BIOL 215 Lecture Notes - Lecture 8: Littorina Saxatilis, Lake Whitefish, Head Louse
Document Summary
Species = group of organisms which can breed together and are ecologically distinctive (usually) Attempt to identify, catalogue and describe species climaxed in mid-18th c with linnhaeus. Di(cid:448)ersifi(cid:272)atio(cid:374) does(cid:374)(cid:859)t reall(cid:455) (cid:374)eed to (cid:271)e e(cid:454)plai(cid:374)ed, it just happe(cid:374)s. orga(cid:374)is(cid:373)s produ(cid:272)e offspring that are slightly different from them each generation is slightly different from the different one, and those differences accumulate. Dandelions: very very many species based on small differences. Reproduce asexually make copies of themselves, but with errors. Asexual reproduction i(cid:374)fi(cid:374)ite (cid:373)utatio(cid:374)s (cid:271)e(cid:272)ause the ge(cid:374)es do(cid:374)(cid:859)t re(cid:272)o(cid:373)(cid:271)i(cid:374)e. 2 theories of what separates species: sexually isolation (regardless of ecological separation), or ecological distinctiveness. Asexual lineages diversify indefinitely but usually become specialized to a limited number of discrete ways of life. Bdelloid rotifer: only known animal group to reproduce exclusively asexually. Found in temperate bodies of water (e. g. puddles, water on leaves), reproduce exclusively by asexual eggs formed by mitosis; yet exist in fairly defined species that are highly specialized.
