Changes In Biodiversity Over Time Flashcards Preview

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Flashcards in Changes In Biodiversity Over Time Deck (34):
1

What are 4 main conditions required for fossilization?

Rapid burial, slow decomposition, further burial, left undisturbed

2

What did animals walk on land?

440-410 mya

3

When did mammals first appear?

160 mya

4

when did flowering plants first appear?

130 mya

5

When did multicellular organisms begin to appear?

600 mya

6

What are trace fossils?

fossils that show evidence of the existence of an organism, like a footprint

7

What are mould fossils?

Fossilized impressions of remains imprinted on rock

8

What are cast fossils

Mould fossils that have been filled in by minerals

9

What is the half-life of carbon 14?

5730 years

10

How old do fossils have to be to for carbon dating to be used?

less than 50,000 years

11

How does carbon dating work?

Carbon 14 isotope decays at a known rate to the more stable nitrogen 14. The ratio of C12: C14 is measured in fossils and then used to determine the age of the fossils based on carbon 14s half-life.

12

What is potassium dating best used for and why?

very old fossils, as potassium 40 has a half-life of 1.25 billion years

13

What does potassium 40 decay to?

Argon 40

14

What is the difference between absolute and relative dating techniques?

Absolute dating techniques give an exact age of the fossil whereas relative dating techniques give an age of a fossil relative to other fossils.

15

What are index fossils?

Fossils of species that are known to have lived within
a specific and short time period

16

Why are index fossils useful?

They enable you to compare fossils of known age to those of unknown to get a relative age

17

What is stratigraphy?

Estimating rock age, based on rock layer position

18

What are homologous structures?

Features in different species with different functions but the same structure

19

What are analogous structures?

Features in different species with the same function but the different structure

20

What do homologous structures show?

that the organisms shared a recent common ancestor (divergent evolution)

21

What do analogous structures show?

that environment impacts evolution. (convergent evolution)

22

What are vestigial structures?

structures in a species that had a function in an ancestor but have little function in the current organism

23

What does developmental biology show?

That when there are similarities between different species embryo's they share a similar developmental gene and hence have a recent common ancestor

24

What occurs during convergent evolution?

When 2 species which different common ancestors develop similar traits as a result of similar selection pressures

25

What occurs during divergent evolution?

When 2 species of the same common ancestor develop different traits as a result of different selection pressures

26

Define extinction

When all members of a species permanently die out and no longer exist

27

Define background extinction

The standard rate at which species become extinct

28

Define mass extinction

A period of time during which an abnormally high number of species died out in a short time span.

29

What is an effect of mass extinction?

It can allow surviving species to expand and diverge

30

How does an organism develop an adaptation?

Through inheriting different traits from its parents.

31

Can individual organisms adapt to their environment?

No, they can adjust but only the species as a whole can develop adaptations over time

32

Where do your traits stem from?

Your genes

33

What is the extinction of the dinosaurs an example of?

Mass extinction

34

How did the dinosaurs going extinct, affect other species?

It allowed mammals to expand and diverge