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Evolution: DNA and the Unity of Life

Unit Overview

Evolution: DNA and the Unity of Life is an eight-week, comprehensive curriculum unit that sharply illuminates the underlying role of genetics in evolution by maintaining a conceptual connection to DNA and heredity throughout. Through paper-based and interactive multimedia lessons, the unit aligns with the Next Generation Science Standards (NGSS) by engaging students in questioning, using models, identifying patterns, analyzing skill-level appropriate data from published scientific studies, and constructing evidence-based arguments.

The unit’s lessons are organized into five modules that are each structured round a guiding question. Modules can be used individually or together in sequence. When used in their entirety and in the suggested sequence, the modules establish an understanding of DNA as a blueprint for all living things, and how it underlies variations in traits that are acted upon by natural selection leading to the diversity of life. A scaffolded claims-evidence- reasoning framework is integrated into the unit to incrementally build skill in constructing arguments from evidence over the course of the module sequence.

  • Complete Evolution curriculum unit
  • NGSS-aligned
  • Integration of underlying genetics concepts
  • Scaffolded approach to building the skill of Argumentation from Evidence
  • Real data, re-packaged in a way that is easy for students to work with

Shared Biochemistry

What shapes the characteristics of all living things?
  • Living things share biochemical features that are encoded by DNA.
  • Proteins underlie the structure and function of living things.
  • Living things make proteins the same way.
  • Living things make similar proteins.
  • The arrangement of DNA building blocks in a gene specifies the order of amino acids in the protein it codes for.
Shared Biochemistry

Common Ancestry

What is the evidence that living species evolved from common ancestral species?
  • The similarities among living things suggest relatedness.
  • Fossils, anatomy, embryos, and DNA sequences provide corroborative lines of evidence about common ancestry, with more closely related organisms having more characteristics in common.
  • DNA underlies the similarities and differences in fossils, anatomy, and embryos.
Common Ancestry


How do the differences arise in DNA that lead to differences in characteristics?
  • Mutation gives rise to variations in genes, called alleles.
  • During sexual reproduction, allele shuffling generates new allele combinations.
  • Mutation and allele shuffling increase variation within a population.

Natural Selection

How do species change over time?
  • Natural selection causes populations to change over time.
  • Natural selection acts on existing heritable variations that confer a reproductive advantage.
  • Natural selection requires three ingredients: variation, heritability, and reproductive advantage.
Natural Selection


How does natural selection lead to the formation of new species?
  • Species differ from one another across multiple heritable traits.
  • Mutation, allele shuffling, and natural selection acting on multiple traits over many generations in reproductively isolated populations cause the divergence in characteristics of living things.

About this Unit


How this Unit Was Developed

This material is based upon work supported by the National Science Foundation under Grant Nos. DRL-1222869 and DRL-1418136. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.