BIS 2B Lecture Notes - Lecture 20: Commensalism, Conditionality

• School: UC-Davis
• Department: Biological Sciences
• Course: BIS 2B
• Professor: Mark Schwartz; Sharon Strauss

Document Summary

To fix approach to character displacement, experimentally manipulate which individuals are being exposed to competition in which kinds of environments and we have shown that changes are heritable. Galapagos finches competition may not be important now (removal experiments would not indicate much competition). If there is little genetic variation, we might not see any evidence of competition between those species because they are already eating different size seeds (evolution has already happened). Now, traits are fixed and there"s no genetic variation. Trait distributions arose because of divergent selection that occurred long ago in order to allow these species to coexist on the same island. Positi(cid:450)e inte(cid:398)a(cid:265)tions : (cid:398)elationships (cid:264)/(cid:451) di(cid:303)(cid:303)e(cid:398)ent spe(cid:265)ies that (cid:398)esult in (cid:264)ette(cid:398) (cid:304)(cid:398)o(cid:451)th, (cid:398)ep(cid:398)odu(cid:265)tion and/o(cid:398) su(cid:398)(cid:450)i(cid:450)al (cid:303)o(cid:398) at least one spe(cid:265)ies in(cid:450)ol(cid:450)ed in the inte(cid:398)a(cid:265)tion (cid:451)ithout ne(cid:304)ati(cid:450)el(cid:457) a(cid:303)(cid:303)e(cid:265)tin(cid:304) the othe(cid:398) spe(cid:265)ies. The(cid:457) mi(cid:304)ht (cid:264)e t(cid:398)ophi(cid:265) (cid:589)one eatin(cid:304) the othe(cid:398)(cid:590) o(cid:398) nont(cid:398)ophi(cid:265) (cid:589)nothin(cid:304) to do (cid:451)ith (cid:303)ood(cid:590) and a(cid:265)t di(cid:398)e(cid:265)tl(cid:457) o(cid:398) indi(cid:398)e(cid:265)tl(cid:457) (cid:589)th(cid:398)ou(cid:304)h a thi(cid:398)d spe(cid:265)ies(cid:590)