What is Evolution ?
Evolution is the process of how organisms have developed over time. Organisms and adaptations are always evolving. They evolve through factors that drive a change in allele frequency. The four ways of change in allele frequency are mutation, genetic drift. migration, and natural selection. The only way a new allele can be created is through mutation. The new allele can either be harmful or helpful, it must be heritable, and or may or may not affect reproductive success. A genetic drift is a random change in allele frequency - something happen where only surviving species is left. Migration is a group of individuals moves from one population to another. Lastly natural selection is similar to "survival of the fittest". It is when only those best suited to the environment and reproduction survive - whoever has the most reproductive success. There are three types of natural selection. One types is directional selection. In directional selection there is a selection against an extreme of a trait and then there is a shift towards another extreme trait. In stabilizing selection there are pressure going against two extremes of a trait - so there is a shift towards trait that is an average of those two traits. Lastly in disruptive selection what happens is the exact opposite of stabilizing selection. There is a shift from the "average" trait to the other two extreme traits. (13) (14)
Evidence of Evolution
There are many different evidences for evolution. The different ones are organism remains, fossils, DNA testing/similarities in DNA, similarities among organisms that are related, similarities in embryo, and natural selection. (12)
There are many different evidences for evolution. The different ones are organism remains, fossils, DNA testing/similarities in DNA, similarities among organisms that are related, similarities in embryo, and natural selection. (12)
Feather Star Evolution
- Passion Flower Feather Stars have little cirri ("feet") that let them grasp onto rocks or coral for shelter.
- Feather Stars use their arms as filters from passing currents,and then pass them down into their mouth.
- The feather stars arms are covered in a sticky substance that help catch food and pass it into their mouths.
- The feather stars arms/structure and a water vascular system that help it move around/swim.
There has been evidence of earlier forms of Feather stars - there are fossils of them left behind. The fossils show how they have developed being that fossils are seen to have a stem or are stalked, where as Feather stars todays aren't. (11)
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