Activity 10

What Is a Species?

Activity 10: 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

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.

Read the introduction.

Activity 10: What Is a Species?Activity 10: What Is a Species?

How do new species separate from existing species?

Challenge

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

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.

Placement of species in the process of separation is as follows:

Activity 10: What Is a Species?

Procedure

Activity 10: What Is a Species?

ProcedureProcedure

How did you classify the barriers to reproduction?

What groupings did you decide on?

Activity 10: What Is a Species?

Procedure

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.

Informal Meeting of the Minds

Activity 10: What Is a Species?

Follow Up

Explain how geographic isolation can lead to speciation.

Analysis 2

Activity 10: What Is a Species?Activity 10: What Is a Species?

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.

Analysis 3

Activity 10: What Is a Species?Activity 10: What Is a Species?

How do new species separate from existing species?

Revisit the Challenge

Activity 10: What Is a Species?Activity 10: What Is a Species?

biological species biological species concept evidence gene flow gene pool species

Key Vocabulary