ecological concepts

Question 1

evolution or biological evolution

Answer 1

the change in a population’s genetic makeup, gene pool, through successive generations
*all species descend from earlier, ancestral species

Question 2

macroevolution

Answer 2

long-term, large-scale changes that lead to new species (speciation), and the loss of other species

Question 3

microevolution

Answer 3

small genetic changes that occur in a pop

Question 4

development of genetic variability through mutations, random changes of the DNA in a cell; brought about by:

Answer 4

• exposure to external agents (radiation, chemicals, etc)

* random mistakes during DNA replication

Question 5

mutations are

Answer 5

random & unpredictable, only source of totally new genetic raw material (without human help), relatively rare events

Question 6

natural selection

Answer 6

process by which a particular beneficial gene or set of genes is reproduced in succeeding generations more than other genes.
This leads to a population of organisms with a greater proportion of individuals better adapted to certain environmental conditions.

Question 7

adaptation or adaptive trait

Answer 7

any genetically controlled structural, physiological, behavioral characteristic that helps an organism survive & reproduce under a given set of environmental conditions.

Question 8

structural adaptations

Answer 8

coloration, mimcry, protective cover, gripping mechanisms

Question 9

physiological adaptations

Answer 9

hibernation, chemical protection

Question 10

behavioral adaptations

Answer 10

migration, various mating behaviors

Question 11

ecological niche

Answer 11

total way of life or role of a species in an ecosystem; all physical, chemical. And biological conditions a species needs to live and reproduce in an ecosystem

Question 12

species

Answer 12

group of organisms that resemble one another in appearance, behavior, chemical makeup and processes, and genetic structure

Question 13

habitat

Answer 13

the physical location in which a species lives

Question 14

generalists

Answer 14

species with a broad ecological niche; can live in many different habitats, eat a variety of foods & tolerate a wide range of environmental conditions; less prone to extinction
EX’s: humans, flies, cockroaches, mice & rats, raccoons,coyotes, channel catfish, various weed species, etc.

Question 15

specialists

Answer 15

species with a narrow ecological niche; may live in only one type of habitat, tolerate only one type or a few types of food, tolerate only a narrow range of environmental conditions; more prone to extinction
EX’s: red-cockaded woodpecker, giant pandas, snail kite, numerous tropical rain forest species

Question 16

native species

Answer 16

species that normally live & thrive in a particular ecosystem in which they evolved or are ‘naturally’ found
EX’s: American bison, American alligator, etc

Question 17

nonnative species

Answer 17

species that migrate into an ecosystem or are deliberately or accidentally introduced into an ecosystem; also known as exotic, alien, or introduced species
EX’s: kudzu, Argentine fire ants, nutria, etc

Question 18

indicator species

Answer 18

species that play roles affecting many other organisms in an ecosystem
EX’s: many birds, frogs, & toads

Question 19

keystone species

Answer 19

species that play roles affecting many other organisms in an ecosystem
EX’s: wolf, leopard, lion, sea otter, great white shark, various bees, bats, & ants

Question 20

how quickly can a species adapt? 3 limitations

Answer 20

1) A change in environmental conditions can lead to adaptation only for traits already present in the gene pool of a population
2) The population’s ability to adapt can be limited by its reproductive capacity
3) Even if a favorable trait is present, most of the population would have to die or become sterile so individuals with the trait could dominate & pass the trait on

Question 21

speciation

Answer 21

formation of 2 species from one species as a result of divergent natural selection in response to changes in environmental conditions
Generalist species adapt to changes better

Question 22

geographic isolation

Answer 22

separation of populations of a species into different areas for fairly long times

Question 23

reproductive isolation

Answer 23

long-term geographic separation of members of a particular sexually reproducing species

Question 24

extinction

Answer 24

complete disappearance of a living species from the Earth; happens when a species cannot adapt & successfully reproduce under new environmental conditions or it evolves into one or more new species

Question 25

types or degrees of extinction

Answer 25

Background Extinction, Mass Extinction, Mass Depletion fossil/geologic evidence suggests that at least 2 mass extinctions & 3 mass depletions have occurred during the past 500 million years

Question 26

dispersal: physical (abiotic factors)

Answer 26

which control the dist of species

Question 27

dispersal: temp

Answer 27

certain species, plants & animals, will only thrive in warm climates, OR only in cold climates; some in both

Question 28

megatherm plants

Answer 28

adapted to high temps

Question 29

microtherm plants

Answer 29

adapted to within stand low temps

Question 30

water

Answer 30

no water = no photosynthesis= no plants= no animals

Question 31

xerophyte

Answer 31

adapted to low moisture conditions

Question 32

hygrophyte

Answer 32

adapted to high moisture conditions | deciduous(drop leaves) vs evergreen trees and plants(keep leaves)

Question 33

light availability

Answer 33

increase light= increase photosynthesis | shade tolerant vs shade intolerant (need direct sunlight)

Question 34

soils

Answer 34

structure, texture both affect plant root systems and thus plant survival and dispersal

Question 35

landforms: elevation

Answer 35

affects T° and moisture

Question 36

landforms: slope steepness

Answer 36

affects water availability, & soil thickness

Question 37

landforms: slope aspect

Answer 37

(compass direction a slope is facing) affects amount of sunlight, and thus T° & moisture levels

Question 38

North facing slope ___ vs south facing slope of a mountain ___

Answer 38

colder and wetter | warmer and drier

Question 39

types of biotic factors: species interaction

Answer 39

``` interspecific competition predation parasitism mutualism commensalism amensalism ```

Question 40

interspecific comp

Answer 40

members of two or more species trying to use the same limited resources in an ecosystem

Question 41

ex's of resources

Answer 41

nutrients (food), water, sunlight, space, mates, “building supplies”, etc

Question 42

if intense comp exists

Answer 42

1) Migration of one species, 2) Shift in habits or behavior through natural selection/evolution, 3) Sharp population decline 4) Extinction from that area

Question 43

resource partitioning

Answer 43

the process of dividing up resources in an ecosystem (each organism developing its own ecological niche), is one way to adapt to these conditions

Question 44

predation

Answer 44

situation in which an organism of one species (the predator) captures and feeds on parts or all of an organism of another species (the prey) EX: *grasshopper eating (preying on) grass or crops *coyote preying on rabbits or mice *often increases the biodiversity of the ecosystem

Question 45

parasitism

Answer 45

interaction between species in which one organism (the parasite) preys on another organism (the host) by living on or in the host; The parasite benefits & the host is often harmed. EX’s: tapeworms, ticks, fleas, mosquitoes, mistletoe, some fungi

Question 46

mutualism

Answer 46

species interaction in which the presence of one species is often essential to the survival of another species, but usually both species benefit from the interaction EX’s: honeybees & flowers (food/pollination), oxpeckers & black rhinoceros (food/removal of parasites), clownfish & sea anemones (protection & food/protection)

Question 47

commensalism

Answer 47

interaction between organisms of different species in which one organism benefits and the other is either helped nor harmed to any great degree EX’s: epiphytes & various trees (epiphyte gains access to water, nutrients, & sunlight while the tree is unharmed)

Question 48

amensalism

Answer 48

the inhibition of one species by another through chemical means EX: certain plants produce toxins & release them into the soil making the soil unusable by other plants, thus inhibiting the growth of competing plants