Changes in biodiversity over time

Question 1

Evidence of evolution

Dating techniques
Define the two main types of dating techniques
-Relative dating

Answer 1

Utilizes what is interestingly termed the principle of superposition (look in fossil record, fossils in rock strata closer to surface is younger than the fossils in deeper rock strata).

Question 2

Evidence of evolution

Dating techniques 
Define the two main types of dating techniques 
-Absolute dating 
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Answer 2

-Carbon 14 dating
potassium-argon dating and argon-39/argon-40 dating
-Electron spin resonance

Question 3

Evidence of evolution
Dating techniques
Relative dating

Define principle of correlation (index fossil)

Answer 3

Refers to index fossil, a fossil that is useful for dating and correlating the rock strata in which it is found.

Question 4

Evidence of evolution
Dating techniques
Relative dating

Characteristics of index fossils
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Answer 4

• distinctive
• abundant (many)
• wide geographic distribution
• short time in geologic history

Question 5

Evidence of evolution
Dating techniques
Absolute dating

Carbon dating

Answer 5

Only valid for fossil under age of 60,000 years (More detail, pg 53)

Question 6

Evidence of evolution
Dating techniques
Absolute dating

Potassium-argon dating

Answer 6

Look at the concentration of argon-40 in the rock near the fossil is determined, we can use this to determine the age of the actual rock. (Extremely old fossils can be dated here).

Question 7

Evidence of evolution
Dating techniques
Absolute dating

Electron spin resonance

Answer 7

Used for fossils between 50,000 and 500,000 years (process is on pg 54)

Question 8

Evidence of evolution

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Answer 8

• Dead organism are rapidly buried and compressed under layers of rock/soil before decomposing
• Oxygen-poor and alkaline conditions are conducive to fossilization.
• Hard-tissues in the organism, including bone, may be replaced by minerals or a carbon film producing mineralised fossil

Question 9

Evidence of evolution

Define transitional fossil

Answer 9

Fossils of organisms that are in the intermediate stage of evolution from one species to another species

Question 10

Evidence of evolution
fossil record

How does mould occur

Answer 10

After a long period of time bones decompose leaving space in rock where body was (cavity)

Question 11

Evidence of evolution
fossil record

How does cast form

Answer 11

The cavity of mould can be filled with another material which will take the impression of the organism ie lava

Question 12

Evidence of evolution

Comparative anatomy

Answer 12

All species have evolved from common ancestor (compare to show relatedness of animals)

Question 13

Evidence of evolution
Comparative anatomy

Define analogous structures

Answer 13

Which have same function but markedly different structures (ie panda thumb)

Question 14

Evidence of evolution
Comparative anatomy

Define vestigial structures

Answer 14

Which are a reduced remnant of a structure that was fully functional in an ancestor (ie tail)

Question 15

Evidence of evolution
Comparative anatomy

Define homologous structures

Answer 15

Structures with very similar morphologies although may serve different functions (ie same hand bones as whale)