Microevolution is the change in gene frequency in a singular population of a species.
Mechanisms of microevolution include:
Population, gene flow (migration), genetic drift, natural selection, and mutation.
- An isolated population of a species could, over a series of generations, change so much from other populations that it may develop into a different species. And example of this is Darwin's finches on the Galapagos Islands. Though the birds were all from the same family (finch), their isolation on the islands was enough for them to develop differentiating traits.
- Gene flow is the outcome of the migration of different populations of the same species meeting and interbreeding. A gene that may appear more in the new population may be seen with more frequency in the offspring of the combined populations.
- Genetic drift is the random chance of a particular trait appearing with more frequency in the next generation.
In this example, the trait for green coloration appears more in the beetle offspring than the trait for brown coloration." Chance" is the keyword.
- Gene mutation is the chemical change in the DNA of an organism, causing its genes to code for new proteins that would effect its lifestyle and make it different from its predecessors. Reasons for mutation include copying errors in the replication of new cells, or exposure to harmful radiation, chemicals, or viruses.
CONTROVERSY:
The conflicting belief to microevolution is macroevolution. Macroevolution is the change in life forms on a mass scale, and is often used in the arguments for Creationism.
EXAMPLES OF MICROEVOLUTION
Since microevolution is found on such a small. molecular scale, change can be seen in the wild within a reasonable timeframe.
- House sparrows in North America: Populations in the north are larger-bodied than those in the south. These differences are called upon by natural selection, as larger bodied birds can often survive cooler temperatures than smaller-bodied birds.
- Studies between 1972 and 1996 show that rising global temperatures have caused hibernating mosquitoes to go dormant later in the year and awaken sooner, forcing them to adjust their growth and reproductive habits.
- Resistance to pesticide in insects and the resilience of bacteria to antibiotics
QUESTIONS
Is the microevolution argument feasible in contrast to macroevolution?
What withstands skepticism better?
Can we see changes in humans within the past century?
The question of the origin of life....did it evolve or was it created? (Micro- vs. Macro-)
posted by wayward pilot @ 3:32 PM
1 comments
