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There is a single common ancestor of all living things today. This organism survived objectively better than any other organism of its time (unless it's the ver

There is a single common ancestor of all living things today. This organism survived objectively better than any other organism of its time (unless it's the very first organism ever, which is very unlikely). Same thing goes for e.g. the last common ancestor of mammals vs an animal living this time that doesn't have an extant grandchild. I think it's possible to define survivability objectively using a little graph theory.

Drdrdrq 8y ago
> There is a single common ancestor of all living things today. Are you sure about that? Viruses too? (depends on your definition of "living" of course) To clarify: I don't know if there is or isn't, I just don't think anyone does.
- gnulinux 8y ago
  Yes we definitely do (not counting virus) because all living things share ~5/10% of their genetic material (like you share 10% of your genes with some bacteria) [1] which is very unlikely if it were purely random. This is of course one evidence, there are more evidence towards this. Read: https://en.wikipedia.org/wiki/Tree_of_life_(biology) https://en.wikipedia.org/wiki/Tree_of_life_(biology) BTW this organism is called LUCA. Read: https://en.wikipedia.org/wiki/Last_universal_common_ancestor https://en.wikipedia.org/wiki/Last_universal_common_ancestor [1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3338800/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3338800/
jibal 8y ago
"There is a single common ancestor of all living things today." No, there isn't. There's an ancestor population. "This organism survived objectively better than any other organism of its time" No, it did not survive. Being an ancestor is not survival. And this has nothing to do with "optimization" ... if evolution optimizes survival, then your "single common ancestor" predated optimization. You're just throwing concepts together to support a prior belief, but the facts don't work that way. "I think it's possible to define survivability objectively using a little graph theory." Maybe you should actually try it. Perhaps then you would notice that your notion of "optimized survivability" is about the future, but you're talking about graphs of the past.

Drdrdrq 8y ago

> There is a single common ancestor of all living things today. Are you sure about that? Viruses too? (depends on your definition of "living" of course) To clarify: I don't know if there is or isn't, I just don't think anyone does.

gnulinux 8y ago
Yes we definitely do (not counting virus) because all living things share ~5/10% of their genetic material (like you share 10% of your genes with some bacteria) [1] which is very unlikely if it were purely random. This is of course one evidence, there are more evidence towards this. Read: https://en.wikipedia.org/wiki/Tree_of_life_(biology) https://en.wikipedia.org/wiki/Tree_of_life_(biology) BTW this organism is called LUCA. Read: https://en.wikipedia.org/wiki/Last_universal_common_ancestor https://en.wikipedia.org/wiki/Last_universal_common_ancestor [1]: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3338800/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3338800/

jibal 8y ago

"There is a single common ancestor of all living things today." No, there isn't. There's an ancestor population. "This organism survived objectively better than any other organism of its time" No, it did not survive. Being an ancestor is not survival. And this has nothing to do with "optimization" ... if evolution optimizes survival, then your "single common ancestor" predated optimization. You're just throwing concepts together to support a prior belief, but the facts don't work that way. "I think it's possible to define survivability objectively using a little graph theory." Maybe you should actually try it. Perhaps then you would notice that your notion of "optimized survivability" is about the future, but you're talking about graphs of the past.