Unit 7
Lesson 15.3
Date Tues 2/21, Wed 2/22
Objective: students can describe how natural variation is used in artificial selection. Students can explain
how natural selection is related to species’ fitness.
State standards: 7 3a. Students know how genetic variation and environmental factors are causes of
evolution. 7a Students know how natural selection acts on phenotype, not genotype. 8a students know
meaning of the phrase ‘survival of the fittest’. 8b. students know that the greater the diversity of a
species, the better the chances for its survival if the environment changes.
Warm up activity: Ch 15 assessment pg 389 # 1-5
Vocabulary:
Artificial selection: Selection by humans for breeding desired traits from the natural variation in a
species (ex: selecting cows that give the most milk)
Descent with modification: principle that each living species has descended, with changes, from other
species over time.
Homologous structures: structures that have different mature forms in different organisms, but
develop from the same embryonic tissues.
Check for understanding: class correct/ discussion of warm up questions/ vocabulary
Active art: artificial selection activity PHSchool.com Web code cbp-5153
Lecture: 15.3
Guided practice: go over materials (skulls) for artificial selection lab. Read instructions, demonstrate
how to travel from table to table, emphasize recording observations as they happen.
SciLinks :links on natural selections Scilinkgs.org webcode cbn-5153
Independent practice: Lab: Artificial selection in Dog breeds (CA Academy kit)
HW:
15.3 section review pg 24-26
Complete lab questions
Read 16.1