According to the Theory of Evolution, Natural Selection is the mechanism by which evolution occurs. Remember: evolution occurs at the level of the population. Individuals do not evolve, populations evolve.
The process of Natural selection is based on the following four postulates (listed in your textbook on page 288):
Postulate 1 - Individual members of a population differ from one another in many respects.
Postulate 2 – At least some of the differences among members of a population are due to characteristics that may be passed from parent to offspring. That is, they are heritable or genetic.
Postulate 3 - In each generation, some individuals in a population survive and reproduce successfully but others do not.
Postulate 4 – The fate of individuals is not determined by luck. Instead, an individual’s likelihood of survival and reproduction depends on its characteristics. Individuals with advantageous traits survive longest and leave the most offspring, a process known as Natural Selection.
Assignment: Choose ONE animal species which is a dophin. Your goal is to describe the way in which an evolutionary change might occur for a particular characteristic (trait) of that species as a result of natural selection. The characteristic could be something like coloration pattern, length of the limbs, or size of the teeth or beak, or any measurable trait that is inherited.
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Choose ONE animal species. Your goal is to describe the way in which an evolutionary change might occur for a particular characteristic (trait) of a population of that species as a result of natural selection.
The characteristic (trait) could be something like coloration pattern, length of the limbs, size of the teeth or beak, or any measurable trait that is inherited.
The organism you choose should be a real one but the evolutionary change in a trait that you describe can be real or fiction.
In your own words,
Explain how the change in this trait occurs. You will describe the trait in the population at the starting point and then what the trait will look like at a later time, as a result of natural selection.
Make sure to explain the process by which the changes occurred. What is the selective pressure? Explain why the change might confer more fitness to a particular environment?
Choose ONE animal species. Your goal is to describe the way in which an evolutionary change might occur for a particular characteristic (trait) of a population of that species as a result of natural selection.
The characteristic (trait) could be something like coloration pattern, length of the limbs, size of the teeth or beak, or any measurable trait that is inherited.
The organism you choose should be a real one, but the evolutionary change in a trait that you describe can be real or fiction.
First, identify the species. Clearly state the name of the SPECIES you are going to be talking about for this assignment. (Make sure you know what is meant by a species.)
Second, clearly state what population of the species you are going to talk about by specifying its geographic location. (Make sure you understand what a population is.)
•Identify a trait of the population to be addressed.
•Explain how this trait varies among individuals.
•Explain how the change in this trait occurs. You will describe the trait in the population at the starting point and then what the trait will look like at a later time, as a result of natural selection.
•Make sure to explain the process by which the changes occurred. What is the selective pressure?
•Explain why the change might confer more fitness to a particular environment.
•Also, explain what change occurs in the environment that causes a change in the characteristic (trait).
To describe how an evolutionary change might occur in dolphins as a result of natural selection, let's take the example of coloration pattern.
First, we need to understand that individual dolphins within a population have variations in their coloration pattern. Some may have darker shades, while others may have lighter shades. This variation is a result of genetic differences passed down from their parents.
Now, let's apply the postulates of natural selection to understand how an evolutionary change in coloration pattern might occur:
Postulate 1: Individual members of a population differ from one another in many respects, including coloration pattern.
In a population of dolphins, there will be natural variation in the coloration pattern of individuals. Some dolphins may have coloration patterns that provide them with advantages in their environment, such as better camouflage or communication.
Postulate 2: At least some of the differences among members of a population are due to characteristics that may be passed from parent to offspring. That is, they are heritable or genetic.
The coloration pattern of dolphins is determined by genes inherited from their parents. If certain coloration patterns are more advantageous in their environment, individuals with those patterns are more likely to pass on their genes to their offspring.
Postulate 3: In each generation, some individuals in a population survive and reproduce successfully, but others do not.
In the dolphin population, individuals with certain coloration patterns may have a better chance of survival and reproductive success. For example, dolphins with coloration patterns that provide effective camouflage are more likely to avoid predators and find prey, increasing their chances of survival and successful reproduction.
Postulate 4: The fate of individuals is not determined by luck. Instead, an individual’s likelihood of survival and reproduction depends on its characteristics. Individuals with advantageous traits survive longest and leave the most offspring, a process known as natural selection.
As a result of natural selection, dolphins with advantageous coloration patterns will survive longer and produce more offspring. Over time, their genes for the favorable coloration pattern will become more prevalent in the population. This gradual change in the frequency of specific coloration patterns is what leads to evolutionary change in the dolphin population.
For example, if the environment favors darker coloration for better camouflage, dolphins with darker coloration patterns will have improved survival and reproduction rates. As a result, the frequency of dolphins with darker coloration patterns will increase over generations.
In summary, an evolutionary change in the coloration pattern of dolphins can occur through natural selection. Traits that provide advantages in survival and reproduction are more likely to be passed on to future generations, gradually leading to a shift in the frequency of those traits within the population.