Specification for theories on human evolution
Paul Crowley (Paul@crowleyp.demon.co.uk)
Tue, 14 Nov 95 00:46:37 GMT
The following is proposed specification for a theory of human evolution.
It is a much expanded version of one I posted a few weeks ago, incorpor-
ating various suggestions from other posters.
I had intended to post a revised AAT which would have met the earlier
specification; however my theory has grown into a more comprehensive
and substantially distinct one; I will post it in a week or so. This
will, I believe, match the expanded specification.
The specification should stand in its own right - it should be used to
measure the value of any suggested theory. I think that it covers all
issues of significance, but if you feel that something of importance has
been omitted, please post.
The essential features are those for which a theory must provide a
reasonable explanation. The more of the optional items that the theory
explains the better, but it could omit or be uncertain about several.
Paul.
Specification for a Theory of Human Evolution (XXT)
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ESSENTIAL FEATURES
The proposed theory (the XXT) should set out the same kind of
explanation as would be provided for the generation of any species.
e1 The ecological niche the species occupied should be clearly
delineated. The XXT must state what circumstances created this new
niche or, if it had existed before, why it was vacant. The XXT
must explain how the CA/new hominid was better adapted to occupy
it, as compared with other animals believed to be present at the
time.
e2 The speciating event and its circumstances should be clearly
described. Preferably this should not involve any kind of natural
catastrophe, but should be the sort of event that would probably
have happened sooner or later, given the environment. If
geographical separation is proposed, possible locations should be
named and the barrier specified. The length of time that the
isolation persisted should be indicated and if relevant, the
reasons for the lack of re-integration on its removal.
e3 The XXT should specify the type of diet and the sources from which
it was obtained. It should state how much water would be needed
in the environment and indicate how it would be obtained.
e4 The XXT should outline the probable predation problems the species
faced and depending on their estimated severity indicate probable
or possible ways in which the species coped with it. The severity
of predation is to be measured against forecast reproduction rates.
Predation by day and by night should be separately described, as
also predation of the young, females, and males if they were
generally in separate groups.
e5 The extremes of temperature, or other climatic conditions, that the
species would regularly encounter should be stated. Day and
night-time temperatures should be stated as should the manner in
which the species coped with them; the degree to which the species
would have to find additional shelter or greater food resources
should be indicated.
e6 The manner of care of the young should be clearly described, both
in infancy and early childhood, and during the day and at night.
e7 The roles of each sex should be described and size, shape, and
physical features of each sex, and the varying degrees throughout
the time period (5mya-present) of sexual dimorphism should be
accounted for.
e8 Any possible competition with other species for food or other
resources should be indicated.
e9 The effect of competition within the species should be stated.
e10 The locomotion capabilites of the species throughout the relevant
period must be clearly specified, both on the ground, in trees or
in any other environment. The probably ability of the species to
escape likely predators in each environment should be described.
e11 The reasons for the development of bipedalism must be clearly shown.
e12 The effects of initial bipedalism on all aspects of the hominid's
activities must be described. This will include caring patterns
for the young, coping with predators and the location of food and
any other resources. The consistent pressure towards better
bipedalism many generations and the selective advantages of this
progression in each generation must be stated.
e13 The XXT should clearly state how it fits in with the fossil record-
making reasonable allowance for current uncertainties and possible
misinterpretations of existing fossil data.
e14 The XXT must give a clear explanation for the increase in brain
capacity and the development of language. The selective pressures,
especially from 3mya, must be stated. It must specify the
mechanisms that enabled the extraordinarily rapid spread of the
large number (up to ten thousand?) of beneficial mutations to spread
throughout the entire species.
e15 The XXT should indicate the location and types of sites where large
quantities of hominid fossils may be found.
e16 The XXT should give a coherent account of the whole of human
evolution from the common ancestor to the dawn of civilisation.
OPTIONAL FEATURES
The XXT should provide an explanation for as many of these as possible.
o1. Nakedness
o2. Greater amounts of hair on males
o3. Distribution of hair on the body
o4. Descended larynx
o5. Presence of subcutaneous fat
o6. Distribution of subc. fat - males/females
o7. No apparent estrous
o8. Menopause
o9. Different kind of sweat glands
o10. Speciation of human flea
o11. Decline of olfactory bulbs
o12. The small genetic variation in homo.sap.sap.
o13. Baboon virus gene
o14. The relatively greater genetic variability in Africa
o15. Apparent regional skull development
o16. Relative abundance of hominid fossils v. chimp fossils
o16. The cry of the human baby
o17. Other apparently instinctive behavioural patterns of modern
hom.sap.sap. particularly those of infants and juveniles.
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