What Is a Species?
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Activity 10: What Is a Species?
Get
Started
Write the questions below and your
answers in your science notebook.



a. What is a species?
b. Some examples of species are:
_______________________________.
c. How do biologists decide if two
populations are of the same or different
species?
Activity 10: What Is a Species?
Introduction
Read the introduction.

The biological species concept is a
method of defining a species based on
whether the organisms actually or can
potentially breed with each other to
produce fertile offspring.
Activity 10: What Is a Species?
Challenge

How do new species separate
from existing species?
Activity 10: What Is a Species?
Procedure
Species Separation
Example number/organism
name
Claim
Evidence to support the claim
Reasoning
Activity 10: What Is a Species?
Procedure
Scientific Argumentation



A claim: your conclusion about the most
logical placement of A and D on the tree
Evidence: the evidence you gathered that
supports the claim
Reasoning: how the evidence you
gathered supports the claim
Activity 10: What Is a Species?
Procedure
Placement of species in the process
of separation is as follows:



Early means they are either still one
species, or that they have just begun
separation.
Mid means they are separating.
Late means they are at the end of
separation, and they have most likely
split into two species.
Activity 10: What Is a Species?
Procedure
Activity 10: What Is a Species?
Procedure


How did you classify the barriers to
reproduction?
What groupings did you decide on?
Activity 10: What Is a Species?
Procedure
Informal Meeting of the Minds



Find a partner from another group and
discuss your definitions for the types of
barriers. Give an example or two for
each.
Ask each other questions.
Be prepared to share your ideas.
Activity 10: What Is a Species?
Follow Up
Analysis 2

Explain how geographic isolation can lead
to speciation.
Activity 10: What Is a Species?
Analysis 3

Lions and tigers do not overlap in range and do
not breed in nature. In captivity, a male lion may
mate with a female tiger and produce offspring.
Although more rare, a male tiger may also mate
with a female lion to produce offspring. In both
cases, the male offspring are sterile, while the
females might or might not be fertile. Explain
where lions and tigers are on the speciation
continuum, according to the biological species
concept. Support your answer with evidence and
reasoning.
Activity 10: What Is a Species?
Revisit the
Challenge

How do new species separate
from existing species?
Activity 10: What Is a Species?
Key
Vocabulary






biological species
biological species concept
evidence
gene flow
gene pool
species
Activity 10: What Is a Species?