Origin Study Guide 5

1 Page
160 Views

Department
Organismic and Evolutionary Biology
Course Code
Organismic and Evolutionary Biology OEB 53
Professor
Andrew Berry

This preview shows half of the first page. Sign up to view the full page of the document.
Description
Julie Vu TF: Pan Pan Jiang THE O RIGIN OF THE SPECIES :CHAPTER 5(L AWS OF VARIATION ) The effects of “use” and “disuse”seem topuzzleDarwin.What arethe observationsthathe istrying to explainandwhat arethe competing hypotheses? Darwin is unsure whether change is a result of disuse leading to atrophy or rather, change results from natural selection reducing the structure. He notes that in cases of artificial selection, it is easy to conclude that use in domestic animals enhances certain parts, while disuse diminishes them, but it is more difficult to observe natural organisms. Darwin, in examining different examples, comes to differing conclusions as to what causes change. For example, when talking about blind animals in caves, he attributes loss of eyes to disuse, because he thinks that the useless eyes could not negatively impact the organisms and thus, not be acted upon by selection. Other modifications, such as the reduction of wing size in some birds, are said to have been acted upon by selection, such as progenitors of the ostrich using its leg more and wings less, resulting in the modern day form. What aretheimplicatio
More Less
Unlock Document

Only half of the first page are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit