Re: Consensus?? Human birth

Loren Haarsma (lhaarsma@retina.anatomy.upenn.edu)
Sun, 7 Feb 1999 16:32:17 -0500 (EST)

Magnus Murphy wrote:

> I am new to this discussion group and began by reading some of the
> archived messages dating as far back as 1995.

Welcome to the group.

> Of course nobody has
> enough time to read everything so I wonder if there is some way I can
> find out if any consensus has been reached on anything that has been
> discussed.

>I got the impression that changing somebody's preconceived
>opinions/beliefs is an impossible task but it would be very informative
>to newcomers like myself if there could be some discussion of what
>consensus has been achieved in the last few years.

At the bottom of this post, I've appended something which briefly
summarizes the range of opinions discussed in this group. It's
dangerous to try to "summarize group consensus." Probably someone will
object to the phrases I choose. But here goes:

--God doesn't work *only* through miracles. God is just as sovereign
over natural laws, and events which happen via natural laws, as he is
over miraculous events.

--"Chance" or "random" events are also under God's sovereign control.
(Whether or not God precisely determines the outcome of every chance
event, or allows creation some freedom in this area, is a subject of
debate.)

--In principle, God could create new life forms _de_novo_, or through
miraculous modification of previously existing lifeforms, or through
providential oversight of the evolutionary mechanisms he created. We
agree that God is free to act as he chooses. (However, we debate which
of these hypotheses best matches the scientific data and the theological
data.)

--Most of the debate on this list was between positions #2b and #3b,
below. Almost everyone who accepts that the earth is old also agrees
that the evidence suggests some biological common ancestry and decent-
through-modification. (Whether that modification was miraculous or via
natural mechanisms was debated, of course.)

--You might think that people who advocated progressive creationism
tended to advocated a concordist interpretation of early Genesis (trying
to match elements of Genesis with known historical developments/events),
while evolutionary creationists tended to argue against concordist
interpretations. That's not what happened, however. Some of the most
actively-writing progressive creationists argued against concordism;
some of the most active evolutionary creationists argued for concordism.

========================

You also write:

> Does the erect
> position and the reasons for that in the evolutionary sense (ability to
> run faster for instance) lead to the necessity of a smaller, narrower
> pelvis?
> ...
> In the reproductive sense there is a direct competition between the
> mother, who will be better off if the baby is small, and the fetus, who
> will be better off if born big (without damage of course)....
> Could this be the reason that human babies are so totally undeveloped in
> comparison to some of the other primate species for instance the large
> apes? Longer gestation to provide further development would of
> necessity lead to larger size and thus an impossible mechanical birth
> problem.

Other people (both in this group, and in scholarly journals) have also
suggested this idea.

Another factor to consider: since human babies are born so comparatively
underdeveloped, they require far greater parental attention in the first
year. This favors strong social groups, where childcare and other tasks
necessary for survival can be shared. It would be hard to care for big-
brained, underdeveloped babies without the strong social group.

I agree that the availability of cesarean section these days will
probably eventually result in ever bigger babies being born, and
possible bigger-brained babies.

---------

> The pelvic floor is an evolutionary newcomer:

I don't have many suggestions about this essay which you contributed,
except for the following two:

> One theory that tries to explain the increased evolutionary fitness of
> Homo sapiens is the development of speech, that made communication and
> thus the development of culture possible. The development of speech
> led to a massive increase in certain parts of the brain, particularly
> the frontal and temporal lobes, with the end result a brain that is
> often over 2000 cc in size.

The way this last sentence is written, it suggests that the development
of speech caused an increased size of those *particular* brain regions.
You might want to re-write that a sentence a little. I've seen some
data comparing brain region sizes and brain developmental programs
across multiple mammal species, and the data suggests that the relative
sizes of brain regions is determined largely by developmental programs
and the timed onset of particular cell line specializations. (I don't
have a reference for this data, sorry. I saw it in a departmental
colloquium and I don't recall the scientist's name.) The development of
speech may have been an important factor in increasing brain size *in
general*, but the massive increases in temporal and frontal lobes in
particular may be due not so much to specific selective pressures for
the functions they perform, as it is due to developmental programs which
control the relative sizes of *all* brain regions. A small re-write of
your last sentence should avoid this potential confusion.

> In the global scheme of things, the integrity of pelvic floor over
> time is after all not all that important. Nature couldn't care less if
> your bottom fell out at age 50. The most important biological
> functions ensuring the survival of our species (reproduction) have
> long been completed at this age.

You want to be careful making this claim. Healthy, active grandparents
can have a profound influence on the survival and reproductive success
of their grandchildren.

================================
================================

Spectrum of views on origins:

Note: Many people don't fall into any one category below, but allow for
some range of possibilities, and a mixture of scenarios.

1a. Young Earth Creation: Appearance of Youth.
Genesis 1-2 is interpreted as recent literal history; the earth and the
universe are a few tens of thousands of years old. Although some
"appearance of age" may have been included in creation (e.g. active
stars, light from the stars "on its way" to earth), proper scientific
measurements would yield ample evidence that the earth and life were
recently created.

1b. Young Earth Creation: Created with Apparent Age.
Genesis 1-2 is interpreted as recent literal history; the earth and the
universe are a few tens of thousands of years old. However, the
universe and the earth were made to "appear" several billion years old.

1c. Young Earth Creation: Apparent Age Due to the Fall.
Genesis 1-2 is interpreted as recent literal history; the earth and the
universe are a few tens of thousands of years old. However, due either
to the fall of man or the fall of Satan, the earth was made to appear
"old."

2a. Progressive Creation with Special Creation of Each Lifeform.
The earth and the universe are several billion years old. At various
times during the creation period, God performed a distinctive miraculous
creation to produce each new lifeform. (de novo creation or
supernatural transformation of an existing lifeform.)

2b. Progressive Creation.
The earth and the universe are several billion years old. At various
times during the creation period, God performed distinctive miraculous
acts to produce lifeforms with certain new features or increased
complexity. (Microevolution can produce some amount of species
diversity, but novel biological or biochemical structures were specially
and miraculously created at the appropriate times. (e.g. perhaps through
miraculous genetic transformations in zygotes.))

2c. Progressive Creation through "Miraculous" Evolution.
Creation occurred through evolution, but the success of evolution is
"surprising;" that is, one would not have expected the evolutionary
process to be as successful as it has been. Thus God must have been
"directing" the evolutionary process, perhaps arranging (or pre-
arranging) for the process to travel along preordained paths, leading to
much better-than-expected outcomes.

3a. Evolutionary Creation with Special Creation of Life.
Creation occurred through evolution and there is nothing surprising
about its success -- we would expect evolution to produce something like
what we see. Nevertheless, creation occurred at God's hand and
evolution was the tool. However, the fact that biological evolution got
started in the first place is surprising.

3b. Evolutionary Creation.
Creation occurred through evolution and there is nothing surprising
about its success; nor is it surprising that evolution got started in
the first place. We would expect abiogenesis and evolution to produce
something like what we see. What is surprising is that the laws of the
universe and physical constants are just right for giving conditions
conducive for a successful evolutionary process.

3b1. Evolutionary Creation with Designed Outcome.
The laws which govern biochemistry and biological evolution are designed
to ensure that life will "self-organize" into particular kinds of
lifeforms. God ordained and intended our existence, and designed the
evolutionary process to achieve it.

3b2. Evolutionary Creation with Selected Outcome.
Biological evolution could, in theory, have followed many different
paths with divergent outcomes. However, the exact path which evolution
took on earth, and the final outcome we see today, were entirely
ordained by God, since every event which appears to us to be "chance" is
actually determined by God.

3b3. Evolutionary Creation with Flexible Outcome.
The exact path which evolution took on earth, and the final outcome we
see today, were not entirely predetermined by God; rather, God gave his
creation a certain degree of "freedom." God also knew that this process
would eventually produce intelligent, personal creatures to whom he
could reveal Himself.

3c. Evolutionary Creation Known only via Special Revelation.
The fact that "the laws of the universe gave rise to a successful
evolutionary process" is not really surprising. Nevertheless, we
believe that creation occurred through God's hand because of God's
special revelation.

4. Deistic Evolution.
God created the universe and the laws of nature, "set them in motion,"
and let them "do their thing" without any intervention.

5. Atheistic Evolution.
The universe is self-existing; there is no creator.

=============================================

Loren Haarsma