Unit 4 (Evolution-Transitional Forms in the Fossil Record)

Question 1

What is a Transitional Form- in regards to the fossil record?

Answer 1

A species that bridges the gap between two species.

Question 2

How did our ancestor move from sea to land? What did this move require?

Answer 2

1. We evolved from fish to amphibian.
2. Lungs and limbs

Question 3

What is the Lungfish? When did lungs evolve?

Answer 3

1. This is a type of fish that evolved lungs.
2. Long before the move to land

Question 4

What are “Lobe-Fins?” When did lobe-fins evolve?

Answer 4

1. Fins with bones!! (Fish use these fins to “walk” along the sea floor)
2. Long before the move to land

Question 5

What did the first limbs evolve from?

Answer 5

“Lobe-fins”

Question 6

What is a “Tiktaalik?” When did they live?

Answer 6

1. A lobe-finned lungfish with a neck and wrist joints.
   (between fish and amphibians)
2. 375 MYA

Question 7

What is a “Ichthyosega?” When did they live?

Answer 7

1. An extinct early tetrapod with fish-like tail and skull.
2. 360 MYA
   (Like a big-ass fish lizard situation)

Question 8

What is a “Archeopteryx?” When did they live?

Answer 8

1. A feathered reptile (between reptiles and birds)
2. 150 MYA
   (Think like a flying dinosaur+feathers)

Question 9

Which came first: feathers or flying birds?

Answer 9

Feathers

Question 10

What makes the platypus and echidna so different? Name three examples.

Answer 10

1. They have a combo of reptilian and mammalian traits.
2. -They have a cloaca
   -They lay eggs
   -They have hair, and produce milk

Question 11

What are the two “miscellaneous” animals he wants us to know?

Answer 11

The platypus and echidna

Question 12

What are two important traits Modern Whales share?

Answer 12

-A blowhole
-Unique ear bones

Question 13

What are four strange features that Modern Whale Embryos have?

Answer 13

1. Hair
2. Hind limb buds
3. Teeth
   (lost before birth ^)
4. Nostrils that migrate back (to become a blowhole)

Question 14

What is the “Ambulocetus?” When did it exist?

Answer 14

1. An ancient whale ancestor that had whale ear bones, and was terrestrial.
2. 49 MYA

Question 15

What is the “Basilosaurus?” When did it exist?

Answer 15

1. An ancient whale ancestor. It was large like a whale but had tiny hind limbs.
2. 40-35 MYA

Question 16

What are the years and order of ancient humans?

Answer 16

1. Australopithecus (4-1 MYA)
2. Homo Erectus (1.8-.3 MYA)
3. Homo Floresiensis (100k-50k YA)

Question 17

“Homo” is latin, what does it translate to?

Answer 17

“Human man”

Question 18

What are two trends in human evolution?

Answer 18

1. Bigger brains
2. Flatter faces

Question 19

What was “Australopithecus?” When did they live?

Answer 19

1. An ancient human ancestor. It was bipedal and small brained.
2. 4-1 MYA

Question 20

Which came first, upright walking or large brains?

Answer 20

Upright walking.

Question 21

What was “Homo Erectus?” When did they live?

Answer 21

1. An ancient human ancestor, that, below the neck is very similar to modern humans. However they had smaller and differently shaped skulls.
2. 1.8-.3 MYA

Question 22

Which ancient human ancestor first used stone tools?

Answer 22

Homo Erectus

Question 23

What was “Homo Floresiensis?” When did they live?

Answer 23

1. These were very similar to modern humans but they did not survive. They were about 3ft tall.
2. 100k-50k YA

Question 24

What are two traits that make the Icefish of Antartica so fascinating?

Answer 24

1. Their blood contains no red blood cells or hemoglobin.
2. They have unique antifreeze glycoproteins called AFGP’s.

Question 25

How did icefish AFGP genes evolve?

Answer 25

They evolved from the gene for a digestive enzyme-> trypsinogen.

Question 26

What is Trypsinogen?

Answer 26

A digestive enzyme

Question 28

Why did icefish loose their hemoglobin and RBC’s?

Answer 28

It makes their blood easier to pump.

Question 29

How do icefish survive?

Answer 29

Their cells receive low-O2 blood, but they receive more of it than other fish.

Question 30

How long do we think it took for the icefish to evolve these strange characteristics?

Answer 30

20+ million years

Question 31

Adaptation to a frigid enviornment over 20 million years made the icefish develop: (3 traits)

Answer 31

1. Loss of genes
2. Evolution of new genes
3. Modified physiology (hearts, gills, skin)
   (Slide 275 ❤️)