Life Over Time and Mass Extinctions Flashcards Preview

BIOL 141 > Life Over Time and Mass Extinctions > Flashcards

Flashcards in Life Over Time and Mass Extinctions Deck (44):
1

Why are plants and animals in India different than Southeast Asia?

India was its own continent until 45 million years ago

2

Angiosperm

flowering plant

3

Gondwana

Ancient supercontinent that consists of Africa, South America, Australia, Antartica, India, and the Arabian Peninsula

4

How do lizard species on mainland California compare in diversity to those found on islands?

Due to greater ecological opportunities on islands, there is greater differences between island species

5

What is exceptional about the early animal faunas from the Ediacaran period just before the Cambrian?

soft-bodied animals are well represented by these fossils

soft bodied fossils are rare

6

Key innovation (evolutionary innovation)

a novel phenotypic trait that allows subsequent success of a taxonomic group

7

Does genetic drift directly cause adaptive radiation?

No

8

Can an unusual event splitting a habitat, such as a hurricane led to adaptive radiation?

No

9

When did Pangea occur?

Late Paleozoic and early Mesozoic era

10

What major evolutionary episode corresponded the closest with the formation of Pangea?

Permian extinctions

11

How do fossils start to form?

Start with burial in sediment

12

Intact fossil

forms when decomposition does not occur and the organic remains are preserved intact

13

Compression fossil

forms when sediments accumulate on top of the organism and become cemented into rocks such as mudstone or shale

the sediments weight compresses the organic material below into a thin, carbonaceous film

14

Cast fossil

forms when organisms decompose after they are buried

the hole that remains fills with dissolved minerals, which creates an accurate cast of the remains

15

Permineralized fossil

forms when organisms decompose extremely slowly

16

Trace fossil

forms when sedimentation and mineralization preserve indirect evidence of an organism in the environment

ex: footprints, tracks, feces

17

Conditions for fossils to occur

1. buried rapidly

2. decompose slowly

18

Habitat bias

Organisms that live in areas where sediments are actively being depositing (beaches, swamps) are much more likely to form fossils than are organisms that live in other habitats

19

Taxonomic and Tissue Bias

Organisms with hard parts, such as bones or shells, are most likely to leave fossil evidence

similar idea applies with tissues

20

Temporal bias

Recent fossils are much more common than ancient fossils

The older a fossil is, the longer it has been exposed to destructive forces

21

Abundance bias

fossil record is weighted towards common species

22

Paleontologists

scientists who study fossils

23

Why is it hard to estimate when species first appeared in the fossil record?

A particular species or lineage can exist for millions of years before leaving fossil evidence

24

Precambrian

Interval between the formation of the earth and the appearance of most animals (541 bya)

Unicellular

Oxygen was virtually absent until photosynthetic bacteria

25

Phanerozoic Eon Eras

Paleozoic, Mesozoic, and Cenozoic

26

Paleozoic Era

starts with appearance of most major animal lineages

ends with the obliteration of almost all multicellular life-forms (end-permian extinction)

initial diversification of the animals, land plants, and fungi, as well as the appearance of land animals

27

Mesozoic Era

begins with end-permian extinction and ends with the extinction of the dinosaurs

gymnosperms were dominant plants

dinosaurs were dominant vertebrates

28

Cenozoic Era

angiosperms were dominant plants

mammals were dominant vertebrates

29

What era are we currently in?

Cenozoic era

30

Adaptive radiation

the sudden appearance of related, diverse species in the fossil record

31

3 Hallmarks of Adaptive radiation

1) monophyletic group

2) speciated rapidly

3) diversified ecologically (occupy many niches)

32

Niche

range of conditions that a species can tolerate and the range of resources that it can use

33

Ecological opportunity

Can trigger adaptive radiation

marked by the availability of more resources

34

When did most modern animal phyla evolve?

Paleozoic

35

When did animals first appear?

Precambrian

36

Flowering plants first appeared during?

Mesozoic era

37

How to determine if two species are an example of adaptive radiation?

Ask yourself if they came from a single lineage

38

Stromatolites

fossilized mats of billions of bacteria cells

oldest found 3.5 bya

39

What era was the Cambrian explosion?

Paleozoic

40

What conditions allowed for the Cambrian explosion?

1) oxygen levels rose rapidly
2) evolution of predation
3) new niches beget more new niches
4) new genes, new bodies

41

What new genes were developed during the Cambrian explosion?

Hox genes

determine where things are placed in the body developmentally

42

3 domains of life

Bacteria, archaea, eucarya

43

Intrinsic factors of adaptive radiation

Evolution of key morphological, physiological, or behavioral traits

These traits are called synapamorphies

44

Extrinsic factors of adaptive radiation

ex: favorable new conditions in the environment