in one day. It is enough to vastly reduce their numbers. |
| What species did not go extinct, but suffered from first strike? | The American Chestnut because of rising popularity of chestnut wood. Pigeon Passenger because of hunting and forest clearing. And, the Heath Hen |
| What were the physical causes of extinction? The traditional favorites? | Sea level change, climate change (which, would mean the Pleistocene should have had major extinctions), Species area effect (overcrowding), volcanism (super volcanoes), and exotic causes |
| Dispute other theories for extinction | Volcanoes were spewing millions of years before the asteroid hit. There was a climate change (warming than cooling) before the KT boundary that ended years after it. |
| What are Raup's 6 Principals? | 1) Species are temporary 2)Species with small populations are easy to kill 3)Widespread species are hard to kill 4)Extinction of widespread species favored by "first strike" 5) " " favored by abnormal stresses to species 6)simultaneous extinction of |
| What are Raup's 6 Principals? (continued) | (con't) species requires stresses that cut across ecological lines |
| How do the three types of extinction (Raup) operate? (field of bullets, fair game and wanton extinction?) | Field of bullets= what lives and dies is completely random (common things don't go extinct, here) Fair game= Natural selection in reverse. bad genes Wanton extinction: Cruel and unfair, bad luck |
| What are the two parts of the Alvarez Hypothesis? | 1) A major impact (comet or asteroid from outer space) occured precisely at the KT boundary. 2) The impact caused the KT extinctions. |
| What are the Alvarez hypothesis and tests? | 1)impact effects will be seen worldwide at the KT 2)Iridium is rare in most rocks, 3)iridium anomalies will be assoc. with impact craters 4)boundary clay will be thin and worldwide 5)find shocked minerals 6)enormous impact crater from 65mya will be found |
| Alvarez discovery? | On a trip to Italy, Walter found 1cm thick boundary clay denoting foram extinction, Iridium concentration 30xs that below & above KT |
| What is the estimated size of the asteroid based on Ir content? | 10kn diameter |
| What was the estimated speed of impactor? | 25km per sec |
| When was the Alvarez Hypothesis publsihed? | 1980 |
| What are examples of proven ideas that had to wait? | Aristarchus discovered that the earth rotates around the sun, Wegener introduced the theory of continental drift, and Mendel explained genes (dominant and recessive) |
| Why are there so few craters on earth? | Earth's surface is dynamic. There are oceans, vegetation and plate tectonics that make craters difficult to find. Small ones are common. |
| What are some new impact indicators and structures? | 1)Coesite and Stishovite-high pressure forms of quartz found at meteor crater 2)Tektites- teardrop shaped glass raindrops 3)shatter cones- point toward the center of an impact structure 4)spherules 5)nanodiamonds |
| What is Shoemaker-Levy 9? | A comet that broke apart and collided with Jupiter in '94. It was the first active impact that could be studied in space |
| Who is Bruce Bohor and what did he do? | Bohor discovered shocked quartz in Montana in 1981, proving that shocked minerals could be found worldwide. |
| What are Deccan Traps? | Large volcanic features in India (basalts) |
| What is the Chicxulub crater? | An impact crater discovered on the Yucatan Peninsula and extending into the ocean. Thick lower impact layer discovered in Haiti by Hildebrand in 1989. Estimated to be 260km in diameter. Surrounded by Cenotes (sinkholes) that trace out the impact ring. |
| More info on finding the Chicxulub crater? | Penfield and Camargo (in 1981) noted gravity and magnetic anomalies in northern Yucatan. Tsunami deposits were found in the Gulf of Mexico in the early 90s helping scientsts find Chix location. |
| How old are Haitian tektites, KT glasses and Chicxulub meltrock? | 65 mya |
| Name two advocates of volcanism | Officer and Drake claim shocked minerals, Ir anomalies and shperules were all from volcanoes |
| What is the importance of the West Bijou Creek in Colorado? | Stack of volcanic ash there can be dated to determine whre the KT boundary occured. (ir anomaly found in shocked quartz taken from ash) |
| Who is Joel Blum? | Blum performed zircon fingerprinting on Haitian glass and compared it to the Chicxulub rocks, discovering that the two matched in terms of 3 different isotopes: oxygen, neodymium, and strontium |
| What is Baptistina? | An asteroid family likely produced by the break up of an asteroid 160 mya following an impact with a smaller body. 65 mya one of the pieces impacted earth creating Chics crater leading to mass extinction (theory proposed in 2007) |
| What is the Signor Lipps Effect? | The more common an organism is, the more likely it is that their observed extinction matches its true extinction. Small organisms are more common (forams and pollen), and large organisms are more rare (dinos and mammals). |
| How can the Signor Lipps Effect be overcome? | Collecting a lot of samples. |
| Last straw for a sick world? | Is the idea that that the end of Mesozoic was a "sick world" and that dinos and other laugh forms were in decline before the impact, which was the last straw in gradual extinction. |
| What supports the idea of sudden extinction? | Peter Ward and the ammonites. At first, the last ammonite was 10 meters below the KT in Spain, but later more were found only inches below clay layer. |
| What do the plants show? | At first, land plant turnover seemed gradual but Kirk Johnson's thesis work showed 79% species extinction in Hell Creek. |
| What is the significance of foraminifera? | The cretaceous layer is white b/c of the abundance of dead foraminifera in it, but the KT boundary contains no white (foraminifera). Brian Huber did work that showed 97% of forams were gone. Keller claims foram extinction started before KT & lasted after |
| Why the Ocean drilling Program? | Done worldwide to study rock below the muddy sea floor. Most famous sample is from Blake Nose, FL were the KT boundary was intact |
| What is the significance of Blake Nose, Fl? | It is where the first intact piece of KT was found and distinctly shows the pre-fireball, fireball and post-fireball layers of KT. Dinos were in Hell Creek found 60cm of boundary and there werent any significant changes in species abundance. |
| What is the significance of Hell Creek? | It has the only rock formation that preserves that last 2 million years of dinosaurs. Dean Dean Pearson's work shows no decline in fossil diversity in this area prior to KT, which goes against the gradual extinction theory. |
| David Fatovsky's graph shows what? | Fatovsky tried to determine whether dinos went gradually or suddenly. Esimates that half of dino genera haven't been found. |
| What does the Stratographic Range show? | Dinosaurs virtually disappeared before the KT |
| What is the No Bone Zone? | A two meter are where there are no bones leading up to the KT boundary in the Hell Creek formation. Possibly caused by sea level rising which is bad for fossil preservation. KT triceratops (youngest dino)found in zone |
| Why bother with species conservation? | 1) Medicine-over half of top 150 prescription drugs come from wildlife 2)food 3)Services:flood protection, water purification, carbon storage, coastline stability 4)Scientific importance 5)Cultural/aesthetic importance |
| Historical abundance? | We live in an already depleted world, and its hypothesized that many species are extinct and remain undiscovered. |
| What is wrong with Charles Offier's theory on volcanoes? | Studies show that India's volcanoes reached their peak 500,000 yers before KT, volcanoes cant distribute impact products worldwide, volcanic sherules are angular not rounded, and balsatic volcanoes are not explosive. |
| What does volcanic activity tell us? | It tells us that the temperature before the extinction occurred was hot and then cold. |
| What are classic problems with the fossil record? | Fossilization is rare so there are gaps in the fossil record, and poor exposure of rocks, as rock layers require rearrangement |
| What was used to date the impact layer? | Iridium. The rate at which it fell to earth was known and the layer contained an abnormal amount. |
| Who suggested that dino extinction was part of a cycle of mass extinctions that occurred 26 million years? | Raup and Seposki |
| How many articulated dino bones have ever been found? | 2100. 1 specimen per 75,000 years |
| What happened to dino diversity nearing the extinction? | The species was becoming more diverse. |
| What is the double boundary layer? | A result of ejecta from the impact raining down in several pulses of material. Well preserved in some places and indicative of an impact. |
| What is ejecta? | Tektites and spherules and hot rock that rained down for hours following the impact that turned to glass and clay. |
| What was the climate like at the end of the Cretacous? | Hot, then cold |
| What is false syllogism? | a syllogism is a logical statement with two premises and a single conclusion, that can be true or false. Ex: all birds have wings; pigeons are birds; therefore all pigeons have wings. |
| Where does this quote come from: "For geologically widespread species, extinction is likely only if the killing stress is so rare as to be beyond the experience of the species" | David Raup's "Extinction: Good Genes or Bad Luck" |
| What is the significance of Gubbio, Italy? | It is the location of the rock where the Alvarezes found contrasting black and white layers. |
| How were insects affected by the impact? | Earth lost insects for approx 9 million years, because those that survived the impact lost their food source, plants. |
| Who called paleontologists just "stamp collectors?" | Luis Alvarez did during a speech in 1982 because according to him, they only collect fossils and put them in boxes |
| James Hutton is... | Known as the father of modern geology. His quote "no powers not natural to the globe" are from Night Comes to the Cretaceous |
| What is one popular hypothesis for the moon's formation? | A giant Mars-sized object impacting with the nearly formed earth sending material into its orbit. |
| What are shatter cones? | Rare geological features that form in the bedrock beneath meteor impact craters or underground nuclear explosions. |
| What are shocked quartz? | A form of quartz that form under intense but controlled pressure. They are evidence of an impact that could not have been generated by a volcano. |
| What are Sudbury, Vredefort, and Manson? | They are all large craters that predated the one at the KT boundary. |
Created by:
100002965767658
Popular Earth Science sets