Microsoft Word Kurzweil, Ray The Singularity Is Near doc

Reversing Aging
It is logical to assume that early in the evolution of our species (and precursors to our species) survival would not have 
been aided—indeed, it would have been compromised—by individuals living long past their child-rearing years. 
Recent research, however, supports the so-called grandma hypothesis, which suggests a countereffect. University of 
Michigan anthropologist Rachel Caspari and University of California at Riverside's San-Hee Lee found evidence that 
the proportion of humans living to become grandparents (who in primitive societies were often as young as thirty) 
increased steadily over the past two million years, with a fivefold increase occurring in the Upper Paleolithic era 
(around thirty thousand years ago). This research has been cited to support the hypothesis that the survival of human 
societies was aided by grandmothers, who not only assisted in raising extended families but also passed on the 
accumulated wisdom of elders. Such effects may be a reasonable interpretation of the data, but the overall increase in 
longevity also reflects an ongoing trend toward longer life expectancy that continues to this day. Likewise, only a 
modest number of grandmas (and a few grandpas) would have been needed to account for the societal effects that 
proponents of this theory have claimed, so the hypothesis does not appreciably challenge the conclusion that genes that 
supported significant life extension were not selected for. 

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Aging is not a single process but involves a multiplicity of changes. De Grey describes seven key aging processes 
that encourage senescence, and he has identified strategies for reversing each one. 
DNA Mutations.
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Generally mutations to nuclear DNA (the DNA in the chromosomes in the nucleus) result in a 
defective cell that's quickly eliminated or a cell that simply doesn't function optimally. The type of mutation that is of 
primary concern (as it leads to increased death rates) is one that affects orderly cellular reproduction, resulting in 
cancer. This means that if we can cure cancer using the strategies described above, nuclear mutations should largely be 
rendered harmless. De Grey's proposed strategy for cancer is preemptive: it involves using gene therapy to remove 
from all our cells the genes that cancers need to turn on in order to maintain their telomeres when they divide. This 
will cause any potential cancer tumors to wither away before they grow large enough to cause harm. Strategies for 
deleting and suppressing genes are already available and are being rapidly improved. 
Toxic Cells.
Occasionally cells reach a state in which they're not cancerous, but it would still be best for the body if 
they did not survive. Cell senescence is an example, as is having too many fat cells. In these cases, it is easier to kill 
these cells than to attempt to revert them to a healthy state. Methods are being developed to target "suicide genes" to 
such cells and also to tag these cells in a way that directs the immune system to destroy them.