bio lab 8: ecology

Question 1

population

Answer 1

defined as a group of individuals of the same species living in the same area

Question 2

intraspecific vs interspecific

Answer 2

called intraspecific
interactions while interactions between members of different species are called
interspecific interactions. These relationships have profound impacts on the success of
both individuals and of the population as a whole. Intraspecific interactions dominate the
study of Population Ecology.

Question 3

community

Answer 3

All of the populations of different species living and interacting in a given ecosystem are
collectively known as a community.

Question 4

species

Answer 4

a group of organisms that can reproduce with each other and produce fertile offspring

Question 5

Peterson moth and assumptions

Answer 5

capturing and marking animals and a second single episode of recapturing individuals.
Marks on the captured individuals should be as unobtrusive as possible, but easily
identifiable during future encounters. Examples of marking include identification bands or
tags, paint markings, fin notches, etc. The marked individuals are released back into their
environment and given time to randomly disperse into their population. The population is
then re-sampled in a recapture event. The number trapped in the second capture is
recorded.
There are several assumptions inherent in this method:
1. All individuals are equally catchable.
2. Marked animals and unmarked animals are captured randomly.
3. Marks are not lost or overlooked.
4. Catchability is not affected by being captured: i.e. previously caught individuals do
not become “trap-shy” or “trap-happy”.
5. The population is closed (no immigration, emigration, birth, or mortality).

Question 6

peterson population estimate equation

Answer 6

N=MC/R

N estimate of the actual size of the population
M number of individuals captured, marked, and released
C the total number of individuals recaptured
R number of marked individuals recaptured

Question 7

behavioural ecology

Answer 7

behavioural Ecology studies the relationship between an organism’s behaviour and the
environment in which that behaviour has evolved or is expressed. It also investigates the
way in which animals interact with their living and non-living environments.

Question 8

behaviour

Answer 8

Behaviours are defined as actions carried out by muscles or glands in response to a
stimulus

Question 9

community ecology

Answer 9

Community Ecology examines how interactions between species, such as predation and
competition, affect community structure and organization. A community is a group of
populations of different species living in close enough proximity to interact.

Question 9

agonisitc behaviours

Answer 9

Male Siamese fighting fish are extremely territorial. When one male Betta sees another, he
begins a series of responses aimed at the intruder. These behaviours are termed agonistic
behaviours (any social behaviour related to fighting, such as aggressive or submissive
behaviours). Male Bettas cannot be kept together in a tank because they will fight to the
death

Question 10

species diversity, species richness a and relative abundance

Answer 10

Species diversity quantifies the organisms that make up a community. It has two
components: species richness and relative abundance. Species richness is the number
of species present. Relative abundance is the proportion that each species represents of all
the individuals in a community. Relative abundance is worked into the species diversity
formula on the next page. We aren’t calculating relative abundance separately.

Question 11

keystone species

Answer 11

Another factor that might decrease species diversity is the loss of a keystone species. A
keystone species is a species whose presence strongly contributes to the diversity of life,
and whose extinction could consequently lead to the extinction of a great variety of other
species.

Question 12

Simpson diversity index

Answer 12

In this exercise you will assess species diversity using the Simpson Diversity Index. This
index measures diversity based on the number of species present and their relative
abundance. One advantage of this technique is that it does not require the user to be trained
in taxonomy (the science or technique of classification). All you have to do is recognize
differences between specimens.