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Ideas about Evolution. Chapter 6, Section 1. What is a species Again?. Group of organisms that can produce fertile offspring. Remember, characteristics of a species are passed from parent to offspring. Evolution. Change in the inherited characteristics of a species.
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Ideas about Evolution Chapter 6, Section 1
What is a species Again? • Group of organisms that can produce fertile offspring. • Remember, characteristics of a species are passed from parent to offspring.
Evolution • Change in the inherited characteristics of a species.
Theory of Acquired Characteristics • Developed by Jean Baptiste de Lamarck in 1809. • States: • Characteristics, or traits, developed in the lifespan of the parent are passed to the offspring. • Has been proven false.
Charles Darwin • Naturalist aboard the HMS Beagle which left England in December of 1831to explore the South American coast, including the Galapagos Islands. • Darwin kept records of the plants and animals encountered during the journey.
Darwin’s Observations • Similar species may develop from a single parent species. • Members of the same population (group of species living in the same area) have to compete for resources in order to survive. • Only those organisms best suited for survival will produce offspring.
Natural Selection • Modern theory of evolution. • Published by Darwin in 1859 in his book, On the Origin of Species. • States: • Organisms with traits best suited for their environment are more likely to survive and reproduce, passing on traits to offspring.
Variation • An inherited trait that makes an individual different from other members of its species. • Result of genetic mutations.
Adaptation • Any variation that makes an organism better suited to its environment.
How can local genes be influenced? • Genes may be brought in or removed by individuals moving into or out of the area. • Geographic Isolation • Group of individuals may be isolated from the rest of the species and develop new traits.
Speed of Evolution • Gradualism • Slow ongoing process in which one species changes to a new species. • Punctuated Equilibrium • Mutation of genes results in the evolution of a new species over a relatively short period of time. • Example: Antibiotic resistance