Homologous and Analogous

Structures

Scientific knowledge is scientists' best explanations for the data from many investigations. Ideas about objects in the microscopic world that we cannot directly sense are often understood in terms of concepts developed to understand objects in the macroscopic world that we can see and touch. Student work should align with this process of science and should be guided by those principles.

Students should also understand that scientific knowledge is gained from observation of natural phenomena and experimentation by designing and conducting investigations guided by theory and by evaluating and communicating the results of those investigations according to accepted procedures. These concepts should be woven throughout daily work.

• Develop explanations based on reproducible data and observations gathered during laboratory investigations.• Recognize that their explanations must be based both on their data and other known information from investigations of others.• Explain how scientific knowledge can be used to guide decisions on environmental and social issues.

Core Standard Describe how biochemical, fossil, anatomical, developmental, and genetic findings are used to determine relationships among organisms and how those relationships are then used to produce modern classification systems. (B.8.1, B.8.2, B.8.3, B.8.4)

Core Standard Describe how modern evolutionary theory provides an explanation of the history of life on earth and the similarities among organisms that exist today. (B.8.5, B.8.6, B.8.7)

9-10.WS.4 Produce clear and coherent writing in which the development, organization, and style are appropriate to task, purpose, and audience.

9-10.WS.5 Develop and strengthen writing as needed by planning, revising, editing, rewriting, or trying a new approach, focusing on addressing what is most significant for a specific purpose and audience.

9-10.WS.6 Use technology, including the Internet, to produce, publish, and update individual or shared writing products, taking advantage of technology’s capacity to link to other information and to display information flexibly and dynamically.

Activity: Evidence of Anatomical Features

[1] Link to PBS Evolution for Students Video

3 How do we know Evolution Happens?

Credible because it is the foundation for our

on-line class session.

http://www.lib.umd.edu/guides/evaluate.ht

ml

Media:Evidence of Anatomical Features- Section 2.pdf PowerPoint introduction to the activity

Media:Evidence_of_Anatomical_Features_Handout.pdf‎ Handout for the activity

Recognition Read how others have recognized the Understanding Evolution website: Understanding Evolution was recognized in December 2010 by the Science Prize for

Online Resources in Education (SPORE). This prize was established to encourage innovation and excellence in education, as well as to encourage the use of high-quality on-line resources by students, teachers, and the public. Read about Understanding Evolution in Science.

Scientific American.com selected Understanding Evolution for a 2004 Science & Technology Web Award in the Biology category.

The Eisenhower National Clearinghouse (ENC) selected Understanding Evolution as an exemplary website, part of their Digital Dozen for October 2004.

Science News Online selected Understanding Evolution for its Science Safari in Cyberspace for April 3, 2004.

http://evolution.berkeley.edu/evolibrary/recognition.php

Assessment:

Media:Evidence_of_Atatomical_Features_Assessment.

pdf Printable Assessment and Rubric for Grading

The internet source used provides free editable

educational rubrics to evaluate student work. As an

organization providing free materials this site is only

as credible as the product you decide to use. I

download a reasonable facsimiles to what I desire, and

then edit them to meet the needs of my students.

1. How does comparative morphology

provide evidence for evolution?

2. What can the presence of homologous

structures signify?

3. What can the presence of analogous

structures signify?

A study of the configuration or the

structure of animals and plants.

http://www.dallasnews.com/sharedcontent/dws/news/nation/stories/DN-

bats_09tex.ART.State.Edition2.432418c.html

http://votebits.com/explore-the-world-of-marine-animals/whale/

Two structures are considered to be

homologous is they have the same

structure; may be used for different

functions.

Two structures are considered to be

analogous if they have the same function,

but not the same structure.

Similar body parts that reflect shared ancestry.

May be used for different purposes in different groups, but the same genes direct their development

A body part that appears very different in appearance may be quite similar in underlying parts.

This indicates a shared ancestry.

Wings that have similar function but

different structure.

Similar structures that evolved separately

in different lineages.

http://news.nationalgeographic.com/news/2011/04/pictures/110407-science-fossils-insects-bugs-mayflies-mayfly-flying/

http://t2.gstatic.com/images?q=tbn:ANd9GcQWBP7aGyaHzETq76PnDkDbOfbbjpSpl3I5foQjvQTWgOzyIvrJ7A

Above shows how alike the structures are of

arms in different species http://sbi3uevolution.wikispaces.com/Analogous+structures

Homologies and Analogies

This is an online activity with a handout to

complete.

You will have 30 minutes to complete this

activity. Open the website and complete the

handout as you move though the pages. When

you are finished, turn your handout in to the

instructor.

In your science journal answer the following questions. Each question will require you to use appropriate vocabulary learned in this session. You may use your book to help you answer the questions. Each answer will require a minimum of 75 words.

1. How does comparative morphology provide evidence for evolution?

2. What can the presence of homologous structures signify?

3. What can the presence of analogous structures signify?

Think of two animals that have parts

which have similar structures , but have

very different functions.

• What are the two animals?

• What parts do they have that are similar?

• What function does each part have that is

different?

Think of two animals that have parts

which do the same thing, but have very

different structures.

• What are the two animals?

• What do they do that is similar?

• What structure does each one have that is

different?