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"Of all the genes in the human genome, 55 percent were already present in the first animal." AFAIK, genes contain base pairs, and a base pair encodes 2 bits of

"Of all the genes in the human genome, 55 percent were already present in the first animal." AFAIK, genes contain base pairs, and a base pair encodes 2 bits of information (computer engineering perspective here ;)) When they say 55% is the same, do they mean: 55% of genes have a similar structure and amount of basepairs, or do they mean: exact same values for the base pairs bit for bit? Like for example gene rs4778138 has an effect on eye color (handwavy first search result of snpedia for the example here). So if in two humans, this rs4778138 has a different value, do they consider both humans to have the same gene (because it is one that encodes eye color to some value in each case), or a different gene (because it encodes a different eye color)?

carbocation 9y ago
Generally, let's say that a gene is a stretch of DNA that encodes some functional product. That product might be a protein, or an RNA that performs some function. Think of these stretches of DNA as distinct entities that can be recognized by start and stop signals. If you say that 55% of the genes in the human genome were already present in the first animal, then you're saying that stretches of DNA which bear a significant similarity to 55% of ours were found in the first animal.
- Retric 9y ago
  It's also far less profound than you might think as cells are extremely complex and don't have that much wiggle room. They hit a local optima after hundred of millions of years so it's a really good one. Not just copying DNA, but also a cell wall and nucleus etc. On top of that multi cellular organisms are on the evolutionary slow lane, they have smaller populations, take longer to reproduce, and don't simply hot patch any random bit of DNA they come across.
  - reubenswartz 9y ago
    This is a great comment and I agree almost completely. However, I think it’s very profound— it says something about the incredible power and versatility of cellular building blocks.
pp19dd 9y ago
They're looking for matching pattern fragments. One good way to visualize how they're assessing that is to take a look at the Genome Projector's DNA walk view. Looks like this: https://i.imgur.com/z3etcmy.png https://i.imgur.com/z3etcmy.png What they've done is assigned A/T/C/G to North/South/West/East and ended up with that walk plot. They go into some detail on the overview page about the significance of the plot, but overall point is that "DNA Walk makes patterns in the genomes sequences apparent. Clustering of repeats, palindromes, horizontally transferred genes, telomeres, and GC skew can be easily spotted using this visualization approach." Interactive E. Coli link can be seen at http://www.g-language.org/g3/ http://www.g-language.org/g3/ (click on the DNA Walk tab view).

carbocation 9y ago

Generally, let's say that a gene is a stretch of DNA that encodes some functional product. That product might be a protein, or an RNA that performs some function. Think of these stretches of DNA as distinct entities that can be recognized by start and stop signals. If you say that 55% of the genes in the human genome were already present in the first animal, then you're saying that stretches of DNA which bear a significant similarity to 55% of ours were found in the first animal.

Retric 9y ago
It's also far less profound than you might think as cells are extremely complex and don't have that much wiggle room. They hit a local optima after hundred of millions of years so it's a really good one. Not just copying DNA, but also a cell wall and nucleus etc. On top of that multi cellular organisms are on the evolutionary slow lane, they have smaller populations, take longer to reproduce, and don't simply hot patch any random bit of DNA they come across.
- reubenswartz 9y ago
  This is a great comment and I agree almost completely. However, I think it’s very profound— it says something about the incredible power and versatility of cellular building blocks.

pp19dd 9y ago

They're looking for matching pattern fragments. One good way to visualize how they're assessing that is to take a look at the Genome Projector's DNA walk view. Looks like this: https://i.imgur.com/z3etcmy.png https://i.imgur.com/z3etcmy.png What they've done is assigned A/T/C/G to North/South/West/East and ended up with that walk plot. They go into some detail on the overview page about the significance of the plot, but overall point is that "DNA Walk makes patterns in the genomes sequences apparent. Clustering of repeats, palindromes, horizontally transferred genes, telomeres, and GC skew can be easily spotted using this visualization approach." Interactive E. Coli link can be seen at http://www.g-language.org/g3/ http://www.g-language.org/g3/ (click on the DNA Walk tab view).