SB3C. Examine the evolutionary basis of modern classification systems. History or the Theory (15.1) State Standard SB3C. Examine the evolutionary basis of modern classification systems.

Revered Greek philosopher & scientist Chapter 15 Evolution 15.1 Darwin’s Theory of Natural Selection Before Darwin Aristotle – 385-322 BC Revered Greek philosopher & scientist Believed organisms were created in a permanent form that could not change over time His ideas were highly influential for centuries

Jean Baptiste de LaMarck – 1800s French naturalist Chapter 15 Evolution 15.1 Darwin’s Theory of Natural Selection Before Darwin Jean Baptiste de LaMarck – 1800s French naturalist Believed inheritance of acquired traits were the driving force of evolution. Believed traits were acquired through use and disuse. Ex: A giraffe had to stretch its neck in order to reach food – so the neck got longer during the giraffe’s lifetime and was passed to the next generation.

Chapter 15 Evolution 15.1 Darwin’s Theory of Natural Selection Before Darwin Geologists were discovering ancient bones, shells, & fossilized plants in England in the 1800s. These items were being found in hillsides & riverbeds & gave new clues about diversity of organisms.

James Hutton & Charles Lyell – Gradualism Chapter 15 Evolution 15.1 Darwin’s Theory of Natural Selection Other Names Who Influenced Darwin James Hutton & Charles Lyell – Gradualism Earth had changed over very long periods of time. Thomas Malthus – Struggle for survival Populations outgrew resources & had to compete.

In 1831, Darwin set sail on the HMS Beagle Chapter 15 Evolution 15.1 Darwin’s Theory of Natural Selection Darwin’s Voyage In 1831, Darwin set sail on the HMS Beagle Darwin’s role on the ship was as naturalist and companion to the captain. His job was to collect biological and geological specimens during the ship’s travel.

Off the west coast of South America Chapter 15 Evolution 15.1 Darwin’s Theory of Natural Selection The Galápagos Islands Off the west coast of South America Each island had a unique climate & geographical features. Darwin began to collect mockingbirds, finches, and other animals on the four islands. He noticed that the different islands seemed to have their own, slightly different varieties of animals.

Populations from the mainland changed after reaching the Galápagos. Chapter 15 Evolution 15.1 Darwin’s Theory of Natural Selection The Galapagos Islands – cont’d Darwin theorized that the island populations came from the same ancestral populations on the mainland. Populations from the mainland changed after reaching the Galápagos.

Chapter 15 Evolution 15.1 Darwin’s Theory of Natural Selection Concepts That Emerged from Darwin’s Work… ADAPTATIONS – inherited traits that may give an individual survival & reproductive advantages over other individuals. Darwin hypothesized that new species could appear gradually through small changes in ancestral species. Darwin inferred that if humans could change species by artificial selection, then perhaps the same process could work in nature (natural selection).

Chapter 15 Evolution 15.1 Darwin’s Theory of Natural Selection Concepts That Emerged from Darwin’s Work… cont’d REPRODUCTIVE ISOLATION – populations that get geographically separated may give rise to adaptations specifically suited to each environment.

Principles of Natural Selection Chapter 15 Evolution 15.1 Darwin’s Theory of Natural Selection Principles of Natural Selection Individuals in a population show variations. Variations can be inherited. Organisms have more offspring than can survive on available resources (overproduction). Variations that increase reproductive success will have a greater chance of being passed on.

Natural Selection was a means of explaining how evolution works. Chapter 15 Evolution 15.1 Darwin’s Theory of Natural Selection Darwin & Wallace Darwin published On the Origin of Species by Means of Natural Selection in 1859. Natural Selection was a means of explaining how evolution works. Wallace also studied & wrote about evolution, emphasizing competition of resources, while Darwin focused on reproductive success. Darwin’s amount of data & thorough explanations caused his theories to be become dominant.

Which is not a principle of Darwin’s theory about Chapter 15 Evolution Chapter Diagnostic Questions Which is not a principle of Darwin’s theory about the origin of species? Individuals show variations. Variations can be inherited. Organisms have more offspring than available resources will support. Offspring always inherit the best traits. A B C D CDQ 1

Which was Charles Darwin’s only qualification Chapter 15 Evolution 15.1 Formative Questions Which was Charles Darwin’s only qualification for his position as naturalist on the Beagle? a degree in theology an interest in science a knowledge of biology an understanding of geology A B C D FQ 1

What was Darwin’s term for selective breeding? Chapter 15 Evolution 15.1 Formative Questions What was Darwin’s term for selective breeding? evolution speciation artificial selection natural selection A B C D FQ 2

What did Darwin infer from his observations of artificial selection? Chapter 15 Evolution 15.1 Formative Questions What did Darwin infer from his observations of artificial selection? Animal breeders could create new species. A similar process could work in nature. Reproductive success could be increased. Variation in a species could be produced. A B C D FQ 3

What is the relationship between the terms Chapter 15 Evolution 15.1 Formative Questions What is the relationship between the terms natural selection and evolution? They mean the same thing. Evolution works against natural selection. Evolution explains how natural selection works. Natural selection explains how evolution works. A B C D FQ 4

Which explains why the tortoises on the different Chapter 15 Evolution Standardized Test Practice Which explains why the tortoises on the different islands of the Galápagos had slightly different variations in their shells? The different tortoises were different species. The environment on each island was different. Each type of tortoise could survive only on its own island. They arrived on the islands from different continents. A B C D STP 1