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1

3 species concepts to consider

species diversity

genetic diversity

ecosystem diversity

**All are necessary for continued survival of species and natural communities

2

Components of species diversity

species concepts
classications
origin of species
measuring species diversity

3

Components of genetic diversity

gene pools
differences among populations

4

Components of ecosystem diversity

physical environments
species interactions
trophic levels
keystone species and resources

5

What is included in species diversity?

all species on earth

represent range of evolutionary adaptations to particular environments

provide many plants and animal products that can be used as food, shelter, and medicine.

6

What are the 2 common definitions of species concepts?

morphological species definition
biological species definition

7

Species concepts: What is the morphological species definition

a group of individuals that is morphologically or biochemically distinct from other groups

-not helpful with scale
-ex. all birds distinct from mammals and reptiles

8

Species concepts: what is the biological species definition

a group of individuals that actually or potentially breed among themselves and do not breed with individuals of other groups

9

What are the issues with the biological species definition?

-unambiguous
-operationally difficult to determine
-not generally useful

10

What are two general problems with trying to classify species?

cryptic biodiversity

hybrids

11

What are the 5 kingdoms that are generally recognized?

plants
animals
fungi
protists
monerans (bacteria)

12

How are species classified, from biggest to smallest classification?

Kingdom
Phylum
Class
Order
Family
Genus, species

13

Name two theories of how new species originate.

transformation of species (phyletic evolution= cladogenesis = speciation)

adaptive radiation

14

What is adaptive radiation?

the evolution of many species from a single ancestor in response to many different environments

seen and studied on islands

general phenomenon
-marsupials (australia)
-mammals (s. am.)
-flowering plants

15

Define the transformation of species

multiplication of species via phyletic evolution/cladogenesis/speciation

16

Can speciation maintain current levels of biodiversity? Why?

no.

rate= higher for extinction than speciation by 1000x

area of habitat = smaller areas prevent speciation.
-less of Earth's surface supports natural communities = less opportunity for speciation and evolution

17

Why can't speciation of most threatened species maintain the current level of biodiversity?

because many threatened species are the sole remaining representatives of their genus or family.

ex. coelacanth in Indian Ocean
Giant panda in China

extinction of these could not be balance by appearance of new species.

18

Three ways to measure species diversity

alpha diversity (species richness)
gamma diversity
beta diversity

*In practice, these are often correlated.

19

What is species richness/ alpha diversity?

a way to measure sp. diversity

"the number of species in a community"

ex. a forest in wisconsin vs. the amazon which would have greater # of species

20

What is gamma diversity

the number of species in a large region (or continent)

includes diverse biological communities or wide geographic areas

21

What is beta diversity?

variability of sp. composition along environmental or geographical gradients

gamma diversity/ alpha diversity = variability

22

Define genetic diversity

the genetic variation within species
-among individuals of a single population
-among geographically separate populations

23

Why is genetic diversity in a gene pool important? (2)

-genetically variable individuals and populations appear to have higher fitness (better survival and reproduction)

-genetic variation is required for evolution in response to a changing environment

24

Define gene pool

total array of genes and alleles in a population

25

How do different genetic alleles arise?

from genetic mutation.

alleles are just a different form of a gene

26

Individuals can be _______ or ________ for a gene.

homozygous
heterozygous

genotype determines their phenotype

27

Monomorphic vs. polymorphic populations

a population has either one allele (monomorphic) or multiple alleles (polymorphic) for a trait

ex. a tribe has only the allele for blonde hair.

28

What is the cause of genetic differences among populations?

Populations often differ genetically
-esp. in widespread sp. that have a broad environmental range

Cause:
-some of the genetic differences may be adaptive and caused by selection

(others may not be adaptive & caused by genetic drift)

29

Selection of an allele vs. genetic drift

selection: differential survival and reproduction of different genotypes

genetic drift: random fluctuations of allele frequencies. not necessarily a good thing. Happens with small populations.

30

Define gene flow

transfer of alleles among populations through migration and mating.

-individuals, seeds, pollen grains
-reduces differences between populations
(which means it opposes genetic drift)