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SELF-SACRIFICE. "In this sense, the senescing leaf continues to function as a source of nutrients to the whole plant, but only at the expense of its own ability to survive." https://lnkd.in/dNWP3KD View in LinkedIn

ABANDONING INDIVIDUAL LIFESTYLES. "In each of these transitions, a group of individuals that could previously replicate independently joins together to form a new, more complex life form that can only replicate as a whole. For example, genes come together to form genomes, cells join together to form multicellular organisms, and multicellular organisms join together to form eusocial societies." http://www.sciencedirect.com/science/article/pii/S0960982213005678 View in LinkedIn

EIGHT MAJOR TRANSITIONS. "The evolution of multicellular organisms represents one of approximately eight major evolutionary transitions that have occurred on earth. The major challenge raised by this transition is to explain why single cells should join together and become mutually dependent, in a way that leads to a more complex multicellular life form that can only replicate as a whole." https://lnkd.in/df8KJQ4 View in LinkedIn

NEW HISTORY. "(i) Cyanobacteria originated before the GOE, (ii) multicellularity coincides with the beginning of the rise of oxygen, and (iii) three clades representing the majority of extant cyanobacteria evolved shortly after the accumulation of atmospheric oxygen." (GOE = Great Oxygenation Event). http://www.pnas.org/content/110/5/1791.full View in LinkedIn

MULTICELLULARITY ROLE. "Our results indicate an origin of cyanobacteria before the rise of atmospheric oxygen. The evolution of multicellular forms coincides with the onset of the GOE and an increase in diversification rates. These results suggest that multicellularity could have played a key role in triggering cyanobacterial evolution around the GOE." (GOE = Great Oxygenation Event). http://www.pnas.org/content/110/5/1791.full View in LinkedIn

SO ENDS a peek into the complexity of the control of leaf fall timing. This is influenced by numerous factors, both internal and external. It remains stunning, to me at least, that despite this complexity, trees march inexorably by species, one by one, exactly in synch, into the autumn leaf coloration and subsequent leaf drop. May your autumns be filled with wonder. View in LinkedIn

ABSCISCIC ACID HORMONE (ABA). "Both the upregulation of genes associated with ABA signaling and a dramatic increase in endogenous ABA levels can be observed in many plants during leaf senescence." https://lnkd.in/dj6JXRP View in LinkedIn

VOLVOX EXAMPLE. "A first well-studied example of emerging intercellular separation of poorly compatible activities is the germ–soma specialization in Volvox. Somatic cells gather nutrients from the environment, and provide germ cells with these nutrients. The somatic cells are flagellated, and the flagella are important for motility and transport of nutrients to the cells. Flagellation and cell division are incompatible, and this fact is probably one of the factors promoting differentiation between somatic and germ cells." http://rspb.royalsocietypublishing.org/content/early/2011/12/05/rspb.2011.1999.short View in LinkedIn

COMPARTMENTAL SOLUTION. "In a multicellular organism, such incompatible processes can take place simultaneously, but compartmentalized into separate cells." http://rspb.royalsocietypublishing.org/content/early/2011/12/05/rspb.2011.1999.short View in LinkedIn

COOPERATIVE BACTERIA. "The tree of life is dominated by single-celled microorganisms that appear to perform a huge range of cooperative behaviours. For example, the growth and survival of bacteria depend upon excreted products that perform a variety of functions, such as scavenging nutrients, communication, defence and movement." http://www.sciencedirect.com/science/article/pii/S0960982207014996 View in LinkedIn