Evidence for Evolution

Question 1

Fossil record

Answer 1

Fossil records: Fossil records are like history books in sedimentary rock layers, showing species from the past.
- Deeper fossils are older and more like ancient species.
- For instance, fish fossils are deepest, showing they came first, then amphibians from fish, and later reptiles from amphibians. This gradual change took millions of years, revealing how life evolved over time.

Question 2

Transitional fossils

Answer 2

Transitional fossils: Fossils that show links between groups of organisms and shares characteristics common to two separate groups
- Whales from land: “Whales had legs, lived in water.”
- Archaeopteryx link: “Bird-like dino with teeth and tail.”

Question 3

Vestigial structures

Answer 3

Vestigial structures: leftovers from an organism’s ancestors that are now reduced or non-functional.
- Geese and webbed feet: Geese live on land but have webbed feet.

Question 4

Biogeography

Answer 4

Biogeography: where organisms live, now and in the past.
- Nearby places have similar species.
- Islands copy nearby lands.
- Fossils show old connections.
- Different neighbors mean more changes.

Question 5

Homologous

Answer 5

Homologous: body parts that are similar in structure, but have a different function
Ex.
- Flippers of penguin and dolphin.

Question 6

Analogous

Answer 6

Analogous: structures that share a common function, but different internal anatomy
Ex: Birds and bats have bones to support their wings, whereas butterflies have chitin.
analogy… bat wing, butterfly wing, & bird wing.

Question 7

Embryology

Answer 7

the study of early, pre-birth stages of an organism’s development.

Question 8

DNA

Answer 8

• Scientists can determine how closely related 2 species are by comparing their DNA.
• Similar DNA patterns indicate the sequences came from a common ancestor.
  Ex. Dogs are related to bears because they have a similar gene sequence.