The lines of evidence for evolution
Grade 9 Science Worksheet - Building Confidence

Circle the best answer.
Read this first
A museum card about shells (model data)
what was found where it was found shells with plain edges deeper rock layers shells with ridged edges shallower rock layers Ari reads a museum card about shells. Which line of evidence for common ancestry does the card show?
- DNA comparison: letters matched between two species
- Fossils: remains in rock layers of different ages show change
- Biogeography: patterns in where species live on Earth
- Homologous structures: matching bone layouts in different animals
A card about a whale (real facts)
feature what is found how the whale moves hind leg bones small bones that remain in the body with flippers and a tail Bo reads a card about a whale. Which line of evidence for common ancestry does the card show?
- Fossils: remains of past life found in rock layers
- Embryology: early forms that match across groups
- Vestigial structures: leftover parts from an ancestor's body
- Biogeography: patterns in where species live on Earth
A scientist's note about three species (model data)
compared what was counted species P with species Q 3 of 100 DNA letters differ species P with species R 20 of 100 DNA letters differ Esme reads a scientist's note about three species. Which line of evidence for common ancestry does the note show?
- DNA comparison: counting matching letters in two species
- Biogeography: patterns in where species live on Earth
- Fossils: remains of past life that alone show how species are related
- Vestigial structures: leftover parts from an ancestor's body
Percent of DNA letters that differ from the pigeon's (model data)
animal percent of letters that differ duck 5 lizard 18 frog 24 trout 31 Kira reads the table. What percent of the pigeon's DNA letters differ from the frog's?
- 31 percent, from the trout's row
- 5 percent, from the duck's row
- 18 percent, from the lizard's row
- 24 percent, from the frog's row
Use the table
Tree: Three animals (model data). Tips, left to right: frog, duck, pigeon. Node X joins frog and node W. Node W joins duck and pigeon. Evidence table beside the tree: percent of DNA letters that differ.
pair percent of letters that differ duck and pigeon 5 pigeon and frog 24 duck and frog 24 Luz reads the tree and the table. Which two animals are the closest relatives?
- The three animals are equally close: the three meet at node X
- Pigeon and frog: they differ more, which shows a closer tie
- Duck and pigeon: they differ least and meet at node W
- Duck and frog: both spend time near water, so they are close kin
Two wings (real facts)
wing job built on bones bird wing flying yes honeybee wing flying no Milo reads a card about two wings. Which word fits the bird wing and the honeybee wing?
- Vestigial: both wings are leftover parts with no use
- Analogous: the same job, but a different build
- Transitional: both wings show a step between two forms
- Homologous: both fly, so both came from one ancestor wing
Two limbs (real facts)
limb job bone layout dog front leg walking same overall layout whale flipper swimming same overall layout Noah reads a card about two limbs. Which word fits the dog leg and the whale flipper bones?
- Homologous: the same bone layout, from a shared ancestor limb
- Transitional: the flipper is a step between two forms in rock
- Vestigial: the flipper is a useless leftover part from a past form
- Analogous: the jobs differ, so the limbs cannot be related
Two model desert plants (model data)
plant home stem percent of DNA letters that differ from the other plant plant P a desert on one continent thick and spiny 44 plant Q a desert on another continent thick and spiny 44 Pia reads a card about two model desert plants. Which word fits their thick spiny stems?
- Analogous: similar traits that arose separately in similar surroundings
- Vestigial: the spines are leftover parts from an ancestor
- Homologous: the same traits show that P and Q share a recent ancestor
- Close relatives: plants that look this alike must be near kin
A card about some snakes (real facts)
animal body part how the animal moves some snakes small pelvic bones without legs Ren reads the word vestigial on a card about snakes. What does vestigial mean?
- A leftover part from an ancestor that had a fuller version
- A part that two unrelated animals build in different ways
- A useless part, so it tells scientists nothing about ancestors
- A new part that helps an animal in a new home
A card about island species (real facts)
place what scientists found Hawaiian Islands many species found nowhere else, distantly related to mainland species Tala reads a card about island species. What does biogeography study?
- How old the rock layers holding a species are
- How many bones two species share in their limbs
- Where species live on Earth, and how those places fit their history
- How many DNA letters two species share