Natural Selection And Its Effect On A Population Essay

The fifth part of the evolution theory is natural selection. Natural selection is an idea that life doesn’t require creation or guidance from a supernatural being. Natural selection depends only on nature in which the population will adapt to their environment while the one who are unable to adapt will die off. But natural selection cannot provide perfection but can only help the creatures to evolve just enough to be able to survive.

According to Darwin and his theory on evolution, organisms are presented with nature’s challenge of environmental change. Those that possess the characteristics of adapting to such challenges are successful in leaving their genes behind and ensuring that their lineage will continue. It is natural selection, where nature can perform tiny to mass sporadic experiments on its organisms, and the results can be interesting from extinction to significant changes within a species.

In The Origin of Species, Darwin calls the process of natural selection or survival of the fittest, the preservation of favorable individual differences and variations, and the destruction of those, which are injurious (Darwin, 1901). Darwin’s theory of evolutionary change and process of natural selection surmises that variations exist in every

Animals fight for survival daily, and sometimes their lives depend on their ability to adapt with their surrounding environments. Natural Selection is the process in which individuals have certain traits that allow

The Grant’s are capable of studying Darwin’s theory of natural selection in action, after gathering data from their colleagues, Peter Boag and Laurene Ratcliffe, who would be their watch on Daphne Island. Peter and Laurene witnessed an important event in natural selection, during a life or death situation with the finches. Though the two scientists were anxious for rain, but they did not receive a single drop that season. Rain would mean reproduction and fertility for the finches; however, the birds were faced with e horrible drought. Food became scarce and the finch population declined. Easy seeds to obtain on the ground were nearly gone. The seeds with tougher defenses, such as the caltrop, were usually untouched, since they were hard to crack. The finches with inadequate beaks did not

Natural selection is the process in which heritable traits that make it more likely for organisms to survive and successfully reproduce become more common in a population over successive generations. Each of us individuals is specifically shaped and formed by our own genetic pattern. We inherit this pattern half from are mother and half from are father. The cause of this is the proximate cause that led it’s phenotype to ultimate causes. Much of we know today about evolution derives from the late great pioneer, Charles Darwin. Charles Darwin was an english naturalist that even from an early age was very interested in outdoor pursuits. Early in his prep career his father tried sending him to the University of Edinburg to pursue his medical

In 1977 a drought reduced the number of small seeds available for the birds, forcing them to rely on larger seeds and nuts, which were difficult for birds with smaller beaks to open. The number of birds unable to eat reduced as they died and gave way to harder beaked finches. Within a couple of generations they had evolved larger beaks. In 2003 another drought struck the Galapagos and as there were many large beaked finches, the food source of nuts dwindled, making the ability to eat smaller seeds an asset. The numbers of larger beaked birds dwindled as food became scarce, leaving the smaller birds to survive and reproduce. Darwin’s theory was not well received when first written in On the Origin of Species, though many scientists today use it as a basis for research in evolution.

In the Galapagos Islands there is an island named, Daphne Major, this island plays as the host of the Galapagos finches. In 1976 - 1977 there was an absolute near extinction of these finches. This is because of the drought of 1976 and 1977 (see figure 1). While the drought made the Finch population dwindle there was a hidden trait that was helping some survive, and that is beak size. Why did the larger beaks help those fortunate Finches survive? Because the only plants that survived where plants like the Tribulus, which produces hard shelled seeds. While there was an abundance of hard shelled seeds there was a shortage of soft shelled seeds. The finches that had the larger beaks weighed more, for example, survivors weighed approx. 12.5g to 17.5g with beak sizes going from 10.5 to 13.6(for evidence see figure 2. This reduced the population because the Finch’s with the smaller beaks couldn't open the harder seeds and had to scavenge for soft seeds which were very rare. The finches with small beaks, then died from starvation

We look at how adaptations happens with natural selections with variations, populations, and over reproduction with the environment. We conducted an experienced and look at finches on Galapagos island through 1976 to 1978 with the offspring to see how natural selection played. What happen was as the food source went down the finches with small beaks could not eat the big nuts with harder shells with the finches with bigger beaks could and passed the trait with the bigger beaks to its offspring to survive. So went the drought took place the birds how to adapt to its surroundings. All adaptations happens when natural selection takes places which makes populations, new species, or even extinct one, adapt.

Natural selection follows three main and related principles under Darwin and Wallace which are variation, heritability, and differential reproductive success. Natural selection is an indispensable mechanism of evolution. First off, to have natural selection, you need diversity among a population such as genetic variation, some species are multi-colored. An example for genetic variation would be the genus delphinidae. Dolphins, pilot whales, and killer whales are all a part of the same family, however they range in colors, shapes, and names making people think they are of a different species when they are all related and have evolved into a large variety.

Evolution is the change in the different types of living organisms which is slow process. Natural Selection is a battle between individuals within species, which results in the survival of those organisms that are better suited to their environment than others. Natural Selection is a mechanism of evolution. There are three conditions of Natural Selection which should meet to be able to survive and reproduce, so they can pass the traits to the next generation. In all species, there are huge numbers of variation in genetic traits which can help them to survive and there are some organisms which have specific characteristics which will help them to survive than other living things. Natural Selection helps species to adjust within the new or existing environment, to able to survive and pass to their offspring. There are competition for resources: However, there are some living things which are better competitors than others which can survive and reproduce. Evolution is result of Natural Selection (Smock 2014).

It is well-documented that the finches of the Galapagos, having radiated from a common ancestor from the mainland ages ago, went on to occupy various ecological niches, adapting beak shapes/sizes suitable for their differing diets. Competition between individuals occupying the same geographic area and similar niches can drive the evolution of various morphologies one way or the other, also known as character displacement. In this example, the medium ground finch, Geospiza fortis, population in one of the islands was changed within the span of one generation due to extreme shifts in the environment. During a year of drought that saw the exhaustion of smaller soft seeds as a food source, birds with smaller beaks died out more readily, given they could not handle and break the coating of the larger seeds that remained. Only birds with larger beaks could handle the large seeds, and as such were able to eat and survive to reproduce. As a result, the following generation of finches showed an increase in average beak size from the previous generation. The inverse occurred when abundant rain the following year saw the scarcity of large seeds and the increased fitness of smaller-beaked

Natural selection leads to evolutionary change when individuals with certain characteristics have a greater survival or reproductive rate than other individuals in a population and pass on these inheritable genetic characteristics to their offspring. The gene pool increases when a mutation changes an allele so there is a new version of the gene and the mutation survives to establish in the gene pool either by genetic drift or positive selection. The gene pool decreases when an allele is eliminated from the gene pool by genetic drift or by negative selection reducing the productive success of those expressing the phenotype. In changing in the gene pool the possible combinations of phenotypic traits change and the population evolves.

Charles Darwin broached the theory of natural selection in his book the Origin of Species, which has been considered the basis of evolutionary biology to this day. Natural selection is when populations of a species evolve over the course of many generations. Darwin believed that species were not created separately, but instead, species were derived from one another. In other words, the evolution of species creates many variations among creatures, and this is because all of those species came from a common ancestor, and characteristics changed to increase the species chance of survival.

GMO stands for Genetically Modified Organism, which is the process of extracting genes from one species into another unrelated species. The process of transferring DNA from two distinct species is through genetic engineering. This displays the new traits of the first donor, which will be part of the genetic make up of the recipient organism. GMO is different from cross breeding or hybridization. Scientists developed GM plants by introducing genes that kill insects and protect crops against viruses. Many of these GM plants require less water so that they are able to grow in areas where water is scarce. The benefit of GMOs help crops grows and ripens faster so that farmers are able to grow more crops throughout the year. On the other hand, GMOs may be harmful to humans if they are not washed and cleaned properly before eating. GMOs include high risk of allergens, toxins, and other unknown side effects that are harmful.