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Evolution Notes. Warm Up- 9/24. Explain “Survival of the Fittest.”. Darwin’s Voyage. Charles Darwin- considered to be the founder of modern evolutionary theory. Darwin’s Voyage. Set sail on the HMS Beagle in 1831 Became the ship’s naturalist Arrived in the Galapagos Islands in 1835
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Warm Up- 9/24 • Explain “Survival of the Fittest.”
Darwin’s Voyage • Charles Darwin- considered to be the founder of modern evolutionary theory.
Darwin’s Voyage • Set sail on the HMS Beagle in 1831 • Became the ship’s naturalist • Arrived in the Galapagos Islands in 1835 • Observed that the animals on the islands were similar to those on the mainland
Darwin’s Voyage • On the Origin of Species- established evolution by common descent as the dominant scientific explanation of diversification in nature.
Theory of Evolution • Theory- an explanation of a phenomenon that has been tested over time. • Evolution- the gradual change in the characteristics of a species over time (aka descent with modification)
Theory of Evolution • Species- a group of organisms whose members look alike and successfully reproduce among themselves.
Theory of Evolution • Natural selection- Organisms that are better adapted to an environment are more likely to survive and reproduce (Survival of the fittest). • Artificial selection is the breeding of certain traits over others.
Evidence of Evolution • Similarities in DNA • Fossil Record • Similarities in Body Structure • Vestigial Structures • Similarities in Early Development
Evidence for Evolution • Genetic Material- All living things contain similar DNA, RNA, and proteins. • What are the components of DNA? RNA? • By comparing DNA sequences of two organisms, scientists can determine whether or not the organisms are closely related. • The relationship can then be used to construct evolutionary pathways.
Evidence for Evolution • Fossil Record-Preserved remains of once-living things found in Earth’s rocks.
Evidence for Evolution • Fossils have found that many simpler life forms exist early in Earth’s history. • The oldest fossils found are bacteria that lived 3.8 billion years ago.
Evidence for Evolution • Other kinds of evidence that support organic evolution are adaptations. • Anatomical • Physiological • Behavioral
What do you notice about these structures?
Anatomical Evidence • Homologous structures- bodily structures that are similar in structure, but different in function, due to sharing a common ancestor
AND … what do you notice about these structures?
Anatomical Evidence • Analogous structures- body parts with similar function but differentstructure. Indicate the organisms had different yet related ancestors.
Warm Up- 10/3 Describe what is happening in the picture above.
Warm Up- 10/2 • Why is it beneficial for Salmon fish to lay THOUSANDS of eggs at one time?
Review • Father of Evolution? • Defining Evolution? Criteria? • Natural Selection • Evidences of evolution
*Theory of Evolution • Theory- an explanation of a phenomenon that has been tested over time. • Evolution- the gradual change in the characteristics of a species over time (aka descent with modification)
*Theory of Evolution • Species- a group of organisms whose members look alike and successfully reproduce among themselves.
*Theory of Evolution • Natural selection- Organisms that are better adapted to an environment are more likely to survive and reproduce (Survival of the fittest). • Artificial selection is the breeding of certain traits over others.
*Evidence for Evolution • Genetic Material- All living things contain similar DNA, RNA, and proteins.
*Evidence for Evolution • Fossil Record-Preserved remains of once-living things found in Earth’s rocks.
What do you notice about these structures?
*HOMOLOGOUS STRUCTURES • Homologous structures- bodily structures that are similar in structure, but different in function, due to sharing a common ancestor
AND … what do you notice about these structures?
*ANALOGOUS STRUCTURES • Analogous structures- body parts with similar function but differentstructure. Indicate the organisms had different yet related ancestors.
What do you notice about these organisms? Take a Look!!
Anatomical Evidence • Embryology- The study of the development of embryos. Can indicate evolution from a common ancestor.
Overproduction- most species produce far more offspring than will/can survive Factors that affect Natural Selection
Factors that affect Natural Selection: Competition- since food and resources are limited, the offspring have to compete to survive Darwin called it: “Struggle for existence”
Factors that affect Natural Selection: Variation- Members within a species have individual differences – these differences must be inheritable. Natural selection won’t work in a population of clones! Remember that a key to variation is sexual reproduction.
Factors that affect Natural Selection: Survival to reproduce: Only those that are better suited to the environment will survive to reproduce. Fit individuals pass on to a portion of their offspring the advantageous characteristics.
Results of Natural Selection • Adaptation- inherited characteristic that increases an organisms chances of survival. • Speciation- formation of a new species • Extinction- disappearance of a species from all parts of its geographical range.
Types of Adaptations • Some adaptations involve changes in the structure of body parts: mimicry and camouflage. • Mimicry- when an organism copies the appearance of another species to protect itself.
Milk Snake • Coral Snake
Types of Adaptations • Camouflage- an adaptation that enables an organism to blend in with its surroundings.
Adaptations The favorable variations are called Adaptations. They are key for survival. These peppered moths are a good example of industrial melanism.
Peppered moth(Example of Genetic Variation) • Why did the population change? • early 1800s = pre-industrial England • low pollution • lichen on trees = light colored bark • late 1800s = industrial • factories = soot coated trees • killed lichen = dark colored bark • mid 1900s = pollution controls • clean air laws • return of lichen = light colored bark
Peppered moth: Evolution in action Year% dark% light 18485 95 1895982 199519 81 ←clean air, light-colored bark ←pollution, dark-colored bark ←Clean Air Act, light-colored bark industrial melanism
Peppered Moth • 2 types: dark vs. light Peppered moth
Types of Speciation Speciation will occur when the gene pools of two populations become separated.
Types of Speciation Behavioral Isolation: multiple species are able to breed, but won’t because different breeding behaviors. Temporal Isolation: Two or more species reproduce at different times.
Quiz What type of isolation is this? • A meadowlarks using 2 different songs to attract mates