Natural Science Forum / Biology / Evolution / October 2005

Am Nat. 2005 Oct;166 Suppl 4:S85-98.
Testosterone in females: mediator of adaptive traits, constraint on sexual
dimorphism, or both?
Ketterson ED, Nolan V Jr, Sandell M.

I would enjoy reading speculations from contributors to sbe on notions about
what caused the so-called 'explosion' of diversity during the Cambrian.  My
purpose here is not to merely reiterate what has been
speculated in documentaries on TV but, rather, to speculate about some

name_and_address_supplied@hotmail.com wrote:-
I have snipped almost all of NAS's response because the part below remains
the most central issue which can be summed up as: the CRITICAL difference
between an empirically based event and just a non empirically based

The current sciam.com website (for Scientific American) has
a small piece on evidence that oxygen content of the earth's
atmosphere was about 10% during the mesozoic, but the % rose
after the K/T extinction event and peaked at about 23% at

http://cyber.law.harvard.edu/people/Zak%20-%20Trust.pdf.
In human business activity trust really matters. Why? Simply because we
cannot cooperate without it. If we cannot cooperate while we inevitably
compete we can't take the enormous individual based gains that only

Is there such a thing as backwards evolution or is it all form fits
function - if the environment changes then so do we. I was wondering for
instance if we use our brains less would the size reduce!
Also is evolution a step by step process or are there times when there is a

Semipermeable lipid bilayers exhibit diastereoselectivity favoring ribose.
Sacerdote MG, Szostak JW.
Howard Hughes Medical Institute and Department
of Molecular Biology, Massachusetts General Hospital,

[On the thread "Most important paper in evolutionary biology",
William Morse wrote:]

Can anyone help me. I have started a course in biotechnology and now
feel that it is above me.  Is there any good books out there that could
help me.  I want to continue with my studies but am finding getting the
information quite hard.

A friend, commenting on replication through a  sun
forced denaturing and annealing process said,
"...the last to denature will be the last and hence slowest to
replicate and thus will be diluted out, depending upon the temperature

Life:
Novel reactions of certain chemicals to
the forced energy from a sun/heat cycle
that increases their stability in that

About a year ago, this newsgroup received an invitation to submit
nominations for 'the most beautiful experiment in biology'.  As
you may know, the title of 'the most beautiful experiment in
molecular biology' has been informally held by the Meselson-Stahl

I am puzzled by the phenomenon of unequal branch lengths in
phylogenetics.  Not so much by the confounding effects
('long branch attraction' and the like) as by what the
existence of unequal branches tells us.

This is in response to the Leslie E. Orgel essay,
"The Origin of LIfe on the Earth.
"It is extremely improbable that proteins and nucleic
acds, both of which are structurally complex, arose