Changes In Biodiversity Overtime

Question 1

Archaean eon

Answer 1

Life first appeared on earth. Earth’s first life forms with prokaryotes. Stromatolites.

Question 2

Proterozoic eon

Answer 2

Eukaryotes appeared. Algae. Earliest evidence of multicellular animals called ediacaran fauna.

Question 3

Cambrian period

Answer 3

Dramatic increase in number of complex marine life forms.

Question 4

Ordovician period

Answer 4

The emergence of first vetebrates.

Question 5

Silurian period

Answer 5

Air- breathing animals first emerged (anthropoids)

Question 6

Devonian period

Answer 6

Jawed marine fishes first evolved, along with armoured placoderms, ray-finned and lobe-finned and sharks.

Question 7

Carboniferous period

Answer 7

Evolution of reptiles and amphibian-like ancestors. Formation of forests.

Question 8

Permian period

Answer 8

Pangea was formed, reptiles diversified, and there was a mass extinction of 90% of the species in that time.

Question 9

Mesozoic era

Answer 9

Triassic period,Jurassic period and the Cretaceous period.

Question 10

Triassic period

Answer 10

Reptiles dominant and have diversified into the first dinosaurs, crocodiles and pterosaurs.

Question 11

Jurassic period

Answer 11

Mammals begun to diversify and birds.

Question 12

Cretaceous period

Answer 12

Small marsupials and insectivores are abundant. First flowering plants (angiosperms).

Question 13

Paleogene period

Answer 13

Placental mammals, birds abundant, primates evolved.

Question 14

Neogene period

Answer 14

First homo species (h. Habillis) evolved.

Question 15

Quaternary period

Answer 15

Change in environment from cold,dry glacial period to wetter and warmer interglacial period. Megafauna existed and then became extinct.

Question 16

Palaeontology

Answer 16

Study of fossils.

Question 17

Fossilisation process

Answer 17

1. Death of an organism.
2. Decay of soft tissues and burial.
3. Sediment accumulation.
4. Uplift and erosion and exposure.
5. Discovery.

Question 18

Types of fossils

Answer 18

• impression
• mineralised
• trace fossils
• mummified

Question 19

Relative dating

Answer 19

Is based of stratigraphy (placed on position of fossil with the strata of rock with the use of index fossils).

Question 20

Radiometric methods in absolute dating

Answer 20

Measures the proportions of naturally occurring isotopes (carbon-14 to carbon-12).

Question 21

Methods in absolute dating

Answer 21

• thhermoluminescene
• radiometric methods
• electron spin resonance

Question 22

Information from examining fossils

Answer 22

• appearance
• structure of the organism
• behaviour

Question 23

Transitional fossils

Answer 23

Any fossils that show intermediate traits and evidence of major change.

Question 24

Biogeography

Answer 24

Study of the distribution of organisms.

Question 25

Homologous features

Answer 25

Fundamental similarity of features of different species due to a common ancestor.

Question 26

Analogous structures

Answer 26

Features of different species have the same function but have evolved separately due to similar selection pressures.

Question 27

Vestigial structures

Answer 27

A reduced structure with no real function but acts as evidence of emergence from a species in which has use of the structure.

Question 28

Development biology

Answer 28

Field of biology that studies the process of growth and development of a zygote to an adult.

Question 29

Natural selection

Answer 29

Process by which individuals that have certain inherited traits are better suited to their environment and thus more likely to survive and produce more offspring

Question 30

Coevolution

Answer 30

Occurs when two interacting species evolve together in a reciprocal response to selection pressures.

Question 31

Mass extinction

Answer 31

Large-scale extinctions

Question 32

Divergent evolution

Answer 32

Spitting of an ancestral species into two different species.

Question 33

Convergent evolution

Answer 33

Independent development of analogous features in unrelated species.

Question 34

Adaptive radiation

Answer 34

From of divergent evolution in which a common ancestor gives rise to a number of new species rapidly.