In Class Assignment: Speciation Jigsaw Activity
Questions
1) Which breed of hen was your group assigned, and which breeds of males were paired
with the female hens (see Table 2 in Tiemann & Rehkämper 2012)?
WCP1 (White Crested Polish) hens and the males paired with these hens were RL (Red
Leghorns) and WCP.
2) Were purebred pairings more successful at reproduction than hybrid pairings, or were
they equally successful? (Hint: What do the stars mean in Figures 5 and 6?) Bonus: What
statistical test did the researchers use, and are the data considered to be numerical or
categorical?
The WCp1 purebred pairings were more successful at reproduction than hybrid pairing because
the purebred mating has a higher fertilization rate than the hybrid mating. The purebred pairing
also has a higher hatching rate.
3) Would you conclude that incipient speciation is occurring between these two breeds?
(Hint: If you are unsure of what the word ‘incipient’ means, look it up in a dictionary.)
I would conclude that incipient speciation did occur between the two breeds because the group of
the species have become genetically isolated from the rest of the species but can still reproduce
with other groups of the species before their gene pool was too distinct.
4) If you answered ‘yes’ to Question 3, at what stage (or stages) is reproductive isolation
(pre-mating, post-mating/pre-zygotic, or post-zygotic)? Refer to your homework reading:
https://openstax.org/books/biology-2e/pages/18-2-formation-of-new-species
The reproductive isolation was pre-mating reproductive isolation because it reduces frequency of
interspecific mating.
5) Clearly justify your answer to Question 4.
Pre-mating reproductive isolation has occurred because
6) What did the researchers do to ensure that sexual behavior was innate and not due to
imprinting (right side of page 2 of Tiemann & Rehkämper 2012)?
