EVOLUTION
We will now explore Evolution; no longer considered a Scientific Theory, but a Scientific Principle. What we now know about evolution all began in the 1800's with Charles Darwin, a naturalist. He took a long journey on the HMS Beagle during which he collected samples and made detailed observations. When he returned from his trip and reflected on his evidence, he developed the idea of Natural Selection. He later published On the Origin of Species containing ideas that threatened religious beliefs at that time.
Natural selection consists of 4 steps with one goal: to be able to live to reproductive age, and produce lots of offspring to pass your genes on to the next generation. The 4 steps detailed by Darwin included:
1. Overproduction-produce more offspring than can survive
2. Genetic Variation-genetic variation (differences in the DNA sequences of genes) gives certain organisms advantages for survival. Genetic variation is responsible for the diversity of species.
3. Struggle to Survive-Organisms compete for food, water, space, and mates. The living things that are successful at surviving to reproductive age AND produce lots of offspring are considered the "fittest". Fit does not mean who can lift the heaviest weight or run the fastest mile!
4. Successful Reproduction-the animals that are the fittest and best suited to their environment (having favorable traits) will live to reproductive age. The fittest will produce lots of healthy offspring and pass down their favorable traits (codes by the genes) to their offspring.
What exactly is Evolution you may ask? Evolution is a process that creates diversity of species. Evolution results from mutations (changes in DNA) over looooong periods of time! These changes sometimes lead to favorable traits. These favorable traits allows the organism to adapt to their environment. Then these favorable traits are passed down to their offspring, and their offspring, and their offspring...
How do we know that evolution occurred? Paleontologists study fossil records that show the changes or disappearance of organisms over time. Anatomy and physiology, and developmental scientists compare homologous structures. Homologous structures are structures, such as bone, that came from the same embryonic tissue that indicate a common ancestor. Embryologists study the similarities of vertebrate embryos during development. Biochemists compare DNA of different organisms. Chromosomes have banding patterns (gene patterns), and scientists are able to compare them in different organisms. The more of these patterns organisms share, the more closely related they are. All evidence of evolution indicates the existence of common ancestors.
One burning question you may have is "did we (humans) come from monkeys"? The answer is no. Primates, such as chimpanzees and apes share a common ancestor, but due to specific mutations that occurred over looooong periods of time, humans became human, and different primates became different primates. Humans diverged from other primates. We do share DNA similarities, and therefore proves that we evolved from a common ancestor. You may also ask, "will monkeys evolve into humans"? This will not happen because humans have evolved very differently from primates. Humans and monkeys most likely will continue to evolve, but into (hopefully) better adapted versions of themselves that will survive our changing environment (i.e., global climate change).
Natural selection consists of 4 steps with one goal: to be able to live to reproductive age, and produce lots of offspring to pass your genes on to the next generation. The 4 steps detailed by Darwin included:
1. Overproduction-produce more offspring than can survive
2. Genetic Variation-genetic variation (differences in the DNA sequences of genes) gives certain organisms advantages for survival. Genetic variation is responsible for the diversity of species.
3. Struggle to Survive-Organisms compete for food, water, space, and mates. The living things that are successful at surviving to reproductive age AND produce lots of offspring are considered the "fittest". Fit does not mean who can lift the heaviest weight or run the fastest mile!
4. Successful Reproduction-the animals that are the fittest and best suited to their environment (having favorable traits) will live to reproductive age. The fittest will produce lots of healthy offspring and pass down their favorable traits (codes by the genes) to their offspring.
What exactly is Evolution you may ask? Evolution is a process that creates diversity of species. Evolution results from mutations (changes in DNA) over looooong periods of time! These changes sometimes lead to favorable traits. These favorable traits allows the organism to adapt to their environment. Then these favorable traits are passed down to their offspring, and their offspring, and their offspring...
How do we know that evolution occurred? Paleontologists study fossil records that show the changes or disappearance of organisms over time. Anatomy and physiology, and developmental scientists compare homologous structures. Homologous structures are structures, such as bone, that came from the same embryonic tissue that indicate a common ancestor. Embryologists study the similarities of vertebrate embryos during development. Biochemists compare DNA of different organisms. Chromosomes have banding patterns (gene patterns), and scientists are able to compare them in different organisms. The more of these patterns organisms share, the more closely related they are. All evidence of evolution indicates the existence of common ancestors.
One burning question you may have is "did we (humans) come from monkeys"? The answer is no. Primates, such as chimpanzees and apes share a common ancestor, but due to specific mutations that occurred over looooong periods of time, humans became human, and different primates became different primates. Humans diverged from other primates. We do share DNA similarities, and therefore proves that we evolved from a common ancestor. You may also ask, "will monkeys evolve into humans"? This will not happen because humans have evolved very differently from primates. Humans and monkeys most likely will continue to evolve, but into (hopefully) better adapted versions of themselves that will survive our changing environment (i.e., global climate change).
Darwin's Trip Log Sheet | |
File Size: | 54 kb |
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homologous_animal_x-rays.pdf | |
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evolution_notes-km.doc | |
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birds_of_a_beak_2013.doc | |
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graphic_organizer_bird_of_a_beak.docx | |
File Size: | 38 kb |
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bird_photos.doc | |
File Size: | 747 kb |
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evidence_of_evolution_labs.doc | |
File Size: | 54 kb |
File Type: | doc |