Date   

Re: ape/OWM c 65 Ma??

 

Marc,
I remember looking into ape/owm monkey split times from the 1930s, 40s and 50s (pre-molecular clock 1960s) they were all much much deeper divergence.

Here is my timeline.
NWM/OWM 75mya (Africa and South America separate)

Ape/OWM 65mya (India separates)

Lessor ape body plan lands in Asia 40mya (loss of tail)

Great ape body plan 30mya (SE Asia) Bipedal, flip of transverse process. Radiation of Pongid looking Great ape at 20-25mya.

HP/Pan split in Asia 22.9mya. (Cerv2 not found in Humans)

17 to 24mya 800,000 to 1,000,000 generations of homo adaptation in a non-climbing niche, perfects bipedal hunting and diving for littoral foods. *** Allopatric speciation (not in Africa), pure directional adaptation of entire population away from climbing toward swimming and running ***

Undomesticated Human shaped ape appears at 2.4mya in Asia and Body plan kicks ass. 340-400 brain genes, survives winter, swims, hunts, gathers. (ALL archaic Homo is a single species.)

1.81mya radiation reaches Africa and Europe at the same time.

Regional adaptation of all archaic populations. Sunless niche populations retain lighter skin and vitamin D storage (Scandinavia, GB, Caucasus, China).
High UV niche develop high levels of melanocytes and do not store vitamin D. (Australia, India, Africa)

Mass cooperation via self-Domestication accelerates in last 300,000 years. Creating a more juvenile body plan and gracile bones. Loss of brain genes and reduced cranial capacity everywhere in last 10,000 years.




-Jack

On Mar 28, 2022, at 10:17 AM, Marc Verhaegen <m_verhaegen@...> wrote:

I'd think it's lot more recent, Jack.
-haplo/strepsi 70 Ma?
-tarsif./Simii 60 Ma?
-Platy-/Cata- 45 Ma?
-OWM/ape 30 Ma?
-great/lesser 20 Ma?
-hom./pongid 15 Ma?
-HP/G 8 Ma?
-H/P 5 Ma?

______



------ Origineel bericht ------
Van: needininfo@...
Aan: AAT@groups.io
Verzonden: maandag 28 maart 2022 16:55
Onderwerp: Re: [AAT] ape/OWM c 65 Ma??

65mya split for OWM/Apes makes sense. India split from Africa in that time period


-Jack


On Mar 26, 2022, at 5:07 AM, Marc Verhaegen <m_verhaegen@...> wrote:

A comparison of humans and baboons suggests germline mutation rates do not track cell divisions
Molly Przeworski cs 2020 PLoS Biology

--
Welcome to the Aquatic Ape Theory Discussion Group








--
Welcome to the Aquatic Ape Theory Discussion Group


Re: Plate Tectonics & hominoid splittings?

Marc Verhaegen
 

Not impossible perhaps, but more likely IMO is this:

India under Asia = unique situation: lots of swamp/mangrove forests,
India in the middle of where apes live,
India further under Asia = great/lesser ape split = W/E = Med Sea / Ind.Ocean,
Mesopotamian Seaway closure split hominids/pongids = W/E,
-pongids followed coasts along Ind.Ocean -> Hylobatids higher into tree,
-hominids in Med & Red Sea, HPG in Red Sea,
-8 Ma = Rift fm = G/HP: G along Rift ->Lucy etc.
-5 Ma = opening Red Sea -> Ind.Ocean?
P along E.Afr.coast, H along S.Asian coast.
Simple, no?

When we didn't agree, Elaine said: let's agree to disagree... :-)

______

Van: f-ceska@...
Aan: AAT@groups.io
Verzonden: zondag 27 maart 2022 16:26
Onderwerp: Re: [AAT] Plate Tectonics & hominoid splittings?

I don't know why the first paragraph was reformatted after sending. Let me try that again...

Prior to 25 Ma continental plate tectonics pushed up against East Africa starting to form the rift. This pushed the eastern seaboard upwards and caused rivers to run backwards, forming the great East African lakes. It would also have flooded the forests and created forested islands, especially in and around Lake Victoria. (Roberts, et al., 2012)

F.

-----Original Message-----
From: AAT@groups.io <AAT@groups.io> On Behalf Of fceska_gr via groups.io
Sent: Sunday, March 27, 2022 5:24 PM
To: AAT@groups.io
Subject: Re: [AAT] Plate Tectonics & hominoid splittings?

I have a new theory of what caused the ape/OWM split, and I think it happened in East Africa.

25+ Ma continental plate tectonics pushed up against East Africa
25+ starting to form the rift. This pushed the eastern seaboard upwards
25+ and caused rivers to run backwards, forming the great East African
25+ lakes. It would also have flooded the forests and created forested
25+ islands, especially in and around lake Victoria. (Roberts, et al.,
25+ 2012)
The earliest fossil evidence comes from 2 species, dating to 25.2 Ma from the Rift Basin of Tanzania: Rukwapithecus fleaglei appears to be more hominoid whereas Nsungwepithecus gunnelli appears to be more OWM (Stevens, et al., 2013).
I believe the apes diverged by becoming more aquarboareal, climbing down the trunks to exploit newly available niches in the flooded forests, while the monkeys remained more arboreal. Over time these apes became bigger in size, more orthograde, longer armed, flatter thoraxes, etc. and they lost their tails. (Verhaegen, et al.) Morotopithecus at 21 Ma represents one of the first fully orthograde apes.
Sometime between 22 - 18 Ma they Hylobatids diverged. Their ancestor made their way to Asia, perhaps over the gomphotherium land bridge (20-19 Ma), and it was there that they returned to the tree tops, became smaller, etc. (Hence why no hylobatids in Africa).

Hominoid apes, e.g. Helipithecus, occupied the Arabian continent / coastal forests around 17 - 16 Ma.
Some form of Griphopithecus made it all the way to central Europe by 16.5 Ma and apes diversified into many different species between 16- 11 Ma, mostly Aquarboreal, orthograde and always close to water. (Europe was very hot, flooded, wet at that time - many inland seas). It was around that time that Pongo diverged and set off for Asia.
11 - 9 Ma - Vallesian crisis - (loss of forest, increase in grassland savannah, arrival of many predators, seasonal food availability) caused most apes to go extinct. A few survived into the late Miocene.
Ouranopithecus (9.8 Ma) may be a branch of the gorilla line that returned to Africa, c. 10 Ma. (de Bonis, et al.) Graecopithecus (7.2 Ma) may have been close to the LCA of Pan/Homo. (Fuss, Boheme, Spassov, et al, 2017) Trachilos shows bipedal hominines in Crete 6.0 Ma. (Gierlinski / Spassov, et al.)
5.9 - 5.3 Ma - the Messinian Salinity Crisis - time to leave!

5.3 Ma - the Zanclean flood cut off the route between Arabia and Africa.
Those that made it across to Africa before the flood followed the African coast of the Red Sea, followed the Rift and eventually all the way down to South Africa, becoming over time less semi-aquatic / more arboreal (Pan).
Those that didn't make it across in time, colonised the Arabian coast of the Red Sea throughout the Pliocene, becoming increasingly aquatic (Homo).
2.6 Ma, Pleistocene cooling and drop in sea-levels.
Pan/Homo come together again at the southern end of the Red Sea / Afar / Rift Valley = Homo habilis
2.5 - 2.0 Ma - the great radiation of Homo out of the Red Sea (north to Georgia, East to China / Indonesia, West to Africa, etc.) (Mansfield, 😊 2022)

Francesca

-----Original Message-----
From: AAT@groups.io <AAT@groups.io> On Behalf Of Marc Verhaegen
Sent: Saturday, March 26, 2022 2:50 PM
To: AAT@groups.io
Subject: [AAT] Plate Tectonics & hominoid splittings?


India under Asia:
1) OWM/ape split: apes colonized India (low, wet, hot) & became
aquarboreal: vertical waders-climbers along the Tethys Ocean,
2) the Himalaya split colobines (E) & cercopithecines (W),
3) India split lesser (E) & great (W) apes (still predom.aquarboreal):
-- hylobatids along the SE.Asian Ind.Ocean coasts,
-- gr.apes along the Tethys=Med.Sea.

The Mesopotamian Seaway closure c 15 Ma split hominids (W) & pongids
(E):
-- pongids along the SE.Asian coastal forests, forcing hylobatids higher into the trees,
-- hominids around the Red & Med.Sea (Graecopith, footprints, Oreopith
etc.) + inland along rivers.
HPG in Red Sea.

E.Afr.Rift fm split Gorilla & HP c 8 Ma:
G followed the rift ->subgenus Praeanthropus Pliocene afarensis
->Pleist. Pr.boisei.

Opening of Red Sea c 5 Ma? = Zanclean flood??:
- Pan fossil subgenus Australopithecus initially followed the E.Afr.coasts ->Pliocene africanus ->Pleist.robustus // E.Afr.apiths,
- Homo followed the S.Asian coasts ->Peistocene shellfish-diving.


??


Re: ape/OWM c 65 Ma??

Marc Verhaegen
 

I'd think it's lot more recent, Jack.
-haplo/strepsi 70 Ma?
-tarsif./Simii 60 Ma?
-Platy-/Cata- 45 Ma?
-OWM/ape 30 Ma?
-great/lesser 20 Ma?
-hom./pongid 15 Ma?
-HP/G 8 Ma?
-H/P 5 Ma?

______



------ Origineel bericht ------
Van: needininfo@...
Aan: AAT@groups.io
Verzonden: maandag 28 maart 2022 16:55
Onderwerp: Re: [AAT] ape/OWM c 65 Ma??

65mya split for OWM/Apes makes sense. India split from Africa in that time period


-Jack


> On Mar 26, 2022, at 5:07 AM, Marc Verhaegen <m_verhaegen@...> wrote:
>
> A comparison of humans and baboons suggests germline mutation rates do not track cell divisions
> Molly Przeworski cs 2020 PLoS Biology


--
Welcome to the Aquatic Ape Theory Discussion Group


Re: ape/OWM c 65 Ma??

 

65mya split for OWM/Apes makes sense. India split from Africa in that time period


-Jack

On Mar 26, 2022, at 5:07 AM, Marc Verhaegen <m_verhaegen@...> wrote:

A comparison of humans and baboons suggests germline mutation rates do not track cell divisions
Molly Przeworski cs 2020 PLoS Biology
--
Welcome to the Aquatic Ape Theory Discussion Group


Re: Plate Tectonics & hominoid splittings?

fceska_gr
 

I don't know why the first paragraph was reformatted after sending. Let me try that again...

Prior to 25 Ma continental plate tectonics pushed up against East Africa starting to form the rift. This pushed the eastern seaboard upwards and caused rivers to run backwards, forming the great East African lakes. It would also have flooded the forests and created forested islands, especially in and around Lake Victoria. (Roberts, et al., 2012)

F.

-----Original Message-----
From: AAT@groups.io <AAT@groups.io> On Behalf Of fceska_gr via groups.io
Sent: Sunday, March 27, 2022 5:24 PM
To: AAT@groups.io
Subject: Re: [AAT] Plate Tectonics & hominoid splittings?

I have a new theory of what caused the ape/OWM split, and I think it happened in East Africa.

25+ Ma continental plate tectonics pushed up against East Africa
25+ starting to form the rift. This pushed the eastern seaboard upwards
25+ and caused rivers to run backwards, forming the great East African
25+ lakes. It would also have flooded the forests and created forested
25+ islands, especially in and around lake Victoria. (Roberts, et al.,
25+ 2012)
The earliest fossil evidence comes from 2 species, dating to 25.2 Ma from the Rift Basin of Tanzania: Rukwapithecus fleaglei appears to be more hominoid whereas Nsungwepithecus gunnelli appears to be more OWM (Stevens, et al., 2013).
I believe the apes diverged by becoming more aquarboareal, climbing down the trunks to exploit newly available niches in the flooded forests, while the monkeys remained more arboreal. Over time these apes became bigger in size, more orthograde, longer armed, flatter thoraxes, etc. and they lost their tails. (Verhaegen, et al.) Morotopithecus at 21 Ma represents one of the first fully orthograde apes.
Sometime between 22 - 18 Ma they Hylobatids diverged. Their ancestor made their way to Asia, perhaps over the gomphotherium land bridge (20-19 Ma), and it was there that they returned to the tree tops, became smaller, etc. (Hence why no hylobatids in Africa).

Hominoid apes, e.g. Helipithecus, occupied the Arabian continent / coastal forests around 17 - 16 Ma.
Some form of Griphopithecus made it all the way to central Europe by 16.5 Ma and apes diversified into many different species between 16- 11 Ma, mostly Aquarboreal, orthograde and always close to water. (Europe was very hot, flooded, wet at that time - many inland seas). It was around that time that Pongo diverged and set off for Asia.
11 - 9 Ma - Vallesian crisis - (loss of forest, increase in grassland savannah, arrival of many predators, seasonal food availability) caused most apes to go extinct. A few survived into the late Miocene.
Ouranopithecus (9.8 Ma) may be a branch of the gorilla line that returned to Africa, c. 10 Ma. (de Bonis, et al.) Graecopithecus (7.2 Ma) may have been close to the LCA of Pan/Homo. (Fuss, Boheme, Spassov, et al, 2017) Trachilos shows bipedal hominines in Crete 6.0 Ma. (Gierlinski / Spassov, et al.)
5.9 - 5.3 Ma - the Messinian Salinity Crisis - time to leave!

5.3 Ma - the Zanclean flood cut off the route between Arabia and Africa.
Those that made it across to Africa before the flood followed the African coast of the Red Sea, followed the Rift and eventually all the way down to South Africa, becoming over time less semi-aquatic / more arboreal (Pan).
Those that didn't make it across in time, colonised the Arabian coast of the Red Sea throughout the Pliocene, becoming increasingly aquatic (Homo).
2.6 Ma, Pleistocene cooling and drop in sea-levels.
Pan/Homo come together again at the southern end of the Red Sea / Afar / Rift Valley = Homo habilis
2.5 - 2.0 Ma - the great radiation of Homo out of the Red Sea (north to Georgia, East to China / Indonesia, West to Africa, etc.) (Mansfield, 😊 2022)

Francesca

-----Original Message-----
From: AAT@groups.io <AAT@groups.io> On Behalf Of Marc Verhaegen
Sent: Saturday, March 26, 2022 2:50 PM
To: AAT@groups.io
Subject: [AAT] Plate Tectonics & hominoid splittings?


India under Asia:
1) OWM/ape split: apes colonized India (low, wet, hot) & became
aquarboreal: vertical waders-climbers along the Tethys Ocean,
2) the Himalaya split colobines (E) & cercopithecines (W),
3) India split lesser (E) & great (W) apes (still predom.aquarboreal):
-- hylobatids along the SE.Asian Ind.Ocean coasts,
-- gr.apes along the Tethys=Med.Sea.

The Mesopotamian Seaway closure c 15 Ma split hominids (W) & pongids
(E):
-- pongids along the SE.Asian coastal forests, forcing hylobatids higher into the trees,
-- hominids around the Red & Med.Sea (Graecopith, footprints, Oreopith
etc.) + inland along rivers.
HPG in Red Sea.

E.Afr.Rift fm split Gorilla & HP c 8 Ma:
G followed the rift ->subgenus Praeanthropus Pliocene afarensis
->Pleist. Pr.boisei.

Opening of Red Sea c 5 Ma? = Zanclean flood??:
- Pan fossil subgenus Australopithecus initially followed the E.Afr.coasts ->Pliocene africanus ->Pleist.robustus // E.Afr.apiths,
- Homo followed the S.Asian coasts ->Peistocene shellfish-diving.


??


Re: Plate Tectonics & hominoid splittings?

fceska_gr
 

I have a new theory of what caused the ape/OWM split, and I think it happened in East Africa.

25+ Ma continental plate tectonics pushed up against East Africa starting to form the rift. This pushed the eastern seaboard upwards and caused rivers to run backwards, forming the great East African lakes. It would also have flooded the forests and created forested islands, especially in and around lake Victoria. (Roberts, et al., 2012)
The earliest fossil evidence comes from 2 species, dating to 25.2 Ma from the Rift Basin of Tanzania: Rukwapithecus fleaglei appears to be more hominoid whereas Nsungwepithecus gunnelli appears to be more OWM (Stevens, et al., 2013).
I believe the apes diverged by becoming more aquarboareal, climbing down the trunks to exploit newly available niches in the flooded forests, while the monkeys remained more arboreal. Over time these apes became bigger in size, more orthograde, longer armed, flatter thoraxes, etc. and they lost their tails. (Verhaegen, et al.)
Morotopithecus at 21 Ma represents one of the first fully orthograde apes.
Sometime between 22 - 18 Ma they Hylobatids diverged. Their ancestor made their way to Asia, perhaps over the gomphotherium land bridge (20-19 Ma), and it was there that they returned to the tree tops, became smaller, etc. (Hence why no hylobatids in Africa).

Hominoid apes, e.g. Helipithecus, occupied the Arabian continent / coastal forests around 17 - 16 Ma.
Some form of Griphopithecus made it all the way to central Europe by 16.5 Ma and apes diversified into many different species between 16- 11 Ma, mostly Aquarboreal, orthograde and always close to water. (Europe was very hot, flooded, wet at that time - many inland seas). It was around that time that Pongo diverged and set off for Asia.
11 - 9 Ma - Vallesian crisis - (loss of forest, increase in grassland savannah, arrival of many predators, seasonal food availability) caused most apes to go extinct. A few survived into the late Miocene.
Ouranopithecus (9.8 Ma) may be a branch of the gorilla line that returned to Africa, c. 10 Ma. (de Bonis, et al.)
Graecopithecus (7.2 Ma) may have been close to the LCA of Pan/Homo. (Fuss, Boheme, Spassov, et al, 2017)
Trachilos shows bipedal hominines in Crete 6.0 Ma. (Gierlinski / Spassov, et al.)
5.9 - 5.3 Ma - the Messinian Salinity Crisis - time to leave!

5.3 Ma - the Zanclean flood cut off the route between Arabia and Africa.
Those that made it across to Africa before the flood followed the African coast of the Red Sea, followed the Rift and eventually all the way down to South Africa, becoming over time less semi-aquatic / more arboreal (Pan).
Those that didn't make it across in time, colonised the Arabian coast of the Red Sea throughout the Pliocene, becoming increasingly aquatic (Homo).
2.6 Ma, Pleistocene cooling and drop in sea-levels.
Pan/Homo come together again at the southern end of the Red Sea / Afar / Rift Valley = Homo habilis
2.5 - 2.0 Ma - the great radiation of Homo out of the Red Sea (north to Georgia, East to China / Indonesia, West to Africa, etc.) (Mansfield, 😊 2022)

Francesca

-----Original Message-----
From: AAT@groups.io <AAT@groups.io> On Behalf Of Marc Verhaegen
Sent: Saturday, March 26, 2022 2:50 PM
To: AAT@groups.io
Subject: [AAT] Plate Tectonics & hominoid splittings?


India under Asia:
1) OWM/ape split: apes colonized India (low, wet, hot) & became
aquarboreal: vertical waders-climbers along the Tethys Ocean,
2) the Himalaya split colobines (E) & cercopithecines (W),
3) India split lesser (E) & great (W) apes (still predom.aquarboreal):
-- hylobatids along the SE.Asian Ind.Ocean coasts,
-- gr.apes along the Tethys=Med.Sea.

The Mesopotamian Seaway closure c 15 Ma split hominids (W) & pongids
(E):
-- pongids along the SE.Asian coastal forests, forcing hylobatids higher into the trees,
-- hominids around the Red & Med.Sea (Graecopith, footprints, Oreopith
etc.) + inland along rivers.
HPG in Red Sea.

E.Afr.Rift fm split Gorilla & HP c 8 Ma:
G followed the rift ->subgenus Praeanthropus Pliocene afarensis
->Pleist. Pr.boisei.

Opening of Red Sea c 5 Ma? = Zanclean flood??:
- Pan fossil subgenus Australopithecus initially followed the E.Afr.coasts ->Pliocene africanus ->Pleist.robustus // E.Afr.apiths,
- Homo followed the S.Asian coasts ->Peistocene shellfish-diving.


??


some recent papers on brain Tp & CC

Marc Verhaegen
 

Cerebral cortical processing time is elongated in human brain evolution
Kosuke Itoh cs 2022 Scientific Reports 12,1103

An increase in nr of neurons is presumed to underlie the enhancement of cognitive abilities in brain evolution.
The evolution of human cognition is then expected to have accompanied a prolongation of net neural-processing time, due to the accumulation of processing time of individual neurons over an expanded nr of neurons.

Here, we confirmed this prediction,
we quantified the amount of prolongation in vivo, using non-invasive measurements of brain responses to sounds in unanesthetized human & non-human primates.
Latencies of the N1 component of auditory-evoked potentials recorded from the scalp were c 40, 50, 60, and 100 ms for marmoset, rhesus, Pan & Hs resp.
The prominent increase in human N1 latency could not be explained by the physical lengthening of the auditory pathway:
it therefore reflected an extended dwell time for auditory cortical processing.
A longer time-window for auditory cortical processing is advantageous for analyzing time-varying acoustic stimuli, e.g. for speech perception.

A novel hypothesis concerning human brain evolution then emerges:
the increase in cortical neuronal nr widened the time-scale of sensory cortical processing:
the benefits outweighed the disadvantage of slow cognition & reaction.

___________

Primate brain size is predicted by diet but not sociality
Alex R DeCasien, Scott A. Williams & James P Higham 2017
Nature Ecology & Evolution 1,0112

The social brain hypothesis posits:
- social complexity is the primary driver of primate cognitive complexity,
- social pressures ultimately led to the evolution of the large human brain.
This has been supported by studies indicating positive relationships between relative brain and/or neocortex size & group size,
but reported effects of different social & mating systems are highly conflicting.

Here, we use a much larger sample of primates, more recent phylogenies & updated statistical techniques:
after controlling for body size & phylogeny, we show:
CC is predicted by diet, rather than multiple measures of sociality:
frugivores exhibit larger brains than folivores.
Our results call into question the current emphasis on social rather than ecological explanations for the evolution of large brains in primates.
We evoke a range of ecological & developmental hypotheses centred on frugivory, incl.
- spatial information storage,
- extractive foraging,
- overcoming metabolic constraints.

Primates, esp. anthropoids, have rel. large CCs vs other mammals.
These observations have led researchers to propose various explanations for the evolution of increased CC in primates:
numerous comparative analyses have been undertaken to identify social and/or ecological variables that explain interspecific variation in overall brain size, or of specific brain regions.

_________

Brain size and thermoregulation during the evolution of the genus Homo
Daniel E Naya, Hugo Naya & Enrique P Lessa 2016
Comp Biochem Physiol A Mol Integr Physiol 191:66-73.
doi 10.1016/j.cbpa.2015.09.017

Several hypotheses have been proposed to explain the evolution of an energetically costly brain in the genus Homo.
Some of these are based on the correlation between climatic factors & CC recorded for Homo the last millions of years.

Here we propose a complementary climatic hypothesis, based on the mechanistic connection between Tp, thermo-regulation & size of internal organs in endothermic spp.
Has global cooling during the last 3.2 Ma imposed an increased energy expenditure for thermoregulation?
could this in hominids represent a driver for the evolution of an expanded brain?
at least, could it imply the relaxation of a negative selection pressure acting upon this costly organ?

1) We assess variation in the energetic costs of thermoregulation & brain maintenance for the last 3.2 Ma.
2) We evaluate the relationship between Earth Tp & brain maintenance cost for the same period, taking into account the effects of body mass & fossil age.
We found:
1) the energetic cost ass.x brain enlargement represents an important fraction (between 47.5 & 82.5 %) of the increase in energy needed for thermoregulation,
2) fossil age is a better predictor of brain maintenance cost than Earth Tp: was (at least) another factor correlated with time more relevant than ambient Tp in CC evolution?
3) there is a significant negative correlation between the energetic cost of brain & Earth Tp, even after accounting for the effect of body mass & fossil age.
Thus, our results expand the current energetic framework for the study of CC evolution in our lineage:
a fall in Earth Tp during the last millions of years may have facilitated brain enlargement.


________

The Possible Role of Body Temperature in Modulating Brain and Body Sizes in Hominin Evolution
Manasvi Lingam 2022
Front. Psychol. doi org/10.3389/fpsyg.2021.774683

Many models have posited that the concomitant evolution of large brains & body sizes in hominins was constrained by metabolic costs.
In such studies, the impact of body Tp has arguably not been sufficiently addressed, although the rates of most physiological processes are Tp-dependent.
Hence, the potential role of body Tp in regulating the nr of neurons & body size is investigated by means of a heuristic quantitative model.
It is suggested:
modest deviations in body Tp (a couple of °C) might allow for substantive changes in brain & body parameters.
In particular, a higher body Tp may prove amenable to
- an increased nr of neurons,
- a higher brain-to-body mass ratio,
- fewer hours expended on feeding activities,
the converse could apply when the Tp is lowered.
Future studies should
- endeavor to explore & incorporate the effects of body Tp in metabolic theories of hominin evolution,
- also integrate other factors: foraging efficiency, diet, fire control.

________


Brain size and neuron numbers drive differences in yawn duration across mammals and birds
Jorg JM Massen cs 2021
Communications Biology 4,503

Recent studies indicate: yawning evolved as a brain-cooling mechanism.

- Larger brains have greater thermolytic needs,
- brain Tp is determined in part by heat production from neuronal activity:
do animals with larger CC & more neurons yawn longer, to produce comparable cooling effects?

We performed the largest study on yawning ever conducted: 1291 yawns of 101 spp (55 mammals, 46 birds).
Phylogenetically controlled analyses revealed robust positive correlations between yawn duration &
1) CC,
2) total neuron nr,
3) cortical/pallial neuron nr in mammals & birds,
which cannot be attributed solely to allometric scaling rules.

These relationships were similar across clades,
mammals exhibited considerably longer yawns than birds of comparable brain & body mass.
These findings provide further evidence suggesting:
yawning is a thermo-regulatory adaptation, conserved across amniote evolution.

_______

Quantifying patterns of endocranial heat distribution:
Brain geometry and thermoregulation.
Jose Manuel de la Cuetara 2012 Am J hum Biol

The mechanisms involved in brain thermo-regulation are still poorly known,
many disagreements still exist concerning the selective cooling capacity of the brain volume.
This issue has also been discussed in human evolution & paleo-neurology, speculating on possible changes ass.x hominid encephalization.
The vascular system is supposed to be the main component responsible for thermo-regulation,
but brain geometry also plays an important role in the pattern of heat distribution.
In fossils, the only neuro-anatomical evidence available for quantitative analyses is the endocranial form, molded by the brain morphology.

Here, we present a quantitative method, based on numerical simulations to quantify & localize variation in heat dissipation patterns ass.x endocranial morphological changes,
we present a case-study on modern humans & chimps.
Thermic maps provide a graphic tool to visualize heat loading on the endocranial surface.
The distribution of the values (thermic spectrum) supplies a quantification, which can help describe & compare the patterns of heat distribution within & between groups.
Absolute values are largely influenced by size differences.
Normalized values suggest further differences ass.x brain shape.
Simulation & numerical modeling are useful to provide a descriptive & quantitative approach to endocranial thermoregulation,
they supply a quantitative tool to investigate ontogenic & phylogenetic changes.
This is particularly relevant in paleo-neurology, considering the large shape & size differences described for fossil hominid brains.

______

The pattern of brain-size change in the early evolution of cetaceans
David A Waugh & JGM Thewissen 2021
PLoS doi org/10.1371/journal.pone.0257803

Most authors have identified 2 rapid increases in rel.brain size (encephalization quotient EQ) in cetacean evolution:
1) at the origin of the modern suborders odonto- & mysticetes, around the Eo-Oligocene transition,
2) at the origin of the delphinoid odontocetes mid-Miocene.
We explore how methods used to estimate brain & body mass alter this perceived timing & rate of cetacean EQ evolution.
We provide new data on modern mammals (mysti-, odontocetes & terrestrial artiodactyls):
- brain mass & endocranial volume scale allometrically,
- endocranial volume is not a direct proxy for brain mass:
inconsistencies in the methods used to estimate body size across the Eo-Oligocene boundary have caused a spurious pattern in earlier relative brain size studies.

Instead, we employ a single method:
we use occipital condyle width as a skeletal proxy for body mass, using a new data-set of extant cetaceans.
We suggest:
cetacean rel. brain size is most accurately portrayed using EQs based on the scaling coefficients as observed in the closely related terrestrial artiodactyls.
Finally, we include additional data for an Eocene whale, raising the sample size of Eocene archaeocetes to 7.
Our analysis of fossil cetacean EQ is different from previous works, which had shown a sudden increase in EQ at the Eo-Oligocene origin of odontocetes.
Instead, our data show:
- brain size increased at the origin of basilosaurids, 5 My before the Eocene-Oligocene transition,
- we do not observe a significant increase in rel.brain size at the origin of odontocetes.

_________


Evolution of the Human Brain:
the key roles of DHA (omega-3 fatty acid) and Δ6-desaturase gene
Didier Majou 2018 d.majou@...
OCL 25, A401 doi org/10.1051/ocl/2017059

The process of hominization involves an increase in brain size.
The development of hominids’ cognitive capital up to the emergence of Hs was due to interactive, iterative & integrative co-evolution, allowing positive selection.
Although this depends on many factors, here we show 3 categories that stand out:
- gene mutations,
- food resources,
- cognitive & behavioral stimulation.
Australopithecus benefited from
- the inactivation of the GULO & uricase genes,
- bipedalism causing the cognitive capital of the Homo genus to develop advantageously.
This evolution depended on 2 factors:
1) a triggering factor: gradual climate change. Homo started to regularly consume meat in addition to plants & insects,
2) a stimulating factor: mutations in the FADS2 gene, which encodes Δ6-desaturase, a key-enzyme for the synthesis of DHA & sapienic acid.
The polymorphism of this gene appears to have been essential in allowing the Homo genus to adapt to its food & for its evolution.
It provides an undeniable advantage in terms of the productivity of fat synthesis (DHA), and may partly explain positive selection.
With the advent of cooking & new mutations producing even more FADS2, the brain reached its maximum size in H.neanderthalensis, in a food eco-system that provided favorable quantities of α-Linolenic acid & DHA,
but the Würm glaciation upset this equilibrium, revealing its fragility as regards to the brain & fertility.
Hs, benefiting from new variants of the FADS2 gene, were able to adapt to this harsh environment,
Neanderthal man was unable to do so, and became extinct.


Re: Plate Tectonics & hominoid splittings?

alandarwinvanarsdale
 

It is not known where the Hominid began geographically. It did seem very unlikely to be all or in part Africa. Now there is some fossil evidence it might have been partly in Africa. The oldest hylobatid now is South Asia, no evidence they were every in Africa or came from Africa. That is one of the most importation refutations of Hominids beginning exclusively in Africa. Hylobatids are certainly the closest living relatives of Hominids. Eurasia appears much more the center of origins and development of Hominids than Africa. ______________________________________________________________________________________________Before large monkeys like Proconsul were thought to be proto-apes. They are not, though now there is some evidence they had some input into Hominids such as HGT or even inter-specific introgression. The same is true for pliopithecoids, which are now known just a little from Africa. Essentially in some cases large bodied monkeys, not ancestral to Hominids, but with some evidence of some input into Hominids even Hominins. __________________________________________________________________________________________________Some pliopithecoids, the fossil record suggests, may have been the first terrestrial bipedal primates. Pliopithecoids are not even Old World monkeys, they are just general early divergent monkeys, and have traits of both Old and New World monkeys as plesiomorphs. And they share a lot of dental morphology with australopiths, too much for coincidence or convergence perhaps.

 

Sent from Mail for Windows

 

From: Jack D.Barnes
Sent: Saturday, March 26, 2022 11:05 AM
To: AAT@groups.io
Subject: Re: [AAT] Plate Tectonics & hominoid splittings?

 

Marc,

I agree with you 100% on the OWM on India for an allopatric speciation into the tailless Apes.  The stem Hylobates landed in SE Asia where great apes were created.  

 

The ancestor of all four extent great Apes (Orang, Gorilla, Chimp and Human) radiated from SE Asia, NOT Africa.  Homo’s ancestor left on India and did not return until 1.8mya.

 

-Jack

 

 

> On Mar 26, 2022, at 7:50 AM, Marc Verhaegen <m_verhaegen@...> wrote:

>

> 

> India under Asia:

> 1) OWM/ape split: apes colonized India (low, wet, hot) & became aquarboreal: vertical waders-climbers along the Tethys Ocean,

> 2) the Himalaya split colobines (E) & cercopithecines (W),

> 3) India split lesser (E) & great (W) apes (still predom.aquarboreal):

> -- hylobatids along the SE.Asian Ind.Ocean coasts,

> -- gr.apes along the Tethys=Med.Sea.

>

> The Mesopotamian Seaway closure c 15 Ma split hominids (W) & pongids (E):

> -- pongids along the SE.Asian coastal forests, forcing hylobatids higher into the trees,

> -- hominids around the Red & Med.Sea (Graecopith, footprints, Oreopith etc.) + inland along rivers.

> HPG in Red Sea.

>

> E.Afr.Rift fm split Gorilla & HP c 8 Ma:

> G followed the rift ->subgenus Praeanthropus Pliocene afarensis ->Pleist. Pr.boisei.

>

> Opening of Red Sea c 5 Ma? = Zanclean flood??:

> - Pan fossil subgenus Australopithecus initially followed the E.Afr.coasts ->Pliocene africanus ->Pleist.robustus // E.Afr.apiths,

> - Homo followed the S.Asian coasts ->Peistocene shellfish-diving.

>

>

> ??

>

>

>

>

>

 

 

--

Welcome to the Aquatic Ape Theory Discussion Group

 

 

 

 

 


Re: Plate Tectonics & hominoid splittings?

 

Marc,
I agree with you 100% on the OWM on India for an allopatric speciation into the tailless Apes. The stem Hylobates landed in SE Asia where great apes were created.

The ancestor of all four extent great Apes (Orang, Gorilla, Chimp and Human) radiated from SE Asia, NOT Africa. Homo’s ancestor left on India and did not return until 1.8mya.

-Jack

On Mar 26, 2022, at 7:50 AM, Marc Verhaegen <m_verhaegen@...> wrote:


India under Asia:
1) OWM/ape split: apes colonized India (low, wet, hot) & became aquarboreal: vertical waders-climbers along the Tethys Ocean,
2) the Himalaya split colobines (E) & cercopithecines (W),
3) India split lesser (E) & great (W) apes (still predom.aquarboreal):
-- hylobatids along the SE.Asian Ind.Ocean coasts,
-- gr.apes along the Tethys=Med.Sea.

The Mesopotamian Seaway closure c 15 Ma split hominids (W) & pongids (E):
-- pongids along the SE.Asian coastal forests, forcing hylobatids higher into the trees,
-- hominids around the Red & Med.Sea (Graecopith, footprints, Oreopith etc.) + inland along rivers.
HPG in Red Sea.

E.Afr.Rift fm split Gorilla & HP c 8 Ma:
G followed the rift ->subgenus Praeanthropus Pliocene afarensis ->Pleist. Pr.boisei.

Opening of Red Sea c 5 Ma? = Zanclean flood??:
- Pan fossil subgenus Australopithecus initially followed the E.Afr.coasts ->Pliocene africanus ->Pleist.robustus // E.Afr.apiths,
- Homo followed the S.Asian coasts ->Peistocene shellfish-diving.


??




--
Welcome to the Aquatic Ape Theory Discussion Group


Re: carnivorous erectus?

alandarwinvanarsdale
 

Human teeth suggest reduced carnivory not increased. This is likely due to fire use and better tools. Still there is no morphological evidence of increased carnivory. In denisovans the teeth suggest increased insectivory. And Penghu suggests a lot of eating of sandy clams. Only some Neanderthal bands were highly carnivorous, surprisingly, others were herbivores.

 

Sent from Mail for Windows

 

From: Marc Verhaegen
Sent: Saturday, March 26, 2022 3:45 AM
To: AAT@groups.io
Subject: [AAT] carnivorous erectus?

 

No sustained increase in zooarchaeological evidence for carnivory after

the appearance of Homo erectus

Andrew Du 2022 PNAS

 

The  appearance of H.erectus shortly after 2.0 Ma is widely considered a

turning-point in human dietary evolution:

- increased consumption of  animal tissues, driving the evolution of

larger brain & body size,

- a reorganization of the gut.

An increase in the size & nr of zoo-archaeological assemblages after the

appearance of H.erectus is often offered as a central piece of

archaeological evidence for  increased carnivory,

but this characterization has yet  to be subject to detailed scrutiny.

Any widespread dietary shift leading  to the acquisition of key traits

in H.erectus should be persistent in  the zoo-archaeological record

through time,

it can only be convincingly demonstrated by a broad-scale analysis that

transcends individual sites or localities.

 

Here we present a quantitative synthesis of the  zoo-archaeological

record of E-Africa from 2.6 to 1.2 Ma.

We show:

several proxies for the prevalence of hominin carnivory are all

strongly related to how well the fossil record has been sampled,

this constrains the zoo-archaeological visibility of hominin carnivory.

When correcting for sampling effort, there is no sustained increase in

the  amount of evidence for hominin carnivory between 2.6 & 1.2 Ma.

Our observations undercut evolutionary narratives linking anatomical &

behavioral traits to increased meat consumption in H.erectus:

other factors are likely responsible for the appearance  of its

human-like traits.

 

 

 

<footer class="nova-legacy-v-publication-item__footer"></footer>W.

Andrew BarrBriana L PobinerJohn Rowan[...]

 

 

 

 

 


Plate Tectonics & hominoid splittings?

Marc Verhaegen
 

India under Asia:
1) OWM/ape split: apes colonized India (low, wet, hot) & became aquarboreal: vertical waders-climbers along the Tethys Ocean,
2) the Himalaya split colobines (E) & cercopithecines (W),
3) India split lesser (E) & great (W) apes (still predom.aquarboreal):
-- hylobatids along the SE.Asian Ind.Ocean coasts,
-- gr.apes along the Tethys=Med.Sea.

The Mesopotamian Seaway closure c 15 Ma split hominids (W) & pongids (E):
-- pongids along the SE.Asian coastal forests, forcing hylobatids higher into the trees,
-- hominids around the Red & Med.Sea (Graecopith, footprints, Oreopith etc.) + inland along rivers.
HPG in Red Sea.

E.Afr.Rift fm split Gorilla & HP c 8 Ma:
G followed the rift ->subgenus Praeanthropus Pliocene afarensis ->Pleist. Pr.boisei.

Opening of Red Sea c 5 Ma? = Zanclean flood??:
- Pan fossil subgenus Australopithecus initially followed the E.Afr.coasts ->Pliocene africanus ->Pleist.robustus // E.Afr.apiths,
- Homo followed the S.Asian coasts ->Peistocene shellfish-diving.


??


Graecop.freybergi

Marc Verhaegen
 

Potential hominin affinities of Graecopithecus from the Late Miocene of Europe
... Madelaine Böhme cs 2017 PLoS ONE

The split of our own clade from the Panini is undocumented in the fossil record.
To fill this gap, we investigated the dento-gnathic morphology of Graecop.freybergi (Pyrgos Vassilissis, Greece) & cf.Graecop.sp (Azmaka, Bulgaria), using new μCT & 3D reconstructions of the 2 known spms.
Pyrgos Vassilissis & Azmaka are currently dated to the early-Messinian at 7.175 & 7.24 Ma.
Mainly based on its external preservation & the previously vague dating, Graecopithecus is often referred to as nomen dubium.
The examination of its previously unknown dental root & pulp canal morphology
- confirms the taxonomic distinction from the significantly older N-Greek hominine Ouranopithecus,
- shows features that point to a possible phylogenetic affinity with hominins.
G.freybergi uniquely shares p4 partial root fusion & a possible canine root reduction with this tribe,
therefore, it provides intriguing evidence of what could be the oldest known hominin.


Comparative isotopic evidence from East Turkana supports a dietary shift within the genus Homo

Marc Verhaegen
 

Comparative isotopic evidence from East Turkana supports a dietary shift within the genus Homo
David Patterson, David R Braun, Kayla Allen & René Bobe 2019
Nature Ecology & Evolution 3(7) doi 10.1038/s41559-019-0916-0

It has been suggested that a shift in diet is one of the key adaptations that distinguishes the genus Homo from earlier hominins,
but recent stable isotopic analyses of fossils attributed to Homo in the Turkana Basin show an increase in the consumption of C4 resources c 1.65 Ma, significantly after the earliest evidence for Homo in the E-African fossil record.
These data are consistent with ingesting more C4 plants and/or animal tissues of C4 herbivores,
but it is also possible that this change reflects factors, unrelated to changes in the palaeo-biology of the genus Homo.

Here we use new & published C* & O*data (n=999) taken from large-bodied fossil mammals & pedogenic carbonates in fossil soils, from E.Turkana (N-Kenya):
we investigate the context of this change in the isotope signal within Homo.
We targeted taxa & temporal intervals unrepresented or undersampled in previous analyses,
so we conducted the first comprehensive analysis of the ecological context of hominin diet at E.Turkana during a period crucial for detecting any dietary & related behavioural differences between early Homo (H.habilis and/or H.rudolfensis) & H.erectus.
Our analyses suggest :
the genus Homo underwent a dietary shift (as indicated by δ¹³Cena & δ¹⁸Oena values) that is
1) unrelated to changes in the E.Turkana vegetation community,
2) unlike patterns found in other E.Turkana large mammals, incl. Paranthropus & Theropithecus.
These data suggest that within the Turkana Basin a dietary shift occurred well after we see the first evidence of early Homo in the region.


"Early hominins evolved within non-analog ecosystems"

Marc Verhaegen
 

Early hominins evolved within non-analog ecosystems
Andrew Du cs 2019 PNAS

Present-day African eco-systems serve as referential models for conceptualizing the environmental context of early hominin evolution,
but to which degree are modern eco-systems representative of those in the past?
A growing body of evidence from E-Africa’s rich & well-dated late-Cenozoic fossil record documents communities of large-bodied mammalian herbivores with ecological structures differing dramatically from today:
modern communities may not be suitable analogs for the ancient eco-systems of hominin evolution.
When & why did the ecological structure of E-Africa’s herbivore faunas come to resemble those of the present?

Here we analyze functional trait changes in a comprehensive data-set of 305 modern & fossil herbivore communities, spanning the last ∼7 Ma.
We show:
nearly all communities prior to ∼700 ka were functionally non-analog, largely due to a greater richness of non-ruminants & mega-herbivores (spp >1000 kg).
The emergence of functionally modern communities
- precedes that of taxonomically modern communities by 100,000s of years,
- can be attributed to the combined influence of Plio-Pleistocene C4 grassland expansion + pulses of aridity after ∼1 Ma.

Given the disproportionate ecological impacts of large-bodied herbivores on vegetation structure, hydrology & fire regimes, it follows:
the vast majority of early hominin evolution transpired in the context of eco-systems that functioned unlike any today.
Identifying how past eco-systems differed compositionally & functionally from those today is key to conceptualizing ancient African environments, and testing ecological hypotheses of hominin evolution.


(not unlikely our Homo ancestors were in S.Eurasia then... --mv)


Re: Danuvius guggenmosi 12 Ma: extended limb clambering = adaptations of bipeds + suspensory apes

Marc Verhaegen
 

I just (re)read the comments:

Marc Verhaegen
added a comment
Thanks for this beautiful article. It confirms the aquarboreal hypothesis, that many Mio-Pliocene hominoids frequently waded bipedally & climbed arms overhead in swampy forests where they typically fossilized, see our 2002 paper "Aquarboral Ancestors?" in Trends Ecol.Evol.17:212-217, and google "bonobo wading" or "gorilla bai".


Nov 19, 2019
Kim Shaw-Williams
added a comment
I agree with Marc Verhaegen, this is an exciting & timely article. I would add that the molars of this hominoid were as omnivorous (human-like) as all of the earlier Miocene hominoids, one of which was 17.5-Ma Morotopithecus, the first obviously orthograde (from habitual bipedal wading) member of our ancient lineage, which we now know became obligately bipedal by 6 Ma, due to the Trachilos seashore footprints of wading children in Crete. Other extant apes are in many ways more secondarily derived than our own lineage, and the extinct ouranopith/australopith lineage was just another sedge-eating branch of the 9.5-Ma Chororapithecus/Gorilla clade. In my view these extant & extinct apes are not at all representative of our ancestors --
conversely in certain ways we are actually more representative of their earliest ancestors.

:-)

______


A new Miocene ape and locomotion in the ancestor of great apes and humans
David Begun cs 2019 Nature

Many ideas have been proposed to explain the origin of bipedalism in hominins, and suspension in great apes (hominids),
but fossil evidence has been lacking.(?? --mv)
It has been suggested that hominin BPism evolved from
- an ancestor that was a palmigrade quadruped (cf living monkeys),
- or from a more suspensory quadruped (cf extant chimps).

Here we describe the fossil ape Danuvius guggenmosi (Allgäu region, Bavaria) for which complete limb bones are preserved,
it provides evidence of a newly identified form of positional behaviour: extended limb clambering.
The 11.62-Ma Danuvius is a great ape, dentally most similar to Dryopithecus & other European late-Miocene apes.
With a broad thorax, long lumbar spine & extended hips & knees (as in bipeds) and elongated & fully extended forelimbs (as in all apes=hominoids), Danuvius combines the adaptations of bipeds & suspensory apes,
it provides a model for the common ancestor of great apes & humans.

Danuvius guggenmosi moved using extended limb clambering, thus combining adaptations of bipeds & suspensory apes, providing evidence of the evolution of BPism & suspension climbing in the common ancestor of great apes & humans.


(yes, this is aquarborealism... :-D --mv)


Danuvius guggenmosi 12 Ma: extended limb clambering = adaptations of bipeds + suspensory apes

Marc Verhaegen
 

A new Miocene ape and locomotion in the ancestor of great apes and humans
David Begun cs 2019 Nature

Many ideas have been proposed to explain the origin of bipedalism in hominins, and suspension in great apes (hominids),
but fossil evidence has been lacking.(?? --mv)
It has been suggested that hominin BPism evolved from
- an ancestor that was a palmigrade quadruped (cf living monkeys),
- or from a more suspensory quadruped (cf extant chimps).

Here we describe the fossil ape Danuvius guggenmosi (Allgäu region, Bavaria) for which complete limb bones are preserved,
it provides evidence of a newly identified form of positional behaviour: extended limb clambering.
The 11.62-Ma Danuvius is a great ape, dentally most similar to Dryopithecus & other European late-Miocene apes.
With a broad thorax, long lumbar spine & extended hips & knees (as in bipeds) and elongated & fully extended forelimbs (as in all apes=hominoids), Danuvius combines the adaptations of bipeds & suspensory apes,
it provides a model for the common ancestor of great apes & humans.

Danuvius guggenmosi moved using extended limb clambering, thus combining adaptations of bipeds & suspensory apes, providing evidence of the evolution of BPism & suspension climbing in the common ancestor of great apes & humans.


(yes, this is aquarborealism... :-D --mv)


ape/OWM c 65 Ma??

Marc Verhaegen
 

A comparison of humans and baboons suggests germline mutation rates do not track cell divisions
Molly Przeworski cs 2020 PLoS Biology

In humans, most germ-line mutations are inherited from the father.
This has been widely interpreted as reflecting the replication errors that accrue during spermatogenesis.
If so, the male bias in mutation should be substantially lower in a closely related species with similar rates of spermatogonial stem-cell divisions, but a shorter mean age of reproduction.
To test this, we resequenced two 3–4 generation nuclear families (29 individuals) of olive baboons Papio anubis (who reproduce at c 10 yrs of age on average),
we analyzed the data in parallel with three 3-generation human pedigrees (26 individuals).
We estimated a mutation rate/generation in baboons of 0.57×10⁻⁸/base-pair, c 1/2 half that of Hs.
But, strikingly, the degree of male bias in germline mutations is c 4:1, similar to Hs:
indeed, a similar male bias is seen across mammals that reproduce months, years or decades after birth.

These results
- mirror the finding in Hs that the male mutation bias is stable with parental ages,
- cast further doubt on the assumption that germline mutations track cell divisions.
Our mutation rate estimates for baboons raise a further puzzle, suggesting a divergence time between apes & OWMs of 65 Ma, too old to be consistent with the fossil record;
reconciling them now requires not only a slowdown of the mutation rate/generation in Hs, but also in baboons.


P.aethiopicus diet

Marc Verhaegen
 

Isotopic evidence for the timing of the dietary shift toward C 4 foods in eastern African Paranthropus
Matt Sponheimer cs 2020 PNAS

New approaches to the study of early hominin diets have refreshed interest in how & when our (sic --mv) diets diverged from other African apes.
A trend toward significant consumption of C4 foods in hominins after this divergence has emerged as a landmark event in human evolution, with direct evidence provided by stable C*isotope studies.

Here we report on detailed C*evidence from the hominin fossil record of the Shungura & Usno Fms (Lower Omo Valley, Ethiopia), which elucidates the patterns of C4 dietary utilization in the robust hominin Paranthropus .
The results show:
- the most important shift toward C4 foods occurred at ∼2.37 Ma, within the temporal range of the earliest known member of the genus, Paranthr.aethiopicus,
- this shift was not unique to Paranthropus, but occurred in all hominins from this fossil sequence.
This uptake of C4 foods by hominins occurred during a period marked by an overall trend toward increased C4-grazing by co-occurring mammalian taxa from the same sequence,
but the timing & geographic patterns of hominin diets in this region differ from those observed elsewhere in the same basin:
environmental controls on the underlying availability of various food sources were likely quite different.
These results highlight the complexities of dietary responses by hominins to changes in the availability of food resources.


Rethinking the ecological drivers of hominin evolution

Marc Verhaegen
 

Rethinking the ecological drivers of hominin evolution
Literature Review 2021 Trends in Ecology & Evolution
Bernard Wood 2021 TREE

A central goal of paleo-anthropology is understanding the role of ecological change in hominin evolution.
Over the past several decades, researchers have expanded the hominin fossil record, and assembled detailed late-Cenozoic paleo-climatic, -environmental & -ecological archives,
but effective use of these data is precluded by the limitations of pattern-matching strategies for inferring causal relationships between ecological & evolutionary change.

We examine several obstacles that have hindered progress,
we highlight recent research that is addressing them by
i) confronting an incomplete fossil record,
ii) contending with datas-ets spanning varied spatio-temporal scales,
iii) using theoretical frameworks to build stronger inferences.
Expanding on this work promises to transform challenges into opportunities, and set the stage for a new phase of PA research.

:-D


carnivorous erectus?

Marc Verhaegen
 

No sustained increase in zooarchaeological evidence for carnivory after the appearance of Homo erectus
Andrew Du 2022 PNAS

The appearance of H.erectus shortly after 2.0 Ma is widely considered a turning-point in human dietary evolution:
- increased consumption of animal tissues, driving the evolution of larger brain & body size,
- a reorganization of the gut.
An increase in the size & nr of zoo-archaeological assemblages after the appearance of H.erectus is often offered as a central piece of archaeological evidence for increased carnivory,
but this characterization has yet to be subject to detailed scrutiny.
Any widespread dietary shift leading to the acquisition of key traits in H.erectus should be persistent in the zoo-archaeological record through time,
it can only be convincingly demonstrated by a broad-scale analysis that transcends individual sites or localities.

Here we present a quantitative synthesis of the zoo-archaeological record of E-Africa from 2.6 to 1.2 Ma.
We show:
several proxies for the prevalence of hominin carnivory are all strongly related to how well the fossil record has been sampled,
this constrains the zoo-archaeological visibility of hominin carnivory.
When correcting for sampling effort, there is no sustained increase in the amount of evidence for hominin carnivory between 2.6 & 1.2 Ma.
Our observations undercut evolutionary narratives linking anatomical & behavioral traits to increased meat consumption in H.erectus:
other factors are likely responsible for the appearance of its human-like traits.



<footer class="nova-legacy-v-publication-item__footer"></footer>W. Andrew BarrBriana L PobinerJohn Rowan[...]

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