Biology 307 – Ecology and Human Affairs

Instructors: Dr. Jana Vamosi (BI 238A)&

Dr. Larry Linton (BI 276C)

Textbook: Ecology of a Changing Planet, 3rd edition

Mark B. Bush

http://cwx.prenhall.com/bookbind/pubbooks/bush3/

More important info:

Notes can be obtained from: http://www.ucalgary.ca/~biol307

E-mail me for questions at: biol307@ucalgary.ca

Marking is going to be based on:1 midterm (Feb. 28th) ----- 50%1 final (non-cumulative) ---50%

Outline

Introduction to Ecology

Evolution and Natural Selection

Physiological Ecology

Behavioural Ecology

Outline

Introduction to Ecology

Evolution and Natural Selection

Physiological Ecology

Behavioural Ecology

Introduction to Ecology

Chapter 1.1-1.3, Bush

Introduction to Ecology

What is Ecology?

The Scientific Method

Ecology versus Evolution

What is Ecology?

The science that attempts to understand the distribution and abundance of organisms

– e.g., why are dandelions abundant in some areas, but virtually absent from other areas?

Dandelion Distribution

vs.

soil characteristics?

herbivores?

seed dispersal?

What is Ecology?

Some questions get at the question of the distribution and abundance of organisms in a more indirect manner

– e.g., what determines which male proboscis monkeys will mate and which will not?

Mate choice in the Proboscis monkey

vs. Environmental Science

The scientific study of the influence of human actions on natural processes

– e.g., how is the rattlesnake’s distribution affected by ranching?

vs. Environmentalism

concern over changes to the environment due to human action

not science

– e.g., how can we encourage hikers to stay on marked trails in mountain meadows?

Introduction to Ecology

What is Ecology?

The Scientific Method

Ecology versus Evolution

The Scientific Method. I.

starting point: observation(s) of a natural phenomenon

hypothesis is proposed to explain phenomenon & predictions made

hypothesis tested (typically with experiments) & results obtained

The Scientific Method. II.

interpret results to determine whether they are consistent with hypothesis

yes? hypothesis supported; no? hypothesis rejected

N.B. hypotheses never proven, only supported

Example

Hypothesis: – Plant species

with fleshy fruits have heavier seeds than plant species with dry fruits

Collect data

Fleshy DrySpondias radlikoferi(1.93g) Cordia alliodora (0.009g)Carica papaya (0.011g) Albizia purpusii (0.03g)Ficus insipida (0.002g) Senna multijuga (0.20g)

mean seed weight (Fl) mean seed weight (Dr)

Scientific method and experiments

The previous example did not involve an experiment

Ecological questions can be approached in a variety of ways (comparative, experimental)

An experiment involves a manipulation of some sort

Example of an experiment

Hypothesis: – Bearberry plants

with fewer flowers will have heavier fruits

Experimental design:

make two groups of equal number of bearberry plants

In one group, leave plants alone (control group)

In the other, cut off some flowers (treatment group)

Data collection and analysis:

Measure the weights of fruit in the plants in the control and treatment groups

If weight(control) < weight(treatment), you have found support for your hypothesis (fewer flowers leads to larger fruit)

Hypothesis Theory

hypotheses are tentative explanations for an observed phenomenon

theories are widely accepted explanations that are broad in scope and have a large body of evidence supporting them

Introduction to Ecology

What is Ecology?

The Scientific Method

Ecology versus Evolution

What is Evolution?

EVOLUTION: genetic changes within a lineage or population that result in population-level phenotypic changes

– PHENOTYPE: the “appearance” of an organism e.g., physiology, anatomy, behaviour; the expression of the genes that have been inherited from the parent.

Ecology versus Evolution

Ecology and evolution are tightly linked

Both ecology and evolution seek to answer the common question of why is the natural world organized as it is

Ecology seeks the more proximate answer while evolution seeks the ultimate answer (i.e., there is a historical element to evolutionary questions)

Dandelion Distribution

vs.

A pattern of potential interest to both ecologists and evolutionary biologists

Example – dandelion distribution

ecologist might measure how abiotic (e.g., sunlight) and biotic (e.g., herbivore density) factors in the two habitats affect dandelions

evolutionary biologist might search for phenotypic traits in the dandelion that may (a) increase ability to survive in the first habitat or (b) prevent colonization and persistence of dandelions in second habitat

Summary

Ecology is an investigative science that relies on the scientific method

The scientific method requires observation, creation of a hypothesis, and data collection to refute or support the hypothesis.

Ecology and evolution are two separate disciplines that overlap in their investigation of the natural world.