Changes in Allele Frequency
There are many ways that organisms all over the world evolve. Different organisms evolve differently depending on the location, climate, resources, etc. A change in allele frequency can change the way an organism performs their behaviors, how they reproduce, their physical appearance. The factors that drive a change in allele frequency are mutations, genetic drifts, migration, and natural selection.
A mutation is a change in the genetic makeup, which is the only way new alleles are created. This form of change in allele frequency can be either harmful or hurtful to different organisms. Furthermore, for a allele change to be called a mutation it must be heritable. Sometimes mutations do not have a purpose at all. For example, blue eyes (picture above)in humans are a mutation but they don't do anything to help or hurt the body.
Genetic Drift, on the other hand, is a random change in allele frequency. There are two forms of this. One is the founder effect, which is when a group of people in one population changes there allele and then they reproduce in a different area causing it to spread. One example of this is the 6 finger in humans, Did you know that 6 fingers is dominant over 5 fingers? The other is called Population Bottleneck, which is when randomly selected populations die out. Another change in allele frequency is migration. For example, if a large population of cheetahs lived in an environment and an earthquake killed a small population of them, the ones that survived are the "natural selection."
Migration is when a group of individuals moves from one place to another, causing a type of gene flow. For example, when a specific type of bird migrates to another island because of climate change, those birds can mate with the native birds and create a new species.
A mutation is a change in the genetic makeup, which is the only way new alleles are created. This form of change in allele frequency can be either harmful or hurtful to different organisms. Furthermore, for a allele change to be called a mutation it must be heritable. Sometimes mutations do not have a purpose at all. For example, blue eyes (picture above)in humans are a mutation but they don't do anything to help or hurt the body.
Genetic Drift, on the other hand, is a random change in allele frequency. There are two forms of this. One is the founder effect, which is when a group of people in one population changes there allele and then they reproduce in a different area causing it to spread. One example of this is the 6 finger in humans, Did you know that 6 fingers is dominant over 5 fingers? The other is called Population Bottleneck, which is when randomly selected populations die out. Another change in allele frequency is migration. For example, if a large population of cheetahs lived in an environment and an earthquake killed a small population of them, the ones that survived are the "natural selection."
Migration is when a group of individuals moves from one place to another, causing a type of gene flow. For example, when a specific type of bird migrates to another island because of climate change, those birds can mate with the native birds and create a new species.
Natural Selection
Natural Selection is when the best of the organisms of the environment in which they live survives in a natural; manner. This can also be referred to as "the survival of the fittest." The ones that survive live on and reproduce, passing on their genes through their gametes.
Stabilizing Selection is one form of natural selection. This is when the environment supports the average or the medium of a factor of a species. For example, if we are collecting data for height of humans. If stabilizing selection is shown, the average height would have the most data. Another example is data from a class's test grades. There are a majority of B's and a little bit of A's and C's or less.
Directional Selection is another for of natural selection. This means that the data portrays that the environment supports either extremes. For instance, the length of ants can be measured and the extreme that would be supported is short. The best used form of Directional Selection is the peppered moths. Lastly, the final form of natural selection is Disruptive Selection. This is when the data proves the environment supports both extremes. One example is the thickness of snakes. Skinny snakes have an advantage of slithering away quicker. Also fatter snakes are ignored by hawks because they are larger and too big for them to consume. |
Evidence of Evolution
Fossil Record- The discovery of prehistoric fossils can portray the changes and evolution of certain species. Relative dating and radiometric dating is used to find out what year or time period it is from.
Geography- When Pangaea was on huge landmass, all different species were in one large area. So when continent began to drift off, species were separated. Species can be similar because of the same ancestors and similar living environments.
Molecular Biology- When the genetics of different organism are compared, and they are more genetically similar, they are more closely related.
Comparative Anatomy- This is when the evidence of body structures or the embryos of the species are used to prove the evolution of species. One example of this is vestigial organs, which is when a species has a structures that were once used but no longer serve a purpose.
Geography- When Pangaea was on huge landmass, all different species were in one large area. So when continent began to drift off, species were separated. Species can be similar because of the same ancestors and similar living environments.
Molecular Biology- When the genetics of different organism are compared, and they are more genetically similar, they are more closely related.
Comparative Anatomy- This is when the evidence of body structures or the embryos of the species are used to prove the evolution of species. One example of this is vestigial organs, which is when a species has a structures that were once used but no longer serve a purpose.
Taxonomy of The Black Lipped Oyster
Kingdom: Animalia
Phylum: Mollusca
Class: Bivalvia
Order: Pterioida
Family: Pteriidae
Genus: Pinctada
Species: Pinctada Margaritifera
(http://pioneerunion.ca.schoolwebpages.com/education/components/scrapbook/default.php?sectiondetailid=2821)
Phylum: Mollusca
Class: Bivalvia
Order: Pterioida
Family: Pteriidae
Genus: Pinctada
Species: Pinctada Margaritifera
(http://pioneerunion.ca.schoolwebpages.com/education/components/scrapbook/default.php?sectiondetailid=2821)
SPECIAL ADAPTATIONS!!
One special adaptation is that these clams have the ability to filter the water they absorb to eat the particles. This is called filter feeding. This system of filter feeding also brings them oxygen to breath. Another adaptations is that the oyster has a hard, tough shell that is used to protect itself and to avoid other enemies. The black lipped oyster, like many other oysters, go through a sex change, from a male to a female, which is another adaptation. In addition, the black lipped oyster has the ability to perform broadcast spawning. This is when the clam releases it's gametes into the ocean. This is a type of special adaptation because it doesn't need any other body structure or function to reproduce.
One special adaptation is that these clams have the ability to filter the water they absorb to eat the particles. This is called filter feeding. This system of filter feeding also brings them oxygen to breath. Another adaptations is that the oyster has a hard, tough shell that is used to protect itself and to avoid other enemies. The black lipped oyster, like many other oysters, go through a sex change, from a male to a female, which is another adaptation. In addition, the black lipped oyster has the ability to perform broadcast spawning. This is when the clam releases it's gametes into the ocean. This is a type of special adaptation because it doesn't need any other body structure or function to reproduce.
There are clam fossils found in the Devonian era. From my point of view, the physical appearance of these clams seemed to have remained the same. A majority of mollusks have not evolved for centuries.