BIO152H5 Lecture Notes - Lecture 12: Sympatric Speciation, Reproductive Isolation, Phylogenetic Tree
Document Summary
Speciation: the process by which one species splits into 2 or more species: many shared characteristics due to shared ancestry, example: dna of flightless and flying cormorants reveals close relatedness. Microevolution vs. macroevolution: microevolution: changes in allele frequencies over time. Micro evolutionary mechanisms: mutation, gene flow, genetic drift, natural selection and sexual selection: macroevolution: the origin of new groups of organism. Mechanism by which new species originate from existing ones. Speciation explains the similarities (unity) and differences (diversity) of life. Defining a specie: specie in latin= appearance among species: evolutionary independent group or population differing in morphology, physiology, biochemistry and dna sequence. How are species defined and identified: biological species concept: Members of the same species can be separated geographically and still be biological same. Ex: brown bear from europe and grizzly bear from na they are potentially because if they are brought together they can still interbreed together for fertile offspring.
