Lecture 1 - Introduction to Evolutionary Biology

What is the central unifying concept of biology?

Evolution

Who said "Nothing in biology makes sense except in the light of evolution"?

Theodosius Dobzhansky

Define biological evolution in the simplest terms.

Change in inherited attributes of populations across generations

What are the two conditions required for evolution?

1. Variation in traits among individuals in a population

2. Traits must be heritable

What ultimately explains the origin of biological diversity at all scales?

Evolution

What six conclusions about evolution have been scientifically verified?

1. Organisms have changed over time

2. Changes are gradual

3. Favorable traits are passed down

4. Lineages split via speciation → biodiversity

5. All species share common ancestry

6. Adaptations arise from natural selection

Define biodiversity.

The diversity of life on Earth; the number and kinds of organisms in a given area

Define adaptation (noun).

A trait that makes an organism better able to survive/reproduce in its environment

Define adaptation (verb).

The evolutionary process that produces and maintains such traits

What are the two main areas of evolutionary biology?

1. Evolutionary history (patterns)

2. Evolutionary mechanisms (processes)

Define microevolution.

Evolutionary changes within species, focusing on mechanisms

Define macroevolution.

Evolutionary changes among species, focusing on history

Why can't evolutionary history and mechanisms be studied independently?

They are interconnected; understanding patterns requires knowing processes, and vice versa

What does a phylogenetic tree represent?

Evolutionary relationships among species via common ancestry

How is a phylogenetic tree different from a family genealogy?

It is uniparental, showing lines of descent from common ancestors

What is the main goal of studying evolutionary mechanisms?

To identify processes responsible for evolutionary change (e.g., natural selection, genetic drift, mutation, migration)

At what biological level do evolutionary mechanisms mainly act?

The population level

What are the four main approaches used in evolutionary biology?

1. Observational (describe/quantify)

2. Theoretical (models)

3. Comparative (data across species)

4. Experimental (manipulate system + statistical analysis)

If a scientist breeds plants under controlled conditions to test inheritance of a trait, what kind of evolutionary study is this?

Experimental

Give 3 examples of why evolution matters in medicine.

• Predicts cancer evolution

• Develops evolution-proof drug treatment

• Explains why some diseases are population-specific

Give 2 examples of why evolution matters in agriculture.

1. Avoid herbicide/insecticide resistance

2. Identify genes important in crop evolution

Why is evolution important in environmental science?

To determine if animals can adapt quickly enough to climate change

Why do some people doubt evolution despite strong evidence?

• It's a recent concept (~165 years old)

• It has personal implications about human origins

• It conflicts with literal interpretations of religious texts

Why is it important to communicate that evolution is as empirically supported as physics or chemistry?

Because many doubts stem from misconceptions about its scientific validity