The lines of evidence for evolution

Grade 9 Science Worksheet

Circle the best answer.

1. Read this first

   A card about Australia (real facts)

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

2. 1.

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

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

3. 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

4. 2.

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

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

5. 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

6. 3.

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

   • 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
   • 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
7. 4.

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

   • The tree and the table disagree, since the pigeon and the bat both fly
   • The bat is closer to the dog, which does not fly, so a shared job does not set kinship
   • The bat and the pigeon are the closest pair, since both use the front limb to fly
   • The pigeon is closer to the bat than the dog is, since the tree joins the pigeon first
8. 5.

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

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

9. Ridges on a model shell fossil by rock age (model data)

   rock age (million years)	ridges on the shell
   50	2
   30	5
   10	8

10. 6.

    Milo predicts a shell fossil from rock aged 20 million years. Which prediction fits the series best?

    • No prediction is possible, since fossils do not show steps in a series
    • About 8 or 9 ridges, the same as the youngest fossil in the series
    • About 2 or 3 ridges, the same as the oldest fossil in the series
    • About 6 or 7 ridges, between the fossils from 30 and 10 million years

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?

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

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?

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

15. The plant family Proteaceae (real facts)

    continent	Proteaceae present
    Australia	yes
    southern Africa	yes
    South America	yes

16. 9.

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

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

17. Two arctic animals in winter (real facts)

    animal	winter covering	home
    arctic fox	white fur	the arctic
    ptarmigan	white feathers	the arctic

18. 10.

    Zee reads a card about two arctic animals. Which explanation fits their white winter coverings?

    • The coverings are analogous, so the two animals are close relatives
    • Similar surroundings favored white coverings; the trait was not inherited from a recent shared ancestor
    • Both look white in winter, so they must be close kin
    • Fur and feathers are the same part, so both came from one ancestor's covering