Biology 307 – Ecology and Human Affairs

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

Dr. Larry Linton (BI 276C)

Textbook: Ecology of a Changing Planet, 3 rd edition

Mark B. Bush

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

More important info:

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

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

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

Outline

v Introduction to Ecology

v Evolution and Natural Selection

v Physiological Ecology

v Behavioural Ecology

Outline

v Introduction to Ecology

v Evolution and Natural Selection

v Physiological Ecology

v Behavioural Ecology

Introduction to Ecology

Chapter 1.1-1.3, Bush

Introduction to Ecology

vWhat is Ecology?

v The Scientific Method

v Ecology versus Evolution

What is Ecology?

v 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?

v 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

v 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

v concern over changes to the environment due to human action

v not science

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

Introduction to Ecology

vWhat is Ecology?

v The Scientific Method

v Ecology versus Evolution

The Scientific Method. I.

v starting point: observation(s) of a natural phenomenon

v hypothesis is proposed to explain phenomenon & predictions made

v hypothesis tested (typically with experiments) & results obtained

The Scientific Method. II.

v interpret results to determine whether they are consistent with hypothesis

v yes? hypothesis supported; no? hypothesis rejected

v N.B. hypotheses never proven, only supported

Example

v Hypothesis: – Plant species

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

Collect data

Fleshy DrySpondias radlikoferi(1.93g) Cordiaalliodora (0.009g)Carica papaya (0.011g) Albiziapurpusii (0.03g)Ficus insipida (0.002g) Senna multijuga (0.20g)

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

Scientific method and experiments

v The previous example did not involve an experiment

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

v An experiment involves a manipulation of some sort

Example of an experiment

v Hypothesis: – Bearberry plants

with fewer flowers will have heavier fruits

Experimental design:

vmake two groups of equal number of bearberry plants

v In one group, leave plants alone (control group)

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

Data collection and analysis:

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

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

Hypothesis → Theory

v hypotheses are tentative explanations for an observed phenomenon

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

Introduction to Ecology

vWhat is Ecology?

v The Scientific Method

v Ecology versus Evolution

What is Evolution?

v 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

v Ecology and evolution are tightly linked

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

v 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

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

v 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

v Ecology is an investigative science that relies on the scientific method

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

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