Marc Verha
Thu, Jun-28-07, 17:17
Discussion with Renato Bender & Nicole Oser at AAT
http://groups.yahoo.com/group/AAT
...
> We would like to stress our point of view here: as we wrote
> above, we are discussing about the possibility of paraphyly
> of hominids, but not of all apes - this means, we did not
> include Marc's theories in our theoretical framework.
> Concerning Marc's ideas: we spent many years studying early
> paleoanthropological theories. In connection with the ideas
> of Max Westenhöfer we had to analyse a lot of
> "Primitivitäts-Hypothesen" - the believe that human beings
> have a pretty independent phylogeny within of primates
> (unbelievable: some placed the emergence of human beings
> even so back in the past that "we" got the first mammals, or
> even the first animals in this planet).
>
> We are explaining this because we see in Marc's
> argumentation a striking similarity with the arguments of
> the primitivists: they also tried to support their specific
> hypothesis on human evolution by a reinterpretation of the
> Dollo's law: a biological principle suggesting that once a
> complex character has disappeared from a lineage, it would
> not reapper later in that lineage as exactly the same
> feature; in other words: evolution is irreversible.
>
> In this reinterpretation the primitivists assumed that also
> simple (in fact a reversible) features are also
> irreversible). We think you should be aware of this point in
> the discussion about Marc's theories. We think, in this
> particular idea Marc is wrong, and we are afraid that most
> scientists would criticize his ideas with the same arguments
> like in the refutation of primitivists like Dacqué,
> Westenhöfer, Klaatsch, and many others. We are unhappy to
> see Marc investing so much in this ideas - we would like to
> cooperate much more with him concerning the origin of
> hominids. At the same time we want to stress the point that
> Marc's ideas force us to keep also such possibilities in
> mind. And we should not forget that the very beginning of
> the Aquatic Theory came froma a primitivist (Westenhöfer).
> Renato & Nicole
I guess this is about my hypothesis that (most?) E.Afr.apiths
are fossil relatives of G rather than of HP, & S.Afr.apiths of
P rather than of H or G?
This has nothing to do with primitivism, but everything with
the evidence: apiths have 0 derived features in common with H:
no v.big brain, no v.long legs, no ext.nose, & the supposedly
derived features (eg, thick enamel, rel.small canines, some
sort of BBism...) are already seen in Miocene gr.apes.
More specifically, there are specific P-like features in
S.Afr.apiths (microwear, sinuses...) & G-like ones in
E.Afr.apiths (orbita morphology, dental prism decussation...,
see my Hum.Evol.papers. This is to be expected evolutionarily:
parallel evolution in similar, but geographically separated
milieus (2 trop.forests in Pliocene Africa, see Jon.Kingdon).
...
> We believe that all speculations about the emergence of
> features in the phylogeny of living beings should be based
> on a very careful analyse of this feature (combined with
> other features) under the aspect of convergence evolution.
> If we want to know why an arboreal mammal lost the tail, we
> should spend a lot of time analysing the function of the
> tail in such environment and consequently the reasons for
> the tail-lost in some. In the last days we saw a lot of
> statements about an hypothetical primate losing the tail in
> an aquatic environment, but almost no comparative data to
> support this idea. Renato & Nicole
A hypothetical *ape* in an *aquarboreal* milieu, you mean? No
statements, but likely conclusions based on different data.
- The Miocene was considerably wetter & hotter than the
Pleistocene
(Mio>Plio>Pleisto), so there were probably a lot more swamp
forests than today, so a lot of Miocene primates might
have been adapted to swamp forests. Note hominoids (wet
forests) were more abundant in the Miocene, and monkeys
(dry forests) today.
- Hominoids crossed the Tethys (hylobatids & pongids live in
Asia today & dryopiths have hominid (sensu HPG) features),
which then consisted of island archipelagoes (ie, with lots
of coastal forests).
- The earliest peri-Tethys hominoids are found in coastal
sediments (Heliopith, Griphopith=Austriacopith) & later
Miocene fossil apes lay in swamp forests (the only probable
exception I know is Ouranopith: presumably in a comparable
milieu & climate as the robust apiths later in Africa: in
more open wetlands).
- Primates are generally arboreal, but Homo was waterside: if
evolution is gradual, the intermediate phase was aquarboreal
(trees+water), so arguably the considerable & at first sight
unexpected differences between monkeys (arboreal) & apes can
be explained by aquarborealism: larger size, tail loss, more
vertical posture, broad thorax...
- DD's ideas (IMO he's completely right): Apes have laryngeal
airsacs. Put an animal with such an airsac in a forest swamp
& it floats vertically, face up. A tail doesn't help in
locomotion there & is disadvantageous (infection, friction,
energy loss...): no wonder the hominoid tail incorporated
into the pelvic bottom (coccyx).
- DD: Parallels with frogs (song, airsacs, tail loss, hindlimb
preponderance, grasping hands...).
- Marcel Williams (he might be generally right here, but the
evidence is more circumstantial): All ex-aquarborealists
seem to have lost the tail: birds, frogs, indris (related to
some subfossil Malagasy"lemurs" from forest swamps), sloths,
apes... ursids? koalas?...
- Tail loss is very unexpected in arboreal creatures. Large
size is a possible explanation, but insufficient (gibbons vs
atelids); besides, large size is another argument pro
aquarborealism. Ground-dwelling in open terrain & large size
is not totally impossible (baboons), but unlikely (Po & Hy
are wholly arboreal). Arm-hanging &/or orthogrady is
sometimes believed to be an explanation, but see atelids.
Rests only aquarborealism AFAICS.
- There's some correlation between tail reduction &
aquaticness in OWMs, eg, Macaca spp with tail reduction are
esp.on islands (eg, the 3 Celebes spp); Nasalis concolor is
the only colobine (very arboreal!) with tail reduction &
lives in mangroves.
- Aquatic endotherms reduce "extremities" (heat loss,
friction...), no wonder the hominoid tail disappeared in an
aquarboreal milieu.
...
> Here we are not sure what you mean by "bipedalism". If you
> are writing about the emergence of bipedalism before the
> splitting Pan/hominids, then see above our statements about
> the theoretical possibility of paraphyly in "hominids". We
> believe that apes and consequently the common ancestor of
> Pan/hominids descended from an ape specialized in
> brachiation locomotion.
There's no evidence of habitual brachiation (fast swinging) in
early apes. The only habitually brachiating apes are
hylobatids. Brachiating is very derived (more derived than
suspension). Fossil evidence even suggests above-branch
locomotion in early apes (even Sivapith! disputed in
Dryopith). Likely, below-branch locomotion evolved in parallel
in hylobatids // pongids // hominids, and only Hy evolved
brachiation. Not unexpectedly below-branch locomotion evolved
in aquarboreals, whether swimming-climbing or wading-climbing:
the water is below the branches...
--Marc
http://groups.yahoo.com/group/AAT
...
> We would like to stress our point of view here: as we wrote
> above, we are discussing about the possibility of paraphyly
> of hominids, but not of all apes - this means, we did not
> include Marc's theories in our theoretical framework.
> Concerning Marc's ideas: we spent many years studying early
> paleoanthropological theories. In connection with the ideas
> of Max Westenhöfer we had to analyse a lot of
> "Primitivitäts-Hypothesen" - the believe that human beings
> have a pretty independent phylogeny within of primates
> (unbelievable: some placed the emergence of human beings
> even so back in the past that "we" got the first mammals, or
> even the first animals in this planet).
>
> We are explaining this because we see in Marc's
> argumentation a striking similarity with the arguments of
> the primitivists: they also tried to support their specific
> hypothesis on human evolution by a reinterpretation of the
> Dollo's law: a biological principle suggesting that once a
> complex character has disappeared from a lineage, it would
> not reapper later in that lineage as exactly the same
> feature; in other words: evolution is irreversible.
>
> In this reinterpretation the primitivists assumed that also
> simple (in fact a reversible) features are also
> irreversible). We think you should be aware of this point in
> the discussion about Marc's theories. We think, in this
> particular idea Marc is wrong, and we are afraid that most
> scientists would criticize his ideas with the same arguments
> like in the refutation of primitivists like Dacqué,
> Westenhöfer, Klaatsch, and many others. We are unhappy to
> see Marc investing so much in this ideas - we would like to
> cooperate much more with him concerning the origin of
> hominids. At the same time we want to stress the point that
> Marc's ideas force us to keep also such possibilities in
> mind. And we should not forget that the very beginning of
> the Aquatic Theory came froma a primitivist (Westenhöfer).
> Renato & Nicole
I guess this is about my hypothesis that (most?) E.Afr.apiths
are fossil relatives of G rather than of HP, & S.Afr.apiths of
P rather than of H or G?
This has nothing to do with primitivism, but everything with
the evidence: apiths have 0 derived features in common with H:
no v.big brain, no v.long legs, no ext.nose, & the supposedly
derived features (eg, thick enamel, rel.small canines, some
sort of BBism...) are already seen in Miocene gr.apes.
More specifically, there are specific P-like features in
S.Afr.apiths (microwear, sinuses...) & G-like ones in
E.Afr.apiths (orbita morphology, dental prism decussation...,
see my Hum.Evol.papers. This is to be expected evolutionarily:
parallel evolution in similar, but geographically separated
milieus (2 trop.forests in Pliocene Africa, see Jon.Kingdon).
...
> We believe that all speculations about the emergence of
> features in the phylogeny of living beings should be based
> on a very careful analyse of this feature (combined with
> other features) under the aspect of convergence evolution.
> If we want to know why an arboreal mammal lost the tail, we
> should spend a lot of time analysing the function of the
> tail in such environment and consequently the reasons for
> the tail-lost in some. In the last days we saw a lot of
> statements about an hypothetical primate losing the tail in
> an aquatic environment, but almost no comparative data to
> support this idea. Renato & Nicole
A hypothetical *ape* in an *aquarboreal* milieu, you mean? No
statements, but likely conclusions based on different data.
- The Miocene was considerably wetter & hotter than the
Pleistocene
(Mio>Plio>Pleisto), so there were probably a lot more swamp
forests than today, so a lot of Miocene primates might
have been adapted to swamp forests. Note hominoids (wet
forests) were more abundant in the Miocene, and monkeys
(dry forests) today.
- Hominoids crossed the Tethys (hylobatids & pongids live in
Asia today & dryopiths have hominid (sensu HPG) features),
which then consisted of island archipelagoes (ie, with lots
of coastal forests).
- The earliest peri-Tethys hominoids are found in coastal
sediments (Heliopith, Griphopith=Austriacopith) & later
Miocene fossil apes lay in swamp forests (the only probable
exception I know is Ouranopith: presumably in a comparable
milieu & climate as the robust apiths later in Africa: in
more open wetlands).
- Primates are generally arboreal, but Homo was waterside: if
evolution is gradual, the intermediate phase was aquarboreal
(trees+water), so arguably the considerable & at first sight
unexpected differences between monkeys (arboreal) & apes can
be explained by aquarborealism: larger size, tail loss, more
vertical posture, broad thorax...
- DD's ideas (IMO he's completely right): Apes have laryngeal
airsacs. Put an animal with such an airsac in a forest swamp
& it floats vertically, face up. A tail doesn't help in
locomotion there & is disadvantageous (infection, friction,
energy loss...): no wonder the hominoid tail incorporated
into the pelvic bottom (coccyx).
- DD: Parallels with frogs (song, airsacs, tail loss, hindlimb
preponderance, grasping hands...).
- Marcel Williams (he might be generally right here, but the
evidence is more circumstantial): All ex-aquarborealists
seem to have lost the tail: birds, frogs, indris (related to
some subfossil Malagasy"lemurs" from forest swamps), sloths,
apes... ursids? koalas?...
- Tail loss is very unexpected in arboreal creatures. Large
size is a possible explanation, but insufficient (gibbons vs
atelids); besides, large size is another argument pro
aquarborealism. Ground-dwelling in open terrain & large size
is not totally impossible (baboons), but unlikely (Po & Hy
are wholly arboreal). Arm-hanging &/or orthogrady is
sometimes believed to be an explanation, but see atelids.
Rests only aquarborealism AFAICS.
- There's some correlation between tail reduction &
aquaticness in OWMs, eg, Macaca spp with tail reduction are
esp.on islands (eg, the 3 Celebes spp); Nasalis concolor is
the only colobine (very arboreal!) with tail reduction &
lives in mangroves.
- Aquatic endotherms reduce "extremities" (heat loss,
friction...), no wonder the hominoid tail disappeared in an
aquarboreal milieu.
...
> Here we are not sure what you mean by "bipedalism". If you
> are writing about the emergence of bipedalism before the
> splitting Pan/hominids, then see above our statements about
> the theoretical possibility of paraphyly in "hominids". We
> believe that apes and consequently the common ancestor of
> Pan/hominids descended from an ape specialized in
> brachiation locomotion.
There's no evidence of habitual brachiation (fast swinging) in
early apes. The only habitually brachiating apes are
hylobatids. Brachiating is very derived (more derived than
suspension). Fossil evidence even suggests above-branch
locomotion in early apes (even Sivapith! disputed in
Dryopith). Likely, below-branch locomotion evolved in parallel
in hylobatids // pongids // hominids, and only Hy evolved
brachiation. Not unexpectedly below-branch locomotion evolved
in aquarboreals, whether swimming-climbing or wading-climbing:
the water is below the branches...
--Marc