Apparently there are different reasons neanderthals encephalized than did homo sapiens.

[melo13]

I may be incorrectly extracting information from this analysis but, according to the study:

" in our more refined analysis, there was no relationship between periods of accelerated change (i.e. large brain residuals) and increased climate variability over 100 ky time-blocks, contrary to what would be expected from Potts' variability selection hypothesis. Nor is there consistent evidence at the super-species level to support either the variability selection or the aridity hypotheses using sea-level indicators . Furthermore, when we use aeolian dust records, which provide a continental indicator for both aridity and variability, we do not find consistent evidence to support either hypothesis . There were no significant models incorporating more than one climate record for any of the taxonomic levels. The main weakness with the palaeoclimate records used in these analyses is that they are unable to explain the large step changes in brain size that have periodically occurred throughout hominin evolution. The most marked and unexplained increase is contemporary with the appearance of H. erectus (or H. ergaster) in Africa. The global sea-level palaeoclimate records have some predictive power for within species change over all hominins and within H. erectus. As we have better resolution in the data from Eurasia, this suggests that sea-level changes are likely to reflect environmental processes at higher latitudes, but they are unable to explain the environmental processes operating within Africa."

 

So if i am reading this correctly does that mean homo sapiens did NOT get as intelligent as they are through climatic variability? So the study suggests neanderthal encephalization was caused by climatic variability While homo sapiens were not. Is this how you perceived this information as well? I am slightly confused, what could have caused our encephalization if not the variability in climate? A demanding social environment? Do you think the differences in causes of encephalization may have caused different "kinds" of thinking between neanderthals and homo spaiens?

 

http://rstb.royalsocietypublishing.org/content/367/1599/2130#sec-18

Edited June 25, 2015 by melo13

[StringJunky]

...I I am slightly confused, what could have caused our encephalization if not the variability in climate? A demanding social environment? Do you think the differences in causes of encephalization may have caused different "kinds" of thinking between neanderthals and homo spaiens?

 

http://rstb.royalsocietypublishing.org/content/367/1599/2130#sec-18

I think the onset of cooking food may have been an important precursor to hominid encephalisation. This activity increases the availability of nutrients and in amounts not available before. With increased caloric intake for less effort, hominids had time for other things besides looking for food which, ultimately, facilitated the reproductive persistence of individuals that were more brains than brawn... putting it simply.

 

Worth reading the article this extract is from:

 

 

The researchers propose that the addition of neurons in large primates comes with a fixed cost of 6 kCal per billion neurons5 per day. Using this cost, additional data regarding extant primate feeding habits, and estimated nutritional information, they calculate that members of the Homo species, in supporting enlarged brains, would consistently require nine hours of feeding per day4.

 

How, then, did human ancestors overcome the metabolic restrictions on brain growth without resorting to increased feeding times? According to Harvard anthropologist Dr. Richard Wrangham, they invented cooking6. Cooking increases the caloric yield of foods by facilitating chewing, digestion, and absorption4. This hypothesis is supported by the recent research by Dr. Herculano-Houzel and her colleague and suggests that the invention of cooking was a prerequisite to encephalization.

 

http://greymattersjournal.com/on-hominid-intelligence/

Edited June 25, 2015 by StringJunky

[melo13]

I think the onset of cooking food may have been an important precursor to hominid encephalisation. This activity increases the availability of nutrients and in amounts not available before. With increased caloric intake for less effort, hominids had time for other things besides looking for food which, ultimately, facilitated the reproductive persistence of individuals that were more brains than brawn... putting it simply.

 

Worth reading the article this extract is from:

 

 

I thank you for the link, I'll have to read it sometime. While I am sure that cooking had a lot to do with the encephalization of early hominids, I feel as though it can easily turn into a "which came first? chicken or the egg" question. Now it is pretty easy to assume that the first ingestion of cooked food was more than likely an accident, but as far as im aware cooking was first "invented" near 800,000 years ago and there are still 2 million years of encephalization to account for, which is possibly explainable by circuit redundancy in the brain. its possible that heat from the sun kills of brain cells that our brain simply just keep growing to keep up with the constant loss of neurons. There is also the heat stress hypothesis http://arxiv.org/ftp/arxiv/papers/1312/1312.5403.pdfbut anyway, i am starting to digress. The main thing I wan't to know is why neanderthals encephalized differently than us and if that effected their brains a different way than ours? If the climatic variability caused neanderthal encephalization and lets say cooking or the social hypothesis is what caused homo sapiens to encephalize do you believe that would have had and impact on why neanderthals are not here anymore? Would the neanderthals grew a more mathematical like intelligence while homo sapien stayed social and developed language?