Crosswords1 min ago
Dawkins, I.d. And The Bird's Egg.
"Ben Stein: What do think is the possibility that intelligent design might turn out to be the answer to some issues in genetics, or in evolution?
Richard Dawkins: Well, it could come about in the following way: it could be that at some earlier time, somewhere in the universe, a civilization evolved by probably some kind of Darwinian means to a very, very high level of technology, and designed a form of life that they seeded onto, perhaps, this planet. Now that is a possibility and an intriguing possibility. And I suppose it's possible that you might find evidence for that if you look at the details of our chemistry, molecular biology, you might find a signature of some sort of designer, and that designer could well be a higher intelligence from elsewhere in the universe. But that higher intelligence would itself have had to have come about by some explicable, or ultimately explicable, process. It couldn't have just jumped into existence spontaneously, that's the point."
So even he is prepared to consider the possibility, but can you read the following and have any doubts?;
THE BIRD'S EGG
The freshly laid bird’s egg is a
complete and self-contained support
system for the developing embryo
within, and thus its yolk must contain,
by necessity, all the nutrients for its
transformation into a fully formed
fledgling – the twenty essential amino
acids to construct its body parts, a dozen
vitamins, sufficient energy-rich fats
(saturated and unsaturated), the
minerals iodine, selenium, phosphorus
and zinc, and that crucial structural
component of the cell wall, cholesterol.
There is certainly perfection in how
the yolk contains all these nutrients
in precisely the right amounts and
proportions, but more perfect still, is how the egg
acquires through its seemingly
impermeable shell the only vital
requirement from the outside world for
the embryo’s development – oxygen.
The egg’s ability to ‘breathe’ is
determined by the shell’s method of
construction. The arrival of the yolk and
enfolding ‘white’ in the uterus activates
dozens of tiny aerosol sprays that squirt a
concentrated solution of calcium
carbonate. The solution hardens to form
columns of calcite packed against each
other ‘like a stack of fence posts’ and
separated by tiny vertical spaces – or
microscopic pores.
This method of construction might
seem a bit haphazard but the ‘total pore
area’ – their number multiplied by their
diameter – must be precisely calibrated
to ensure the correct flow of gases in and
out of the shell: too high and the oxygen dependent
metabolism goes into
overdrive, too low and the embryo within
will suffocate through lack of oxygen or
be poisoned by the accumulation of
carbon dioxide.
Thus the ‘total pore area’ of the ten
thousand pores in the shell of a 60g
chick’s egg is determined by its
requirement, over the 21 days of its
incubation, to take up six litres of oxygen
and expel as waste products 4.5 litres of
carbon dioxide and 11 litres of water
vapour.
The volume of gases exchanged are,
biologist Hermann Rahn discovered in
the 1970s, perfectly ‘attuned’ to the size
of the embryo with a direct correlation
between the total pore area and the mass
of the egg – from the 300 pores of the
tiny darting hummingbird to the 30,000
of the 1kg egg of the lumbering emu.
The practicalities of how the number and
size of the pores in an eggshell is so
exquisitely determined, Birkhead
observes, ‘is completely unknown’.
Next, colour. In the final hours before
the egg is laid, a further set of aerosol
sprays squirt coloured dyes over the
calcite to provide the ground colour of
the egg’s surface – blue or green, yellow,
red or brown. And when this dries,
another set of sprays provides the spots
and streaks as if, Birkhead remarks,
‘Jackson Pollock were trickling paint
across a canvas from a heavily loaded
brush’.
Richard Dawkins: Well, it could come about in the following way: it could be that at some earlier time, somewhere in the universe, a civilization evolved by probably some kind of Darwinian means to a very, very high level of technology, and designed a form of life that they seeded onto, perhaps, this planet. Now that is a possibility and an intriguing possibility. And I suppose it's possible that you might find evidence for that if you look at the details of our chemistry, molecular biology, you might find a signature of some sort of designer, and that designer could well be a higher intelligence from elsewhere in the universe. But that higher intelligence would itself have had to have come about by some explicable, or ultimately explicable, process. It couldn't have just jumped into existence spontaneously, that's the point."
So even he is prepared to consider the possibility, but can you read the following and have any doubts?;
THE BIRD'S EGG
The freshly laid bird’s egg is a
complete and self-contained support
system for the developing embryo
within, and thus its yolk must contain,
by necessity, all the nutrients for its
transformation into a fully formed
fledgling – the twenty essential amino
acids to construct its body parts, a dozen
vitamins, sufficient energy-rich fats
(saturated and unsaturated), the
minerals iodine, selenium, phosphorus
and zinc, and that crucial structural
component of the cell wall, cholesterol.
There is certainly perfection in how
the yolk contains all these nutrients
in precisely the right amounts and
proportions, but more perfect still, is how the egg
acquires through its seemingly
impermeable shell the only vital
requirement from the outside world for
the embryo’s development – oxygen.
The egg’s ability to ‘breathe’ is
determined by the shell’s method of
construction. The arrival of the yolk and
enfolding ‘white’ in the uterus activates
dozens of tiny aerosol sprays that squirt a
concentrated solution of calcium
carbonate. The solution hardens to form
columns of calcite packed against each
other ‘like a stack of fence posts’ and
separated by tiny vertical spaces – or
microscopic pores.
This method of construction might
seem a bit haphazard but the ‘total pore
area’ – their number multiplied by their
diameter – must be precisely calibrated
to ensure the correct flow of gases in and
out of the shell: too high and the oxygen dependent
metabolism goes into
overdrive, too low and the embryo within
will suffocate through lack of oxygen or
be poisoned by the accumulation of
carbon dioxide.
Thus the ‘total pore area’ of the ten
thousand pores in the shell of a 60g
chick’s egg is determined by its
requirement, over the 21 days of its
incubation, to take up six litres of oxygen
and expel as waste products 4.5 litres of
carbon dioxide and 11 litres of water
vapour.
The volume of gases exchanged are,
biologist Hermann Rahn discovered in
the 1970s, perfectly ‘attuned’ to the size
of the embryo with a direct correlation
between the total pore area and the mass
of the egg – from the 300 pores of the
tiny darting hummingbird to the 30,000
of the 1kg egg of the lumbering emu.
The practicalities of how the number and
size of the pores in an eggshell is so
exquisitely determined, Birkhead
observes, ‘is completely unknown’.
Next, colour. In the final hours before
the egg is laid, a further set of aerosol
sprays squirt coloured dyes over the
calcite to provide the ground colour of
the egg’s surface – blue or green, yellow,
red or brown. And when this dries,
another set of sprays provides the spots
and streaks as if, Birkhead remarks,
‘Jackson Pollock were trickling paint
across a canvas from a heavily loaded
brush’.
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Wow those are some large sentences !
As for the bird's egg, so what ? Given sufficient time and enough variation and an environment that culls that which fails to improve, or gets worse, that is exactly what one would expect. That even if it isn't the best design that an intelligence could come up with, it evolves to be fit for purpose. No; I have no doubts about evolution.
As for the bird's egg, so what ? Given sufficient time and enough variation and an environment that culls that which fails to improve, or gets worse, that is exactly what one would expect. That even if it isn't the best design that an intelligence could come up with, it evolves to be fit for purpose. No; I have no doubts about evolution.
-- answer removed --
Perhaps in part there's too much emphasis on "success" and "failure", as if it's one or the other, and only perfection achieves success. But this isn't true. You don't need a perfect modern-day birds' egg to incubate a chick. While the modern-day form of the birds' egg is still relatively better for incubation than, say, an egg with a thinner shell, or a smaller yolk, or a less permeable membrane for gas exchange, or not quite so well camouflaged a spot pattern, eggs without these "perfect" features will still be enough. Over the long term, after the passing of many, many generations, evolutionary pressures would tend to favour the "better" egg over the not-so-good substitutes, but it's a mistake to regard that "better" egg as absolutely necessary. As a result, returning to my first post -- the birds' egg is not irreducibly complex, so the rest of the argument simply falls flat.
Anyway, each bird species has a different style of egg, in colour, size, incubation period, etc etc. Even within species there exist variations, and in general any two eggs aren't perfectly identical.
Anyway, each bird species has a different style of egg, in colour, size, incubation period, etc etc. Even within species there exist variations, and in general any two eggs aren't perfectly identical.
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