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SO ENDS this topic of mass extinctions. It is a remarkable history of boom and bust events in life’s history, from great abundance to hanging by a thread. What is evident, is that it is hard to snuff life out, even in the face of cataclysmic events. Some life forms will survive. Even when you look at the growth and survival of seedlings, there is an evident force to survive at all costs in any conditions. Life is a fiercely determined force. View in LinkedIn

COMPLEX AND UNPREDICTABLE. “The evolutionary response to mass extinction is slow on human time scales, difficult to predict owing to the contingencies of postextinction conditions including the identity and evolutionary dynamics of the survivors, and geographically heterogeneous.” http://www.pnas.org/content/98/10/5393.full/Donnie) View in LinkedIn

FORCE OF CHANGE. “Extinction itself promotes biotic interchange. Asymmetries in ancient biotic interchange generally appear to reflect geographic differences in extinction intensity. The end-Cretaceous extinction shows, however, that although biotic interchanges pervade the postextinction world, simple linear relationships can break down to produce unexpected source-sink patterns.“ http://www.pnas.org/content/98/10/5393.full/Donnie) View in LinkedIn

HOMOPLASTY VS HETROPLASTY. “A mammalian cell has a single nucleus which contains a single genome. The genomic DNA is identical across all cells in an organism. A mammalian cell has many mitochondria and every mitochondria has its own (circular) genome. All the many individual copies of mtDNA exist independently of each other. If all the mtDNA in a cell are identical, then they are homoplasmic. (Common, "normal" situation). If one (or more) of the mtDNA in a single cell acquires a mutation, then the cell will have a mix of mutant-mtDNA and WT-mtDNA. These cells are now heteroplasmic.” https://lnkd.in/eeWUxj8 View in LinkedIn

"EXTRANUCLEAR INHERITANCE or cytoplasmic inheritance is the transmission of genes that occur outside the nucleus. It is found in most eukaryotes and is commonly known to occur in cytoplasmic organelles such as mitochondria and chloroplasts or from cellular parasites like viruses or bacteria." This breaks all of Mendel’s famous genetic laws. https://lnkd.in/eWiwdUk View in LinkedIn

"HETEROPLASMY is the presence of more than one type of organellar genome (mitochondrial DNA or plastid DNA) within a cell or individual. It is an important factor in considering the severity of mitochondrial diseases. Because most eukaryotic cells contain many hundreds of mitochondria with hundreds of copies of mitochondrial DNA, it is common for mutations to affect only some mitochondria, leaving most unaffected." https://lnkd.in/eHYuPyQ View in LinkedIn

EMERGENCE OF EVOLVABILITY. “At the time of writing then, we are still a long way from knowing whether autocatalytic sets offer a plausible model for the emergence of evolvability.” https://lnkd.in/euzMX5X View in LinkedIn

REPRODUCTION IN NATURE is not limited to organisms, nor to cells, but also the very organelles within cells, such as the mitochondrion, chloroplast and nucleus, all of which originated in an ancient foreign engulfment. Their reproduction is rather independent from the rest of the organism's cells. View in LinkedIn

MOLECULAR FITNESS. "It has been suggested that "...some autocatalytic sets will reproduce more rapidly than others and hence will have higher Darwinian fitness" and, therefore, "we have evolution without a genome." https://lnkd.in/euzMX5X View in LinkedIn

REPRODUCTION IN NATURE is not limited to organisms, nor to cells, but also the very organelles within cells, such as the mitochondrion, chloroplast and nucleus, all of which originated in an ancient foreign engulfment. Their reproduction is rather independent from the rest of the organism's cells. View in LinkedIn