CLUSTER M1A Lecture Notes - Lecture 3: Allopatric Speciation, Ecosystem Diversity, Dna Replication
Document Summary
Biodiversity- the range of different types of organisms and biological systems in a given area. Survey ship set out from england (with charles darwin) Galapagos islands: each island supported its own form of tortoise, mockingbird, finch. Natural selection: organisms struggle to survive and reproduce, too many progeny, not all can survive, variation among individuals and species, traits are inherited. If the fittest survive in a certain environment, then their traits will be passed on to progeny. Theory of natural selection: wrote origin of species in 1859. Mechanism of evolution: (1) mutation- genes are unit of heredity, consist of dna. Dna replication produces exact copies, most of the time. Isolated populations become different, can no longer interbreed become different species (geographic speciation) (4) genetic drift- random events, independent of ability to survive and reproduce, can substantially change small populations. Life arose around 3. 5 billion years ago (only microscopic forms for 2 billion years)
