{"id":277107,"date":"2023-09-03T21:51:04","date_gmt":"2023-09-03T19:51:04","guid":{"rendered":"https:\/\/climatescience.press\/?p=277107"},"modified":"2023-09-03T21:51:18","modified_gmt":"2023-09-03T19:51:18","slug":"when-climate-change-really-was-an-existential-threat","status":"publish","type":"post","link":"https:\/\/climatescience.press\/?p=277107","title":{"rendered":"When Climate Change Really Was an Existential Threat"},"content":{"rendered":"\n
\"\"<\/figure>\n\n\n\n

<\/p>\n\n\n\n

From Watts Up With That?<\/a><\/p>\n\n\n\n

\"\"<\/figure>\n\n\n\n

Guest \u201cCould have used the Extinction Rebellion back then!\u201d by David Middleton,<\/p>\n\n\n\n

\n

AUGUST 31, 2023<\/p>\n\n\n\n

Early ancestral bottleneck could\u2019ve spelled the end for modern humans<\/h3>\n\n\n\n

by\u00a0Chinese Academy of Sciences<\/a><\/p>\n\n\n\n

How a new method of inferring ancient population size revealed a severe bottleneck in the human population which almost wiped out the chance for humanity as we know it today.<\/em><\/p>\n\n\n\n

An unexplained gap in the African\/Eurasian fossil record may now be explained thanks to a team of researchers from China, Italy and the United States.<\/p>\n\n\n\n

[\u2026]<\/p>\n\n\n\n

These findings indicate that early human ancestors went through a prolonged, severe bottleneck in which approximately 1,280 breeding individuals were able to sustain a population for about 117,000 years. While this research has illuminated some aspects of early to middle Pleistocene ancestors, there are many more questions to be answered since uncovering this information.<\/p>\n\n\n\n

[\u2026]<\/p>\n\n\n\n

Reasons suggested for this downturn in human ancestral population are mostly climatic: glaciation events around this time lead to changes in temperatures, severe droughts<\/a>, and loss of other species, potentially used as food sources for ancestral humans.<\/p>\n<\/blockquote>\n\n\n\n

\"\"
The African hominin fossil gap and the estimated time period of chromosome fusion is shown on the right. Credit:\u00a0Science\u00a0(2023). DOI: 10.1126\/science.abq7487<\/em><\/figcaption><\/figure>\n\n\n\n
\n

An estimated 65.85% of current genetic diversity may have been lost due to this bottleneck in the early to middle Pleistocene era, and the prolonged period of minimal numbers of breeding individuals threatened humanity as we know it today.<\/p>\n\n\n\n

[\u2026]<\/p>\n\n\n\n

More information:<\/strong> Wangjie Hu et al, Genomic inference of a severe human bottleneck during the Early to Middle Pleistocene transition, Science<\/em> (2023). DOI: 10.1126\/science.abq7487<\/a>. www.science.org\/doi\/10.1126\/science.abq7487<\/a><\/p>\n\n\n\n

Nick Ashton et al, Did our ancestors nearly die out?, Science<\/em> (2023). DOI: 10.1126\/science.adj9484 , www.science.org\/doi\/10.1126\/science.adj9484<\/a><\/p>\n\n\n\n

Journal information:<\/strong> Science<\/a> Phys.Org<\/a><\/p>\n<\/blockquote>\n\n\n\n

What was going on from 1,000-800 ka that may have nearly wiped out our ancestors? Temperatures plunged, glaciers and ice sheets started expanding, sea levels fell & began oscillating with <\/p>\n\n\n\n

and atmospheric CO2<\/sub>\u00a0dropped to its lowest level in 400 million years.<\/p>\n\n\n\n

\"\"
Pliocene-Pleistocene Sea Level and CO2<\/sub>\u00a0(Miller et al., 2020<\/a>)<\/figcaption><\/figure>\n\n\n\n

Reference<\/h3>\n\n\n\n

Kenneth G. Miller et al. ,Cenozoic sea-level and cryospheric evolution from deep-sea geochemical and continental margin records.Sci. Adv.<\/em>6<\/strong>,eaaz1346(2020).DOI:10.1126\/sciadv.aaz1346<\/a><\/p>\n\n\n\n

<\/p>\n","protected":false},"excerpt":{"rendered":"

Early ancestral bottleneck could\u2019ve spelled the end for modern humans<\/p>\n","protected":false},"author":121246920,"featured_media":277116,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_coblocks_attr":"","_coblocks_dimensions":"","_coblocks_responsive_height":"","_coblocks_accordion_ie_support":"","_crdt_document":"","advanced_seo_description":"","jetpack_seo_html_title":"","jetpack_seo_noindex":false,"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[1],"tags":[691818056,691818076,691822301],"class_list":{"0":"post-277107","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","6":"hentry","7":"category-uncategorized","8":"tag-climate-change","9":"tag-co2","10":"tag-glacial-cycles","12":"fallback-thumbnail"},"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/09\/0post_apocolpse.jpg?fit=1280%2C720&ssl=1","jetpack_likes_enabled":true,"jetpack_sharing_enabled":true,"jetpack_shortlink":"https:\/\/wp.me\/paxLW1-1a5t","jetpack-related-posts":[{"id":278041,"url":"https:\/\/climatescience.press\/?p=278041","url_meta":{"origin":277107,"position":0},"title":"The Great Climate Change Science Bottleneck","author":"uwe.roland.gross","date":"09\/09\/2023","format":false,"excerpt":"In the realm of climate change science, it appears that a select few wield significant power. As highlighted in Jessica Weinkle\u2019s article, there\u2019s a concentrated influence in the hands of a handful of individuals. These individuals not only shape the narrative but also control the trajectory of global climate change\u2026","rel":"","context":"In \"Climate change\"","block_context":{"text":"Climate change","link":"https:\/\/climatescience.press\/?tag=climate-change"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/09\/image-298.png?fit=1200%2C628&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/09\/image-298.png?fit=1200%2C628&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/09\/image-298.png?fit=1200%2C628&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/09\/image-298.png?fit=1200%2C628&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/09\/image-298.png?fit=1200%2C628&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":274634,"url":"https:\/\/climatescience.press\/?p=274634","url_meta":{"origin":277107,"position":1},"title":"The Great Climate Change Science Bottleneck","author":"uwe.roland.gross","date":"20\/08\/2023","format":false,"excerpt":"In a\u00a0video of an April IPCC scenario workshop, a panel discussion argued that the IPCC does not have any scenarios it merely assess scenarios. 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There are too many (i.e. a powerful few) who design, select, and prioritize scenarios while also being influential\u2026","rel":"","context":"In \"Climate change\"","block_context":{"text":"Climate change","link":"https:\/\/climatescience.press\/?tag=climate-change"},"img":{"alt_text":"","src":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/08\/0Bottleneck.jpg?fit=1200%2C628&ssl=1&resize=350%2C200","width":350,"height":200,"srcset":"https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/08\/0Bottleneck.jpg?fit=1200%2C628&ssl=1&resize=350%2C200 1x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/08\/0Bottleneck.jpg?fit=1200%2C628&ssl=1&resize=525%2C300 1.5x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/08\/0Bottleneck.jpg?fit=1200%2C628&ssl=1&resize=700%2C400 2x, https:\/\/i0.wp.com\/climatescience.press\/wp-content\/uploads\/2023\/08\/0Bottleneck.jpg?fit=1200%2C628&ssl=1&resize=1050%2C600 3x"},"classes":[]},{"id":275055,"url":"https:\/\/climatescience.press\/?p=275055","url_meta":{"origin":277107,"position":2},"title":"New Grand Canyon Monument stirs controversy with 1.1 million acre designation","author":"uwe.roland.gross","date":"22\/08\/2023","format":false,"excerpt":"In Episode 378 of District of Conservation, Gabriella focuses on two important stories from Arizona that have national relevance. 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