question
Species may become extinct for many different reasons. Brainstorm with your group and list five different factors that might cause a large number of species to become extinct
answer
1. Drought2. Invasive species3. An Increase in a rival species population4. Human interference5. Climate change
question
According to Model 1, approximately how long did each of these eras last?
answer
Ordovician, Devonian, Permian, Triassic, Cretaceous
question
The line on the graph is never flat. What does this tell you about the rate of extinctions over time?
answer
Extinctions are always happening, and the rate of extinction never spikes or dips
question
To what does the y-axis on the graph in Model 1 refer?
answer
Total Extinction Rate Per Millions of Years
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question
The line never reaches zero. What does this tell you?
answer
Extinction has and will always be happening.
question
What are the names of the three eras identified on the x-axis in Model 1?
answer
Paleozoic, Mesozoic, Cenozoic
question
Every mass extinction leads to the rise of prominence of new groups of organisms Using resources from the internet, research what type of organisms were dominant after each of the five mass extinctions
answer
Triassic- Therapsids & ArchosaursOrdovician- trilobites, brachiopods, corals, and more marine life Devonian- conodonts & TrilobitesPermian- Therapsids, Archosaurs & ReptilesCretaceous- Alligators, Crocodiles, Birds, Lizards & Salamanders.
question
What is the source of the data collected to produce the graphs used in this activity?
answer
Paleontoloy and ecology records
question
In light of your group's answers to the previous questions, what would you predict to be the long-term result of a sixth mass extinction?
answer
The loss of many animal species and mass climate/ecosystem change
question
Look at your group's answers to Question 10. Were any of these explanations given in the Read this! box also on your list? If not and them now.
answer
Yes, Climate change
question
What appears to be one criterion that scientists use when defining the timing of geologic periods?
answer
Scientists tend to base periods off of when extinctions occur
question
List the period in which each mass extinction begins and ends
answer
Mass Extinction 1 begins in (Ordovician) and ends in (Silurian)Mass Extinction 2 begins in (Devonian) and ends in (Carboniferous)Mass Extinction 3 begins in (Permian) and ends in (Triassic)Mass Extinction 4 begins in (Triassic) and ends in (Jurassic)Mass Extinction 5 begins in (Cretaceous) and ends in (Paleogene)
question
Circle the five major mass extinctions on the graph in Model 1
answer
Circle the 5 largest spikes on Model 1
question
The letters below each era refer to discrete time periods that are listed in the table below. Complete the columns to indicate the approximate length of time each period lasted. (Part 3)
answer
CenozoicP: 65.5N: 23.5
question
The letters below each era refer to discrete time periods that are listed in the table below. Complete the columns to indicate the approximate length of time each period lasted. (Part 2)
answer
MezoicT: 251J: 200C: 145
question
The letters below each era refer to discrete time periods that are listed in the table below. Complete the columns to indicate the approximate length of time each period lasted. (Part 1)
answer
PaleozoicE: 542O: 488S: 444D: 416C: 359P: 299
question
According to Model 1, approximately how long did each of these eras last?
answer
Paleozoic: 2,799 Million YearsMesozoic: 596 Million YearsCenozoic: 89 Million Years
question
What data could you collect that would support the idea that we are currently at the start of the sixth mass extinction?
answer
The number of species populations now and how it compares to past generations
question
Many biologists propose that we are currently in a sixth major extinction. If this is true, this mass extinction event may be the first caused by one of the earth's inhabitants, humans. What human action do you think may cause this increased rate of extinction today?
answer
Pollution of ecosystems
question
Predict what wold have happened if all of the early mammals living 66 million years ago had died out in the cretaceous mass extinction
answer
No mammal species would exist today, including humans.
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What evidence do you see from Model 2 that large scales adaptive radiation occurred following the five mass extinctions?
answer
There is always a large recovery in number of families shown in Model 2
question
How did the extinction of the dinosaurs allow the adaptive radiation of mammals to occur
answer
Mammals had less predators to worry about, allowing them to increase in population.
question
Propose an explanation for why small rodents were able to survive the Cretaceous mass extinction.
answer
When other species decreased during the cretaceous extinction, this left room for small rodents to rise and thrive.
question
Using the graph in Model 2, estimate how long it takes for the number of families to recover after a mass extinction
answer
Between 400 & 20 million years (150 million years average ish)
question
What is the Immediate effect of mass extinctions on the number of families of organisms?
answer
It decreases the number of families dramatically
question
On the graph in Model 2, mark the location of the five mass extinction events depicted in Model 1 with arrows
answer
On Graph 2, draw arrows where the 5 mass extinctions were on model 1. (Use the answers from question 6 for help)
question
The number of families of organisms is an indicator of biodiversity. Looking at the graph, what can you conclude about the biodiversity on Earth over the time period shown?
answer
It has increased over time
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What is the overall trend shown in the graph in Model 2
answer
a plateau during the Paleozoic era and a slow climb at the beginning of the mesoic era
question
How is the dependent variable in Model 2different from that in Model 1?
answer
Its the number of Families instead of individuals
