Natural Selection & Evolution

62. Describe Charles Darwin’s theory of natural selection: All living things compete for resources, only those that are best adapted will obtain those resources. Those that are BEST FIT will survive, reproduce, and pass on those traits to their offspring. Those that are least fit will die.

63. What are the mechanisms of evolution? Describe each Natural Selection leads to an evolutionary change when some individuals with certain traits in a population have a higher survival and reproductive rate than others and pass on these inheritable genetic features 

Reproductive/geographical isolation the inability of a species to breed successfully with related species due to geographical, behavioral, physiological, or genetic barriers or differences.

Gene flow may change the frequency and/or the range of alleles in the populations due to the migration of individuals or gametes that can reproduce in a different population. 

Genetic drift a random event that happens by chance in nature that influences or changes allele frequency

mutations can affect the phenotype and in turn, reduce the fitness of an organism or lead to the reproductive success and adaptability of an organism to its environment.

Recombination  is a process by which pieces of DNA are broken and recombined to produce new combinations of alleles. creating genetic diversity

Common Ancestory 64. Which of the structures below indicate a common ancestor? Analogous structures do NOT indicate common ancestory, but HOMOLOGOUS Structures do.

Homologies 65. This pictures is showing the % of amino acids that are the same as a humans. Amino acids are coded for by the DNA This is Molecular Homology

Explain the evolution of the two fish The two fish most likely became separated by the Panama canal creating reproductive isolation. After many years of separation each fish changed and the two can no longer reproduce which means they are now two different species. This is known as speciation.