History of life

Question 1

Fossil – physical evidence from an organism that lived in the past. Fossils provide the only direct evidence about:

Answer 1

what organisms looked like, where they lived (habitat), when they lived (how old they are), some information on how they lived.

Question 2

Define fossil record

Answer 2

the total collection of fossils that have been found throughout the world.

Question 3

name the limitations of the fossil record.

Answer 3

• anything that doesn’t live by water or are mostly made of tissue wont fossilize

Question 4

____________ – organisms that live in areas with active sediment deposition more likely to be fossilized (e.g., beaches, wetlands)

Answer 4

habitat bias

Question 5

_____________ – organisms with hard parts (e.g., bones, shells) or tissues with tough layers (e.g., pollen) are more likely to decay slowly.

Answer 5

Taxonomic & tissue bias

Question 6

___________ – recent fossils are more common than ancient fossils.

Answer 6

Temporal bias

Question 7

____________ – organisms that were abundant, widespread URQUHART, and present for a long time are better represented in the fossil record.

Answer 7

Abundance bias

Question 8

what does Precambrian mean?

Answer 8

collective name for first three eons

Question 9

what does the precambrian include?

Answer 9

Hadeon, Achaean, Proteozoic.
4.6 bya –> 542 mya
-most life was unicellular throughout most of this time
- low O2 levels for first 2 billion years after life evolves.

Question 10

What does the Phanerozoic eon include?

Answer 10

3 eras: Paleozoic, Mesozoic, Cenozoic
542 mya –> present

Question 11

What is a Niche?

Answer 11

The niche of an organism is the functional role that it plays within an ecosystem.

Question 12

Define Adaptive radiations

Answer 12

when a single lineage rapidly diversifies into many desendant lineages with a wide diversity of forms and ecological niches

Question 13

___________ – favourable new environmental conditions = Ecological opportunity *islands

Answer 13

Extrinsic
e.g. adaptive radiation of 150 species of anolis lizards in the carribbean islands

Question 14

_____ – evolution of innovative morphological, physiological, or behavioural traits

Answer 14

Intrinsic
ex.
Flowers – innovative reproduction structure that led to diversification of angiosperms into 250,000 species.
Feathers/wings – innovative morphology (feathers) that gave some dinosaurs the ability to fly. Today there is ~10,000 species of birds.

Question 15

what does Daushantuo mean?

Answer 15

microscopic early animals

Question 16

Mass Extinction definition

Answer 16

Rapid extinction of large number of diverse organisms around the world
-Mass extinction: occurs when at least 60% of species present goes extinct within 1 million years.
-Caused by exceptionally harsh, sudden, temporary changes in the environment (e.g. asteroid collisions, volcanic eruptions)

Question 17

Define Background extinctions

Answer 17

• Normal environmental change
• Emerging disease
• Predation/competition

Question 18

Define End-Permian Extinction

Answer 18

-The largest mass extinction – 90% of life went extinct.
-Cause is unknown.
-This time period there was a increase of CO2, SO2 = global warming, acid rain, water/ocean acidification
- Increase anoxia.
- Drop in sea levels.
- Low atmospheric O2

Question 19

Define End-Cretaceous Extinction

Answer 19

-Due to an impact asteroid, 10km in diameter
-Fireball
-Wipe out dinosaurs (mostly), pterosaurs, marine reptiles.
-*Mammals, birds, crocodiles, amphibians survived