Science - Lesson #4: Gel Electrophorisis / Evolutionary Tree

Lesson #4:

DNA Evidence of Evolution:

Gel Electrophorisis

and

Evolutionary Tree

Learning Target

Analyze DNA banding patterns from gel electrophoresis to determine evolutionary relationships of the terminator pig and interpret an evolutionary tree.

Success Criteria ✅

I am successful when I can...

🔍 Identify which organisms are most closely related by examining an evolutionary tree.
🧪 Interpret DNA band patterns from gel electrophoresis results to compare genetic similarities.
🧬 Explain how gel electrophoresis provides evidence for evolutionary relationships.
🌳 Describe how evolutionary trees represent common ancestry and divergence between species.
🤔 Justify claims about which species are more closely related using DNA evidence from a gel.

Standards:

🎯 HS-LS4-1:

Communicate scientific information that common ancestry and biological evolution are supported by multiple lines of empirical evidence.

Reminders:

EOU Evolution Exam on Thursday, May 1st

Part #1

Warm-Up

Part 2

Recap

Dinner Table Discussion

Turn and Talk:

Imagine you are having dinner with the fam, and they ask, "What did you learn today in Biology?".

To

What are we learning about?

Through

What story are we learning it through?

Today's Investigation

Yesterday, we learned that there is evolutionary evidence, such as embryonic similarities and homologous bone structure , that shows the "terminator" pig shares a common ancestor with pigs, whales and hippos.

Scientists want to figure out which of the three species is the closest relative to the terminator pig. We may have to change the name.

Part 3

4 Box Induction

Which modern day species is most similar to the "Terminator Pig"?

Evolution Lesson 4: Gel Electrophoresis

Part 4

Echo-Echo

Choral-Choral

Vocabulary

Gel Electrophoresis: a laboratory method that lets scientists sort DNA (or proteins) by size. If the bands travel the same distance, it means that the DNA is similar.

Used for:

1) Paternity tests

2) Crime-Scene Samples

3) Comparing species DNA

Evolutionary Tree (or Phylogenetic Tree): is a branching diagram that shows how different species are related through common ancestors. By following the branches back, you can see which species share a more recent ancestor—and are more closely related.

Part 4:

3 Turn n' Talks

Evolutionary Tree

Turn n' Talk Numero Dos

Explain what species are most related according to the tree. What evidence have we reviewed over the last two days that supports the hippo and terminator pig being most closely related?

Tier 2

Structure

Feature

Evidence

Similarity

Tier 3

Common Ancestor

Homologous Structure

Embryonic Similarities

Evolutionary Tree

Gel Electrophoresis

DNA

Turn n' Talk Numero Tres:

Explain what species are most related according to the tree. What evidence have we reviewed over the last two days that supports the hippo and terminator pig being most closely related?

Write three sentences using the conjunctions BECAUSE, BUT and SO on the paper provided.

Tier 2

Structure

Feature

Evidence

Similarity

Tier 3

Common Ancestor

Homologous Structure

Embryonic Similarities

Evolutionary Tree

Gel Electrophoresis

DNA

Part 6

S.I.T Protocol

Directions:

1) Read the article

S - Write down one surprising fact

I - Write down one interesting fact

T - Write down one troubling fact

Lesson #4: Evolution

Part 7

Take-Away - Key Concepts

🔑 Key Concepts: Evolutionary Trees & Gel Electrophoresis

Species that share more DNA are more closely related.
Comparing DNA helps scientists figure out how recently two organisms shared a common ancestor.
Evolutionary trees show how species have changed and split over time.
These trees help visualize evolutionary relationships and are based on shared traits or DNA evidence.
Gel electrophoresis is a tool used to compare DNA.
This lab technique separates DNA fragments by size, creating a pattern that can be analyzed.
Matching DNA band patterns suggest a close evolutionary relationship.
The more bands two organisms have in common, the more DNA they share.
Using DNA is more accurate than just comparing physical traits.
Similar body structures can sometimes be misleading, but DNA provides stronger evidence for relationships.