What is evolution?
Evolution is the changing of organisms characteristics over time to adapt to the changing environment. The best fit organisms to survive the changing environment are usually ones to reproduce and create offspring. Eventually over many generations, species would gain different characteristics that may help them survive making them the "fittest".
Charles Darwin's theory of evolution is called descent with modification. This theory was the idea that all species of organisms emerged and developed through natural selection of small, inherited variations that increase the individuals ability to compete, survive, and reproduce.
Jean Baptiste Lamarck's idea of evolution is called inheritance of acquired characteristics. This idea was that organisms lose characteristics they do not require and develop characteristics that are useful for their survival. These characteristics then were passed onto organisms offspring. This was also known as the use/disuse theory.
Charles Darwin's theory of evolution is called descent with modification. This theory was the idea that all species of organisms emerged and developed through natural selection of small, inherited variations that increase the individuals ability to compete, survive, and reproduce.
Jean Baptiste Lamarck's idea of evolution is called inheritance of acquired characteristics. This idea was that organisms lose characteristics they do not require and develop characteristics that are useful for their survival. These characteristics then were passed onto organisms offspring. This was also known as the use/disuse theory.
Gradualism vs Punctuated Equlibrium
Gradualism:
Gradualism is selection and variation that happens more gradually. Scientists believe that species with a long evolution evolved mostly by gradualism. Small variations in a species happens over time in gradualism and would be hard to notice over a short period of time. These changes happen very gradually over a long period of time and help a species better adapt to their environment and make them more fit to survive.
Punctuated Equilibrium:
In punctuated equilibrium change happens in spurts. There are periods with very little change and then one huge change can suddenly occur, often through genetic mutations. The mutations that occur in punctuated equilibrium are very helpful to the individuals in their environments. Punctuated Equilibrium can also result in other causes such as a huge change in the environment that result in more rapid changes in the actual organism.
Gradualism is selection and variation that happens more gradually. Scientists believe that species with a long evolution evolved mostly by gradualism. Small variations in a species happens over time in gradualism and would be hard to notice over a short period of time. These changes happen very gradually over a long period of time and help a species better adapt to their environment and make them more fit to survive.
Punctuated Equilibrium:
In punctuated equilibrium change happens in spurts. There are periods with very little change and then one huge change can suddenly occur, often through genetic mutations. The mutations that occur in punctuated equilibrium are very helpful to the individuals in their environments. Punctuated Equilibrium can also result in other causes such as a huge change in the environment that result in more rapid changes in the actual organism.
Explain ways in which a gene pool can change
There are five ways in which a gene pool can be changed. A gene pool can be changed through natural selection, mutations, genetic drift, gene flow, and non-random mating.
Natural selection: Natural selection is the process by which individuals that are better suited to their environment survive and reproduce most successfully, which is also called survival of the fittest. This can result in a change in the gene pool because the genes that are detrimental to survival are eliminated from it.
Mutations: A mutation is a change in a DNA sequence that affects genetic information and can be be passed on to future generations, resulting in a possible change in the gene pool.
Genetic drift: Genetic drift is a random change in allele frequencies that occurs in small populations. This is caused by random fluctuations in allele frequencies due to accident & chance losses removing one allele more than another.
Gene flow: Also know as gene migration, gene flow is the transfer of alleles or genes from one population to another. This can introduce new variations into a population causing a change in the gene pool.
Non-random mating: A pattern where individuals with similar genotypes and/or phenotypes mate with one another more frequently than under a random mating pattern. This can introduce specific genes into a gene pool by selection or selectively breeding for specific traits. Example: Animals breeding together that are similar in size.
Natural selection: Natural selection is the process by which individuals that are better suited to their environment survive and reproduce most successfully, which is also called survival of the fittest. This can result in a change in the gene pool because the genes that are detrimental to survival are eliminated from it.
Mutations: A mutation is a change in a DNA sequence that affects genetic information and can be be passed on to future generations, resulting in a possible change in the gene pool.
Genetic drift: Genetic drift is a random change in allele frequencies that occurs in small populations. This is caused by random fluctuations in allele frequencies due to accident & chance losses removing one allele more than another.
Gene flow: Also know as gene migration, gene flow is the transfer of alleles or genes from one population to another. This can introduce new variations into a population causing a change in the gene pool.
Non-random mating: A pattern where individuals with similar genotypes and/or phenotypes mate with one another more frequently than under a random mating pattern. This can introduce specific genes into a gene pool by selection or selectively breeding for specific traits. Example: Animals breeding together that are similar in size.
Is Evolution true?
In my opinion I believe evolution is true. I agree with the fact that all living organisms have descended with changes from a common ancestor and are still slowly changing to best suit their environment. Scientists use fossils, comparative anatomy (homologous structures), comparative embryology (similar embryos), and molecular evidence (similar DNA, molecular clock) to support that evolution is true. If evolution were not true, it would be impossible for organisms to survive with the rapid changing environments and humans would have never come to be as evolved as we are today.
Dichotomous Key
1. a. Has eight legs...........................................go to 3
b. Does not have eight legs........................go to 2
2. a. Has wings.................................................go to 4
b. Does not have wings...............................go to 6
3. a. Has a furry body......................................Tarantula
b. Does not have a furry body....................Black Widow
4. a. Has antennas............................................go to 5
b. Does not have antennas.........................Bat
5. a. Has a long thin body................................go to 10
b. Does not have a long thin body.............Fly
6. a. Has antennas............................................go to 7
b. Does not have antennas.........................go to 8
7. a. Has legs.....................................................go to 9
b. Does not have legs..................................Snail
8. a. Has eyes....................................................Snake
b. Does not have eyes..................................Earthworm
9. a. Has more than six legs............................Centipede
b. Does not have more than six legs..........go to 11
10. a. Has clear wings......................................Dragonfly
b. Does not have clear wings....................Butterfly
11. a.Has a wide hard shell on back..............Cockroach
b. Does not have a wide hard shell on back.....Ant
b. Does not have eight legs........................go to 2
2. a. Has wings.................................................go to 4
b. Does not have wings...............................go to 6
3. a. Has a furry body......................................Tarantula
b. Does not have a furry body....................Black Widow
4. a. Has antennas............................................go to 5
b. Does not have antennas.........................Bat
5. a. Has a long thin body................................go to 10
b. Does not have a long thin body.............Fly
6. a. Has antennas............................................go to 7
b. Does not have antennas.........................go to 8
7. a. Has legs.....................................................go to 9
b. Does not have legs..................................Snail
8. a. Has eyes....................................................Snake
b. Does not have eyes..................................Earthworm
9. a. Has more than six legs............................Centipede
b. Does not have more than six legs..........go to 11
10. a. Has clear wings......................................Dragonfly
b. Does not have clear wings....................Butterfly
11. a.Has a wide hard shell on back..............Cockroach
b. Does not have a wide hard shell on back.....Ant