The sunshine is getting brighter.  Unless I missed something, you agree with Gary and you're both
agreeing that micro and macro are inseparable.  One is but the other in microcosm (both physical and
time).  My daughters were no bigger day-to-day.  When did my babies become a women?

Marlo
Florida

Monfils, Paul wrote:

> Gary Rosenberg wrote:
>
> <His more general request for one phylum giving rise to
> another is also problematic. If I found evidence that one phylum gave rise
> to another, I would consider the phyla to be synonyms, so the example would
> evaporate.>
>
> ** If one phylum can't give rise to another, wouldn't all extant phyla have
> to be present in the fossil record all the way back to the Pre-Cambrian?
> There weren't any Chordates in the Cambrian.  Where did they subsequently
> come from, if not from pre-existing phyla?  Are chordates therefore
> synonymous with whatever preceded them?  If new classes can't arise from
> pre-existing ones, why were there no mammals in the Paleozoic - and where
> did they subsequently come from, if not from pre-existing classes
> (presumably reptiles)?
>
> <If one thinks that a combination of
> microevolution and macroevolution occur, there is no reason to expect that
> the point at which the mollusk line and crustacean line diverged was
> macroevolutionary. Maybe it was a microevolutionary divergence, and then
> macroevolutionary changes happened somewhere along the branches>
>
> ** Since virtually all spontaneous mutations of any major proportions are
> lethal, and virtually all survivable (without medical intervention)
> mutations are minor in their effect, it is reasonable to say that every
> divergence is "microevolutionary".  If mollusks and crustaceans did in fact
> diverge from some common ancestral form, it didn't happen by half of a
> litter growing legs while their siblings grew a foot and a shell.
> Evolutionary changes are small.  Seconds are small.  But string together 3
> billion or so of them and you get a century.  Evolution is typically
> sloooooow.  But even at the rate of one survivable mutation per thousand
> years, a million changes will occur in a billion years.  Can a species
> change in a million ways and still be assignable to the same family?  order?
> class?  phylum?
>
> <What if something evolved entirely by macroevolution? Blammo, in one giant
> mutation, something vastly different appeared>.
>
> ** Actually this happens all the time.  We call such changes "birth
> defects".  In nature, they die, so the changes do not become incorporated
> into the species.
> In our own species we are happily able to save some individuals so
> afflicted, by bringing our relatively superior intelligence into play, but
> only when the effects of such genetic change are relatively minor.
>
> <For the purposes of debate on Conch-L, can we define microevolution as
> "gradual genetic change within a species" and macroevolution as "genetic
> changes that lead to large scale differences above the species level"?>
>
> ** Yes, we can do that - provided we can also define "microtime" as the
> amount of time required to bring about genetic changes within a species, and
> "macrotime" as the amount of time required to produce large scale
> differences above the species level.  If we can divide ongoing evolutionary
> change into "types" based on amount of time, I don't see why we can't divide
> time into "types" based on amount of evolutionary change??  How about
> "microrust" for the process that causes slight changes in a piece of iron
> exposed to the elements, and macrorust . . . oh dear, I am getting either
> silly or sarcastic, neither of which I like to be, so I'll stop.
>
> Paul M.



--
Marlo
Merritt Island, Florida
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