NetNews Usenet Archive 1993 #3/NN_1993_3.iso/spool/sci/skeptic/22784

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From: [e-mail] (Kalki Dasa)
Newsgroups: sci.skeptic,alt.atheism
Subject: Re: Eve Mitochondia?
Message-ID: <[e-mail]>
Date: Sat, 23 Jan 93 02:44:42 EST
References: <[e-mail]>
Organization: Kalki's Infoline BBS, Aiken, SC, USA
Lines: 296

[e-mail] (G T Clark) writes:

>     While the "Eve" hypothesis is not proven,and is in my view
> unprovable due to competition between mitochondria,I think I should
> point out that it states that all PEOPLE are descended from one woman.
>     It claims this because all you mitochondria,and therefore all
> your mitochondrial DNA,come from your mother.

I posted the following article some time ago, but since the
"Mitochondrial Eve" issue seems to be coming into vogue again, here it
is one more time:

From Back to Godhead magazine, Sept/Oct 1992

WAS THERE AN EVE?

by Sadaputa Dasa

(c) 1992 by the Bhaktivedanta Book Trust
Used by permission.

In a 1987 article in the prestigious journal Nature, three biochemists
published a study of mitochondrial DNA's from 147 people living on five
continents. The biochemists stated, "All these mitochondrial DNA's stem
from one woman who is postulated to have lived about 200,000 years ago,
probably in Africa."[1]

The story became a sensation. The woman was called the African Eve, and
Newsweek put her on its cover. There she was -- the single ancestor of
all living human beings.

Eve was one in a population of primitive human beings. But all human
lineages not deriving from her have perished. For students of human
evolution, one important implication of this finding was that Asian
populations of Homo erectus, including the famous Peking ape men, must
not have been among our ancestors. Those ape men couldn't have descended
from Eve, it was thought, because they lived in Asia before 200,000
years ago.

Mitochondrial DNA (mtDNA) carries genetic instructions for the
energy-making factories of human cells. Unlike other genetic material,
it is transmitted to offspring only from the mother, with no
contribution from the father. This means that the descent of mtDNA makes
a simple branching tree that is easy to study.

Computer studies on the sample of 147 people (who represent the world
population) show that the original ancestral trunk divided into two
branches. Only Africans descended from one branch. The rest of the
population, as well as some Africans, descended from the other. The
inference was that the stem was African. In 1991 another analysis of
exact sequences from 189 people confirmed this and indicated that Eve
was roughly our ten-thousandth great-grandmother.

THE FALL OF EVE

Unfortunately, however, Eve quickly fell down. In 1992 the geneticist
Alan Templeton of Washington University stated in the journal Science.
"The inference that the tree of humankind is rooted in Africa is not
supported by the data."[2] It seems that the African Eve theory evolved
from errors in computer analysis.

The ancestral trees had been drawn from mtDNA sequences through what is
called the principle of parsimony. The figure below gives a rough idea
of how this was done. To create the figure, I used sequences of four
letters to stand for the genetic information in mtDNA. In (1) I started
with abcd as the original ancestor, and by making single changes, or
mutations, I produced descendants avcd and abud. Then from avcd I got
two more descendants, avcn and rvcd, again by single mutations.

-----------------------------------------------------------------------

avcn        rvcd          abud       avcn           rvcd         abud
  \         /              /           \              \          /
    \     /              /               \              \      /
      \ /              /                   \              \  /
     avcd            /                       \           avud
         \         /                           \         /
           \     /                               \     /
             \ /                                   \ /
(1)          abcd                     (2)          avun


avcn        rvcd         abud
 \           |           /
   \         |         /
     \       |       /
       \     |     /
         \   |   /
           \ | /
(3)        rbun

-----------------------------------------------------------------------
Examples of evolutionary trees. Tree 1 represents the evolution of a
gene sequence. Each change from one letter to another represents a
mutation. Trees 2 and 3 show other possible evolutionary histories
yielding the same results. Such are the ambiguities involved in figuring
out evolutionary histories from existing gene sequences. (See text).
------------------------------------------------------------------------

Let's suppose we are given the sequences avcn, rvcd, and abud and we are
asked to deduce their ancestry. How would we go about this? The method
used by the scientists studying mtDNA was to say that ancestors and
descendants should be as similar as possible. One way to measure how
similar they are is to count the number of mutations from ancestor to
descendant in the tree of descent. A tree with few mutations shows high
similarity, so it is a good candidate for the real ancestral tree. Such
a tree is said to be parsimonious.

For example, tree (1) has four mutations, and tree (3) has eight.
Scientists would argue that (1) is therefore more likely to resemble the
real ancestral tree. This seems promising, since in this case tree (1)
is in fact the real tree. But tree (2) requires five mutations, and so
it is nearly as parsimonious. Yet (2) shows a completely different
pattern of ancestors.

The problem with the parsimonious tree method is that in a complex case
there are literally millions of trees that are equally parsimonious.
Searching through them all on a mainframe computer can take months.
According to Templeton, the original findings on African Eve came from
computer runs that missed important trees. When further runs were made,
a tree with African roots turned out no more likely than one with
European or Asian roots.

The parsimonious tree method rests on the idea that similar organisms
should share close common ancestors, and less similar organisms more
distant ones. This idea is the central motivating concept behind the
theory of evolution. Since the span of recorded human history is too
short to show evolutionary changes that mean very much, evolutionists
are forced to reconstruct the history of living species by comparing
likenesses and differences in living and fossil organisms.

For example, man and ape are said to share a close common ancestor
because man and ape are very similar. In the late nineteenth century
there was a famous debate between the anatomists Thomas Huxley and
Richard Owen over whether or not human beings were cousins of apes. Owen
maintained that they weren't, because a feature of the human brain, the
hippocampus major, was not found in the brains of apes. But Huxley won
the debate by showing that apes really do have a hippocampus major.
Before triumphantly presenting his evidence for this to the British
Association of Science, Huxley had written to his wife, "By next Friday
evening they will all be convinced that they are monkeys."[3]

WHY MAN AND APE ARE SIMILAR

Of course, man and ape really are similar. So if they don't descend from
a close common ancestor, how can one account for this? Biblical
creationists propose that God created man and ape separately by divine
decree. To many scientists this story seems unsatisfactory. The
geneticist Francisco Ayala indicated why in a discussion of the close
likenesses between human beings and chimpanzees. He remarked, "These
creationists are implying that God is a cheat, making things look
identical when they are not. I consider that to be blasphemous."[4] In
other words, why would God fake a record of apparent historical change?

To illustrate the idea behind Ayala's comment, consider the legs of
mammals. In all known land mammals, the leg bones are homologous, or
similar in form. Thus all mammals have a recognizable thigh bone, shin
bone, and so on. Now imagine that genetic engineering becomes highly
perfected. A genetic engineer might want to create an animal with legs
suitable for a particular environment. But would he do this by simply
modifying the shapes of the standard mammalian leg bones to make another
typical mammalian leg? Why not create a whole new set of leg bones
suitable for the task at hand? And if human engineering might do this,
why not God? The answer that God's will is inscrutable doesn't sit well
with many scientists.

It is certainly not possible to second guess the will of God. But the
Vedic literature offers an account of the origin of species that
explains the patterns of similarity among living organisms. According to
the Srimad Bhagavatam, living beings have descended, with modification,
from an original created being. All species, therefore, are linked by a
family tree of ancestors and descendants. Forms sharing similar features
inherit those features from ancestral forms that had them. So the theory
given in the Bhagavatam accounts for the likenesses and differences
between species in a way comparable to that of the theory of evolution.

But these two theories are not the same. The neo-Darwinian theory of
evolution says that species descended from primitive one-celled
organisms and gradually developed into forms more and more complex. In
contrast, the Bhagavatam says that Brahma, the original created being,
is superhuman. Brahma generated beings called prajapatis, who are
inferior to him. These in turn produced generations of lesser beings,
culminating in plants, animals, and human beings as we know them. From
the prajapatis on down, these successive generations generally came into
being by sexual reproduction.

The theory of evolution says that species have emerged by mutation and
natural selection, with no intelligent guidance. But the Bhagavatam
maintains that the entire process of generating species is planned in
detail by God.

INTELLIGENT DESIGNER

This point brings us back to the question why species should be linked
by patterns of homology.

Several points can be made. The first is that the genetic engineer
designing one special-purpose mammal might find it convenient to
introduce one special design. But if he wanted to create an entire
ecosystem of interacting organisms, he might want to do it with a
general scheme in which he could produce different types of organisms by
modifying standard plans.  So a standard mammalian plan could be used as
the starting point for producing various mammals, and similar plans
could be used for birds, fish, and so on. It would be most efficient to
organize these plans into a parsimonious tree to make short the design
work needed.

This idea can overcome one of the drawbacks of the theory of evolution.
Many living organisms have complex structures that evolutionists have a
hard time accounting for by mutations and natural selection. Observed
intermediate forms linking organisms that have these structures to those
that don't are notoriously lacking. Evolutionists have often found it
hard to imagine convincing possibilities for what these intermediate
forms might be. But the structures are easy to account for if we posit
an intelligent designer.

To illustrate this point, consider the problem of writing computer
programs. A programmer will often write a new program by taking an old
one and modifying it. After doing this for a while, he winds up
producing a family tree of programs. But the changes required to go from
one program to another are often extensive. They're not the kind you'd
be likely to get by randomly zapping the first program with mutations
and waiting to get a new program that operates in the required way.

The point could be made, however, that a finite human engineer may need
efficient design methods but God is unlimited and doesn't need them. Why
then should He use them? We can't second guess God, but a possible
answer is waiting for us to consider in the Bhagavatam (2.1.36). There
Krsna, the Supreme Personality of Godhead, is celebrated as the topmost
artist:

        Varieties of birds are indications of His masterful artistic
        sense. Manu, the father of mankind, is the emblem of His
        standard intelligence, and humanity is His residence. The
        celestial species of human beings, like the Gandharvas,
        Vidyadharas, Caranas, and Apsaras, all represent His musical
        rhythm, and the demoniac soldiers are representations of His
        wonderful prowess.

Orderly patterns of design are also natural in artistic works. Just as
Bach dexterously combines and modifies different themes in his fugues,
so the Supreme Artist may orchestrate the world of life in a way that
shows order, parsimony, and luxuriant novelty of form. The patterns of
parsimonious change follow naturally from the procreation of species.
The novelty flows from Krsna's creative intelligence and cannot be
accounted for by neo-Darwinian theory.

SUBTLE ENERGIES

This brings us to our last point. The life forms descending from Brahma
include many species unknown to us. The higher species, beginning with
Brahma himself, have bodies made mostly of subtle types of energy
distinct from the energies studied in modern physics. Manu, the
Gandharvas, and the Vidyadharas are examples of such beings.

We may speak of the energies studied by modern physics as gross matter.
The bodies of ordinary beings, animals, and plants are all made of this
type of matter. If they have descended from beings with bodies made of
subtle energy, then there must be a process of transformation whereby
gross forms are generated from subtle. Such a process, the Bhagavatam
says, does in fact exist.

So the Bhagavatam's explanation of the origin of species makes the
following two predictions: (1) There should exist subtly embodied beings
that include the precursors of grossly embodied organisms, and (2) there
should be a process of generating gross form from subtle form. It would
be interesting to see if there is any empirical evidence that might
corroborate these predictions.

REFERENCES

[1] Rebecca Cann, Mark Stoneking, and Allen Wilson, "Mitochondrial DNA
    and Human Evolution," Nature, Vol. 325, January 1, 1987.
[2] Sharon Begley, "Eve takes another Fall," Newsweek, 3/1/92.
[3] Wendt, 1972, p. 71.
[4] Joel Davis, "Blow to Creation Myth," Omni, August, 1980.

END OF ARTICLE

Sadaputa Dasa (Richard L. Thompson) earned his Ph.D. in mathematics from
Cornell University. He is the author of several books, of which the most
recent is Vedic Cosmography and Astronomy.

Posted by Kalki Dasa for Back to Godhead



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