IB Biology Topic D4.1.8 Modelling of Sexual and Natural Selection Revision Notes (SL/HL)

IB Biology Topic D4.1.8 Modelling of Sexual and Natural Selection Revision Notes (SL/HL) | RevisionDojo

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Endler's Guppies Model How Predation Balances Two Selection Pressures

Traits evolve under selection pressures that shape survival and reproduction.
John Endler used guppies to model how natural selection and sexual selection can pull one trait in opposite directions.

The Trait: Number of Spots on Male Guppies

Male guppy spot number is heritable, so it can respond to selection.
Sexual selection
1. Females prefer males with more spots, so it favours brighter males.
Natural selection
1. Predators see brighter males more easily, so it favours duller males.

The Setup: Three Levels of Predation

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Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

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Endler's Guppies Model How Predation Balances Two Selection Pressures

Traits evolve under selection pressures that shape survival and reproduction.
John Endler used guppies to model how natural selection and sexual selection can pull one trait in opposite directions.

The Trait: Number of Spots on Male Guppies

Male guppy spot number is heritable, so it can respond to selection.
Sexual selection
1. Females prefer males with more spots, so it favours brighter males.
Natural selection
1. Predators see brighter males more easily, so it favours duller males.

The Setup: Three Levels of Predation

Definition

Paywall

(on a website) an arrangement whereby access is restricted to users who have paid to subscribe to the site.

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Note

Lorem ipsum dolor sit amet, consectetur adipiscing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam quis nostrud exercitation.

Excepteur sint occaecat cupidatat non proident

Tip

Lorem ipsum dolor sit amet, consectetur adipiscing elit.
Sed do eiusmod tempor incididunt ut labore et dolore magna aliqua.
Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris.
Duis aute irure dolor in reprehenderit in voluptate velit esse cillum.

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A - Unity and Diversity9 subtopics

B - Form and Function10 subtopics

C - Interaction and Interdependence9 subtopics

D - Continuity and Change12 subtopics

IB Biology Topic D4.1.8: Modelling of Sexual and Natural Selection Notes

Endler's Guppies Model How Predation Balances Two Selection Pressures

The Trait: Number of Spots on Male Guppies

The Setup: Three Levels of Predation

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account

Endler's Guppies Model How Predation Balances Two Selection Pressures

The Trait: Number of Spots on Male Guppies

The Setup: Three Levels of Predation

anim nostrud sit dolore minim proident quis fugiat velit et eiusmod nulla quis nulla mollit dolor sunt culpa aliqua

Duis aute irure dolor in reprehenderit

Excepteur sint occaecat cupidatat non proident

Unlock the rest of this chapter with a free account

A - Unity and Diversity9 subtopics

B - Form and Function10 subtopics

C - Interaction and Interdependence9 subtopics

D - Continuity and Change12 subtopics