You addressed it to me.
Has anyone ever directly observed the "evolution" of a single-celled organism to a multi-celled organism?
Boraas (1983) reported the induction of multicellularity in a strain of Chlorella pyrenoidosa (since reclassified as C. vulgaris) by predation. He was growing the unicellular green alga in the first stage of a two stage continuous culture system as for food for a flagellate predator, Ochromonas sp., that was growing in the second stage. Due to the failure of a pump, flagellates washed back into the first stage. Within five days a colonial form of the Chlorella appeared. It rapidly came to dominate the culture. The colony size ranged from 4 cells to 32 cells. Eventually it stabilized at 8 cells. This colonial form has persisted in culture for about a decade. The new form has been keyed out using a number of algal taxonomic keys. They key out now as being in the genus Coelosphaerium, which is in a different family from Chlorella.
Boraas, M. E. 1983. Predator induced evolution in chemostat culture. EOS. Transactions of the American Geophysical Union. 64:1102.
placemarker
altruism
One entry found for altruism.
Main Entry: al·tru·ism
Pronunciation: 'al-tru-"i-z&m
Etymology: French altruisme, from autrui other people, from Old French, oblique case form of autre other, from Latin alter
1 : unselfish regard for or devotion to the welfare of others
2 : behavior by an animal that is not beneficial to or may be harmful to itself but that benefits others of its species
- al·tru·ist /-tru-ist/ noun
- al·tru·is·tic /"al-tru-'is-tik/ adjective
- al·tru·is·ti·cal·ly /-ti-k(&-)lE/ adverb