BIOL 1108 Lecture Notes - Lecture 3: Species, Reproductive Isolation, Winnowing

21 views4 pages
24 Oct 2018
School
Department
Course

Document Summary

Imagine for a moment a world without speciation, the process that produces new and distinct forms of life. Life would have originated and natural selection would have done its job of winnowing advantageous mutations from disadvantageous ones, but the planet would be inhabited by a single kind of generally adapted organism. Instead of the staggering biological diversity we see around us - by current estimates, between 10 and 100 million species call earth home - there would be just a single life- form. From a biological perspective, the planet would be a decidedly dull place. Evolution is as much about speciation, the engine that generates this breathtaking biodiversity, as it is about adaptation, the result of natural selection. Reproductive isolation is the key to the biological species concept. Reproductive isolation is caused by barriers to reproduction before or after egg fertilization. Speciation underlies the diversity of life on earth. Speciation can occur with or without natural selection.

Get access

Grade+20% off
$8 USD/m$10 USD/m
Billed $96 USD annually
Grade+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
40 Verified Answers
Class+
$8 USD/m
Billed $96 USD annually
Class+
Homework Help
Study Guides
Textbook Solutions
Class Notes
Textbook Notes
Booster Class
30 Verified Answers

Related Documents

Related Questions