Humans pass the time from generation to generation and finally remember the two generations before them. Ancestors whose traces are always within us. Who really is the first father of mankind? How beautiful is her mother? Based on probabilities

1. Introduction to Mitochondrial Eve
Where? When? How?
Based on Example
ON THE
ORIGIN
OF EVE
Sayed Mohammad Mohammadi

2. Mitochondrial DNA is only passed from mother to child, explains the study’s lead author Alana Alexander, a
postdoctoral researcher at the University of Kansas, who conducted the research while she was a doctoral student
at Oregon State University (OSU).
Caption

3. The female carrier of the mitochondrial DNA sequence from which
all modern human mitochondrial DNA sequences are derived,
postulated to have lived in Africa 150,000–200,000 years ago;
(more generally) the last common female ancestor of all modern
humans.
The most robust statistical examination to date of our species'
genetic links to "mitochondrial Eve" the maternal ancestor of all
living humans con
fi
rms that she lived about 200,000 years ago.
The holder of this title is believed by some to have lived about
150,000 years ago in what is now Ethiopia, Kenya or Tanzania. The
time she lived is calculated based on the molecular clock technique
of correlating elapsed time with observed genetic drift.
MITOCHONDRIA L
EVE

4. Caption
Sperm Whales Have an “Eve”

5. All of the sperm whales in the world descended from
just one female who lived tens of thousands of years
ago. That surprising result comes from an examination
of the mitochondrial DNA of more than 1,600 sperm
whales from all over the world. Fittingly, researchers
have named her Eve.
Mitochondrial DNA is only passed from mother to child,
explains the study’s lead author Alana Alexander, a
postdoctoral researcher at the University of Kansas,
who conducted the research while she was a doctoral
student at Oregon State University (OSU).
Alexander initially tested the samples at the behest of
the nonpro
fi
t whale conservation organization Ocean
Alliance. The organization had previously shown that
sperm whales carry toxic levels of heavy metals in
their bodies, and they sought the help of OSU’s Marine
Mammal Institute to con
fi
rm that each of the samples
in that study had come from a different whale.
Yet while carrying out this fairly routine analysis,
Alexander stumbled upon signs of Eve’s intriguing
genetic legacy.
“Previous papers had suggested that sperm whales
maybe had low mitochondrial diversity,” Alexander
says. But her assumption had been that this low
diversity was an accidental side-effect of not having
enough data.
In her new analysis, Alexander conducted genetic tests
on 542 samples that had been collected over the past
fi
ve and a half years by Ocean Alliance and compared
them to data from previous studies of more than 1,000
additional whales published over the past 15 years.
“We thought that the additional samples might uncover
more diversity.”
Instead, they did the exact opposite.

6. Sperm whales have existed for millions of years, but
Alexander’s research suggests that Eve only appeared on
the scene in the past 10 to 80 thousand years. How she
came to dominate the sperm whale family tree remains a
mystery. Alexander says the research suggests that at
some point Eve and her descendants out-competed other
females—though it’s unclear how—and spread their
genetic lineage throughout the world.
The fact that Eve’s DNA has been found all over the world
opens up additional questions. Today, only male sperm
whales travel far from where they are born. Females tend
to stay put, so Eve’s mitochondrial DNA should have as well.
But, for some reason, it didn’t.
The new genetic study also reveals that the current lack
of female sperm whales migrating puts a limit on genetic
fl
ow for the species—an issue in the face of anthropogenic
climate change and other threats, which are isolating
sperm whales into smaller, geographically isolated sub-
populations. Populations in Eve’s time may have been more
able to mingle with each other over time. That opportunity
is now no longer available.
Alexander says this suggests that management strategies
for sperm whales may need to prioritize females, not
necessarily populations as a whole. If all of the females in
a given location die out, it now appears unlikely that any
new females would migrate to replace them.
Vanessa Tossenberger, policy director for Whale and
Dolphin Conservation, who was not af
fi
liated with the
study, agreed. “What this study has introduced is another
reason why it is so important to protect females if we
want to conserve a population,” she says. “It also
demonstrates the strong
fi
delity and the slow expansion
of the species following whaling. This needs to be taken
into in account for any established quotas that exist or
could exist in the future.”

7. The length of the complete mtDNA of the sperm whale is 16,428 nt.

8. Sperm whales adopt the
"marguerite formation"
to defend a vulnerable
pod member.

9. 1 in 200 Men Are
Direct Descendants of
Genghis Khan
In 2003 a groundbreaking historical genetics paper
reported results which indicated that a substantial
proportion of men in the world are direct line
descendants of Genghis Khan. By direct line, I mean
that they carry Y chromosomes which seem to
have come down from an individual who lived
approximately 1,000 years ago. As Y chromosomes
are only passed from father to son, that would
mean that the Y is a record of one’s patrilineage.

10. Could biological selection be responsible?
Although this possibility cannot be entirely ruled out, the small
number of genes on the Y chromosome and their specialized
functions provide few opportunities for selection…It is therefore
necessary to look for alternative explanations. Increased
reproductive
fi
tness, transmitted socially from generation to
generation, of males carrying the same Y chromosome would lead to
the increase in frequency of their Y lineage, and this effect would be
enhanced by the elimination of unrelated males ...
A factor of 1.36 per generation is crazy high. In theory of course drift
could do this, but in theory the molecules of gas in a room could all
congeal to one corner. As noted in the text the Y chromosome is not
rich in biologically useful genes. It may be that in the near future we’ll
fi
nd something peculiar about the carriers of this particular
haplotype, but until then, this map speaks for itself.