Royal jelly, a thick, milky substance secreted by young nurse honeybees to feed a bee colonyâs larvae, most notably the queen larvae, is a rich source of nutrients, as well as acetycholine, a neurotransmitter that plays a critical role in cognitive function.
The origin of the eukaryotic cell is a milestone in the evolution of life, since eukaryotes include all complex cells and almost all multicellular organisms. The timing of this series of events is hard to determine; Knoll (2006) suggests they developed approximately 1.6â2.1 billion years ago.
This first major flowering of multicellular eukaryotes (organisms with neucleated cells), which is known as the Cambrian explosion, marks the onset of the Cambrian periodâthe first period of the first era (the Paleozoic) of the Phanerozoic eon (Mayr 2001). The Phanerozoic eon is divided into three eras: The Paleozoic, Mesozoic, and Cenozoic.