Subject: [Homestead] Our most recent COMMON ancestor is only a few thousand years iin our past.
Date: Fri, 01 Oct 2004 15:57:36 -0700
No, it's not that stupid biblethumper BISHOP USHER drivel, it's that
prior to a fully COMMON ancestor, ancestor lines direrge, thought they
are still ancestors and still human.
YALE News Release
CONTACT: Janet Rettig Emanuel, 203-432-2157 or janet.emanuel AT yale.edu
<mailto:janet.emanuel@yale> #269
For Immediate Release: 1 p.m. EDT, September 29, 2004
*/"Most Recent Common Ancestor" of All Living Humans Surprisingly
Recent /*
*New Haven, Conn.* -- In this week's issue of Nature, a Yale
mathematician presents models showing that the most recent person who
was a direct ancestor of all humans currently alive may have lived just
a few thousand years ago.
Chang established the basis of this research in a previous publication
with an intentionally simplified model that ignored such complexities as
geography and migration. Those precise mathematical results showed that
in a world obeying the simplified assumptions, the most recent common
ancestor would have lived less than 1,000 years ago. He also introduced
the "identical ancestors point," the most recent time -- less than 2,000
years ago in the simplified model -- when each person was an ancestor to
all or ancestor to none of the people alive today.
The current paper presents more realistic mathematical and computer
models. It incorporates factors such as socially driven mating, physical
barriers of geography and migration, and recorded historical events.
Although such complexities make pure mathematical analysis difficult, it
was possible to integrate them into an elaborate computer simulation
model. The computer repeatedly simulated history under varying
assumptions, tracking the lives, movements, and reproduction of all
people who lived within the last 20,000 years.
These more realistic models estimate that the most recent common
ancestor of mankind lived as recently as about 3,000 years ago, and the
identical ancestors point was as recent as several thousand years ago.
The paper suggests, "No matter the languages we speak or the color of
our skin, we share ancestors who planted rice on the banks of the
Yangtze, who first domesticated horses on the steppes of the Ukraine,
who hunted giant sloths in the forests of North and South America, and
who labored to build the Great Pyramid of Khufu."
The results can also work backwards, into the future. According to
Chang, "Within two thousand years, it is likely that everyone on earth
will be descended from most of us."
Other authors are Douglas L.T. Rhode of the Massachusetts Institute of
Technology and Steve Olson of Bethesda, MD. The National Institutes of
Health supported this research.