Topic I - Taxonomy and Scientific Method

Taxonomy

Discipline of naming organisms and classifying them

Nomenclature

System of rules for naming things

Folk Taxonomy

Local name for an animal/species, may not be a rigorous scheme to capture biological relationships

Linnaean System

Developed by Carl Linnaeus, classification system based on grouping species using similarities.

Kingdom
Phylum
Class
Order
Family
Genus
Species

Taxon/Taxonomic Unit

A unit of classification at any rank (species, class, genus, etc.)

Binomial Nomenclature

Name first begins with its genus (capitalized), second part is the species. Additionally, authority (person who discovered it) and year of discovery are added.

Iris germanica (Linnaeus, 1753)

Limitation of Linnaeus

1. At high levels, groups and families may not be comparable.

   -Features/characters may be informative in one group, but not useful in another.

   -Number of features also may be different (features needed to differentiate).

2. Evolutionary relationship is not depicted

   -Foundation is based on similarity, not genealogy or evolutionary relationships

Evolutionary Theory

Started by Darwin, idea that organisms descend from their ancestors through a process of modifications

Theory

Set of broad/comprehensive explanations of a part of the natural world. Must be based on evidence from repeatable experiments.

Characteristics of Theories

-Broad in nature

-Strong evidence supports it

-Helps guide future research

-Often contains multiple hypotheses or other theories

Facts and Data

Facts - Indisputable observations/information

Data - Recorded observations in two forms;

1. Qualitative - discrete units (such as colour)

2. Quantitative - Continuous/numerical records (height)

Hypothesis

Possible explanation of a natural event, has to be based on factual data and should be testable and falsifiable

Characteristics of Hypotheses

-Specific or narrow in nature

-Supported by evidence

-Helps provide a predictive explanation for testing

-Should be falsifiable

Observation Questions

Mechanistic Question - “What or how”, not directly linked to evolution

Evolutionary Question - “Why did it adapt, in what process, etc”

Inductive Reasoning

A logical process to reach a conclusion by repeated observations.

Deductive Reasoning

A logical process to reach a conclusion from a premises assumed to be true. Formulates ideas leading to a hypothesis.

“If A is true and B is true, C should be true.”

Controlled Experiment

Scientific test with one, or several independent factors being modified. Has two main groups;

1. Control group, variables remain unchanged, needed to determine if modifications cause observed results

2. Experimental group, group undergoing variable changes.

Correlation

Two things tend to progress and change together, but do not cause one another.

Causation

Changes in one thing causes changes in another.