Answers 1. oxygen levels in the atmosphere determine the maximum size of flying insects
2. the absence or presence of aerial predators influences dragonfly size
When are the data sets correlated and when are they not correlated? - Correct Answers -O2 levels first
half are correlated, but second half is not
-birds began to evolve and diversify at this second half
-a little later, their maneuverability improved
--alula feathers helped with steering
--pygostyl was a stiff tail feather that allowed for more controlled movement
What are the conclusions regarding the graphs about O2 and predators? - Correct Answers -high levels
of O2 during the carboniferous enabled insects to get so big
-later in earth's history: maximum insect size was constrained by predators and did not follow changes
in O2 levels
What does pO2 mean? - Correct Answers partial pressure of oxygen
according to the introduction, which variables influence in general the maximum body size of insects?
This is the list of potential explanations for the giant dragonflies, NOT the conclusions drawn. - Correct
Answers -oxygen concentration
-temperature
-evolution of the first birds
What type of data do the authors use to answer the question? Where did the data come from? - Correct
Answers They used prediction based off fossils and prior knowledge of how insects behave in hyper
oxygen conditions to predict the sizes of dragonflies through the history of their lifestyle. They used
charts and graphs to compare these findings.
, Describe you figure. Use your own words to explain the axes labels. - Correct Answers The x-axis is how
long ago (mya). The bottom y is atmospheric O2 and the top y is wing length.
what are the black bars in the top part? - Correct Answers the maximum size of every 10 million years
What do the top and bottom half of the figure show? - Correct Answers the top is wing length over time
and the bottom is atmospheric O2 over time
how do the authors use the data to come to their different conclusions? - Correct Answers based off of
the maximum wing length and how it lines up with the atmospheric O2 to draw correlations with size
and O2
how do the data support or reject the two hypotheses that we developed in class? - Correct Answers
when there was a strong correlation between the top and bottom, the O2 was likely the main influence,
but once the correlation stopped its likely predation took over
how would you now phrase the explanation for the size of the dragonflies during and after the
carboniferous? - Correct Answers the dragonflies were likely larger because of an increase in
atmospheric O2
new alleles - Correct Answers arise from random mutations
What is natural selection? - Correct Answers -the most fundamental process in biology
-all organisms: subject to natural selection; the result of natural selection
What are the shrikes birds called? - Correct Answers "impaler"
What is the important takeaway from the shrikes discussion? - Correct Answers simple because the
short-horned ones were just eaten by shrikes
study the horns lizard worksheet - Correct Answers