Reproductive Barriers & Evidence-Based Speciation Analysis.
This digital lesson examines how new species form using real biological examples and structured student choice. Students investigate speciation as a process driven by population separation, selective pressures, and reproductive isolation.
Students work through the lesson using a choice-based structure:
they select two of four leveled activities focused on different speciation mechanisms
they then study the well-documented speciation of apple flies and hawthorn flies, choosing from multiple analytical angles within that case
they analyze additional real-world examples of speciation to compare patterns and outcomes
Across all pathways, students are expected to:
explain how populations become reproductively isolated
connect environmental or behavioral changes to genetic divergence
use evidence from case studies rather than relying on definition-based explanations
The lesson is built around materials adapted from University of Utah resources and organized into an interactive Google Slides format that supports independent work and guided discussion.
This lesson is designed to support:
understanding of speciation as a mechanism of evolution
application of evolutionary concepts to real data
comparison of multiple speciation scenarios
structured student choice without changing learning goals
It functions well as:
a core speciation lesson within an evolution unit
an applied case-study investigation
or a follow-up to instruction on natural selection and population divergence
Grade & Course Recommendation:
Middle School:Grade 8 honors life science, conceptual introduction to speciation and isolation mechanisms.
High School:Grade 9–10 Biology, evolution or population genetics unit.
Cross-Curricular Connections:
Math Integration: Students interpret population graphs and isolation timelines.
ELA Integration: Construct written explanations comparing allopatric and sympatric speciation.
Geography / Environmental Science Integration: Connects to biogeography and habitat change.
Daily slide + literacy - based exit ticket included with purchase
HS-LS4-1: Communicate scientific information that common ancestry and biological evolution are supported by multiple lines of empirical evidence.
Connection: Students use examples such as stickleback fish, fireflies, and fruit flies to explain how reproductive barriers lead to divergence.
HS-LS4-2: Construct an explanation based on evidence that the process of evolution primarily results from genetic variation and natural selection.
Connection: Students evaluate how reproductive isolation and allele frequency changes drive speciation.
HS-LS4-3: Apply concepts of statistics and probability to support explanations that organisms with advantageous heritable traits tend to increase in proportion to those lacking the traits.
Connection: Students analyze data on fruit fly allele frequencies to determine whether speciation is occurring.
HS-LS4-4: Construct an explanation based on evidence for how natural selection leads to adaptation of populations.
Connection: Students interpret how changes in timing, mating behavior, or habitat preference can produce new species over time.
Science & Engineering Practices:
Analyzing and interpreting data
Constructing explanations
Engaging in argument from evidence
Communicating scientific information
Crosscutting Concepts:
Cause and effect
Patterns
Stability and change
Systems and system models
Grades 9–12:
CCSS.ELA-LITERACY.RST.9-10.1 / RST.11-12.1: Cite specific textual and data-based evidence to support analysis of scientific concepts. (Students cite data from fruit fly studies and examples of reproductive barriers.)
CCSS.ELA-LITERACY.RST.9-10.7 / RST.11-12.7: Integrate quantitative or technical information expressed in words with visual data. (Students combine charts of allele frequency with descriptions of behavioral isolation.)
CCSS.ELA-LITERACY.RST.9-10.8 / RST.11-12.8: Evaluate the validity of reasoning and the relevance of evidence in scientific arguments. (Students decide whether speciation is occurring based on evidence.)
CCSS.ELA-LITERACY.WHST.9-10.1 / WHST.11-12.1: Write arguments supported by evidence to explain biological processes. (Students construct an explanation for how one species becomes two.)
Reproductive Barriers & Evidence-Based Speciation Analysis.
This digital lesson examines how new species form using real biological examples and structured student choice. Students investigate speciation as a process driven by population separation, selective pressures, and reproductive isolation.
Students work through the lesson using a choice-based structure:
they select two of four leveled activities focused on different speciation mechanisms
they then study the well-documented speciation of apple flies and hawthorn flies, choosing from multiple analytical angles within that case
they analyze additional real-world examples of speciation to compare patterns and outcomes
Across all pathways, students are expected to:
explain how populations become reproductively isolated
connect environmental or behavioral changes to genetic divergence
use evidence from case studies rather than relying on definition-based explanations
The lesson is built around materials adapted from University of Utah resources and organized into an interactive Google Slides format that supports independent work and guided discussion.
This lesson is designed to support:
understanding of speciation as a mechanism of evolution
application of evolutionary concepts to real data
comparison of multiple speciation scenarios
structured student choice without changing learning goals
It functions well as:
a core speciation lesson within an evolution unit
an applied case-study investigation
or a follow-up to instruction on natural selection and population divergence
Grade & Course Recommendation:
Middle School:Grade 8 honors life science, conceptual introduction to speciation and isolation mechanisms.
High School:Grade 9–10 Biology, evolution or population genetics unit.
Cross-Curricular Connections:
Math Integration: Students interpret population graphs and isolation timelines.
ELA Integration: Construct written explanations comparing allopatric and sympatric speciation.
Geography / Environmental Science Integration: Connects to biogeography and habitat change.
Daily slide + literacy - based exit ticket included with purchase
HS-LS4-1: Communicate scientific information that common ancestry and biological evolution are supported by multiple lines of empirical evidence.
Connection: Students use examples such as stickleback fish, fireflies, and fruit flies to explain how reproductive barriers lead to divergence.
HS-LS4-2: Construct an explanation based on evidence that the process of evolution primarily results from genetic variation and natural selection.
Connection: Students evaluate how reproductive isolation and allele frequency changes drive speciation.
HS-LS4-3: Apply concepts of statistics and probability to support explanations that organisms with advantageous heritable traits tend to increase in proportion to those lacking the traits.
Connection: Students analyze data on fruit fly allele frequencies to determine whether speciation is occurring.
HS-LS4-4: Construct an explanation based on evidence for how natural selection leads to adaptation of populations.
Connection: Students interpret how changes in timing, mating behavior, or habitat preference can produce new species over time.
Science & Engineering Practices:
Analyzing and interpreting data
Constructing explanations
Engaging in argument from evidence
Communicating scientific information
Crosscutting Concepts:
Cause and effect
Patterns
Stability and change
Systems and system models
Grades 9–12:
CCSS.ELA-LITERACY.RST.9-10.1 / RST.11-12.1: Cite specific textual and data-based evidence to support analysis of scientific concepts. (Students cite data from fruit fly studies and examples of reproductive barriers.)
CCSS.ELA-LITERACY.RST.9-10.7 / RST.11-12.7: Integrate quantitative or technical information expressed in words with visual data. (Students combine charts of allele frequency with descriptions of behavioral isolation.)
CCSS.ELA-LITERACY.RST.9-10.8 / RST.11-12.8: Evaluate the validity of reasoning and the relevance of evidence in scientific arguments. (Students decide whether speciation is occurring based on evidence.)
CCSS.ELA-LITERACY.WHST.9-10.1 / WHST.11-12.1: Write arguments supported by evidence to explain biological processes. (Students construct an explanation for how one species becomes two.)
