177 lines
6.8 KiB
Markdown
177 lines
6.8 KiB
Markdown
---
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created_at: '2014-11-14T13:24:16.000Z'
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title: The Neanderthal correlation (2008)
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url: http://www.nature.com/nature/journal/v453/n7194/full/453562a.html
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author: Digit-Al
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points: 92
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story_text: ''
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comment_text:
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num_comments: 46
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story_id:
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story_title:
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story_url:
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parent_id:
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created_at_i: 1415971456
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_tags:
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- story
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- author_Digit-Al
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- story_8606956
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objectID: '8606956'
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year: 2008
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---
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A question of breeding.
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“You don't really want to know,” Beth said, her eyes glancing up from
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her messy desk to the clock and back down without meeting mine.
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“I do want to know,” I insisted. After three years of correlating the
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reconstructed Neanderthal genome with modern human populations, she had
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to have found something interesting. The idea had sounded great when she
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had suggested it, and the grant committee had loved my proposal. But
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with the final report ten months overdue, they wouldn't approve any new
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proposals.
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“You'll wish you hadn't said that if I tell you,” she said, staring
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down. “People are going to be upset about this.”
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“I want to know,” I insisted. What I really wanted was a report to drop
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on the contract officer's desk, but saying that hadn't worked the last
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time. Or the time before that. Beth gets too deep into her research. I
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run a big human-genetics lab. I deliver results; I don't invest my ego
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in big-picture hypotheses or in worrying why the Neanderthals died out.
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“I don't have an oar in the debate over whether or not the
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Neanderthals interbred with Cro-Magnons. I just want to know what the
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data
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say.”
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*Image: JACEY*
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“Really?” she asked, not looking convinced at all. “You said that the
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last time, remember?”
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I didn't. I tried to ignore her obsessions. “Please,” I asked.
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“It's not just you. Nobody is going to want to hear this. Believe me,
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John, believe me.”
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“I'm a scientist. I want to know the truth\!” More importantly, I wanted
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to finish the contract; that was my job as principal investigator. I'd
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always succeeded before; that was why after two decades at the
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university I was department chair and Beth was still a research
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assistant.
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“Are you sure?” Beth asked, looking a little less uncertain.
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“Yes,” I said, trying to smile. “I know you've got something very
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interesting to tell me.” That sometimes worked.
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She nodded, her usually expressionless face showing a shadow of a smile.
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“I found strong genetic correlations between Neanderthals and modern
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subpopulations,” she said. “A lot more than I had expected.”
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“What about correlations coming from the last common ancestor?” That was
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the safe correlation. Sapiens and Neanderthals had split around 800,000
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years ago, so they had to share lots of genes that chimps didn't have.
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“Some are,” she said. “They're easy to find because they're in all
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modern populations. These genes are present in only some modern
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subpopulations, and the statistics show only about 25,000 years of
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divergence between the Neanderthals and Sapiens. That has to be
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interbreeding. The earlier studies had missed it because they hadn't
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considered the changing impact of natural selection over time.”
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“You can back that up?”
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“Absolutely.” Beth was always meticulous about her data.
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I didn't have to force a smile. “That's fascinating,” I said. “It will
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make *Nature* for sure.” It would get a lot of people hot under their
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collective collars, but that was fine. Evidence of interbreeding with
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Neanderthals would create a new paradigm for hybridization being behind
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the rapid advance of modern humans and make me famous. “What genes are
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involved?”
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“That's the surprise,” Beth said, and she smiled so broadly that she
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looked almost attractive despite her unkempt red-grey hair and
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nondescript clothes.
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“Oh?”
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“The genes for red hair and pale skin didn't match well enough to show a
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correlation, but I found a correlation for genes linked to other traits.
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There's a gene cluster linked to advanced mathematics skills,
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information processing, logic, analytical intelligence, concentration
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skills, obsession–compulsion and Asperger's syndrome. That cluster
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correlates very strongly. I can trace some genes back to the
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interglacial around 450,000 years ago, and others back to another burst
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of evolutionary innovation during the Eemian interglacial about 130,000
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years ago.” She rambled on with endless details.
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Something wasn't right. She was linking genes for advanced mental skills
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to Neanderthals. “I'm confused,” I said when she paused for a breath.
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“You're correlating genes linked to modern human intelligence with
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Neanderthal populations. What am I missing?”
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“You didn't want to hear me, I knew that.”
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“No, I want to hear you. I just asked a question.”
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“You don't, because I already told you.”
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I looked at Beth blankly, realizing I was missing a key part of the
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puzzle. “You said these were Neanderthal genes?”
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“Yes, they were,” she said. “They weren't in the modern human genome
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until Neanderthals interbred with Cro-Magnons between 25,000 and 30,000
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years ago.”
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“Advanced mathematical processing? Shouldn't that have been missing from
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the Neanderthal genome?”
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“No, I found that Neanderthals lacked genes linked to successful
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socialization and management skills. They could count perfectly well,
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but they couldn't deal with groups. Socialization genes came from
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Sapiens”
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“You're trying to tell me ...” I said, but my mental censor blocked the
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idea.
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“That human mathematical intelligence came from Neanderthals? That's
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what the data say. The Cro-Magnons had the social skills. But that isn't
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all.”
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I stared at her. I couldn't tell that to the research council.
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As usual, she couldn't read the warning look on my face. “The
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hybridization was successful in the Stone Age, but the environment has
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changed. I found that modern culture selects for socialization but
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against the Neanderthal traits for mathematics and intelligence,” she
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said, and looked down. “I don't know how you'll survive when our genes
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are
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gone.”
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## Author information
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## Affiliations
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1. ### Jeff Hecht (<http://www.jeffhecht.com>) is Boston correspondent for *New Scientist* and contributing editor to *Laser Focus World*.
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## Authors
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1. ### Search for Jeff Hecht in:
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- [Nature Research
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journals](/search/executeSearch?sp-q=%22Jeff+Hecht%22&sp-p=all&pag-start=1&sp-c=25&sp-m=1&sp-s=date_descending)
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•
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- [PubMed](http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=search&term=Jeff+Hecht)
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•
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- [Google
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Scholar](http://scholar.google.co.uk/scholar?as_q=&num=10&btnG=Search+Scholar&as_epq=&as_oq=&as_eq=&as_occt=any&as_sauthors=%22Jeff+Hecht%22&as_publication=&as_ylo=&as_yhi=&as_allsubj=all&hl=en)
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