こんな能力が有ったら、人間社会も今とは大分違ったものに成ってたんだろうなぁ。 0126世界@名無史さん2016/12/21(水) 18:26:15.240 妄想乙 0127世界@名無史さん2016/12/21(水) 18:34:08.850 人間以外には利他的をとる動物はいないことがほぼ判明。 Chimpanzees may be helpful, but humans are the only primates that are kind to others, study suggests・・・ http://www.latimes.com/science/sciencenow/la-sci-sn-kindness-chimpanzees-humans-20161220-story.html0128世界@名無史さん2016/12/24(土) 12:11:14.730 難産は人間のメスにしか見られないが、その理由は、直立歩行と赤ん坊の脳が大きい所に あると考えられてきた。でもそうではない、いや、少なくともそれだけでは説明しきれない、 として、他の説が出てきている。
Human childbirth suddenly became more difficult about 10,000 years ago There is one striking feature archaeologists have noticed when comparing the skeletons of early farmers with their hunter-gatherer ancestors. The farmers were noticeably shorter in stature, probably because their carbohydrate-rich diet was not particularly nutritious compared to the protein-rich hunter-gatherer diet.・・・ In general, the shorter a woman, the narrower her hips. In other words, the shift to farming almost certainly made childbirth a little bit more challenging. On top of that, the carbohydrate-rich diets that became more common with farming can cause a developing foetus to grow larger and fatter. That makes the baby harder to deliver. Combine these two factors and human childbirth -- which might have been relatively easy for millions of years -- suddenly became more difficult about 10,000 years ago.・・・ http://www.bbc.com/earth/story/20161221-the-real-reasons-why-childbirth-is-so-painful-and-dangerous
農業革命は、ヒトを利己主義化しただけじゃなく、難産までもたらしたんだね。 改めて、釈迦が「生・老・病・死」を苦と捉えたスゴさを思う。 0129世界@名無史さん2016/12/24(土) 16:42:02.720 はやくヒトのメスをもっと安産型に進化させろ! 下半身がムッチムチの熟女で上半身はロリみたくスラっとしてるのがいいんだ 頭でっかちは絶滅しろ、脳味噌もこれからはむやみに巨大化させず効率化の時代だ! 0130世界@名無史さん2016/12/24(土) 22:19:58.600 そういえば第二次性徴の発現の時期も、現生人類になってからでも大きく変わってるんだろうか 現代は栄養状態が良くて早熟だというけど、それでも安全に出産できるのは早くて16歳以上 初潮が今より遅ければ、安全な初産年齢も遅くなる 大昔の平均寿命が20代なんて時代だと、短い平均寿命はあくまで幼児死亡率の高さの反映が多いにしても、老化もそれなりに早かったんでは 生涯に3人も産めれば御の字で、それも無事に育たない確率も高い よく生き残れたな。 それかクロマニヨン人とかホモサピエンス・イダルトゥは今の人類とは別種レベルに生・老・病・死のサイクルが短かったのか? そういえばこんな映画があったな https://ja.wikipedia.org/wiki/%E3%82%B8%E3%83%A3%E3%83%83%E3%82%AF_(%E6%98%A0%E7%94%BB) 0131世界@名無史さん2016/12/24(土) 22:22:45.490 Wikipediaの記事へのリンクが張れなかったのでこっち http://eiga-kaisetu-hyouron.seesaa.net/article/127829922.html http://blog.livedoor.jp/chw_xgs/archives/2473767.html0132世界@名無史さん2016/12/30(金) 22:16:43.460 パートナーの浮気への嫉妬心について論じたコラム。 ・・・marrying for love and expecting sexual fidelity for life is a fairly modern concept.・・・
一夫一婦制じゃない昔や現在の社会では、嫉妬心は少なくとも目には見えない。 In ancient China, she reports, sisters recruited one another as "back-up" wives for their husbands. In Botswana, co-wives work with rather than against one another and value each other as mutual benefactors. "Among Tibetan brothers who share the same wife,・・・sexual jealousy is rare." ・・・
・・・The similarities between humans and chimps are well known, but one important difference has to do with group size. Chimpanzees, on average, can maintain a group size of about 45, says Dunbar. “This appears to be the largest group size that can be maintained through grooming alone,” he says. In contrast, the average human group is about 150, known as Dunbar’s Number. The reason for this, says Dunbar, is that humans have the capacity to reach three times as many social contacts as chimps for a given amount of social effort. Human religion emerges out of this increased capacity for sociality.・・・
・・・supernovae?cataclysmic explosions of dying stars-showered the Earth with cosmic rays between around 8 million and 2.6 million years ago.
When this space radiation entered the lower atmosphere, it triggered a process known as ionization which may have produced a huge increase in cloud-to-ground lightning strikes. This in turn could have led to an uptick in forest fires around the world.
The authors of the study suggest that these fires could have been one factor in the development of bipedalism?a characteristic that may have allowed our ancestors to better adapt to the savannas that replaced the burnt forests of northeast Africa.・・・ https://www.newsweek.com/ancient-supernovae-wildfires-human-ancestors-upright-14374240195世界@名無史さん2019/05/30(木) 12:06:01.610 超新星爆発 ↓ ガンマ線直撃 ↓ 雲の増加 ↓ 寒冷化・氷河期 ↓ 大量絶滅
この本買って読み始めたのだが、冗長な文章にとにかくいらいらする 0198世界@名無史さん2019/07/11(木) 21:33:18.190 今回、ギリシャで発見された頭蓋骨片は、 「アフリカ以外で最古の人間の化石である」 ・・・ その主張が立証され、多くの科学者がさらに証拠を求めているとすれば、この発見は 人類の歴史の重要な章を書き換え、その頭蓋骨はヨーロッパで最古だと知られている ものよりも16万年以上も前のホモ・サピエンスの化石になるだろう。 Piece of skull found in Greece ‘is oldest human fossil outside Africa’・・・ If the claim is verified - and many scientists want more proof - the finding will rewrite a key chapter of the human story, with the skull becoming the oldest known Homo sapiens fossil in Europe by more than 160,000 years.・・・ https://www.theguardian.com/science/2019/jul/10/piece-of-skull-found-in-greece-is-oldest-human-fossil-outside-africa