aquatic diets

[littor...@gmail.com]

Stable isotope-based diet reconstructions of Turkana Basin hominins
Thure E Cerling cs 2013 doi org/10.1073/pnas.1222568110

Hominin fossil evidence in the Turkana Basin in Kenya from c 4.1 to 1.4 Ma samples 2 archaic early hominin genera, and records some of the early evolutionary history of Paranthropus & Homo.
Stable C isotopes in fossil tooth enamel are used to estimate the fraction of diet derived from C3 or C4 resources in these hominin taxa.
- The earliest hominin species in the Turkana Basin, Au.anamensis, derived nearly all of its diet from C3 resources.
- By c 3.3 Ma, the later Kenyanthr.platyops had a very wide dietary range—from virtually a purely C3 resource-based diet to one dominated by C4 resources.
- By c 2 Ma, hominins in the Turkana Basin had split into 2 distinct groups:
-- spms attributable to the genus Homo provide evidence for a diet with a c 65/35 ratio of C3- to C4-based resources,
-- Par. boisei had a higher fraction of C4-based diet (c 25/75 ratio).
Homo sp. increased the fraction of C4-based resources in the diet through c 1.5 Ma,
P. boisei maintained its high dependency on C4-derived resources.

Isotopic evidence shows their diet was primarily C4 with rel.high δ13C values: “An apparent C4-based diet is one based on aquatic resources in which algae have elevated δ13C values because of bicarbonate uptake during photosynthesis; for this example, algae or fish then have δ13C values with an apparent C4 component.”

IOW, only incredible imbeciles believe their ancestors ran after antelopes.

[Primum Sapienti]

The link

https://www.pnas.org/doi/10.1073/pnas.1222568110

Stable isotope-based diet reconstructions of Turkana Basin hominins

Junbe 3, 2013


The REAL abstract:

Abstract
Hominin fossil evidence in the Turkana Basin in Kenya from ca. 4.1 to 1.4 Ma
samples two archaic early hominin genera and records some of the early
evolutionary history of Paranthropus and Homo. Stable carbon isotopes in

fossil tooth enamel are used to estimate the fraction of diet derived from C3

or C4 resources in these hominin taxa. The earliest hominin species in the
Turkana Basin, Australopithecus anamensis, derived nearly all of its diet
from
C3 resources. Subsequently, by ca. 3.3 Ma, the later Kenyanthropus platyops

had a very wide dietary range—from virtually a purely C3 resource-based diet

to one dominated by C4 resources. By ca. 2 Ma, hominins in the Turkana Basin
had split into two distinct groups: specimens attributable to the genus Homo
provide evidence for a diet with a ca. 65/35 ratio of C3- to C4-based
resources,
whereas P. boisei had a higher fraction of C4-based diet (ca. 25/75 ratio).

Homo sp. increased the fraction of C4-based resources in the diet through

ca. 1.5 Ma, whereas P. boisei maintained its high dependency on C4-derived
resources.

"We use the terms C3- and C4-based resources throughout our discussion,
because our isotopic method cannot distinguish between a plant-based diet, a
meat-based diet, and an omnivorous diet. Thus, based on isotopes alone, we
consider that the diets of the early hominins that we have investigated could
be primarily herbaceous (C3 and C4 plants), or they could be a secondary C3-
or C4-based diet, an apparent C3- or C4-based diet, or an omnivorous diet. A
secondary C3- or C4-based diet could be a meat- or insect-based diet (in
which
the δ13C values are derived from the basal herbaceous diet of the prey). An

apparent C4-based diet is one based on aquatic resources in which algae have
elevated δ13C values because of bicarbonate uptake during photosynthesis

(40);

for this example, algae or fish then have δ13C values with an apparent C4

component (41, 42). Lastly, an omnivorous diet is a combination of the above
resources: primary herbaceous diet along with secondary C3- or C4-derived
components (i.e., meat or insects) or apparent components (i.e., aquatic).

"The stable carbon isotope signature of a meat-based diet depends on the
nature
of the prey: small bovid herbivores less than ca. 10 kg (e.g., dik-dik and
other
neotragines) tend to be browsers and have C3-based diets (14, 32), whereas
large
herbivores can have diets that are C3-based (browsers such as most
tragelephines,
black rhinos, and giraffes), C4-based (grazers such as warthogs, zebra,
alcelaphines,
reducines, and bovines), or mixed (e.g., impala, and some gazelles). Thus,
the size
of prey may be important in considering possible secondary diet C3 or C4
resources.
Other small mammals (e.g., hyrax, lagomorphs, or rodents) could have been an
important dietary resource and would contribute to isotope mixing lines
between
C3- and C4-based end member values."


See also

http://www.pnas.org/content/early/2013/05/31/1222559110
Diet of Australopithecus afarensis from the Pliocene Hadar Formation,
Ethiopia.

Abstract:
The enhanced dietary flexibility of early hominins to include
consumption of C4/crassulacean acid metabolism (CAM) foods (i.e.,
foods derived from grasses, sedges, and succulents common in tropical
savannas and deserts) likely represents a significant ecological and
behavioral distinction from both extant great apes and the last common
ancestor that we shared with great apes. Here, we use stable carbon
isotopic data from 20 samples of Australopithecus afarensis from Hadar
and Dikika, Ethiopia (>3.4�2.9 Ma) to show that this species consumed
a diet with significant C4/CAM foods, differing from its putative
ancestor Au. anamensis. Furthermore, there is no temporal trend in the
amount of C4/CAM food consumption over the age of the samples
analyzed, and the amount of C4/CAM food intake was highly variable,
even within a single narrow stratigraphic interval. As such, Au.
afarensis was a key participant in the C4/CAM dietary expansion by
early australopiths of the middle Pliocene. The middle Pliocene
expansion of the eastern African australopith diet to include
savanna-based foods represents a shift to use of plant food resources
that were already abundant in hominin environments for at least 1
million y and sets the stage for dietary differentiation and niche
specialization by subsequent hominin taxa.

[I Envy JTEM]

Primum Sapienti wrote:

> The REAL abstract:

> See also

What I find most interesting here, even more so than the fact that you are
posting "Cites" you don't understand, is that I argue a far more recent
dating for the LCA than is conventionally accepted, and both your "Cites"
fall within my range. So maybe these are on the Chimp side of the divide
and are completely irrelevant to human evolution.

Another thing to consider -- well, not you per se. You won't consider
anything that doesn't come from the nice man living in your tv -- is that
if one entertains Out of Asia or any model other than strict Out of
Africa/Replacement purity... well, who cares? Seriously. Who cares? Why
would anyone care?

A final point of interest, one you may fling dung at but certainly will never
grasp, is that nobody is saying that there was only one population in
existence. Even Out of Africa purists insists that there were many, Many,
MANY populations, "Different Species," all existing well after someone
stood upright and ran after a water buffalo causing them to evolve the
ability to stand upright and run after water buffalo...

Neanderthals, at least TWO distinct populations now labelled as
Denisovan, each as removed as much from each other as they were
from the Neanderthals... the Red Dear People... some "Unknown
Ancestor" in Africa, one in Eurasia.. the west African archaic that is
clearly not modern but has since been relabelled as "Modern" to get
rid of it...

Oo! Mungo Man's population! The LM3 line that we know BILLIONS
of people descend from!

So here you are, a short bus riding, hockey helmet wearing "Paleo
Anthropologist," though with slightly less of a urine stench than is
the norm for your ilk, claiming that your very own goddamn stupid
model has to be wrong, because there was only ever one population
and if you think you can misread something as proving that an
inland population never ate a clam then no population anywhere
could have.

Amazing. Well, no, it's par for the course. Totally expected.

But you have yourself a great day anyway. You can still contribute
to society, you can still make a difference, one that doesn't involve
science, reading, thinking or interacting with others.

Good luck with that, and God bless!



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