Basic Tree Thinking Assessment David A

Basic Tree Thinking Assessment David A. Baum, Stacey DeWitt Smith, Samuel S. Donovan

This quiz includes a number of multiple-choice questions you can use to test yourself on your ability to accurately interpret evolutionary trees. Insofar as real biological examples have been used they are accurate based on current knowledge.

Amoeba Red Alga Green alga Moss Pine

1) By reference to the tree above, which of the following is an accurate statement of relationships? a) A green alga is more closely related to an red alga than to a moss b) A green alga is more closely related to a moss than to a red alga c) A green alga is equally related to a red alga and a moss d) A green alga is related to a red alga, but is not related to a moss

Lizard Crocodile Dinosaur Bird

2) By reference to the tree above, which of the following is an accurate statement of relationships? a) A crocodile is more closely related to a lizard than to a bird b) A crocodile is more closely related to a bird than to a lizard c) A crocodile is equally related to a lizard and a bird d) A crocodile is related to a lizard, but is not related to a bird

Seal Horse Giraffe Hippopotamus Whale

3) By reference to the tree above, which of the following is an accurate statement of relationships? a) A seal is more closely related to a horse than to a whale b) A seal is more closely related to a whale than to a horse c) A seal is equally related to a horse and a whale d) A seal is related to a whale, but is not related to a horse

Tomato Fern Sponge Mouse Mushrooma

4) Which of the five marks in the tree above corresponds to the most recent common ancestor of a mushroom and a sponge? Salmon Newt Human Lizard Snake

e d b a

5) If you were to add a trout to the phylogeny shown above, where would its lineage attach to the rest of the tree?

Rabbit Turtle Crocodile Bird

6) Given the tree above, what would you expect the common ancestor marked ‘A’ to look like? a) Most like a rabbit because it is the only included ancestor of A b) Most like a turtle because it is the most direct descendant of A c) Most like a crocodile because a crocodile is known to be a “living fossil” d) An equal mix of rabbit, turtle, crocodile, and bird features, because it is an ancestor of all of them e) One cannot say without a model of how traits evolve along the branches of this tree

G F A B C E D G B D E C A F

a b

G F A B C E D G A B E D C F

c d

7) Which of the four trees above depicts a different pattern of relationships than the others?

B C F D G E B D E C G A F A

a b

E G newpath93.8637newpath176.3581 288.6459 300.3084 moveto125 moveto125 303 303 26 26 205.5600 -2.2026 -79.9920270 arc125 arcn2 303 setlinewidthstroke 26 -90 -79.9920 arc2 setlinewidthstroke newpath92.4112newpath125.0000 330.8335 243.0000 moveto125 moveto125 303 303 34 34 139.7637 -90.0000 205.5600 -90 arcn125 arc2 303 setlinewidthstroke 34 270 205.5600 arcn2 setlinewidthstroke newpath71.0723newpath74.1171newpath129.8514newpath131.2717 329.3022271.2048newpath175.8829newpath178.9276 moveto125362.6713277.7475 329.3022271.2049 moveto125303 51 153.4350211.5348 moveto125 303 1717 182.6630 83.2902-79.9920 303 5151 2.4375 arc2arcn226.56512.4375-31.5348 setlinewidthstroke setlinewidthstroke arcn2 arc2 -2.2026 -2.2026 setlinewidthstroke arcn2 arc2 setlinewidthstroke

newpath118.7283newpath73.6419 300.3084A 362.6713 moveto125 moveto125 303 303 43 43 182.6630 95.3145 139.7637 arc2arcn2 setlinewidthstroke setlinewidthstroke c d D F A G C E D B F B 8) Which of the four trees above depicts a different pattern of relationships than the others?

retractable loss of claws ears

abdominal testes

short tail

9) In the above tree, assume that the ancestor had a long tail, ears, external testes, and fixed claws. Based on the tree and assuming that all evolutionary changes in these traits are shown, what traits does a seal have? a) long tail, ears, external testes, and fixed claws b) short tail, no ears, external testes, and fixed claws c) short tail, no ears, abdominal testes, and fixed claws d) short tail, ears, abdominal testes, and fixed claws e) long tail, ears, admoninal testes, and retractable claws

o r

n s

e s

d o m

o u

m t d

i b

o n k l w p i r u a l e e s e O F C L Y P loss of true tree leaves

tree seeds

true leaves

10) In the above tree, assume that the ancestor was a herb (not a tree) without leaves or seeds. Based on the tree and assuming that all evolutionary changes in these traits are shown, which of the tips has a tree habit and lacks true leaves? a) Lepidodendron b) Clubmoss c) Oak d) Psilotum e) Fern

Basic Tree Thinking Assessment David A. Baum, Stacey DeWitt Smith, Samuel S. Donovan

Amoeba Red Alga Green alga Moss Pine

‘b’ is correct. The last common ancestor of a green alga and a moss is at node x whereas the x last common ancestor of a red alga and a moss is at the “deeper” node, y. If you picked y ‘c’ you are reading along the tips.

Lizard Crocodile Dinosaur Bird

‘b’ is correct. The last common x ancestor of a crocodile and a bird is at node x whereas the last common ancestor of a y crocodile and a lizard is at the “deeper” node, y. If you picked ‘a’ you are reading along the tips.

Seal Horse Giraffe Hippopotamus Whale

‘c’ is correct. The last common ancestor of a seal and a whale is at node y, as is the last common ancestor of a seal and a horse. x All descendants of node x are equally related to the seal. If you picked ‘a’ you are reading along y the tips.

Tomato Fern Sponge Mouse Mushrooma

4) Which of the five marks in the tree above corresponds to the most recent common ancestor of a mushroom and a sponge? ‘d’ is the correct answer. ‘a’ is a living species and is not an ancestor. ‘e’ is an ancestor of a sponge but not of a mushroom. ‘b’ and ‘c’ are common ancestors of a sponge and a mushroom, but they are more ancient common ancestors than ‘d’. Salmon Newt Human Lizard Snake

‘c’ is the correct answer. This depends on only the knowledge that c a salmon and a trout are very closely related. Therefore they must share a more recent common e ancestor with each other than with any other included species. d Position ‘c’ is the only place such b an ancestor could be. a

5) If you were to add a trout to the phylogeny shown above, where would its lineage attach to the rest of the tree? ‘e’ is the correct answer. ‘a’ is wrong: all included species are descendants of A. ‘b’ is worng: Rabbit Turtle Crocodile Bird a turtle is no more a direct descendant of A than are crocodiles or birds. ‘c’ is wrong: while the claim might suggest that the common ancestor of a bird and a crocodile was more like a crocodile, it says little about A. ‘d’ is wrong: an “equal” mix is hard to imagine. A

G F A B C E D G B D E C A F

a b

G F A B C E D G A B E D C F

c d

7) Which of the four trees above depicts a different pattern of relationships than the others?

‘c’ is the correct answer. In all the other trees C is more closely related to E and D than to B. In ‘c,’ C is more closely related to B than to E or D.

E B C F D G B D E C G A F A

a b

E G newpath93.8637newpath176.3581 288.6459 300.3084 moveto125 moveto125 303 303 26 26 205.5600 -2.2026 -79.9920270 arc125 arcn2 303 setlinewidthstroke 26 -90 -79.9920 arc2 setlinewidthstroke newpath92.4112newpath125.0000 330.8335 243.0000 moveto125 moveto125 303 303 34 34 139.7637 -90.0000 205.5600 -90 arcn125 arc2 303 setlinewidthstroke 34 270 205.5600 arcn2 setlinewidthstroke newpath71.0723newpath74.1171 329.3022271.2048newpath175.8829newpath178.9276 moveto125 329.3022271.2049 303 51 153.4350211.5348 moveto125 182.6630 303 5151 arc2arcn226.5651-31.5348 setlinewidthstroke setlinewidthstroke -2.2026 -2.2026 arcn2 arc2 setlinewidthstroke newpath129.8514newpath131.2717 362.6713277.7475 moveto125 303 1717 83.2902-79.9920 2.4375 2.4375 arcn2 arc2 setlinewidthstroke newpath118.7283newpath73.6419 300.3084 362.6713 moveto125 moveto125 303 303 43 43 182.6630 95.3145 139.7637 arc2arcn2 setlinewidthstroke setlinewidthstroke D A c d F A G C E D B

F B

8) Which of the four trees above depicts a different pattern of relationships than the others?

‘a’ is the correct answer. In all the other trees C is more closely related to E and D than is B. In ‘a,’ B is more closely related to E and D than is C. ‘d’ is the correct answer. Tracing up from the ancestor one retractable loss of claws ears sees that the only changes are in tail abdominal length and testes testes position. For the other traits it seals have the short ancestral condition. tail

o r

n s ‘a’ is the correct e s

d o m

o u

m t answer. Clubmosses d

i b

o n k l w p i r u a l e are not trees. Oak e s e O F C L Y P (and yew) are trees loss of true but they have tree leaves leaves. Psilotum lacks leaves, but it is not a tree. A fern tree has leaves and is seeds not a tree. true leaves