There are different interspecific interactions, relationships between€¦ · are affected by interactions with biotic and abiotic factors by describing the activities below: 1.Symbiosis

• There are different interspecific

interactions, relationships between

the species of a community (what’s

the definition of a community

again?).

• While you’re at it, what’s the

definition of “interspecific”?

Introduction

Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

Here’s some inTRAspecific stuff before we

get back to the inTERspecific stuff

https://www.facebook.com/ScienceNOW/v

ideos/10154345906945108/

1:45. ties together a few things, like Gene

editing with CRISPR

• Possible interspecific interactions are introduced in

Table 53.1, and are symbolized by the positive or

negative affect of the interaction on the individual

populations.

1. Populations may be linked by

competition, predation, mutualism and

commensalism.


• Competition.

• Interspecific competition for resources can

occur when resources are in short supply.

• There is potential for competition between

any two species that need the same limited

resource.

• The competitive exclusion principle: two

species with similar needs for the same limiting

resources cannot coexist in the same place.


• The ecological niche is the sum total of an

organism’s use of abiotic/biotic resources in the

environment.

• The competitive exclusion principle can be

restated to say that two species cannot coexist

in a community if their niches are identical.

• This is the “this town’s not big enough for the

both of us” principle.

• What are some possible outcomes of this

competition?


• Classic experiments confirm this principle.

Fig. 53.2


• Resource partitioning is the differentiation of

niches that enables two similar species to

coexist in a community. Watch here new stuff!

Fig. 53.2Fig. 53.3


http://ucsdnews.ucsd.edu/pressrelease/uc_san_diego_biologists_discover_timesharing_strategy_in_bacteria?utm_content=bufferdaa8f&utm_medium=social&utm_source=facebook.com&utm_campaign=buffer

• Character displacement is the tendency for

characteristics to be more divergent in sympatric

populations of two

species than in

allopatric

populations of the

same two species.

• Hereditary changes

evolve that bring

about resource

partitioning.

Fig. 53.4


2.D.1.b. Explain how an organism activities

are affected by interactions with biotic and

abiotic factors by describing the activities

below:

1.Symbiosis (mutualism, commensalism,

parasitism)

2.Predator–prey relationships

3.Water and nutrient availability,

temperature, salinity, pH

• Predation. All these fit into the predator category.

• A predator eats prey.

• Herbivory, in which animals eat plants.

• In parasitism, predators live on/in a host and

depend on the host for nutrition.

• Predator adaptations: many important feeding

adaptations of predators are both obvious and

familiar.

• Claws, teeth, fangs, poison, heat-sensing

organs, speed, and agility.


3.E.1.a. Organisms exchange information

with each other in response to internal

changes and external cues, which can

change behavior. Explain how each situation

below relates to this statement.

1.Fight or flight response

2.Predator warnings

3.Protection of young

4.Plant-plant interactions due to herbivory

5.Avoidance responses

3.E.1.a. Organisms exchange information

with each other in response to internal

changes and external cues, which can

change behavior. Explain how each situation

below relates to this statement.

1.Fight or flight response

2.Predator warnings

3.Protection of young

4.Plant-plant interactions due to herbivory

5.Avoidance responses

• Plant defenses against herbivores include chemical

compounds that are toxic. IN AP SYLLABUS

• And look at this connection with communication TED talk

17 min . Or do a Wood Wide Web make-a-graph?

• Behavioral defenses include fleeing, hiding, self-defense,

noises, and mobbing, flocks, herds, etc.

• Camouflage includes cryptic coloration, deceptive

markings.

Fig. 53.5Copyright © 2002 Pearson Education, Inc., publishing as Benjamin Cummings

http://www.bbc.com/earth/story/20141111-plants-have-a-hidden-internet

https://www.ted.com/talks/paul_stamets_on_6_ways_mushrooms_can_save_the_world

Justify scientific claims, using

evidence, to describe how timing

and coordination of behavioral

events in organisms are regulated

by several mechanisms.

Create a representation that describes

how organisms exchange information in

response to internal changes and

external cues, and which can result in

changes in behavior. Bird songs.

• Mechanical defenses include spines.

• Chemical defenses include odors and toxins

• Aposematic coloration is indicated by

warning colors, and is sometimes associated

with other defenses (toxins). Group gains by

possible sacrifice of individuals.

Fig. 53.6


• Mimicry is when organisms resemble other

species.

• Batesian mimicry is where a harmless

species mimics a harmful one.

Fig. 53.7


• Müllerian mimicry is where two or more

unpalatable species resemble each other, like

this bee and its wasp mimic.

• Even plants can mimic.


Fig. 53.8

http://phenomena.nationalgeographic.com/2014/04/24/the-most-versatile-impressionist-in-the-forest/

• Mutualism is where

two species benefit from

their interaction.

• Commensalism is

where one species

benefits from the

interaction, but other

is not affected.

• An example would

be barnacles that

attach to a whale.

• How about this one?Fig. 53.9


Here’s a really neat look at termites!

• https://www.youtube.com/watch?v=e02keFYEW

eU

• 7 minutes. Well worth it!!

• And a shorter, 1 min., example in puffer fish

https://www.youtube.com/watch?v=e02keFYEWeU

https://www.youtube.com/watch?v=otGAVREKULI

Amensalism: is an interaction in which one organism is harmed, while

the other is neither affected nor benefited. An example is when one species

exudes a chemical compound as part of its normal metabolism that is

detrimental to another organism. The bread mold penicillium is a common

example; penicillium secrete penicillin, a chemical that kills bacteria. A

second example is alleopathy such as when black walnut tree (Juglans nigra),

secretes a chemical that harms or kills some species of neighboring plants.

• Coevolution and interspecific interactions.

• Coevolution refers to reciprocal evolutionary

adaptations of two interacting species.

• When one species evolves, it exerts selective

pressure on the other to evolve to continue the

interaction.

• For example, adaptations for speed in both

cheetahs and antelopes.

• Flowers and their pollinators are classic

examples.


• The trophic structure of a community is determined

by the feeding relationships between organisms.

• The transfer of food energy from its source in

photosynthetic organisms through herbivores and

carnivores is called the food chain.

• These concepts were first revealed by the work of

Charles Elton, the “father” of Ecology.

2. Trophic structure is a key factor in

community dynamics


• Charles Elton first

pointed out that the

length of a food

chain is usually four

or five links, called

trophic levels.

• He also recognized

that food chains are

not isolated units but

are hooked together

into food webs.

Fig. 53.10


2.D.1.c. Using one of the examples below, explain

how the stability of populations, communities and

ecosystems is affected by interactions with biotic

and abiotic factors.

1.Water and nutrient availability

2.Availability of nesting materials and sites

3.Food chains and food webs

4.Species diversity

5.Population density

6.Algal blooms

• Food webs.

• Which one(s) are the

producers?

• Which one(s) are

ONLY primary

consumers?

• What transforms

food chains into

food webs?

• A given species may

weave into the web at

more than one trophic

level.Fig. 53.11


4.C.4.a.Explain why natural and artificial

ecosystems with fewer component parts

and with little diversity among the parts

are often less resilient to changes in the

environment.

4.C.4.b.Describe why keystone species,

producers, and essential abiotic and

biotic factors contribute to maintaining

the diversity of an ecosystem.

• Dominant species are those in a community that

have the highest abundance or highest biomass (the

sum weight of all individuals in a population).

• If we remove a dominant species from a

community, it can change the entire community

structure from the bottom up.

• These are often producers.

3. Dominant species and keystone species

exert strong controls on community

structure. Bottom up, Top down regulation


4.B.3.c.Using the following examples,

explain how species-specific and

environmental catastrophes, geological

events, the sudden influx/ depletion of

abiotic resources or increased human

activities affect species distribution and

abundance.

1.Loss of keystone species

2.Kudzu

3.Dutch elm disease

• Keystone species

exert an important

regulating effect

on other species

in a community. Top

down.

Fig. 53.14


The Pisaster experiments done by Robert

Paine in Washington and elsewhere

• Demonstrated that some species that were not

dominant in terms of biomass or numbers exert a

high amount of control on the community they are

a part of. Often at the top of the food chain, can

you see how these keystone species are part of a

feedback system much like we have seen with

blood sugar and lactose and other chemicals, just

on a larger scale? Here’s his story. 20 min.

• Regulatory systems evolve naturally to result in

the homeostatic balances you see in nature.

http://www.hhmi.org/biointeractive/some-animals-are-more-equal-others-keystone-species-and-trophic-cascades

• If they are removed, community structure is greatly

affected. See this classic story of wolves in Yellowstone.

Fig. 53.15


http://www.flixxy.com/how-wolves-changed-an-entire-ecosystem.htm

• Ecological succession is the transition in species

composition over ecological time.

• Primary succession begins in a lifeless area where

soil has not yet formed.

3. Ecological succession is the sequence of

community changes after a disturbance


• Mosses and lichens colonize first and cause the

development of soil. Pioneer communities.

• An example would be after a glacier has retreated.


Fig. 53.19


• Secondary succession occurs where an existing

community has been cleared by some event, but the

soil is left intact. Like after a fire.

• Grasses grow first, then trees and other

organisms. Climax communities.


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There are different interspecific interactions, relationships between€¦ · are affected by interactions with biotic and abiotic factors by describing the activities below: 1.Symbiosis