Transcript Evolution
Evolution The Puzzle of Life’s Diversity Charles Darwin Proposed the Theory of Evolution The father of evolution Made the greatest contributions to our understanding of how species evolved over time. Fossils Preserved remains of ancient oragnisms. – Why are they different then what lives here on earth now. Artificial Selection The process of humans selecting the variations that they find most attractive or useful, and breeding or reproducing those traits in the new offspring. Natural selection Allowing nature to take its course naturally letting the animals mate and the flowers pollinate without any human interference. AKA: Survival of the Fittest – Weaker animals and unfavorable plant characteristics will die off over time. Evolution by Natural Selection 3 Related Hypothesis Darwin hypothesized that high birth rates and a shortage of life’s basic needs would force organisms into competition for resources. He termed this theory: – The Struggle for Existence: Members from each species compete regularly to obtain food, living space, and other necessities of life. Evolution by Natural Selection 3 Related Hypothesis Darwin also hypothesized that in order for organisms to survive they must be well suited to their environment. He termed this theory the: – Survival of the Fittest: Individuals that are better suited to their environment survive and reproduce most successfully. Evolution by Natural Selection 3 Related Hypothesis Darwin lastly hypothesized that over long periods of time, natural selection produced organisms that have different structures resulting in today’s species looking different than their ancestors from generations past. He called this theory: – Descent with Modification: Each living species has descended, with changes, from other species over time. What does the word fitness mean? Is it your athletic ability? Is it how nice you look in your clothes? Fitness: The ability of an individual to survive and reproduce in its specific environment. So what is an adaptation? Um….. Is it a plug for my cell phone? Adaptation: An inherited characteristic that increases and organisms chances for survival. Evidence of Evolution Darwin argued that living organisms have been evolving on the earth for millions of years. His evidence is found in: – Fossil Records – Geographical Distribution of living species – Homologous structures – Similarities in embryonic development