The lines of evidence for evolution

Grade 9 Science Worksheet - Challenge Me

Circle the best answer.

1. Read this first

   Use the table

   Tree: Four animals (model data). Tips, left to right: frog, lizard, ostrich, duck. Node Y joins frog and node X. Node X joins lizard and node W. Node W joins ostrich and duck. Evidence table beside the tree: early embryo features and percent of DNA letters that differ from the duck's.

   animal	early embryo gill slits and tail	percent of letters that differ from the duck's
   ostrich	yes	6
   lizard	yes	22
   frog	yes	33

2. 1.

   Ari reads the tree and the table. Which claim uses both the embryo column and the DNA column?

   • All share early embryo features, and the DNA ranks the frog as the duck's closest relative, since it differs most
   • The lizard is the duck's closest relative, since both have four limbs and the embryos match
   • All share early embryo features, and the DNA ranks the ostrich as the duck's closest relative
   • The embryo column ranks the animals, so the frog is closest to the duck

3. Front limbs of a model swimming animal (model data)

   rock age (million years)	front limb	bones
   50	walking leg	upper arm bone, two lower arm bones, digits
   35	paddle	the same bones
   20	flipper	the same bones
   today	flipper of a living swimmer	the same bones as the oldest leg

4. 2.

   Bo reads the fossil rows and the living flipper. Which claim uses both lines of evidence?

   • The flipper appeared at once, since the paddle and the flipper have the same layout
   • The fossils alone settle the flipper's history, so the bone layout adds nothing
   • The flipper and the leg are analogous, so the bone layout is just a coincidence
   • The leg changed into a flipper in steps, and the matching bones fit one ancestor

5. A model cave animal and two relatives (model data)

   animal	eyes	percent of DNA letters that differ from surface animal S
   cave animal C	small and sightless	3
   animal T	working	25

6. 3.

   Esme reads a table about a model cave animal C. Which claim uses both lines of evidence?

   • C's eyes are useless, so they add nothing to what the DNA shows about how C is related to S
   • C is not related to S, since the eyes of C and S look so different from each other
   • C's eyes are vestigial and its DNA is near S's, so its ancestors likely had working eyes
   • T is closer to S than C is, since T has the larger gap in DNA letters and so more kinship

7. Three wings (real facts)

   animal	wing job	wing built on bones	front limb bone layout
   bat	flying	yes	same overall layout as the bird's
   bird	flying	yes	same overall layout as the bat's
   honeybee	flying	no	not built on those bones

8. 4.

   Jun asks why bat and bird wings share bones while the honeybee wing does not. Which explanation fits?

   • Bat and bird bones come from a shared ancestor limb; honeybee flight arose separately
   • Bat and bird bones match because flying shaped them, so no shared ancestor is needed for either
   • The honeybee wing is much smaller than the others, so size decides which parts match
   • The three wings do the same job of flying, so the three came from one ancestor's wing

9. DNA comparisons of a pine, a frog and a spruce (model data)

   comparison	letters compared	letters that match
   one segment, pine and frog	20	18
   many segments, pine and frog	1000	380
   many segments, pine and spruce	1000	960

10. 5.

    Kira sees that one DNA segment of a pine and a frog matches in 18 of 20 letters. Which explanation fits?

    • Many segments are less reliable than one segment, since more letters add more chance of error
    • The pine and frog look nothing alike, so the DNA match must be an error in the data
    • One segment can match by chance in distant relatives, so compare more DNA and structures
    • The pine and frog are close relatives, since 18 of 20 letters is a match of 90 percent

11. Two model birds (model data)

    feature	flightless bird B	flying bird F
    wing size	small, too small to lift B	large
    wing bone layout	same as F's	same as B's
    use of the wings	help B keep its balance	flight

12. 6.

    Luz notes that the small wings of a model flightless bird B still have a use. Why can they be called vestigial?

    • They are leftover parts of an ancestor's wings; a use now does not change that
    • Small wings are analogous to flight wings, so they cannot be leftovers
    • A part with any use cannot be vestigial, so the wings are not evidence
    • The small wings are growing larger each year, so they are new rather than leftover

13. Notebook

    Notes on two model swimmers (classmate's notebook), 4 lines. Columns: line, entry. Line 1: Animals P and Q both have fins and smooth bodies for swimming. Line 2: Their DNA differs in 41 of 100 letters. Line 3: So P and Q must be close relatives, because they look so much alike. Line 4: DNA and early development should also be compared.

14. 7.

    Milo reads a classmate's notebook about two model swimmers. Which line has the mistake?

    • Line 1: swimmers cannot have fins and smooth bodies
    • Line 2: DNA letters cannot be counted as a percent
    • Line 4: DNA and early development do not matter when two animals look alike
    • Line 3: looking alike does not prove close kinship

15. Notebook

    Notes on three species (classmate's notebook), 4 lines. Columns: line, entry. Line 1: Species P, Q and R each have the same gene. Line 2: P differs from Q in 3 of 100 letters and from R in 18 of 100. Line 3: So R is the closest relative of P, because R has the larger difference. Line 4: A tree built from the DNA data would test the idea.

16. 8.

    Noah reads a classmate's notebook about three species and one gene. Which line has the mistake?

    • Line 2: 3 of 100 is a larger difference than 18 of 100 letters
    • Line 1: three different species cannot each have the same gene
    • Line 4: DNA data cannot be used to build a tree of relatives
    • Line 3: a larger difference shows a more distant relative

17. Notebook

    Notes on whale hind leg bones (classmate's notebook), 4 lines. Columns: line, entry. Line 1: Whales have small hind leg bones. Line 2: The bones do not help a whale swim. Line 3: So the bones say nothing about whale ancestors. Line 4: Land animals have leg bones in a matching layout.

18. 9.

    Pia reads a classmate's notebook about whale hind leg bones. Which line has the mistake?

    • Line 4: land animals have no leg bones, so there is nothing to compare
    • Line 2: bones in a whale's body help it swim, so this is wrong
    • Line 3: vestigial bones are leftovers that do say something about ancestors
    • Line 1: whales have no hind leg bones, because they have no hind legs

19. Two model gliders (model data)

    animal	glide surface	percent of DNA letters that differ from the other glider
    glider P	a skin flap between front and back legs	38
    glider Q	a skin flap along the ribs	38

20. 10.

    Tala judges a claim about two model gliders. Which claim and reason fit best?

    • The gliders are close relatives, since both glide in much the same way
    • The gliders are close relatives, since a 38 percent difference is a large one
    • The flaps are analogous and arose separately, since the builds and the DNA differ
    • The gliders are close relatives, since analogous flaps show a recent shared ancestor