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Flashcards in Chapter 4: Evolution Deck (37)
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1

Define: Divergent Evolution

increases differences between species as a result of living in [slightly] different environments

2

Define: Convergent Evolution

decreases differences between [unrelated] species as a result of adapting in similar environments

3

Define: Mutation

Accidental changes in DNA

4

Allopatric Speciation

When new species are generated as a result of the same species being separated into different geographical locations

5

Directional selection

When a trait is driven in one direction(ex. if all snails adapt to have thick shells)

6

Stabilizing Selection

When a intermediate trait is favoured(ex. all snails adapt to have shells of intermediate thickness)

7

Disruptive Selection

When traits diverge in two or more directions(ex. some snails have thick shells, some have thin shells)

8

Sympatric Speciation

When species from populations become reproductively isolated within the same area(ex. species mating at different seasons)

9

Phylogenetic Trees

Diagrams representing the divergence and relationship between species, and how certain traits have evolved.

10

What is the average time a species tends to exist on Earth?

1-10 million years

11

Extirpation

Local extinction

12

What does it mean for a species to be ENDEMIC to a region?

Endemic species only exist in one region on Earth

13

What constitutes a mass extinction?

when 50-95% of all species on Earth go extinct within a relatively short amount of time

14

What mass extinction are we currently living in?

6th- Anthropocene

15

When did the mass extinction of the dinosaurs occur?

~66 million yrs ago

16

Ecosystem

communities and the nonliving material and forces they interact with

17

Biosphere

All the living things on earth and the areas they inhabit

18

What was the largest mass extinction?

Permian-Triassic ~252 mya

19

define: cell

The smallest unit of living
matter able to function
independently, made up of organelles

20

List the hierarchy of matter within organisms from smallest to largest: organ system, organism, molecule, tissue, organelles, atom, organ, macro-molecule

atom, molecule, macro-molecule, organelle, cell, tissue, organ, organ-system, organism

21

What is the distinction between a community and a population?

Community consists of all the different species living within a region, a population is only one species

22

What is a species' NICHE?

the species use of resources and functional role within a community(habitat use, food selection)

23

Community Ecology

focuses on interactions among species

24

Population Ecology

investigates the quantitative dynamics of how individuals within a species interact

25

Ecosystem Ecology

studies living and nonliving components of systems to reveal patterns

26

Define a SPECIALIST(with regards to species)

A species that has a very specific niche, usually very good at what they do but are vulnerable to change

27

Define a GENERALIST(with regards to species)

A species with a very broad niche, able to live in many different habitats/environments

28

What are the benefits/drawbacks of HIGH vs. LOW density population of a species?

High: Easier to find mates, but more competition, vulnerability to predators, and more likely to catch disease
LOW: Harder to find mates, but can leave with more space and resources

29

What are the three different types of population distribution? Which one is the most common in nature?

Random: individuals are located haphazardly in space with no specific pattern(not common)
Uniform distribution: individuals are evenly spaced.(occurs when individuals hold territories or otherwise compete for space)
Clumped distribution: organisms arrange themselves according to the availability of the resources they need to survive (MOST common)

30

Define: Crude birth/death rate

Number of births/deaths per 1000 individuals in a given time frame