Investigate The Conquest of Land by Animals

Question 1

Due to trace fossils being common from about 450MYA, what does that suggest about invertebrates and vertebrates?

Answer 1

It suggests that invertebrates colonised the land long before our vertebrate ancestors

Question 1

What is the first accepted evidence for animals occupying terrestrial environments?

Answer 1

The footprints & tracks of myriapods (a group with elongated bodies & numerous leg-bearing segments): Millipedes and eurypterids.

Question 2

What are Terrestrial Vertebrates?

Answer 2

(animals with a backbone) who spend the majority of their lives on land. While terrestrial vertebrates form a minor proportion of all invasive species, their impacts are often disproportionately high.

First ventured on land during the middle of the Devonian period. During this period vertebrate fish diversified and became a dominant group of oceanic animals.

Question 3

Advantages of life on land?

Answer 3

-Sunlight is stronger ( water filters out parts of the colour spectrum within the first two meters).

-More Carbon Dioxide in the atmosphere THAN in the ocean (good for photosynthesis = plants)

-Mineral nutrients are plentiful in the soil (good for plants)

Question 4

Disadvantages/Challenges of Life on Land:

Answer 4

-Less available water

-No support against gravity (plants need some form of structure support)

-Gas exchange (having to utilise AIR rather than WATER)

-Reproduction (simply releasing sperm or eggs into the water will no longer work so a new system needs to be developed)

Question 5

sameas other

How did fish ancestors come out of water?

Answer 5

Converting their FINS to LIMBS
&
breathing UNDER-WATER to AIR-BREATHING

Question 6

How did animals move from water to land?

Answer 6

A STRONG pelvic girdle and laterally positioned, forward-facing legs allowed them to walk.

AND

The evolution of lungs allowed the amphibians to move away from the water for extended periods of time

Question 7

How did CYANOBACTERIA affect the GEOSPHERE?

Answer 7

-The formation of BIF’S

-The increase in oxygen levels was also creating additional oxidation in some of the surface minerals.

-Hydroxide & oxide minerals INCREASED clay-based rocks from the Proterozoic Eon.

-Great Oxygenation Event

-Carbon dioxide removed

Question 8

How did CYANOBACTERIA affect the ATOMOSPHERE?

Answer 8

-Fundamental shift in the composition of the atmosphere.

-Reduction of Co2 & CH4 from atmosphere (may have lead to global cooling = SNOWBALL EARTH)

-Ozone developed

-Co2 combines to create new organic molecules

Question 9

How did CYANOBACTERIA affect the HYDROSPHERE?

Answer 9

-The cyanobacteria were in the shallow waters of the ocean, which means the oxygen levels in the hydrosphere changed first.

-Snowball earth covered oceans in ice

-Co2 removal in oceans decreases pH

Question 10

What is a mould formation?

Answer 10

The imprint LEFT BY THE ORGANISM on the material that surrounded it. ( 2D + Inside Shell)

Question 11

What is a cast formation?

Answer 11

A mould fossil that is FILLED IN WITH MINERALS that harden over time. (3D + Outside Shell)

Question 12

What are Trace Fossils?

Answer 12

Trace Fossils are the tracks, trails, impact marks and footprints that organisms made when they were alive.

These fossils have the ability to capture an event that only lasted a few seconds and that occurred about 100 million years ago.

Question 13

What do footprints of trace fossils show?

Answer 13

-Type of organism?
-How tall?
-How fast?
-How many?
-How heavy?
-Which direction?

Question 14

What do coprolites (feces) of trace fossils show?

Answer 14

-Type of organism?
-What diet?
-What features about the digestion?
-What environment?

Question 15

What is an index fossil used for?

Answer 15

Date rocks. The presence of an index fossil in a sedimentary rock indicates that it was formed during a particularly short period.

Question 16

A good index fossil has these 5 characteristics:

Answer 16

1) Distinct
2) Globally widespread
3) Abundant
4) Limited to a particular geological time
5) Robust & Preserves well

Question 17

How is absolute dating conducted?

Answer 17

It is based on the fact that living organisms—like trees, plants, people, and animals—absorb carbon-14 into their tissue. When they die, the carbon-14 starts to change into other atoms over time. Scientists can estimate how long the organism has been dead by counting the remaining carbon-14 atoms. Therefore if we know what those are, we can collect uncontaminated samples, and then we receive an understanding of the sample’s age.

Question 18

What is relative dating? and how is it done?

Answer 18

The process of determining if one rock or geologic event is older or younger than the other, without knowing their specific ages.

(Less detailed)

Done through: Stratigraphic correlation and Superposition.

Question 19

What is bracketing?

Answer 19

Occurs when you have similar fossils, where there is some sort of overlap in time.

Question 20

Conquest of land for animals:

Answer 20

arthropods developed exoskeletons, amphibians developed limbs, amniotic egg

Question 21

Conquest of land for plants:

Answer 21

developed vascular systems, roots, waxy cuticles and seeds

Question 22

Conditions in forming fossils:

Answer 22

-Sinks to water bead
-Quickly buried
-Sediment turned to rock
-Minerals dissolve
-Exposure of fossil