Evolution Ideas

Vocabulary words to study from the textbook Chapter 13 sections 1 & 2 & 3 pgs words total

I. Early Models of Evolution 1. Species: A group of organisms that share similar characteristics and can reproduce among themselves and produce fertile offspring 1. Species: A group of organisms that share similar characteristics and can reproduce among themselves and produce fertile offspring Millions of species of different kinds live on Earth today Millions of species of different kinds live on Earth today Many of these shared characteristics are inherited Many of these shared characteristics are inherited 2. Change in these inherited characteristics is known as evolution 2. Change in these inherited characteristics is known as evolution

A. Hypothesis of Acquired Characteristics 1. In 1809, Lamarck proposed a hypothesis of how organisms change over time 1. In 1809, Lamarck proposed a hypothesis of how organisms change over time Lamarck suggested that traits developed during a parent’s lifetime can be inherited by its offspring Lamarck suggested that traits developed during a parent’s lifetime can be inherited by its offspring Examples: Muscles, Hermit crab’s claws Examples: Muscles, Hermit crab’s claws This hypothesis is called the inheritance of acquired characteristics This hypothesis is called the inheritance of acquired characteristics Data shows that traits are not passed down in this manner Data shows that traits are not passed down in this manner

II. Darwin’s Model of Evolution 1. In December, 1831, the HMS Beagle sailed from England with a naturalist named Charles Darwin on board 1. In December, 1831, the HMS Beagle sailed from England with a naturalist named Charles Darwin on board 2. They visited the Galapagos Islands and Darwin saw a huge variety of organisms 2. They visited the Galapagos Islands and Darwin saw a huge variety of organisms He hypothesized that these organisms must have originally come from mainland South and Central America He hypothesized that these organisms must have originally come from mainland South and Central America He did not see same type of organisms on mainland He did not see same type of organisms on mainland

Darwin’s Voyage Map

A. Darwin’s Observations 1. Darwin observed 13 species of finches that were all similar to each other except for differences in body size, beak shape, and eating habits 1. Darwin observed 13 species of finches that were all similar to each other except for differences in body size, beak shape, and eating habits He also noted that they were similar to mainland finches He also noted that they were similar to mainland finches 2. Darwin said that these birds had to compete for food and space 2. Darwin said that these birds had to compete for food and space He hypothesized that those birds with beak shapes that allowed them to eat available food survived longer and eventually became a different species He hypothesized that those birds with beak shapes that allowed them to eat available food survived longer and eventually became a different species

III. Natural Selection 1. In 1859, Darwin published On the Origin of Species 1. In 1859, Darwin published On the Origin of Species 2. Darwin’s theory became known as evolution by natural selection 2. Darwin’s theory became known as evolution by natural selection 3. Natural selection means that organisms with traits best suited to their environment are more likely to survive and pass those traits to more offspring 3. Natural selection means that organisms with traits best suited to their environment are more likely to survive and pass those traits to more offspring

The Principles of Natural Selection A. Organisms produce more offspring than can actually survive A. Organisms produce more offspring than can actually survive B. Differences occur among individuals of the same species B. Differences occur among individuals of the same species C. Some differences are passed to offspring C. Some differences are passed to offspring D. Some differences are beneficial D. Some differences are beneficial Help them survive and reproduce Help them survive and reproduce E. Over time, individuals with those beneficial traits increase and evolve into a new species E. Over time, individuals with those beneficial traits increase and evolve into a new species

IV. Variation and Adaptation Variation: An inherited trait that makes an individual different from other members of its species Variation: An inherited trait that makes an individual different from other members of its species Result from mutations in an organism’s genes Result from mutations in an organism’s genes Can result in evolution of a new species Can result in evolution of a new species Adaptation: Any variation that makes an organism better suited to its environment Adaptation: Any variation that makes an organism better suited to its environment

A. Changes in Source of Genes Change in genotype can result in change in phenotype Change in genotype can result in change in phenotype Environmental factors can bring about changes Environmental factors can bring about changes Example: New members entering into an area Example: New members entering into an area

B. Geological Isolation What can isolate a small group of organisms from the main population? What can isolate a small group of organisms from the main population? Mountains Mountains Lakes/Rivers Lakes/Rivers Certain variations can become more common in a smaller population and lead to evolution of that population Certain variations can become more common in a smaller population and lead to evolution of that population

Physiological conditions, behavioral conditions or geographical barriers, that prevent potentially interbreeding populations from cross-fertilization. Geographic isolation can lead to reproductive isolation. C. Reproductive Isolation

Population: a group of individuals of the same species in a given area Speciation Speciation: is the evolutionary process by which new biological species arise. Reproductive isolation can lead to speciation. C. Reproductive Isolation

V. Speed of Evolution 1. Gradualism: A slow, ongoing process by which one species changes into a new species 1. Gradualism: A slow, ongoing process by which one species changes into a new species Darwin Darwin Example: The camel (Figure 1, p. 154) Example: The camel (Figure 1, p. 154) 2. Punctuated Equilibrium: A model showing rapid evolution when the mutation of a few genes results in the appearance of a new species over a relatively short period of time 2. Punctuated Equilibrium: A model showing rapid evolution when the mutation of a few genes results in the appearance of a new species over a relatively short period of time

Punctuated Equilibrium Today 1. Penicillin: An antibiotic that once easily killed bacteria cells 1. Penicillin: An antibiotic that once easily killed bacteria cells 2. Now, many bacteria are no longer harmed by penicillin 2. Now, many bacteria are no longer harmed by penicillin 3. Most bacteria developed antibiotic resistance to the drug 3. Most bacteria developed antibiotic resistance to the drug

HOW? A. A few cells had a variation that allowed themto survive. A. A few cells had a variation that allowed them to survive. B. When other bacteria cells are killed bypenicillin, these survived. B. When other bacteria cells are killed by penicillin, these survived. C. These resistant bacteria survived andreproduced more bacteria cells with resistance. C. These resistant bacteria survived and reproduced more bacteria cells with resistance.

GRADUALISM Occurs Slowly Gradual change Tens of millions of years A series of mutations and variations over time into a new species Example The evolution of camel. There are intermediate forms between the first and present day camel

PUNCTUATED EQUILIBRIUM Occurs rapidly Sudden change of an organism into another form A few thousand years to 1 million years Mutations result in the appearance of a new species over a relatively short period Example Penicillin resistant to bacteria Evolution of bears pg. 160

Niche The specific area in its ecosystem that an organism or population inhabits and how it responds to the distribution of resources and competitors.

Generalist Species Is able to thrive in a wide variety of environmental conditions & can make use of a variety of different resources. Most omnivores are generalists Examples: Humans, raccoons

Specialist Species Can only thrive in a narrow range of environmental conditions or has a limited diet. Most herbivores are specialists Examples: Koala, (eats only eucalyptus leaves) Eucalyptus is itself a specialist. Is only found in Australia

Generalist vs. Specialist Species When environmental conditions change, generalists are able to adapt, while specialists tend to fall victim to extinction much more easily.

Flash fox and rabbit population simulation

13.1 Section Review (evidence)p. 265(1-9) 13.2 Section Review(ideas)p. 270(1-7) 13.3 Section Review(ideas)p. 275(1-7) 13 Chapter Assessment p. 279Vocab (1-8), Concepts (1-12)