The lines of evidence for evolution

Grade 9 Science Worksheet

Circle the best answer.

1. Read this first

   A card about a flightless bird (real facts)

   feature	what is found
   kind of bird	a bird that does not fly
   wings	present, though the bird does not fly

2. 1.

   Ari reads a card about a flightless bird. Which statement does the card support?

   • The wings are new, since a bird that does not fly must have gained them lately
   • The wings are vestigial: leftovers of a part an ancestor used differently
   • The wings are not evidence, since a part the bird does not use shows nothing
   • The wings are analogous, since they look like the wings of flying birds

3. A card about Australia (real facts)

   place	what is found
   Australia	a great variety of marsupials, and other mammal groups absent

4. 2.

   Bo reads a card about Australia. Which line of evidence does the card show?

   • DNA comparison: letters matched between two species
   • Homologous structures: the same bone layout in different limbs
   • Biogeography: a pattern in where groups live, set by long isolation
   • Embryology: early forms that match across groups

5. A card about vertebrate embryos (real facts)

   stage	what is seen
   early embryos of vertebrates	gill slits and a tail
   adults of land animals	gill slits and tail gone
   adult fish	gill slits kept

6. 3.

   Esme reads a card about vertebrate embryos. Which statement fits the card?

   • Adults keep their early features, so embryos and adults look the same
   • The gill slits and tails that vanish are useless, so they show nothing
   • The embryos match because the adults match, so embryos add no evidence
   • Early features match across groups that look different as adults

7. Use the table

   Tree: Five animals (model data). Tips, left to right: trout, frog, pigeon, bat, dog. Node Z joins trout and node Y. Node Y joins frog and node X. Node X joins pigeon and node W. Node W joins bat and dog. Evidence table beside the tree: percent of DNA letters that differ from the dog's.

   animal	percent of letters that differ from the dog's
   trout	34
   frog	28
   pigeon	22
   bat	8

8. 4.

   Jun reads the tree and the table. Which statement fits both?

   • The pigeon is the dog's closest relative, since its row is in the middle
   • The trout is the dog's closest relative, since its 34 percent is the biggest gap
   • The frog is the dog's closest relative, since both stand on four limbs on land
   • The bat is the dog's closest relative: it differs least and joins at node W
9. 5.

   Kira reads the tree and the table. The bat and the pigeon both fly. Which statement fits?

   • The pigeon is closer to the bat than the dog is, since the tree joins the pigeon first
   • The bat and the pigeon are the closest pair, since both use the front limb to fly
   • The bat is closer to the dog, which does not fly, so a shared job does not set kinship
   • The tree and the table disagree, since the pigeon and the bat both fly
10. 6.

    Luz reads the tree and the table. Animal N is new. Where does the evidence place N?

    • At the root, since a new animal cannot be placed until more is known
    • On the dog and bat branch, joining below node W
    • Beside the frog, since N is a middle value in the table
    • Beside the pigeon, since its 21 percent is the biggest gap and shows the closest tie

11. Three mainland species compared with the island birds (model data)

    mainland species	beak shape	percent of DNA letters that differ from the island birds
    species A	thin	3
    species B	stout	12
    species C	thin	18

12. 7.

    Noah predicts which mainland species gave rise to model island birds with stout beaks. Which prediction fits best?

    • Not one of the three, since island birds have no mainland relatives
    • Species B, since its beak looks the same as the island birds' beaks
    • Species A, since its DNA differs least from the island birds'
    • Species C, since its 18 percent is the biggest gap and shows the closest tie

13. Resistant bacteria per 100 in a lab culture with an antibiotic (model data)

    round	resistant bacteria per 100
    1	2
    2	7
    3	24

14. 8.

    Pia reads about a model lab culture of bacteria with an antibiotic. What happens in round 4 if the antibiotic stays?

    • The share falls back to 2, since the antibiotic makes each bacterium lose resistance
    • The share stays at 24, since resistance appears when the antibiotic is added
    • The share rises above 24, since resistant bacteria keep dividing
    • No change is seen, since evolution shows in fossils alone over millions of years

15. The horse fossil series (real facts)

    genus	lived (million years ago)	what the fossils show
    Eohippus	55 to 42	the first horse-like species
    Mesohippus	40 to 30	teeth and legs suited to grazing
    Hipparion	23 to 2	larger in size
    Equus	now	the only genus left

16. 9.

    Ren reads the horse fossil series. Which statement does the series support?

    • Mesohippus is older than Eohippus, since its numbers are smaller
    • Horse-like forms changed in steps over about 55 million years
    • Fossils alone give evidence that horses have ancestors, since no other evidence exists
    • Eohippus and Mesohippus lived at the same time, since their ranges overlap

17. The plant family Proteaceae (real facts)

    continent	Proteaceae present
    Australia	yes
    southern Africa	yes
    South America	yes

18. 10.

    Tala reads a card about the plant family Proteaceae. Which explanation fits best?

    • Each continent made the same plant family on its own, since the climates match
    • Their ancestors grew on one southern supercontinent before it broke apart
    • The family arose after the continents split, which is why it grows on the three continents
    • Seeds crossed the ocean last year and spread across the three continents