Natural Selection

Natural Selection The unequal survival and reproduction that results from the presence or absence of particular traits

Natural Selection Only those individuals that are well suited to their environment survive and produce offspring unsuccessful individuals do not survive, or they produce fewer offspring, and their less suitable traits therefore disappear from the population

Natural Selection The environment dictates the direction and amount of change

Natural Selection English naturalist, Charles Darwin, observed in 1859 that organisms in a population differ slightly from each other in form, function, and behavior

Benefits to Natural Selection Adds complexity to ecosystems

5 Main Elements of Natural Selection All species have genetic variation 2. The environment produces many challenges to an individual’s ability to reproduce 3. Organisms tend to produce more offspring than what the environment can support; therefore creating competition for survival

5 Main Elements of Natural Selection Individuals within a population that are better able to cope with environmental challenges tend to leave more offspring 5. The traits of the individuals best suited to a particular environment tend to increase in a population overtime

Natural Selection As the populations of a given species change, so does the species

Natural Selection Vocabulary Adaptation- an inherited trait that increases an organisms chance of survival and reproduction in a certain environment Variation- differences within the same species Evolution- the change in genetic characteristics of a population from one generation to the next

“Survival of the Fittest” Those organisms best suited to their environment (adaptations) will survive to reproduce, passing on their genes with the adaptation(s) to their offspring.