Charles Darwin's Explanation Of Characteristics

Charles Darwin, as a young biologist in the 1800’s, sailed across the Pacific Ocean on board a research vessel named the H.M.S. Beagle. During his travels, Darwin began to notice how isolated populations of organisms had developed unique features. For example, he discovered several species of sparrows living on the Galapagos Islands. He noted how the sparrows all had different types of beaks, each specially adapted to gathering food in the desolate terrain. Some had short, stout beaks for eating seeds while others had long, thin beaks that were able to extract invertebrates from the rocky shores. His observations led him to formally develop the hypothesis of evolution as a possible explanation for the emergence of distinct features within …show more content…
We define speciation as the process by which a group of genetically and reproductively distinct organisms emerges from a ‘parent’ population. It is possible for humans to witness the effects of evolution on a small scale. Species display a variation of characteristics - humans, for example, have brown, green or blue eyes, blonde hair or brown hair, and so on. Typically, the characteristics make the organism better suited for survival within their environment. FOr example, human populations who have lived historically in tropical regions have darker skin (which has higher levels of melatonin) to protect them from the hot rays of the sun. However, when environmental pressures change, the characteristics displayed within the population will begin, over generations, to change to.
The four main forces that drive evolution are natural selection, mutation, gene flow and genetic drift. Natural selection is the process involving the organism adapting to environmental factors. This could be factors such as climate, availability of food sources and predation. Organisms that have physical characteristics that enable them to flourish their environment will survive to reproduce, passing those beneficial characteristics onto their offspring. Those organisms with undesirable traits will die without …show more content…
Genes are bits of code, or segments of DNA, that underlie the physical characteristics of organisms. Genes are easily damaged and can mutate, leading to novel expressions of the gene. These mutations can lead to either positive or negative characteristics, depending on how they affect the organism 's survival. Natural selection will select for good mutations while negative traits will be selected against.
Another force of natural selection is gene flow. This is when a population that develops a unique and beneficial trait passes it along to other populations. When individual members of a population migrate to another population, they can pass along their unique traits via reproduction. Beneficial mutations that are selected for over a period of time will begin to become more common within a population, leading to a change in frequency of that gene within the population (from obscure to dominant). This process is known as genetic