On Thu, 22 Feb 1996 13:14:30 GMT you wrote:
DT>Abstract: Questioning the idea that macro-evolutionary theories
>have any "necessary predictions" about the nested patterns found
>in the living world, and drawing attention to the low accuracy
>of predictions based on the tree analogy.
>Terry Gray wrote (20 February) in response to Stephen Jones:
>
>TG: "This raises an interest question that I pursued with one of
>our philosophers here at Calvin. Do similarities and the nested
>patterns found in biological world support common design and
>common ancestry equivalently?....To my surprise, he said
>no and gave all sorts of reasons why the common ancestry
>hypothesis was to be preferred from a philosophy of science point
>of view".
I am still wondering why it must be either-or. Why can it not be
both-and? It is not difficult imagining an Intelligent Designer
creating new designs based at least partly on pre-existing genetic
code.
The real issue is not whether there is a tree of life (creationists
could for the sake of argument concede there was), but what made it
grow?
DT>This is an interesting question - particularly because of the way
>predictions are said to emerge from the differing perspectives
>of the natural world. I am conscious that the issue is addressed
>by Kurt Wise in his chapter on "The origin of life's major
>groups" in _The Creation Hypothesis_, J.P. Moreland (ed), IVP,
>1994. Kurt has four points on pages 217-221. I would be
>interested to get reactions to them. To assist interaction, I
>am paraphrasing Kurt in what follows.
>The nested hierarchy of biological form has been linked with
>"common ancestry" using the analogy of the "evolutionary tree".
>This is scrutinised in the four points below.
>
>1. The analogy with real trees breaks down, as there is a strong
>tendency for the twigs and outer leaves to occupy most of the
>space available to them. This is not so in the biological world:
>"most of the morphospace is unfilled". Kurt considers various
>options for explaining these observations and concludes: "It is
>unclear that any currently proposed macroevolutionary process
>could truly produce a nested hierarchy of form".
This might give the impression that Kurt is confusing the analogy
of a tree with a real botannical tree. In fact Kurt Is not, saying:
"But the analogy of an evolutionary tree as an explanation for the
nested hierarchy of form meets up with a few difficulties. If it is a
`tree,' then it is a very unusual tree indeed." (Wise K.P., "The
Origin of Life's Major Groups", in Moreland J.P. ed., "The Creation
Hypothesis", InterVarsity, 1993, p219)
DT>2. The tree analogy also breaks down when examining the overall
>morphology of the trunk, branches and twigs. By analogy, the
>various groups of organisms are predicted to have arisen by
>gradual divergence. However, there is not a convergence in
>morphology in organisms as one goes back in time. "Most major
>groups remain identifiable by modern characters". Evidence for
>branching events is therefore highly controversial.
This is strong evidence for a forest, rather than a single tree.
Evolutionists maintain the tree analogy by arguing that the tree is
really a bush (Gould)
DT>3. In real trees, the trunk/branch connections and branch/twig
>connections can be clearly seen. Transitions between major
>groups of organisms are controversial and rare.
Indeed. If "The evolutionary trees that adorn our textbooks have data
only at the tips and nodes of their branches" (Gould S.J, "Evolution's
Erratic Pace, Natural History, May 1977, p13-14), then how do
Darwinists know there really is a tree, and not a number of trees?
DT>4. As a real tree grows, the number of branches and twigs
>increases with time, with twigs increasing in number faster than
>the branches. This has been described as a "cone of increasing
>diversity". This however, has not been observed as far as major
>groups are concerned - earth history has seen a LOSS of major
>groups with time! (cf Gould's _Wonderful Life_).
This is a major problem to Darwinists. The actual shape of the tree
(an inverted cone of increasing diversity) is the exact opposite
expected by Darwinist macro-evolutionary theory.
TD>Kurt contrasts the lack of evolutionary explanations for the
>observations with that supplied by ID. By analogy with human
>creativity, a nested hierarchy is expected. Based on this
>analogy, all the major features of the fossil record outlined
>above can be readily explained. "And if the gaps between major
>groups were so large that speciation has had insufficient time
>to bridge them, the general stasis of major groups and the marked
>nested hierarchy of biological form through time would be an
>expected result".
I am not sure that Kurt's argument is sound here. Humans almost never
create in a nested hierarchy of form. They classify things after the
event in a nested hierarchy (eg. a library) but books are not written
in in such a pattern. Books transpose topics, eg. Theology -
Philosophy - Science, and they have to be cross-referenced in any
library index.
>TG: "Unfortunately, I wasn't taking notes, so I can't remember
>all of the details. But part of his argument had to do with what
>sorts of questions one could ask of each model and what sorts of
>expectations each theory would lead to. Part of the argument had
>to do with the fact that the common design argument made no
>necessary predictions about the patterns we see, but that common
>ancestry did: for example, the amount of diversity in a given
>family (say the cat family) and their biographical distribution
>and the degree of diversity over time. Part of the argument
>related to the fruitfulness of a theory in provoking additional
>questions or additional research".
DT>The predictions made drawing on the evolutionary tree analogy are
>not successful - yet these have dominated thinking on these
>issues over the past century. What are the "necessary
>predictions" of common ancestry - and if they are not based on
>the tree analogy, on what are they based?
An evolutionary tree is not the only way to depict life's nested
hierarchy of form. Cladists find an evolutionary tree is less helpful
than a cladogram. Michael Pitman ("Adam and Evolution", Rider & Co:
London, 1984), prefers the metaphor of chinese boxes.
DT>The "cat family" example is not going to help here - for I
>suspect that "common descent" below the Family level is a common
>perspective of evolutionists and ID advocates. The latter are
>likely to see the cat family, along with other families, as
>Basic Types - with members related by interbreeding and
>hybridisation and best understood as descendants of an ancestral
>population. The real differences between evolutionary theory and
>ID are to be found in their treatment of the
>order/class/phylum/kingdom levels of classification. Hence
>Kurt's repeated reference to "major groups".
Agreed. Creationists focus on natural groups (eg. cat's, dogs, etc) as
their basic taxonomic unit.
God bless.
Stephen
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