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Flashcards in Exam 3 Deck (55):
1

Earth's age

4.55 Billion years

2

Evolution

Change in allele frequency within a POPULATION from one generation to the next

3

Selection vs Genetic drift

Selection-species with more advantageous traits are more likely to survive and reproduce
Genetic drift-evolution due to random chance

4

Microevolution vs Macroevolution

Microevolution-evolution within a species
Macroevolution-evolution at or above species level

5

Phylogenetic trees

Show the relationships between species

6

Homologous characters

Common characteristics between multiple species (Ex. having a spinal column)

7

Vestigial traits

Loss of a function as opposed to a gain
(Ex. our tailbone, Emu ability to fly, dolphins ability to smell)

8

Vestigial genes

When a gene is "turned off" because it's not necessary for survival (aka "pseudogenes")

9

Selection

Process by which organisms better adapted to their environment survive and pass on their genes

10

Relationship between selection, adaptation, fitness, evolution

Species with these traits are more likely to survive

11

Directional selection

Shift average of a trait in either direction (whole bell curve moves right or left)

12

Stabilizing selection

Eliminates extremes, (bell curve narrows on edges/less bell shape)

13

Diversifying selection

Favors extremes, eliminates intermediate (Bell curve in middle splits into two on ends)

14

Sexual selection

Favoring traits that increase the ability to mate and produce offspring

15

Sexual selection vs selection for survival

Sexual selection attracts more mates but makes one a target for predators

16

Coevolution

Continuous evolution between two or more different species

17

Red queen hypothesis

One evolving to keep up with the other time and time again (keep running just to stay in the same place)
(Ex. Monarchs and milkweeds, orchids and moths, bat's tongues and flowers, Darwin's orchid)

18

Genealogical species concept

Defines species based on evolutionary relationships

19

Speciation

Formation of new and distinct species in the course of evolution

20

Allopatric speciation

Physical barrier to gene flow (Ex. mountains, rivers, continental drift)
(Shrimp separated when the isthmus of Panama rose)

21

Sympatric speciation

No physical barrier to gene flow (Ex. hybridization of plants

22

Gradualism vs Punctuated equilibrium

Gradualism-slow process of small evolutionary changes.
Punctuated equilibrium-rapid evolution followed by periods of stasis

23

Evidence for evolution

Uplift of the Andes
Finch beak size evolves in response to rainfall and available seeds in the Galapagos
E. coli experiment

24

Phylogenies

The development or evolution of a particular group of organisms.

25

Biodiversity

Variety of life in the world or in a particular habitat

26

Inputs of light reactions

Light, H20

27

Speciation rates on a phylogeny

Increase with reproductive isolation

28

Inputs of Calvin cycle

ATP, NADPH, CO2

29

Outputs of Calvin cycle

Sugars

30

Desired product vs byproduct

Desired product-glucose
Byproduct-O2

31

Chlorophyll

Pigment that turns chloroplasts green

32

Chloroplast anatomy and role in photosynthesis

Stroma-fluid area inside the cell (cytoplasm of plant cells)
Thylakoid-disk shaped membrane that contains chlorophyll

33

Light reactions vs. Calvin cycle

LR-occur in thylakoids
Calvin cycle-occurs in stroma

34

Stomata/guard cell and function

Stomata-pores in the leaves of plants that allow gas exchange
Guard cells-cells surrounding stomata that open of close the pore

35

CAM vs C3 photosynthesis, process, evolution

CAM-Stomata open during the nighttime (prevent a lot of water escaping)
C3-Stomata open during the day

36

Role of stomata

Let CO2 into the plant cells, but water can evaporate

37

Parasitic plants

Energy obtained from host
No need for photosynthesis

38

Evolution and origin of chloroplasts

Originated from a photosynthetic bacteria that was engulfed by a larger cell

39

Climate change

Changes in temperature (usually higher), changes in weather patterns (more rain, less rain), more extreme weather events

40

Historical climate change

Wobbling of the earth, angle changes and can cause events like ice ages

41

Methods for getting climate data

Dendrochronology-counting tree rings, youngest rings at edge, thicker rings correspond to higher temps/moisture (measure back 13,000 years)
Ice cores/fossil air-collect date, temperature, and CO2 concentration (data back to at least 500,000 years ago

42

Hockey stick result

Steady rate and then dramatic increase creating a hockey stick shape

43

Greenhouse effect

Higher CO2 creates higher temperatures

44

Threats of climate change/why how they're threats

Glaciers melt-less home for animals
Sea levels rise-less area for humans
Habitats shift upwards-nowhere to go
Populations become more isolated-
Lower genetic diversity

45

Organisms response to climate change

Migrate-move
Phenotypic plasticity-change phenotype (reproducing earlier)
Evolve-beneficial adaptations to arise

46

Morphological species concept

Species defined by their physical characteristics
Different species have different physical characteristics
Only one useable on fossils

47

Biological species concept

Species defined by their ability to interbreed and produce offspring
Can interbreed=same species
Can't=different species

48

Sometimes hybrids are fertile

Especially in plants

49

Morphological species concept

PROS
Easy to use
Only option for fossils
CONS
Convergent evolution
Cryptic species
Phenotypic plasticity

50

Biological species concept

PROS
Highly intuitive
Directly relates to gene flow
CONS
Clearly distant species that can still interbreed
Useless for asexual organisms

51

Genealogical species concept

Defines species based on evolutionary relationships
A species is a unique and distinct evolutionary lineage

52

Genealogical species concept

PROS
Based on evolutionary relationships and DNA
CONS
Hardest to use, (time and money)
Still have to subjectively decide species vs. variety within species

53

Reproductive isolation

Barriers to gene flow between populations promote speciation
Reproductive isolation is critical to speciation, regardless of the species concept used

54

Pre-mating barriers

Temporal, behavioral, geographic

55

Pattern of selection that drives speciation?

Diversifying selection