09 Sep Step one: Observation ?Write a short summary, approximately a paragraph, of Table 2.1. Try to give a concise (short) but rich description of each of the four guppy pools.? Write a shor
Step one: Observation
- Write a short summary, approximately a paragraph, of Table 2.1. Try to give a concise (short) but rich description of each of the four guppy pools.
- Write a short summary, approximately a couple of sentences, of Tables 3 and 4. These tables discuss different characteristics related to guppy mating.
Step Two: Draw a Conclusion
- What selection pressures caused the variation in the color pattern of male guppies? Support your claims with evidence.
- Is it better to be bright or drab if you are a male guppy? Support your claims with evidence.
9/8/22, 1:31 PM Discussion 3: Evolution by Natural Selection – BSC1005 GEN BIO NON-MAJOR ONLINE 703103
https://bconline.broward.edu/d2l/le/555048/discussions/topics/837706/View 1/2
Discussion 3: Evolution by Natural Selection Available on Sep 4, 2022 12:01 AM. Access restricted before availability starts.
Available until Sep 11, 2022 11:59 PM. Access restricted after availability ends. Must post first.
BSC1005 GEN BIO NON-MAJOR ONLINE 703103 RA
Discussions List View Topic Settings Help
Subscribe
Original Post – Due two days before the due date.
This discussion provides you with some data about four pools of guppies. These pools have
different turbidity (i.e. cloudiness), make-up of predators, depths, locations, numbers of
guppies, and contain bright or drab-colored male guppies. Your goal is to first observe the
data given about the pools and note any patterns you see that might relate to the color
patterns of the male guppies. Selection pressures are an aspect of the environment that
causes a change in characteristics over time. Then you will decide which of the selection
pressures on the male guppies have resulted in the variations in color patterns you see in the
data. The data you need for this assignment is posted in D2L titled "Data for Evolution by
Natural Selection Discussion."
Step one: Observation
1. Write a short summary, approximately a paragraph, of Table 2.1. Try to give a concise
(short) but rich description of each of the four guppy pools.
2. Write a short summary, approximately a couple of sentences, of Tables 3 and 4. These
tables discuss different characteristics related to guppy mating.
Step Two: Draw a Conclusion
1. What selection pressures caused the variation in the color pattern of male guppies?
Support your claims with evidence.
2. Is it better to be bright or drab if you are a male guppy? Support your claims with
evidence.
Respond to your peers – Due by the due date.
NOTE: Only those student who have submitted a main post two days before due date are eligible to respond to peers.
9/8/22, 1:31 PM Discussion 3: Evolution by Natural Selection – BSC1005 GEN BIO NON-MAJOR ONLINE 703103
https://bconline.broward.edu/d2l/le/555048/discussions/topics/837706/View 2/2
Rubrics
Evolution by Natural Selection Discussion
Start a New Thread
Filter by:
Sort by:
Author First Name A-Z
You must start a thread before you can read and reply to other threads
Go through the majority of the posts and respond to two other students. Both of your
responses should be grammatically correct, well thought out, and further the
discussion. Some common ways to further a discussion are to ask a question, share
something related to the topic, or expand on a topic. Responses should be approximately a
paragraph in length.
For example, in this topic, you might note similarities and differences in your observations.
You may also find you disagree with a peer's assessment of what causes the color variations
or the benefit of being bright or drab. Remember to always support your claims with
evidence!
All Threads
,
BSC 1005: Color Variation in Guppies (Poecilia reticulata)
What selection pressure causes the variation in color pattern of male guppies?
Introduction. Guppies ( Poecilia reticulata) exhibit a complex color pattern polymorphism, in which males display a variety of colors and color patterns (Endler 1980). Guppies are native to the mountain forest streams of northeastern Venezuela, Margarita, Trinidad and Tobago (Endler 1978). Male color patterns are so different in these natural populations that no two males are alike. The color patterns consist of a mosaic of spots or patches varying in color, size, position and reflectivity (Figure 1). The patterns range from bright and conspicuous to more subtle and cryptic (inconspicuous). These patterns are controlled by genes on both the X and Y chromosome, and are only expressed in males.
Figure 1. Variation in guppy male color pattern (left and right columns). Center column shows females.
Photo: Kimberly Hughes
The Task. Use the data in the following tables to search for characteristics in the habitat and other selective pressures that might promote differences in male color pattern.
Table 2.1. Information About the Pools Where the Venezuelan Guppies Were Found
|
Characteristic |
Pool |
|||
|
1 |
2 |
3 |
4 |
|
|
Type |
Deep (at a bend in the stream) |
Deep (above a natural rock dam) |
Shallow (at a bend in the stream) |
Deep (above a 6 ft. waterfall) |
|
Pool location (see Figure 2.3) |
50 m upstream from the river |
100 m upstream from the river |
150 m upstream from the river |
200 m upstream from the river |
|
Turbidity of water (NTU) |
Ranges between 27.50 and 36.25 |
Ranges between 8.75 and 27.50 |
Ranges between 3.00 and 8.75 |
Ranges between 3.00 and 8.75 |
|
Predatory fish in the pool (total) |
28 |
15 |
6 |
0 |
|
Cichlids |
12 |
0 |
0 |
0 |
|
Rivulus |
6 |
10 |
6 |
0 |
|
Acara |
10 |
4 |
0 |
0 |
|
Guppies found in the pool (total) |
102 |
165 |
187 |
231 |
|
Bright males |
5 |
50 |
76 |
108 |
|
Drab males |
41 |
19 |
10 |
5 |
|
Bright females |
0 |
0 |
0 |
0 |
|
Drab females |
56 |
96 |
101 |
118 |
Note: Turbidity is the cloudiness or haziness of a !uid. Nephelometric turbidity unit (NTU) range in value from 0 (completely clear) to 50 (no light passes through the !uid).
Guppy Behavior and Female Preference Data Sheet
Overview: Guppy Mating System
· Prior to mating, males display to females using a sigmoid display. Females observe males then can select a male to mate with using a glide motion.
· There is very little male-male aggression.
Table 3. Factors Affecting Female Mate Preference
Factor |
Effect on Female Preference |
Orange spots |
In general, when given a choice between males with dull, small orange spots or bright, big orange spots, females preferred to mate with males with big, bright orange spots. |
|
Male boldness towards predators |
When predators are present, male guppies may move toward them to inspect them.Females prefer males who move towards predators to inspect them (i.e. males who are more bold), because they may be more informed about the predators in their habitat. |
|
Novelty |
When given a choice between males they have interacted with before, and novel (new) males they have never seen, females chose to mate with novel males. |
Table 4. Fema le Preference for Bright Males
|
Pool |
Female Preference for Bright Males |
|
1 |
2 |
|
2 |
4 |
|
3 |
7 |
|
4 |
9 |
(scale 1-10: 10 = very strong preference)
References: Breden & Stoner (1987); Houde & Endler (1990); Godin & Dugatkin (1996)
image1.jpeg
