Friday, January 02, 2009

Genetic and Cultural Transfer Rates

The human genome contains just over 3 billion DNA base pairs, or around 750 million bytes of data. (3 billion BP x 2 bits/BP = 6 billion bits / 8 bits/byte = 750 million bytes.)

Only about 3% of that, or around 22.5 million bytes, make up the 22,000 or so genes that define our bodies. The remaining 97% is so-called junk DNA. (Some have proposed encoding cultural or scientific works into the junk DNA of humans or other creatures, such as cockroaches [1], but that will not concern us here.)

Next consider a typical human who (with a mate) produces 2 children during the 25-year span of a “generation.” Each child contains half the genes of each parent, so for the sake of argument we can suggest that two children will contain roughly all their parents’ genes.

Twenty-five years contain about 9,131 days, so the rate of transmission of human genetic information is approximately:

All Information: 750 MB / 9,131 days = 82,138 bytes / day
"Good" Information: 22.5 MB / 9,131 days = 2,464 bytes / day

Culture, on the other hand, is regarded as information (e.g., how to make fires or wheels) that is NOT genetically transmitted, but rather handed down from generation to generation via oral tradition, training, or other forms of communication.

An example of possible non-human culture is “sponging” by dolphins [2]. A species of dolphin looks for edible prey by stirring up sediment with its nose. Some of these dolphins (but not all) find a piece of sponge that fits over their nose, reducing wear and tear. Some mothers apparently teach this behavior to their offspring while others do not. Humans of course teach their offspring a much larger range of behaviors, but this is an example of the basic process in action.

Point 1: Even in humans, let alone other life forms, it appears that the rate of cultural (non-genetic) information transfer is dwarfed by the rate of genetic information transfer.

Considering only the “good” DNA that makes up your known-useful genes, to transmit 2,464 bytes per day of cultural information to the next generation, assuming 2,000 characters per page, one would have to compose at least 1-1/4 pages of written material per day, every day for 25 years. Human text is redundant, and can often be compressed by a factor of 10 (e.g., with a “zip” program), so in reality to transmit 2,464 unique bytes per day might require (say) 10 pages of typing.

A person who completes college and continues to read regularly might well receive 10 (uncompressed) pages of information every day for 25 years, but few if any individuals will transmit that amount of information!


Writers in the field of systems evolution (e.g., Heylighen) believe that our information that is worth conveying was generally obtained via a process of “blind variation and selective retention” (or "BVSR") [3]. Certainly this applies to genetic information, in which Nature makes blind changes and retains those that make the organism more fit for survival.

Further it has been proven that the process of concept formation is “NP-complete” [4], meaning that to generate explanatory hypotheses or deliberative plans there is no shortcut other than trying all possible combinations of (relevant) hypotheses to see which ones work. This can account for the relatively slow pace of cultural progress. (After it was discovered that an electric current can move a magnet, it required over 10 more years to discover that moving a magnet will generate an electric current!)

Like sponging dolphins, we have accumulated a wealth of knowledge and procedures, mostly if not entirely by random means [5], retained those that increased our fitness for survival, and handed down this knowledge in the form of non-genetic cultural information.

Point 2: Our genetic heritage transmits the BVSR’s of a few billion years of biological evolution, whereas our cultural heritage transmits the BVSR’s of a few million years of cultural evolution. Thus parents may be correct to place greater emphasis on their offspring contracting a suitable marriage than on completing higher education, which after all is merely a cultural transmission, and hence a far less significant transfer of historical data.

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[1] Dennis Overbye, “Human DNA, The Ultimate Spot for Secret Messages” (June 26, 2007)

[2] sponging dolphins

[3] Heylighen, BVSR

[4] Josephson

[5] It is further suggested that even when we purposely search for information, such as via structured research and engineering efforts, every process we follow was a result of prior BVSR. Hence while we can speed up the process, we cannot alter its fundamental “blindness,” and thus relative sluggishness. Finding “perfected” ideas is no easier today than in centuries past, even if we now have more of them to work with.

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