**Optional (FL only).** Trends in human evolution

Grade 9 Science Worksheet

Circle the best answer.

2. 1.

   Ari measures how long H. erectus and H. sapiens overlap on the timeline. How many years is it?

   • 410,000 years
   • 190,000 years
   • 110,000 years
   • 0 years
3. 2.

   Bo reads the timeline. How many years separate the end of Au. afarensis from the start of H. habilis?

   Use the picture in question 1.

   • 900,000 years
   • 550,000 years
   • 1,450,000 years
   • 1,550,000 years
4. 3.

   Esme compares range lengths. About how many times as long as the 0.3 million years of H. sapiens is the range of Au. afarensis?

   Use the picture in question 1.

   • 12.8 times
   • 9.8 times
   • 0.3 times
   • 3 times

5. Read this first

   Three phases of brain growth (Smithsonian phases)

   phase	from (million years ago)	to (million years ago)	brain growth
   first	6	2	slight
   second	2	0.8	with body size
   third	0.8	0.2	fastest

6. 4.

   Jun reads three phases of brain growth. In which phase did brain size grow fastest?

   • In the third phase, from 0.8 to 0.2 million years ago
   • At one steady pace through the three phases
   • In the second phase, from 2 million to 0.8 million years ago
   • In the first phase, from 6 to 2 million years ago

7. Earliest evidence for four trends (Smithsonian dates)

   trend	evidence from (million years ago)
   walking on two legs	about 6
   stone toolmaking (sharp flakes for cutting)	at least 2.6
   handaxes	about 1.76
   color symbols (ocher)	by 0.35

8. 5.

   Luz compares two rows of the table. Which statement about handaxes and color symbols fits it?

   • Handaxes have evidence from about 1,410,000 years after color symbols
   • Color symbols and handaxes have evidence from the same time
   • Color symbols have evidence from about 1,410,000 years after handaxes
   • Color symbols have evidence from about 2,110,000 years after handaxes

9. Jaws, teeth and brains of three species

   species	jaw	teeth	brain size (cubic centimeters)
   Au. afarensis	long and projecting	larger	380 to 450
   H. habilis	less projecting than Au. afarensis	smaller	600 to 750
   H. sapiens	less heavily developed	smaller	1,130 to 1,260

10. 6.

    Noah reads the table from the top row to the bottom row. Which trend does it show?

    • Jaws became larger as teeth became smaller
    • Jaws and teeth became smaller as brains became smaller
    • Jaws and teeth became smaller as brains became larger
    • Jaws and teeth became larger as brains became larger

11. Average adult brain mass

    group	mass (grams)
    chimpanzee	384
    modern human	1,352

12. 7.

    Pia divides the modern human brain mass by the chimpanzee brain mass, to the nearest tenth. What is the result?

    • 3.5
    • 0.3
    • 2.5
    • 3.0
13. 8.

    Model tree (simplified, not to scale). Ren reads the model tree and its dates. What does node X stand for?

    • A bonobo that gave rise to the chimpanzee
    • The shared ancestor of humans and chimpanzees, about 6 million years ago
    • The shared ancestor of chimpanzees and bonobos, about 2 million years ago
    • The earliest chimpanzee, which the human line came from
14. 9.

    Tala looks for a species that was living at both 1.5 and 1.0 million years ago. Which species fits?

    • H. sapiens
    • H. erectus
    • H. habilis
    • No species, since each species ended before the next began
15. 10.

    Model tree (simplified, not to scale). Zee says humans came from chimpanzees. Which reply fits the model tree?

    • Right: the chimpanzee tip sits beside the human tip, so it is the ancestor
    • Wrong: node W is an earlier species, about 6 million years ago, that both lines descend from
    • Wrong: humans came from bonobos, which split off about 2 million years ago
    • Right: node W is a chimpanzee species that lived about 6 million years ago