A fossil shows evidence of a tetrapod living in shallow water 375 million years ago. What does this suggest about the transition from aquatic to land animals?
Tetrapods lived only in the deepest parts of the ocean
Some vertebrates were beginning to adapt to life on land
All animals had already moved completely onto land
Land plants forced animals to leave the water
During the Cambrian Period, most life forms were aquatic. What does the fossil record from this time reveal?
Humans and mammals becoming the dominant life forms
Land plants and forests covering Earth’s continents
Large dinosaurs living on land and in the oceans
Water covered the majority of the Earth
organism that comes before descendants
ancestor
The "one bone"- "two bones" - "many bones" indicates __________
limb bones develop randomly w/no evolutionary significance
tetrapods first evolved wings instead of legs
all tetrapods share a common ancestor.
tetrapods evolved completely independently
an unborn organism in the very early stages of development
embryo
evolutionary tree; shows ancestors, descendants, over a long time
cladogram
What does a cladogram show?
The size of organisms
The order in which fossils are found
Evolutionary relationships among organism
The age of rocks
What was the main type of life during the Ordovician Period?
Birds
Dinosaurs
Marine invertebrates like brachiopods and mollusks
Mammals
when every individual of a species dies out
extrinction
layered rock formed as sediments compress and cement togetherp; often contains fossils
sedimentary rock
states that oldest rocks are on the bottom while younger ones are close to the top
law of superpositions
variety of living organisms in a particular area or on Earth as a whole
biodiversity
Which type of organisms is least likely to appear in the fossil record?
Animals with shells
Soft-bodied organisms like worms and jellyfish
Dinosaurs
Fish with bones
Why are land plants important in evolution?
They produced shells for protection
They allowed animals to colonize land
They could fly
They replaced fish in oceans
Why didn’t the soft parts of early animals usually fossilize?
Early animals lived only on land, far from where fossils for
Fossils can only form in very cold climates
Soft parts were too small to be seen by scientists
Soft tissues decayed or were eaten before they preserved
any living thing that can carry out life processes on its own
organism
process where organisms change/diversify over a long time
evolution
a scientist who studies fossils
paleontologist
a trait that evolves over time from common ancestor
derived trait
Which of the following animals does NOT follow the one → two → many → digits pattern?
Amphibians
Humans
None of the above; all follow the pattern
Fish
Which animal is least closely related to the others?
wolf
kitty cat
horse
tortoise
Which two animals are most closely related according to the cladogram?
Leopard and house cat
Wolf and tortoise
Horse and tortoise
Horse and tortoise
Dolphin embryos show four limbs, and baby dolphins are born with hair. Why is it important for scientists to study embryos as well as adult organisms?
Embryos are easier to observe than adults.
embryos can show features that isn't seen in adults
embryos helps scientists predict the size of the adult anima
Adult organisms do not have any bones.
a collection of fossils that give clues to the history of life on Earth
fossil record
traces of organisms' activities; burrows, footprints, drag marks
trace fossil
a vertebrae with 4 limbs (birds, amphibians, reptiles, mammals)
tetrapod
the remains of ancient organisms
fossil
Why doesn’t the fossil record show all organisms that have ever existed?
Fossilization is rare, soft-bodied organisms decay, and many
All organisms are equally likely to become fossils
Most organisms never lived long enough to be important
Scientists have already found every fossil on Earth
the prefix "tetra" means ____
four
Which of the following can studying embryos help scientists understand?
How species may be related through common ancestors
How fast an animal can run
The exact color of an adult animal
Which species is the smartest
remains of the actual organism; shells, bones, teeth preserved
body fossil
Which of the following correctly describes the “one bone → two bones → many bones → digits” pattern?
Does not relate to evolution
Only found in humans
Shows how vertebrate limbs are related and adapted
Only occurs in fish
What would a paleontologist NOT do?
Study fossils to learn about ancient life.
Track the migration of living animals
Compare fossil evidence to modern organisms.
Use rock layers to determine the age of fossils.
During which period did the first tetrapods appear?
Devonian
Ordovician
Silurian
Cambrian
Organisms that share more traits on a cladogram are:
Always the same species
The same age
more closely related
Less closely related
Early tetrapods were fully aquatic but were developing structures that would later allow movement on land
this occured during the Cambrian Period
this occured during the Jurassic Period
this occured during the Devonian Period
this occured during the Permian Period
In a sequence of rock layers, what would scientists expect to find in the oldest (bottom) layer?
Fossils of flowering plants and insects
Fossils of early life forms like algae or marine animals
Fossils of birds and dinosaurs
Fossils of mammals and humans
What were the first organisms on Earth?
land plants
amphibians
Single-celled prokaryotes
dinosaurs
Which statement best describes biodiversity?
Stayed the same until humans appeared
it gradually increased when animals moved onto land
Only marine animals existed until the Mesozoic
Dinosaurs were the only contributors to biodiversity
Why is this bone pattern important?
shows a common ancestor, how limbs adapted for environments
It proves that fish could not evolve into land animals
It only applies to birds
shows that vertebrate limbs are all completely different
organism that comes after ancestors
descendants
the prefix "terre" means
land/earth
What is the significance of the “digits” in the pattern?
allow animals to swim, walk, climb, or manipulate objects
They make the limb shorter
They are just for decoration
They are only found in humans
In a sequence of rock layers, what would scientists expect to find in the youngest (top) layer?
Fossils of simple bacteria and algae
Fossils of dinosaurs only
Fossils of early marine animals from the Cambrian Period
Fossils of mammals, birds, flowering plants, and humans
Fossilization requires certain conditions. Which of the following helps a fossil form?
Rapid burial in sediment
Being eaten by predators
Floating on the ocean surface
Exposure to air and sunlight