BIOCHEM 1 & 2

The theory of evolution is that every living organism that exist on earth today have all come from descended organisms. The theory of evolution was discovered and researched by Charles Darwin Every organism today are all related because they come from common ancestors. Evolution is not the replacement of older species with newer species it is when new traits evolve over a period of time. Organisms leave evidence of their existence through fossils. Fossils are preserved remains of a once living organism. Different types of fossils are bones, footprints, petrified wood etc. Organisms that share common ancestors usually have similar traits. Scientist studied evolutionary relationships between species by comparing their anatomy. Scientist suspect that birds evolved from dinosaurs. Scientist use genes, proteins, and DNA to discover evolutionary relationships. Natural selection is the process in how organisms are more likely to survive. An example of this is the peppered moth. The peppered moth has the ability to camouflage itself against blackened tree barks. Evolution is not only a change in species but also, the creation of entirely new species this is called speciation. Sometimes speciation is due to geographical isolation when a physical border separates two populations. Organisms of different species cannot reproduce and breed a fertile offspring because of isolating mechanisms. Isolating mechanisms can mean that species cannot reproduce or reproduce a healthy offspring.