Exam #2

Referring to specific features that you have recorded for the skulls, answer the following questions, making sure that you address all parts of each question.  When relevant, be sure to cite the actual specimens you studieddo not simply say, for example, the brain gets bigger or the forehead gets more vertical.  TL;DR:  Answer questions by using and referring to your actual data values. 
You may need to do a little additional research to answer some of the questions.  If you choose to use the internet as a resource, you MUST include the URLs of the sites you usedcite them!  Also, answers must be in your own words!  If your answers appear to be simply copied or paraphrased from an outside source, you will receive zero credit.
Your answers should be single-spaced and numbered/lettered by  (around 500 words).  Dont obsess over word count, just be sure to answer each question thoroughly.

1. In what ways are the most ancient early hominins specifically similar to modern apes (chimpanzee or gorillarefer to images of skulls in your lab book or online)?  How are they different?
2.  Describe the changes to the BRAINCASE through time overall by answering the following questions. 
a.) Which hominins begin to show an increase in the rear portion of the brain (with what species does the maximum width rise above the base of the skull)?
b.) Which hominins begin to show an increasingly vertical forehead (frontal bone angle), more than 45 degrees? 
c.) Which genus shows the biggest changes through time in post-orbital constriction (brains)? 
d.) Comparing these three trends, which appears to develop faster, the back or front of the brain?
3. a.) What changes in the Opisthion Index do you see through time?   Note that larger numbers indicate that the spine is located more centrally beneath the skull rather than slightly towards the back of the skull, and that the face is more orthognathic versus prognathic.
b.) How do you think this relates to type of bipedality (habitual or obligate)?  Look up these terms if you need.
4.  a.) What changes in the Cranial Capacity do you see through time?  Note the smallest and the largest by species
b.) What measurements did you get for the modern human versus Neanderthals?
c.)  Do you think your measurements were accurate?
5 a.) Which of all the species studied have a sagittal crest? 
b.) What does this feature indicate (what is it for)? What happened to this lineage?
6.  a.) Describe the trend in faces (prognathic/orthognathic) through time–which species start to become more orthognathic? 
b.) Do you see any similar trend in the nasal bones and/or brow ridges?  
7.  a.) Which species has the largest molar size and which species has the smallest molar size? 
b.) Which species has the least difference between premolars and molars?  Which species has the most?
c.) Hypothesize why molar sizes would be larger or smaller for the species you found them in. 
8.  What features would you say are the most different in modern Homo sapiens compared to previous species? 
9.  What features were the easiest to measure or describe?  Which were the most difficult?