The Australopithecine and Early Hominin Thread

Galvasean

It's been a long time coming, but regular posters of this forum will be delighted to know that the first major analysis of 'Ardi' (Ardipithecus ramidus) has been released.
The findings are exremely important as it reveals 'Ardi' to be the earliest known upright ape, living some 1 million years before the famous 'Lucy' (Australopithecus afarensis). 'Ardi' would have been able to walk and probably even run upright, while retaining the ability to climb around in trees, albeit slowly. One thing which has been ruled out in 'Ardi' is knuckle walking, like that of modern apes such as gorillas and chimps. 'Ardi' also had human like canines, again, unlike the aforementioned apes. These two factors mean that the previously held assumption that human ancestors of the time would have looked and behaved like modern chimps to be wrong.

A DETAILED ANALYSIS of human-like fossils discovered in Ethiopia has taken mankind back in time, a million years closer to the “missing link” ancestor we share with the great apes. In the process, scientists have been forced to rethink human evolution and what the missing link must have looked like.

It overturns the widely held view that chimpanzees and gorillas must be typical of the look and behaviour of our shared ancestors. The research proves that the modern apes are very poor models for the last common ancestor, opening up a whole new perspective on the separate tracks taken by ape and human evolution. A staggering amount of data has come from an intensive study, lasting several years, of a human-like or hominid animal called Ardipithecus ramidus.

Full article here.

Goduznt Xzst

If you sign up for free you can access the research articles on Ardi here:

http://www.sciencemag.org/ardipithecus/

Galvasean

The Discovery Channel will soon be showing a program called 'Discovering Ardi'.
Watch this space.

JuliusCaesar

Amazing stuff. Only read the Ir Times article. I'm always astonished at the conclusions they come to on what seems to be little evidence. From no (little) canine teeth to, that means that pair bonding was in place, rather than the Alpha male gets all the females & the rest of the males get what they can on the sly.

Wondering how the pair-bonding hypothesis stands in relation to the men have to have sex with lots of women to maximise reproductive potential theory (I know they are not exclusive) and how that impacts on modern behaviour (which is constantly justified in terms of what is 'natural')

Galvasean

Article on National Geographic on Ardi's sex life. Read at your own peril...

http://news.nationalgeographic.com/news/2009/10/091001-ardipithecus-ramidus-ardi-oldest-human-fossils-sex.html

Wibbs

Interesting one alright that shows bipedalism come well before intelligence and tool use. It clearly held serious advantages(considering it's disadvantages). A sexual reason may be possible, but I dunno.

I agree with JuliusCaesar, there does seem to be a lot of extrapolation going on, which is one of the bugbears I have about hominid research. They'll (pretty much rightfully) dismiss the aquatic ape theory, yet go off on wild conjecture of their own on even scanter evidence.

For a start how do they know other canines came from a male? They simply don't. Without a pelvis or near complete skull it could just have been a more robust female within the gender limits of that species. We all know women that are 4"11 and women who are much taller and more robust. That's with the benefit of numbers. If we dug up one of the 4"11 ones in a million years time there's no way we could suggest that all female sapiens were 4'11. It's complete conjecture. Smaller canines could simply be an adaptation to a particular diet.

Much more recently in our history finds in georgia seem to suggest a big dimorphism in the genders of homo erectus, which would suggest that a harem type thing may have been going on there.

I'm not so sure about the pair bonding thing. Even in our own species we're pretty variable in this. Many cultures practice male harem/many wives type arrangements, yet we're considered pair bonding types? I think ones culture informs that theory as much as anything. If a Maasai scientist was asked he may well see the many wives theory as being more valid.

It is an interesting find though that pushes a form of bipedalism much further back. Jusging by the foot anatomy, it does look like an intermediate form too. A "missing link" for bipedalism.

Wibbs

The funny thing about bipedalism is we're the only ones now who do it it(feck off if you mention birds:D) among the apes. It seems to have been an advantageous adaptation and at one point there were many species, seven or more IIRC so far discovered that were out at the same time who were upright walkers of a hominid form. This is pretty much the first time in bipedal and hominid history that there is only one hominid on the planet. Go back 150,000 years and there were three we know of. If the "hobbit" and associated legends are to be believed up to 12000 years ago there was another and the locals say that they even may have lasted until historical times.

I have to say though for all my skeptical take on the interpretation of the finds, this is a monumental discovery in our human ancestry. It's such a pity that it seems to be only a small area in Africa where we can get this stuff. Where elsewhere is more written of our past? That said it's amazing that we even have that, so few are the remains of hominids from any era. From homo habilis on we have places where you damn near have to search for ordinary rocks among the tools of that hominid, yet of them we have so so little and even the association with their tools is a pretty loose one. Turkana boy http://upload.wikimedia.org/wikipedia/commons/2/2d/Turkana_Boy.jpg is probably the most complete skeleton of an early hominid(erectus). He's pretty much more complete than any neandertal skeleton we have. Bloody magnificent looking bugger he is too.

*start of wistful and wishful thinking*....All the talk over the years of "bigfoot" "wildmen" and the "yeti" (even trolls in europe) may be a race memory of the idea of the other bipedal creatures. Interestingly the idea or legends of wildmen do not show up in isolated islands. So no legends in hawaii or new zealand etc. Marco polo said he saw a captured one on his travels. Not a great witness you say, but he was pretty accurate in his zoological descriptions(amazing for his time actually) and he saw the primitive prizewalskis horse long before it was described or accepted by western science. It always fascinated me the idea that maybe, just maybe there may be some still left. Before I get moved to the paranormal forum:D No less an authority than Dr Jane Goodall is also fascinated by some of the reports of wildmen and behaviour reported and has spoken of her interest more than once

Only recently there was an expedition to Sumatra looking for the Orang Pendek. http://www.extreme-expeditions.com/journal/journal.php?id=6139626791866939117 Personally for me the most promising as some good witnesses have reported seeing it. Including an eminent Orang utan field researcher. It's reported not to have feet like a human either more like Ardi. Another detail that intrigues. Nor is it 10foot tall either. God luv me but here's a pic of the footprint. I know I know I'm going to be banned it's from the Sun *hangs head in shame* http://www.thesun.co.uk/sol/homepage/news/weird/2661919/Jungle-ape-man-spotted-by-Brits.html

Its only in the early part of the 20th century that the mountain gorilla was finally taken out of the realms of legend and the "Lion killer" chimps of the Congo have only been very recently described this century and little is still known of them. They're much bigger than normal chimps and have saggital crests.

Oh to see an Ardi type creature in the flesh. One helluva rush and strange feeling, so I for one have a little hope that they're not just a race memory and somewhere tonight in some remote place something bipedal may still walk. *end wishful and wistful rant*:o:)

Galvasean

Interesingly, it appears that Ardipithecus lived in the woods, as opposed to open savanah as had been assumed.

'On the west we find lots of Ardipithecus fossils and they're associated with a lot of woodland and forest animals,' he said. 'And then there's a break; Ardipithecus and most of the monkeys that live in trees disappear, and grass-eating animals become more abundant.'

The carbon isotope ratios of the Ardipithecus teeth also tell the story of a woodland creature, he said.

'The diet of the Ardipithecus is much more on the woodland and forest side,' he said. 'It's got a little bit more of the grassland ecosystem carbon in its diet than that of a chimpanzee but much less than its fully bipedal savanna-dwelling descendents, the australopithecines.'

This evidence, along with the anatomical studies indicating that Ardipithecus could walk upright but also grasped tree limbs with its feet, suggests that this early hominid took its first steps on two legs in the forest long before it ventured very far into the open grassland, Ambrose said

Full article here:
http://www.sciencecentric.com/news/article.php?q=09100940-early-hominid-first-walked-on-2-legs-the-woods

JuliusCaesar

Thanks for the article links. Fascinating. Of course this isn't the only field in which speculation is rife - archaeology too....and maybe the behavioural sciences
I'm very temped to link this thread with the monogamy discussion on After Hours, where there are amazing 'facts' being propounded about the natural/primitive/historical state of humans, backed up by reference to chimps and bonobos....and very dodgy notions of world history....But that's a different topic altogether!
If only we could Time Travel!

marco_polo

Wibbs wrote: »

Marco polo said he saw a captured one on his travels. Not a great witness you say, but he was pretty accurate in his zoological descriptions(amazing for his time actually) and he saw the primitive prizewalskis horse long before it was described or accepted by western science.

Damned with faint praise

Just watched the documentary there interesting stuff indeed, it certainly throws most of the previous assumptions of the last common ancestor out the window. What was also very encouraging was the number of African scientists involved in the project, which bodes well for the prospects of making other important discoveries on the Continent in the future.

Scarinae

I got this from the New Scientist website:

The discovery of an early human fossil in southern China may challenge the commonly held idea that modern humans originated out of Africa.

Jin Changzhu and colleagues of the Institute of Vertebrate Palaeontology and Palaeoanthropology in Beijing, announced to Chinese media last week that they have uncovered a 110,000-year-old putative Homo sapiens jawbone from a cave in southern China's Guangxi province.

The mandible has a protruding chin like that of Homo sapiens, but the thickness of the jaw is indicative of more primitive hominins, suggesting that the fossil could derive from interbreeding.

If confirmed, the finding would lend support to the "multiregional hypothesis". This says that modern humans descend from Homo sapiens coming out of Africa who then interbred with more primitive humans on other continents. In contrast, the prevailing "out of Africa" hypothesis holds that modern humans are the direct descendants of people who spread out of Africa to other continents around 100,000 years ago.

The study will appear in Chinese Science Bulletin later this month.

Out of China?
"[This paper] acts to reject the theory that modern humans are of uniquely African origin and supports the notion that emerging African populations mixed with natives they encountered," says Milford Wolpoff, a proponent of the multiregional hypothesis at the University of Michigan.

Others disagreed. Erik Trinkaus, an anthropologist at Washington University in St Louis, Missouri, questioned whether the find was a true Homo sapiens.

"You need to keep in mind that 'Homo sapiens' for most Chinese scholars is not limited to anatomically modern humans," he says. "For many of them, it is all 'post Homo erectus,' humans."

Chris Stringer of London's Natural History Museum said that it was too early to make far-reaching conclusions. "From the parts preserved, this fossil could just as likely be related to preceding archaic humans, or even to the Neanderthals, who at times seem to have extended their range towards China."

The present analysis of the mandible focused almost exclusively on determining the fossil's age. The researchers said a follow-up study would give a more complete treatment on what exactly the find represents.

There is also a picture of the 110,000-year-old jawbone, which Chinese scientists are saying is from a Homo sapiens:

Galvasean

Interesting that it should be unveiled so soon after the African Algeripithecus was proven not to be part of the human ancestry.

PS: In before Wibbs says "I told ya so"

Wibbs

Just in the door, but I told you so :D

Yitzhak Rabin

"You need to keep in mind that 'Homo sapiens' for most Chinese scholars is not limited to anatomically modern humans," he says. "For many of them, it is all 'post Homo erectus,' humans."

Forgive me if this is obvious to everyone else, I'm an absolute amateur.

What is a post-erectus human? Is this what people refer to when they are speaking of Heidlbergesensis(sp?) and Cro-Magnon? Were the Homo eretus' in Asia/Europe evolving on similar lines to those in Africa (i.e in a Homo Saipien Direction?)

Also if as this study concludes that Modern Homo Saipiens are a result of inter-breeding between Homo Sapiens from Africa and more primitive Hominids from Europe/Asia, then why are people who have never left Africa, such as the San, practically identical to other humans?

I'm sure all I've said is rife with mistakes in classification, spelling and understanding, but if anyone knows what I'm trying to say could they answer?

marco_polo

yekahs wrote: »

Forgive me if this is obvious to everyone else, I'm an absolute amateur.

What is a post-erectus human? Is this what people refer to when they are speaking of Heidlbergesensis(sp?) and Cro-Magnon? Were the Homo eretus' in Asia/Europe evolving on similar lines to those in Africa (i.e in a Homo Saipien Direction?)

Also if as this study concludes that Modern Homo Saipiens are a result of inter-breeding between Homo Sapiens from Africa and more primitive Hominids from Europe/Asia, then why are people who have never left Africa, such as the San, practically identical to other humans?

I'm sure all I've said is rife with mistakes in classification, spelling and understanding, but if anyone knows what I'm trying to say could they answer?

Not sure if this tree is the latest classification, but it should be relatively close.



As for the homo sapiens terminology it can be a little confusing, for example some scholars would classify the species Homo Sapiens as having two subspecies Homo Sapiens Neanderthalensis (Neanderthals) and Homo Sapiens Sapiens (Modern humans) others would clasify Homo Sapiens and Homo Neanderthalensis as distinct species. I don't even know which one to use

A relatively unbiased bite-sized introductory page to the competing theories can be found here: http://anthropology.si.edu/HumanOrigins/faq/Encarta/diversity.htm

Galvasean

marco_polo wrote: »

Not sure if this tree is the latest classification, but it should be relatively close.

Looks pretty up to date to me, considering it has Ardipithecus in it. I also like how Homo floresiensis is seperated from the branch since it's place as a seperate species is heavily disputed.

marco_polo

Galvasean wrote: »

Looks pretty up to date to me, considering it has Ardipithecus in it. I also like how Homo floresiensis is seperated from the branch since it's place as a seperate species is heavily disputed.

Didn't notice that , it would have answered my question nicely.

Wibbs

yekahs wrote: »

What is a post-erectus human? Is this what people refer to when they are speaking of Heidlbergesensis(sp?) and Cro-Magnon? Were the Homo eretus' in Asia/Europe evolving on similar lines to those in Africa (i.e in a Homo Saipien Direction?)

Bloody good questions. At the moment it seems the consensus(very vaguely described by mise) is that erectus spread out across the world. Evolved little enough locally(except maybe in europe and flores) but continued to evolve in africa. This erectus became "us" as such and we then went out from africa and replaced all previous relict hominids(erectus/neandertal) without much if any interbreeding and they've left no genetic legacy to us. A theory I personally have so many issues with.

Also if as this study concludes that Modern Homo Saipiens are a result of inter-breeding between Homo Sapiens from Africa and more primitive Hominids from Europe/Asia, then why are people who have never left Africa, such as the San, practically identical to other humans?

Could be any number of reasons. Genes don't just flow out, they can flow back too. Plus the San say would be different in many genetic markers to say an Icelander or a Japanese. Obviously there are outward differences. As you know yourself many of those are a phenotype thing, rather than a genotype. That said there are differences. Red hair and pale skin is a classic one. Found in europe and very rare elsewhere. Red hair and pale skin is also found in neandertals. the modern range of both those features damn near perfectly overlaps the ancient range of the Neandertals. Now local conditions will very often make local adaptations across different species, but it seems too much like a coincidence to me anyway.

Other bone diffs show up too. There are features in relict erectus populations that are found in moderns in the same areas today, but not found in relict populations and moderns elsewhere. AFAIR the knee and the angles of the jaw are two. So a modern Chinese population will have the same feature as the relict one, but that feature is absent in The African or European, relict and modern where something of their own continuity exists.

Now I'm not saying that we don't come from Africa, nor am I saying current populations evolved entirely from local relict hominids. It's not an either or IMHO. Its more complex than that. I would say we did interbreed back and forth with previous humans, but the bulk of our genes is african sapiens. Its just that of the genome examined there isn't obvious evidence yet of their contribution. That's easily enough explained by the example I gave in another thread.

Ok lets look at some of the genetic evidence. Lets look at what marco_polo mentioned about the story of who survived. OK I'm of european stock. Lets say I marry an african lassie and we have two sons. One of them marries a japanese woman and the other marries a south american woman from the high andes. If we look at their kids mitichondrian DNA it'll show that they're either Japanese or Andean indian. No trace of African or European. If you look at their Y chromosome DNA they'll look like Europeans. In both cases No trace of African DNA at all, yet they would share the genetic heritage of the oldest people on the planet. That's just over 3 generations, yet we're supposed to believe that over 100's of 1000's generations we're not missing out some huge chunks of what is going on? I dont buy it.

The second problem is that even if you take the genetic clocks as a good indicator, there are some issues there too. Among the various human groups on the planet today there are specific genes that are older than this supposed single migration 100,000 odd years ago. There are markers exclusive to Asians and Europeans and Africans that are older than 120,000 years. Older than 200,000 years. That makes no sense if it's a purely out of africa migration 100,000 yrs ago.

Now this is of course my personal madness take on it. It's obviously riddled with conjecture. My opinion is that much of the current theory is just as riddled with conjecture. The lines have been drawn and the current science is "gospel", or at least opposing theories are not as examined or researched as they could or should be. That goes both ways too. Ask an Chinese scientist about pure out of africa and he or she will likely poo poo it with as much vigour as an African scientist would poo poo theirs.

I go with Buddha on this stuff, take the middle path as that's where more "truth" is likely to be found.

marco_polo

Report of a large a mDNA study from Asia.

http://www.scientificamerican.com/article.cfm?id=asia-populated-in-one-migrator


/Hides from Wibbs

Wibbs

Yea but again it's mDNA they're pinning this on. That ignores the Y chromosome stuff entirely. The resolution is too small and too much is being pinned on genetic clocks etc. I still don't buy it. There are huge chunks missing. They even say this themselves where populations that are seemingly distinct dont appear to be on the mDNA to the degree expected.

darjeeling

Wibbs wrote: »

Yea but again it's mDNA they're pinning this on. That ignores the Y chromosome stuff entirely. The resolution is too small and too much is being pinned on genetic clocks etc. I still don't buy it. There are huge chunks missing. They even say this themselves where populations that are seemingly distinct dont appear to be on the mDNA to the degree expected.

This latest study is based on 55,000 single nucleotide positions (SNPs) in the nuclear genome, not on mtDNA.

marco_polo

darjeeling wrote: »

This latest study is based on 55,000 single nucleotide positions (SNPs) in the nuclear genome, not on mtDNA.

That would be my bad, forcive habit to write mDNA

darjeeling

marco_polo wrote: »

That would be my bad, forcive habit to write mDNA

Ah. And I should have written 'single nucleotide polymorphisms'.

I must have a read of the full article later on.

darjeeling

It's another mighty paper (here) - a hundred authors and reams of data, most of it in the supplement (here, for those with access).

The project analysed over 1,700 new human samples from Asia, representing around 70 populations, adding them to existing European and African samples. The scientists looked at 55,000 individual polymorphic base positions - SNPs - throughout the autosomal genome (some analysis is based on a sub-set of 20,000 SNPs, allowing extra populations to be added).

The overall picture shows all modern East and South-East Asian populations sharing relatively recent common ancestry. The divergence of these Asian populations from European populations occurred earlier, and the divergence of European and Asian from African populations earlier still.

Genetic diversity decreases linearly the further North you go sampling in Asia, consistent with people arriving first in the south and later spreading further north.

The different models of the peopling of Asia that the paper compares are all based on modern populations having common ancestry around 5,000 generations ago. They differ in whether there were one or two waves of migration into Asia during this time. Under one scenario, some modern Asian populations might have diverged the full 5,000 generations in the past. However, the scenario that better fits the data has Asian populations diverging less than 2,000 generations ago within Asia.

That's only the headline points - there's a huge amount more in the supplement.

Galvasean

Lists seem to be all the rage these days. The Huffington post included Ardi in it's top ten animals of the decade:
http://www.huffingtonpost.com/frans-de-waal/the-animal-noble-prizes-o_b_400977.html

Ardi, also known as Ardipithecus ramides. It is a bit embarassing to include this 4.4 million old human ancestor in a list of animals, but since Ardi had a chimp-size brain and grasping big toes, she was definitely not human, which makes her an animal. Given her reduced canine teeth, it is assumed she was relatively peaceful, perhaps more like bonobos than chimpanzees. We assume that she was smart, but it has proven hard to test her. No videos of Ardi!

Galvasean

Some doubts as to whether Ardi was all that closely related to humans or even lived in woodlands have emerged:
http://news.yahoo.com/s/ap/20100527/ap_on_sc/us_sci_human_ancestor

Adam Khor

http://www.dailymail.co.uk/sciencetech/article-2062514/Revealed-The-face-missing-link-ape-man.html



Ye

dlofnep

Some sweet sideburns. Thanks for the post!

Galvasean

Wasn't expecting it to look quite so human.

Rubecula

Nice friendly smile, just before it rips your arms off?

Actually looks like someone famous, just can't think who.

Galvasean

Adam Khor

He named Homo habilis and Paranthropus boiseii


http://www.google.com/hostednews/afp/article/ALeqM5h-b1QZ1K6OgRsVjXELQpd2vIWGZg?docId=CNG.2617a5813d3cd45e9f090ff4722280ef.181

Galvasean

Nominated for 3 Nobel prizes. Quite the life he led.

Adam Khor

A study Australopithecus sediba's teeth reveals that if dined on bark and bushes, among other things.

http://www.science20.com/news_articles/trees_australopithecus_sediba_had_caveman_diet_you_want_no_part-91543



What caught my eye is that, according to a scientist, its diet would be "similar to that of today's savannah chimpanzees", which makes me wonder whether these apes too hunted and ate other animals once in a while (not small animals and insects, but larger game, the same way savannah chimps are known to kill and eat baboons, for example).

Wibbs

Wouldn't surprise me if they did AK. There are suggestions that even gorillas, a very herbivorous ape also eats meat on occasion. Orangs will do it too when fruit is scarce.

Capt'n Midnight

Many herbivores will take meat to supplement their diet if presented with the opportunity.

https://www.youtube.com/watch?v=Gp-0BtK1zIk

Adam Khor

Wibbs wrote: »

Wouldn't surprise me if they did AK. There are suggestions that even gorillas, a very herbivorous ape also eats meat on occasion. Orangs will do it too when fruit is scarce.

I wouldn´t be surprised if gorillas ate meat too. I already knew about the orangs. :>

Weird fact about slow lorises (the primates eaten by the orangs in the article you linked to)- they are poisonous. They produce a toxic substance from glands in their elbows, and then they lick their elbows (try doing that, I dare you XD) and then spread the poison with their tongue all over their fur which keeps both predators and parasites away.
Of course, since they get poison in their mouth they also get automatically a venomous bite. I think African pottos too have a slightly toxic bite.

I wonder if orangutans are immune to this poison, or if the ingested toxin has a weaker effect than if it was injected through the loris bite- which has been known to cause fatal allergic reactions to humans if I remember clearly.

Adam Khor

http://www.sciencedaily.com/releases/2012/07/120712162744.htm

Mickeroo

another article on what I think is the same find. Claiming this is the most complete pre-human skeleton ever?

http://www.firstpost.com/fwire/most-complete-pre-human-skeleton-discovered-scientists-377732.html

Wibbs

Just on the pic alone it looks very complete, rapidly buried and fossilised where it died and luckily encased in a harder rock than usual keeping it together. Most hominid remains are very spread out or have rotted/broken up before burial or where dispersed after burial due to erosion processes.

Galvasean

I would have imagined its sheer cuteness would deter most predators from eating the slow loris...

Adam Khor

Galvasean wrote: »

I would have imagined its sheer cuteness would deter most predators from eating the slow loris...

Chimps eat these, so...

steddyeddy

Adam Khor wrote: »

I wouldn´t be surprised if gorillas ate meat too. I already knew about the orangs. :>

Weird fact about slow lorises (the primates eaten by the orangs in the article you linked to)- they are poisonous. They produce a toxic substance from glands in their elbows, and then they lick their elbows (try doing that, I dare you XD) and then spread the poison with their tongue all over their fur which keeps both predators and parasites away.
Of course, since they get poison in their mouth they also get automatically a venomous bite. I think African pottos too have a slightly toxic bite.

I wonder if orangutans are immune to this poison, or if the ingested toxin has a weaker effect than if it was injected through the loris bite- which has been known to cause fatal allergic reactions to humans if I remember clearly.

Western gorillas do eat termites. I think the addition of meat to a diet opens it up to new enviromental niches and possibly increases its range.

Adam Khor

Seems they ate even more of it than baboons do.

http://www.sciencedaily.com/releases/2012/12/121214200916.htm

I'm guessing this didn´t happen often:

Black Swan

I seem to recall reading an old book sometime ago at university, I think it was by Henry G. Bieler, MD, called Food Is Your Best Medicine (probably out of print now), wherein he did research on the composition of human teeth, claiming that about 10 percent had evolved for meat eating, the remaining 90 percent for other non-meat foods. He then prescribed a diet based upon this observation. He mentioned nothing about "grass" eating, but it may fall into the 90 percent function.

Adam Khor

Black Swan wrote: »

I seem to recall reading an old book sometime ago at university, I think it was by Henry G. Bieler, MD, called Food Is Your Best Medicine (probably out of print now), wherein he did research on the composition of human teeth, claiming that about 10 percent had evolved for meat eating, the remaining 90 percent for other non-meat foods. He then prescribed a diet based upon this observation. He mentioned nothing about "grass" eating, but it may fall into the 90 percent function.

I am currently under the impression that grass is high in silica which makes it very abrasive, definitely not good for your teeth :pac:



Plus, dogs pee on it.

We can't digest grass.

steddyeddy

Our ancestors must have produced a lot of cellulase in order to digest grass.

Ziphius

I wonder if the palaeodiet devotees in the diet and nutrition forum would be interested in this

Wibbs

Judging by the shapes of their torsos which are big bellied compared to our more V shape and they had enough of a gut to break down plant material alright. Teeth wise they tended to be bigger and flatter for crushing plant material.

When we get to Erectus the picture changes. Their teeth have been tested and have been found to be much better at processing meat. Their bodies became the modern template too. Commanding fire and making tools externalised a lot of the digestive tract too. Chew a raw potato and you've your work cut out, cook it and it's lovely and soft. Ditto for meat in general. Slicing tasks were taken over by tool use.

Our bodies seem to reflect these changes. Our guts got shorter and our teeth generally get smaller the more recent the human. Even in modern humans our teeth have reduced in size even over the last 20,000 years. Modern native Aussies would have about the biggest teeth overall, followed by Europeans. Funny enough we have very thick enamel considering our jaw size and bigger tooth roots. Thicker than chimps for example. Usually found in animals with high bite strengths. IIRC I read a study which found we've apparently the most efficient bite of any great ape hence we need the robust teeth.

Rubecula

We eat bread which is made from grass (wheat)