It’s possible that humans cannot increase their own intelligence with the same efficiency as they do so with fully controlled animals. But it’s very unlikely for this value to be so low as to be displaced by the changes caused by climactic cycles.
Crows can use tools but human hand is much more effective in that and evolved to do it.
Okay, so you do know that tool usage does not require ‘the growth of universal hand and bipedality’. It’s quite a stretch from ‘greatly increased efficacy‘ to ‘requires’.
If one is serious about increasing the intelligence of mice, he will soon hit the limit: the size of the mice brain is too small. So he will breed for larger mice with larger heads. Then changes in pelvis bones, communication methods, hair and hand structure as well as bipedality have to follow. At the end he will get something very similar to human being. And all that changes will take rather long time.
Your conflating several different aspects of intelligence in the single word ‘intelligence’.
Just because certain features necessary to enable advanced tool usage takes many millions of years to evolve, if ever, this does not automatically imply that therefore only events occurring over longer duration cycles, such as climactic cycles, are the primary ones that matter for determining intelligence in humans.
There can be several hundred factors going into determining overall intelligence, even if you enumerated hundreds of them, this does not even disprove what mice studies have shown to a reasonable level of confidence.
To be entirely honest this seems like confused thinking, how could changes over millions of years credibly dismiss into insignificance factors that change four orders of magnitude quicker? Real world observations of human behaviour, genetics, epigenetics, anthropology, etc., all provide ample evidence that climatic cycles are not the primary driver of intelligence adaption since the last ice age.
Several people come independently to the idea that climate changes are needed for the evolution of intelligence. For example, besides Budyko, Waltham wrote:
Given this link between climate change and species diversity, it is plausible that planets with high climate variability may be less likely to produce intelligent observers than planets with more stable conditions. However, it is also arguable that the ultimate emergence of intelligent species is actually encouraged by adverse conditions because these help to clear ecological niches (cf. the adaptive radiation of mammals following demise of the dinosaurs) and because evolutionary innovations may be particularly advantageous during testing times [cf. the emergence of Homo sapiens during the relatively unstable Neogene … and the emergence of multicellular life around the time of the Neoproterozoic glaciation] (Waltham, 2011).
It looks like you argue that climate change can’t be the only factor contributing to the rise of human intelligence, and this is true. Many species didn’t evolve intelligence despite climate change.
What I argue is that the increase of universal ability to adaptation (that is intelligence) was an evolutionary path to just one species in the situation when specialization was less favorable as conditions was unstable.
Intelligence tends to appear only in a world that is close to its end.
The main reason for the emergence of intelligence near the end of the world is that intelligence is a general adaptation that outperforms specialized adaptations in a rapidly changing world, which in the case of Earth is a world with an unstable climate.
From your post. And in my first comment:
Increases in intelligence can not be primarily due to adaptations arising from changing climactic conditions as climactic conditions fluctuate on a much slower cycle, even in the most recent few million years, than changes in intelligence. Local environmental conditions can significantly affect measurable intelligence within a few generations, and if extreme enough, with just one generation.
And in my latest comment:
Just because certain features necessary to enable advanced tool usage takes many millions of years to evolve, if ever, this does not automatically imply that therefore only events occurring over longer duration cycles, such as climactic cycles, are the primary ones that matter for determining intelligence in humans.
There can be several hundred factors going into determining overall intelligence, even if you enumerated hundreds of them, this does not even disprove what mice studies have shown to a reasonable level of confidence.
If you instead wish to talk about:
What I argue is that the increase of universal ability to adaptation (that is intelligence) was an evolutionary path to just one species in the situation when specialization was less favorable as conditions was unstable.
That’s fine, the evolutionary path may lead to one species or multiple, I don’t have any opinion on that. I agree that specialization does seem less favourable when conditions are unstable, and so on.
My points were limited to the relative increase of intelligence in different timescales.
Probably the crux of our discussion is the speed of climate change. Is it changing on 3 millions years timescale, tens of thousands or hundreds? If it changes in millions of years then it seems that its effect on intelligence evolution is negligible and I thing it is what you mean.
However, the last few million years there were constant Ice ages, and the climate changed at least every 10 thousand years. Moreover, as Budyko wrote, the colder is climate, the less stable it is. We could see such short term instability 20-10 000 from now when event like Young Drias (sudden short cooling for around a thousand years) had happened.
So, given that human life span is much longer than the one of mice, climate change happened on the duration of 10-100 generations, and it could create enough selective pressure to increase universality—or to give success to the species which have such universality.
So, given that human life span is much longer than the one of mice, climate change happened on the duration of 10-100 generations,
Climate change has never happened in any duration of 10 human generations since the emergence of humans, even the Younger Dryas event like you mentioned was much longer than that, being easily 40 generations long. Excluding the last 200 years which are far too recent to have had significant effects on evolutionary development.
However, the last few million years there were constant Ice ages, and the climate changed at least every 10 thousand years.
The climate before the last glacial maximum has not ‘changed at least every 10 thousand years’, even the shortest interglacial periods are much longer than that.
Where are you getting these erroneous facts from?
Considering I’ve only spent, at most, an hour on all my comments so far, that I could find all these errors of fact and logic really lowers the credibility of your paper. You and your coauthors need to seriously reevaluate the arguments and clear up erroneous facts.
You need to look not on the duration of the YD, but on the time of the transition to YD. It was very quick. “The change was relatively sudden, taking place in decades, and it resulted in a decline of temperatures in Greenland by 4~10 °C (7.2~18 °F),[3] and advances of glaciers and drier conditions over much of the temperate Northern Hemisphere.”
Presumably you got this claim from the wikipedia article, if you actually read the paper cited this would have been revealed to be a misleading claim as the first figure prominently shows.
Fig. 1 shows some oscillations lasting a few decades in length but by the nature of oscillations they reverted back to the baseline within that time period. Actual lasting changes in the measured values primarily occurred in the period from roughly 14.7 ka BP to 12.8 ka BP.
In fact this interval is prominently highlighted by the paper authors via a different background color on the chart.
Since I am not your editor I will leave off here and let your editor correct any further mistakes.
It’s possible that humans cannot increase their own intelligence with the same efficiency as they do so with fully controlled animals. But it’s very unlikely for this value to be so low as to be displaced by the changes caused by climactic cycles.
Okay, so you do know that tool usage does not require ‘the growth of universal hand and bipedality’. It’s quite a stretch from ‘greatly increased efficacy‘ to ‘requires’.
If one is serious about increasing the intelligence of mice, he will soon hit the limit: the size of the mice brain is too small. So he will breed for larger mice with larger heads. Then changes in pelvis bones, communication methods, hair and hand structure as well as bipedality have to follow. At the end he will get something very similar to human being. And all that changes will take rather long time.
Your conflating several different aspects of intelligence in the single word ‘intelligence’.
Just because certain features necessary to enable advanced tool usage takes many millions of years to evolve, if ever, this does not automatically imply that therefore only events occurring over longer duration cycles, such as climactic cycles, are the primary ones that matter for determining intelligence in humans.
There can be several hundred factors going into determining overall intelligence, even if you enumerated hundreds of them, this does not even disprove what mice studies have shown to a reasonable level of confidence.
To be entirely honest this seems like confused thinking, how could changes over millions of years credibly dismiss into insignificance factors that change four orders of magnitude quicker? Real world observations of human behaviour, genetics, epigenetics, anthropology, etc., all provide ample evidence that climatic cycles are not the primary driver of intelligence adaption since the last ice age.
Several people come independently to the idea that climate changes are needed for the evolution of intelligence. For example, besides Budyko, Waltham wrote:
Will you address the several unaddressed points so far in prior comment?
It looks like you argue that climate change can’t be the only factor contributing to the rise of human intelligence, and this is true. Many species didn’t evolve intelligence despite climate change.
What I argue is that the increase of universal ability to adaptation (that is intelligence) was an evolutionary path to just one species in the situation when specialization was less favorable as conditions was unstable.
From your post. And in my first comment:
And in my latest comment:
If you instead wish to talk about:
That’s fine, the evolutionary path may lead to one species or multiple, I don’t have any opinion on that. I agree that specialization does seem less favourable when conditions are unstable, and so on.
My points were limited to the relative increase of intelligence in different timescales.
Probably the crux of our discussion is the speed of climate change. Is it changing on 3 millions years timescale, tens of thousands or hundreds? If it changes in millions of years then it seems that its effect on intelligence evolution is negligible and I thing it is what you mean.
However, the last few million years there were constant Ice ages, and the climate changed at least every 10 thousand years. Moreover, as Budyko wrote, the colder is climate, the less stable it is. We could see such short term instability 20-10 000 from now when event like Young Drias (sudden short cooling for around a thousand years) had happened.
So, given that human life span is much longer than the one of mice, climate change happened on the duration of 10-100 generations, and it could create enough selective pressure to increase universality—or to give success to the species which have such universality.
Climate change has never happened in any duration of 10 human generations since the emergence of humans, even the Younger Dryas event like you mentioned was much longer than that, being easily 40 generations long. Excluding the last 200 years which are far too recent to have had significant effects on evolutionary development.
The climate before the last glacial maximum has not ‘changed at least every 10 thousand years’, even the shortest interglacial periods are much longer than that.
Where are you getting these erroneous facts from?
Considering I’ve only spent, at most, an hour on all my comments so far, that I could find all these errors of fact and logic really lowers the credibility of your paper. You and your coauthors need to seriously reevaluate the arguments and clear up erroneous facts.
You need to look not on the duration of the YD, but on the time of the transition to YD. It was very quick. “The change was relatively sudden, taking place in decades, and it resulted in a decline of temperatures in Greenland by 4~10 °C (7.2~18 °F),[3] and advances of glaciers and drier conditions over much of the temperate Northern Hemisphere.”
Presumably you got this claim from the wikipedia article, if you actually read the paper cited this would have been revealed to be a misleading claim as the first figure prominently shows.
See https://escholarship.org/uc/item/6n89h7c3#metrics
Fig. 1 shows some oscillations lasting a few decades in length but by the nature of oscillations they reverted back to the baseline within that time period. Actual lasting changes in the measured values primarily occurred in the period from roughly 14.7 ka BP to 12.8 ka BP.
In fact this interval is prominently highlighted by the paper authors via a different background color on the chart.
Since I am not your editor I will leave off here and let your editor correct any further mistakes.