BIOL 1005 Lecture Notes - Lecture 13: Parapatric Speciation, Chromosome, Reproductive Isolation
Document Summary
Species-a group of individuals which share a common gene pool (interbreed) and are reproductively isolated from all other such groups. Ecological distribution of populations of species: allopatric species- the species never occur in the same geographical area (population of different species never overlap, sympatric species- the populations of two species overlap through most of their geographical distribution. The extra number of chromosomes in plant species results in very rapid reproductive isolation in most cases, Introgression- incorporation of some genes of one species into the gene complex of another as a result of successful hybridization: parapatric speciation- speciation in which populations are contiguous and touch only on the distributional limit of each population. Isolating mechanisms -prevent species from interbreeding and/or production of fertile offspring. Embryo- a zygote which has begun cell division. Fetus-generally defined as the stage of development when the embryo is recognized as having an appearance similar to the adult form.
