Chapter 9. Milosz Szymoniak Arelis Diaz Tiffany Lavallee. Dr. B’s Question #7.
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Natural Selection may take one of three forms: directional (also called purifying), stabilizing (also called balancing), and disruptive (also called diversifying) selection. Distinguish between these types and give real-life examples of each.
Belk and Borden
http://www.britannica.com/eb/article-49874/eerent sets of alleles evolution
~In stabilizing selection, individuals with extreme characteristics die off or fail to reproduce resulting in populations of individuals with intermediate characteristics.
~It favors the norm, the common, the average traits in a population.
~Stabilizing selection is most common in unchanging environments.
This is My Xena,an Alaskan Malamute
She weighs 30 more lbs
This is a Siberian Husky
Look at the Siberian Husky, a dog bred for working in the snow. The Siberian Husky is a medium dog, males weighing 16-27kg (35-60lbs). These dogs have strong pectoral and leg muscles, allowing it to move through dense snow. The Siberian Husky is well designed for working in the snow. If the Siberian Husky had heavier muscles, it would sink deeper into the snow, so they would move slower or would sink and get stuck in the snow. Yet if the Siberian Husky had lighter muscles, it would not be strong enough to pull sleds and equipment, so the dog would have little value as a working dog. So stabilizing selection has chosen a norm for the size of the Siberian Husky.