How did the giraffe get its long neck

How did the giraffe get its long neck? (How do things evolve? )

Evolution

Theory of Evolution • Evolution: the process in which significant changes in the inheritable traits of a species occur over time • Acceptance has never been universal • Culture and religion - own beliefs • Many now believe that the work is dynamic: change is natural and unavoidable • 500 years ago most people thought that life was immutable - unchanged, unchanging • Earth was thought to have a recent origin

What helped sway belief? • Fossils - provide great important scientific insights into the past not only for extinction but also to witness diversity of years past • Geographic knowledge - earth is old, and life had changed

Evidence from the Past • Fossils: any preserved remains or traces of an organism or its activity • Late 17 th century - locations were mapped where fossils had been found • Most common are hard body parts such as shells, bones and teeth • Formed when body gets trapped in sediments and eventually harden into sedimentary rocks

Fossils con’t • Perimineralized fossil: a fossil formed when dissolved minerals precipitate from a solution in the space occupied by the organisms remains • Organisms can also be preserved almost nearly intact when conditions aren’t met for fossilization

Study of Fossils • Palaeontology: scientific study of fossil remains – Began in the 18 th century • 250, 000 identified fossils • Less than 1% of them live today • Cathastrophism: numerous global catastrophes in the past had repeatedly caused the extinction of species that were then replaced by new forms • Relative Age: estimate of the age of a rock in comparison to another • Absolute Age: estimate of the actual age of a rock or fossil specimen

Early Thoughts on Evolution • While many believe Darwin to be the founder of the idea of evolution, many before him were starting the process • Comte de Buffon (1701 - 1788) • Similar structures observed between different species

• Jean Baptiste Lamark – Giraffes – Environmental influences might be responsible for adaptations and for them to be passed on to next generation – Evolution progresses according to the ability of species to acquire features based on use and disuse http: //www. youtube. com/watch? v=V 8 KIv. ICf. GEM