Evolution- The Broad Patterns of Evolution Flashcards Preview

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Flashcards in Evolution- The Broad Patterns of Evolution Deck (32)
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1

What macroevolutionary changes does the fossil record show? (3)

1. Emergence of terrestrial vertebrates
2. Origin of photosynthesis
3. Long-term impacts of mass extinctions

2

What are the biases in favour of the species that have the chance of becoming a fossil?

1. Existed for a long time
2. Were abundant and widespread
3. Had hard parts
4. Lived in shallow aquatic habitats

3

How are rocks and fossils dated?

- The sedimentary strata reveal the relative ages of fossil
- Absolute age can be determined by radiometric dating

4

How are isotopes related to rocks and fossils?

- A parent isotope decays to a daughter isotope at a constant rate
- Each isotope has a known half life, the time required for half the parent isotope to decay

5

How are Carbon-12 and Carbon-14 useful?

- Organism accumulates carbon during life
- Ratio of 14^C to 12^C or 14^C to 14^N can be used to determine the fossils age

6

What are the 3 eons of the geologic record?

1. Archaean
2. Proterozoic
3. Phanerozoic

7

What are the 3 eons within the Phanerozoic eon?

1. (Pre-cambrian) Paleozoic
2. Mesozoic
3. Cenozoic

8

How are photosynthesis and the oxygen revolution related?

- Earliest types of photosynthesis didn't produce oxygen
- Oxygenic photosynthesis probably evolved in Cyanobacteria

9

How did the accumulation of Oxygen affect the planet?

- Resulted in a toxic challenge for most organisms
- Created an opportunity to gain an abundant energy from light and opportunities to exploit new ecosystem

10

What is endosymbiosis?

-Prokaryotic ancestors of mitochondria and plastids probably gained entry to host cell as undigested prey or internal parasites
- As they became more interdependent hosts, endosymbionts became a single organism

11

How are mitochondria and plastids related?

- Splitting resembles binary fission
- Homologous membrane structure and function
- Both have own circular DNA
- Similar ribosome structure to prokaryotes

12

What is the Colonial Connection?

The first multicellular organisms were colonies of prokaryotes

13

What is the Cambrian Explosion?

It refers to the sudden appearance of fossil resembling modern phyla in the Cambrian period. It provided the first predator-prey interactions

14

What is the geologic time scale?

- Cenozoic: 0-65 mya
- Mesozoic: 65-251 mya
- Paleozoic- 251-542 mya
- Pre-cambrian: 542 mya- 4.6 bya

15

What do plate tectonics do?

They describe how earth's crust is composed of plates floating on earth's mantle. Tectonic plates move slowly through the process of continental drift

16

What do oceanic and continental plates do?

They can collide, separate, or move past each other

17

What are the consequences of continental drift? (3)

- Deepening of ocean basin
- Reduction in shallow water habitat
- Colder and drier climate in land

18

What are two of the most famous mass extinctions?

1. Permian
2. Cretaceous

19

What is the Permian extinction?

- Claimed 96% or marine animal species and 8/27 orders of insects
-Caused by volcanic eruptions

20

What is the Cretaceous extinction?

- Doomed many marine and terrestrial organisms especially non-feathers dinosaurs
- Large meteor impact

21

What are the consequences of mass extinctions? (3)

1. Alter ecological communities
2. Take from 5-100 million years for diversity to recover
3. Pave the way for adaptive radiations

22

What are adaptive radiations?

Evolution of diversely adapted species from a common ancestor upon introduction to new environmental opportunities

23

What are some worldwide adaptive radiations?

- Mammals underwent one after the extinction of non bird dinosaurs
-Photosynthetic prokaryotes, large predators in the Cambrian, land plants, and tetrapods

24

What are some regional adaptive radiations?

-Can occur when organisms colonize new environments with little competitions for example the Hawaiian islands

25

What do developmental genes control?

The rate, timing, and spatial pattern of changes in organisms from during development into and adult

26

What is heterochrony?

An evolution or a change in the rate or timing of developmental events. It can have a significant impact on body shape

27

What is paedomorphosis?

The rate of reproductive development accelerated compared to somatic development

28

What are homeotic genes?

They determine the position of basic features, such as where wings and legs develop on a bird or the arrangement of floral structures

29

What are Hox genes and what happens if they're expressed in the wrong location?

Hox genes provide positional info for development of fins in fish and limbs produced in tetrapods. If in the wrong location, body part can be produced in the wrong location

30

What is the comparison between tinkering and evolution?

It is a process in which new forms arise by the slight modification of existing forms