Gene Pools and Speciation

Topic 10.3: Gene Pools and Speciation

Essential Idea: Gene pools change over time.

At SHS, Topic 10.3 is taught in the following class unit(s):

Natural Selection (unit 19)
Speciation (unit 21)

Statements & Objectives:

10.3.U1 A gene pool consists of all the genes, and their different alleles, present in an interbreeding population.

Define gene pool.
Given data, calculate allele frequencies of genes in a gene pool.
Given data, calculate genotype frequencies for genes in a gene pool.

10.3.U2 Evolution required that allele frequencies change with time in populations.

Define evolution.
Outline five factors that can cause evolutionary change.

10.3.U3 Reproductive isolation of populations can be temporal, behavioral or geographic.

Compare allopatric and sympatric speciation.
Define reproductive isolation.
Explain temporal, behavioral and geographic isolation as mechanisms of speciation.
Describe an example of temporal, behavioral and geographic reproductive isolation.
Define speciation.

10.3.U4 Speciation due to divergence of isolated populations can be gradual.

Outline a limitation of the idea of evolution through gradualism.
Identify gradualism from graphs of morphology changes over time.
Define gradualism.

10.3.U5 Speciation can occur abruptly.

Define punctuated equilibrium.
Outline a possible cause of rapid speciation events.
Identify punctuated equilibrium from graphs of morphology changes over time.

10.3.A1 Identifying examples of directional, stabilizing and disruptive selection.

Define stabilizing, disruptive and directional selection.
Use graphs to illustrate or identify stabilizing, disruptive and directional selection.

10.3.A2 Speciation in the genus Allium by polyploidy.

Outline how polyploidy has led to many species of Allium.
List example species in the genus Allium (by common name)

10.3.S1 Comparison of allele frequencies of geographically isolated populations.

Compare allele frequencies of two populations.
Describe how variations in the allele frequencies of a gene may be evidence of speciation.

10.3.NOS Looking for patterns, trends and discrepancies- patterns of chromosome number in some genera can be explained by speciation due to polyploidy.

Define polyploidy.
Outline causes of polyploidy.

Explain how polyploidy can lead to speciation.

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When One Big Cat Is Almost Like the Other (2019-09-16)
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Speciation far from the madding crowd (2018-07-04)
How much space do you need to evolve a new mammal? These worm-eating mice have the answer (2018-05-15)
Why does evolution sometimes repeat itself? Spider-eating spiders may hold the answer (2018-03-08)
Two become one: two raven lineages merge in 'speciation reversal' (2018-03-02)
New Bird Species Arises From Hybrids, as Scientists Watch (2017-12)
Microbes can draw the line between species (2013-07-18)
Monkey's face says, 'Don't mate with me' (2014-06-26)
'Killer sperm' prevents mating between worm species (2014-07-29)
As Animals Mingle, a Baffling Genetic Barrier (2014-08-05)
Alternate mechanism of species formation picks up support, thanks to a South American ant (2014-08-21)
Lions in West and Central Africa apparently unique (2016-08-11)
Three new sub-species of snow leopard discovered (2017-05-11)
Washington's State Fish Has A Remarkable Evolutionary Past (2014-04-23)
Gene doubling shapes the world: Instant speciation, biodiversity, and the root of our existence (2014-09-30)
Finding the Speed of Evolution in the Study of Bird Beaks (2017-02-01)
Tiny fossil reveals what happened to birds after dinosaurs went extinct (2017-07-10)
Dino-killing asteroid's impact on bird evolution (2017-09-21)
African clawed frog genome contains two full sets of chromosomes from 2 two extinct ancestors (2016-10-19)
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