Sean Car­roll, at Pre­pos­ter­ous Uni­verse, has a neat graph show­ing how ideas migrate between fields, and how dis­cov­er­ies in one field cas­cade into oth­ers. Enough the­o­rists read the phe­nom­e­no­log­i­cal lit­er­a­ture that results grad­u­al­ly seed the the­o­ry and push new ques­tions to the front. As with can­cer vac­cines, there will be some who stick with the old research pro­grams, keep­ing the hearth warm for the next great dis­cov­ery. But as more is learned about the uni­verse, the­o­rists real­ize that they are try­ing to prove some­thing dif­fer­ent than they thought, and new research flour­ish­es.
The oth­er end of the spec­trum has oth­er use­ful qual­i­ties. Plant ecol­o­gists devel­oped a set of tools to deal with com­pe­ti­tion and pre­dict­ing when com­pe­ti­tion would lead one species to take over, and when the com­peti­tors could co-exist. Because plants are sta­tion­ary and com­pete for car­bon and nitro­gen, it’s easy to devel­op some straight­for­ward mod­els of competition.

Why car­bon and nitro­gen? Car­bon is struc­tur­al, and also ener­gy. Cel­lu­lose, the build­ing block of plants, is most­ly car­bon with oxy­gen and hydro­gen thrown in, so tak­ing up car­bon allows height and width. Nitro­gen is pro­tein, chem­i­cal activ­i­ty. Since there’s rarely enough nitro­gen, and car­bon is avail­able as car­bon diox­ide, it’s easy to talk about a sin­gle lim­it­ing resource, and com­pet­i­tive strate­gies for extract­ing that resource. In cer­tain envi­ron­ments, oth­er resources are lim­it­ing, like water, iron, salts, or potas­si­um. But every plant is look­ing for the same thing in the same places.

Ani­mals move around. Some are big, and can move around a lot. Oth­ers are small, and can get into lit­tle nooks and cran­nies. The stuff they want is dif­fer­ent. They still need car­bon and nitro­gen, but it has to be in a par­tic­u­lar form, plant, oth­er ani­mal, fun­gus, etc. They need to sleep, to mate, to stay warm. They have to watch for preda­tors and care for off­spring. And they do all that in com­pli­cat­ed spa­tial ways. 

So ani­mal ecol­o­gists devel­oped dif­fer­ent the­o­ries and approach­es. The lan­guage of the com­mu­ni­ties shift­ed. The focus changed. Plant ecol­o­gists devel­oped robust the­o­ries of resource com­pe­ti­tion. Ani­mal ecol­o­gists devel­oped more sophis­ti­cat­ed mod­els of the niche. Nich­es are ways of talk­ing about resources, but plant ecol­o­gists don’t talk in ways that ani­mal ecol­o­gists do, and I think there’s a lot of dupli­cat­ed effort.

One ques­tion that con­stant­ly hov­ers in the back of my mind is: how to inte­grate these approach­es? How do I take the sophis­ti­cat­ed plant ecol­o­gy and gen­er­al­ize it to motile species which com­pete for dif­fer­ent resources at dif­fer­ent times and by dif­fer­ent means.

Maybe it’s impos­si­ble. Maybe plants are spe­cial. But maybe plants are just as com­pli­cat­ed as ani­mals, and it’s just a mat­ter of see­ing the sim­plic­i­ty in ani­mal ecol­o­gy, rather than impos­ing com­plex­i­ty on plants.

Ecol­o­gists all read papers from both sides. Why do these divi­sions per­sist, even though we rec­og­nize our com­mon pur­pose and we use almost iden­ti­cal lan­guage? The inter­change between dis­ci­plines is much freer among ecol­o­gists than between dif­fer­ent branch­es of physics. The great the­o­ret­i­cal ecol­o­gists don’t care whether their the­o­ry is applied to plants or animals. 

Does that mean that habits of thought are sep­a­rat­ing these groups, or that there are real and irrec­on­cil­able dif­fer­ences? I don’t know which it is. So we just move ahead. 

“Move” by Miles Davis from the album Birth Of The Cool
(1949, 2:34).