The lines of evidence for evolution
Grade 9 Science Worksheet - Challenge Me
Circle the best answer.
Read this first
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 Bo reads the fossil rows and the living flipper. Which claim uses both lines of evidence?
- The fossils alone settle the flipper's history, so the bone layout adds nothing
- The leg changed into a flipper in steps, and the matching bones fit one ancestor
- The flipper appeared at once, since the paddle and the flipper have the same layout
- The flipper and the leg are analogous, so the bone layout is just a coincidence
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 Esme reads a table about a model cave animal C. Which claim uses both lines of evidence?
- T is closer to S than C is, since T has the larger gap in DNA letters and so more kinship
- 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
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 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
- The three wings do the same job of flying, so the three came from one ancestor's wing
- 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
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 Kira sees that one DNA segment of a pine and a frog matches in 18 of 20 letters. Which explanation fits?
- The pine and frog are close relatives, since 18 of 20 letters is a match of 90 percent
- 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
- Many segments are less reliable than one segment, since more letters add more chance of error
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 Luz notes that the small wings of a model flightless bird B still have a use. Why can they be called vestigial?
- 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
- 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
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.
Milo reads a classmate's notebook about two model swimmers. Which line has the mistake?
- Line 4: DNA and early development do not matter when two animals look alike
- Line 1: swimmers cannot have fins and smooth bodies
- Line 3: looking alike does not prove close kinship
- Line 2: DNA letters cannot be counted as a percent
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.
Noah reads a classmate's notebook about three species and one gene. Which line has the mistake?
- 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 2: 3 of 100 is a larger difference than 18 of 100 letters
- Line 3: a larger difference shows a more distant relative
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.
Pia reads a classmate's notebook about whale hind leg bones. Which line has the mistake?
- Line 3: vestigial bones are leftovers that do say something about ancestors
- Line 2: bones in a whale's body help it swim, so this is wrong
- Line 1: whales have no hind leg bones, because they have no hind legs
- Line 4: land animals have no leg bones, so there is nothing to compare
Medium ground finches on Daphne Major (real facts)
time seeds average bill size after a wet period few large hard seeds, many small soft seeds smaller than before 1987 and after larger seeds more available the trend toward smaller bills stopped Ren judges a claim about medium ground finches on Daphne Major. Which claim and reason fit best?
- The population changed, since bill size is inherited and small-billed birds had more offspring
- Each bird's bill shrank as it grew up, which made the average bill size fall across the group
- Bill size changes with the seeds a bird finds, so it is not inherited from one bird to the next
- This shows nothing about evolution, since fossils alone can show change over long periods of time
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 Tala judges a claim about two model gliders. Which claim and reason fit best?
- The flaps are analogous and arose separately, since the builds and the DNA differ
- The gliders are close relatives, since a 38 percent difference is a large one
- The gliders are close relatives, since analogous flaps show a recent shared ancestor
- The gliders are close relatives, since both glide in much the same way