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Cancer was the best thing that ever happened to me, he writes.

If you asked me to choose between wining the Tour de France and cancer, I would choose cancer. Odd as it sounds, I would rather have the title of cancer survivor than winner of the Tour because of what it has done for me as a man.

I don’t know why I got the illness, but it did wonders for me, and I wouldn’t want to walk away from it. Why would I want to change, even for a day, the most important and shaping event in my life?

The one thing the illness has convinced me of beyond all doubt more than any experience I’ve had as an athlete is that we are much better than we know. We have unrealized capacities that sometimes only emerge in crisis.”

Mitochondrial Eve: The Mother of Us All

Ancestral Line: “Mitochondrial Eve”

Our story begins in Africa sometime between 150,000 and 170,000 years ago, with a woman whom anthropologists have nicknamed “Mitochondrial Eve.”

She was awarded this mythic epithet in 1987 when population geneticists discovered that all people alive on the planet today can trace their maternal lineage back to her.

But Mitochondrial Eve was not the first female human. Homo sapiens evolved in Africa around 200,000 years ago, and the first hominids?characterized by their unique bipedal stature?appeared nearly two million years before that. Yet despite humans having been around for almost 30,000 years, Eve is exceptional because hers is the only lineage from that distant time to survive to the present day.

Which begs the question, “So why Eve?”

Simply put, Eve was a survivor. A maternal line can become extinct for a number of reasons. A woman may not have children, or she may bear only sons (who do not pass her mtDNA to the next generation). She may fall victim to a catastrophic event such as a volcanic eruption, flood, or famine, all of which have plagued humans since the dawn of our species.

None of these extinction events happened to Eve’s line. It may have been simple luck, or it may have been something much more. It was around this same time that modern humans’ intellectual capacity underwent what author Jared Diamond coined the Great Leap Forward. Many anthropologists believe that the emergence of language gave us a huge advantage over other early human species. Improved tools and weapons, the ability to plan ahead and cooperate with one another, and an increased capacity to exploit resources in ways we hadn’t been able to earlier, all allowed modern humans to rapidly migrate to new territories, exploit new resources, and outcompete and replace other hominids, such as the Neandertals.

It is difficult to pinpoint the chain of events that led to Eve’s unique success, but we can say with certainty that all of us trace our maternal lineage back to this one woman.

The L Haplogroups: The Deepest Branches

Ancestral line: “Eve” > L1/L0

Mitochondrial Eve represents the root of the human family tree. Her descendents, moving around within Africa, eventually split into two distinct groups, characterized by a different set of mutations their members carry.

These groups are referred to as L0 and L1, and these individuals have the most divergent genetic sequences of anybody alive today, meaning they represent the deepest branches of the mitochondrial tree. Importantly, current genetic data indicates that indigenous people belonging to these groups are found exclusively in Africa. This means that, because all humans have a common female ancestor, “Eve,” and because the genetic data shows that Africans are the oldest groups on the planet, we know our species originated there.

Haplogroups L1 and L0 likely originated in East Africa and then spread throughout the rest of the continent. Today, these lineages are found at highest frequencies in Africa’s indigenous populations, the hunter-gatherer groups who have maintained their ancestors’ culture, language, and customs for thousands of years.

At some point, after these two groups had coexisted in Africa for a few thousand years, something important happened. The mitochondrial sequence of a woman in one of these groups, L1, mutated. A letter in her DNA changed, and because many of her descendants have survived to the present, this change has become a window into the past. The descendants of this woman, characterized by this signpost mutation, went on to form their own group, called L2. Because the ancestor of L2 was herself a member of L1, we can say something about the emergence of these important groups: Eve begat L1, and L1 begat L2. Now we’re starting to move down your ancestral line.

Haplogroup L2: West Africa

Ancestral line: “Eve” > L1/L0 > L2

L2 individuals are found in sub-Saharan Africa, and like their L1 predecessors, they also live in Central Africa and as far south as South Africa. But whereas L1/L0 individuals remained predominantly in eastern and southern Africa, your ancestors broke off into a different direction, which you can follow on the map above.

L2 individuals are most predominant in West Africa, where they constitute the majority of female lineages. And because L2 individuals are found at high frequencies and widely distributed along western Africa, they represent one of the predominant lineages in African-Americans. Unfortunately, it is difficult to pinpoint where a specific L2 lineage might have arisen. For an African-American who is L2?the likely result of West Africans being brought to America during the slave trade?it is difficult to say with certainty exactly where in Africa that lineage arose.

Fortunately, collaborative sampling with indigenous groups is currently underway to help learn more about these types of questions and to possibly bridge the gap that was created during those transatlantic voyages hundreds of years ago.

Haplogroup L3: Out of Africa

Ancestral line: “Eve” > L1/L0 > L2 > L3

Your next signpost ancestor is the woman whose birth around 80,000 years ago began haplogroup L3. It is a similar story: an individual in L2 underwent a mutation to her mitochondrial DNA, which was passed onto her children. The children were successful, and their descendants ultimately broke away from the L2 clan, eventually separating into a new group called L3. You can see above that this has revealed another step in your ancestral line.

While L3 individuals are found all over Africa, including the southern reaches of sub-Sahara, L3 is important for its movements north. You can follow this movement of the map above, seeing first the expansions of L1/L0, then L2, and followed by the northward migration of L3.

Your L3 ancestors were significant because they are the first modern humans to have left Africa, representing the deepest branches of the tree found outside of that continent.

Why would humans have first ventured out of the familiar African hunting grounds and into unexplored lands? It is likely that a fluctuation in climate may have provided the impetus for your ancestors’ exodus out of Africa.

The African Ice Age was characterized by drought rather than by cold. Around 50,000 years ago the ice sheets of northern Europe began to melt, introducing a period of warmer temperatures and moister climate in Africa. Parts of the inhospitable Sahara briefly became habitable. As the drought-ridden desert changed to savanna, the animals your ancestors hunted expanded their range and began moving through the newly emerging green corridor of grasslands. Your nomadic ancestors followed the good weather and plentiful game northward across this Saharan Gateway, although the exact route they followed remains to be determined.

Today, L3 individuals are found at high frequencies in populations across North Africa. From there, members of this group went in a few different directions. Some lineages within L3 testify to a distinct expansion event in the mid-Holocene that headed south, and are predominant in many Bantu groups found all over Africa. One group of individuals headed west and is primarily restricted to Atlantic western Africa, including the islands of Cabo Verde.

Other L3 individuals, your ancestors, kept moving northward, eventually leaving the African continent completely. These people currently make up around ten percent of the Middle Eastern population, and gave rise to two important haplogroups that went on to populate the rest of the world.

Haplogroup N: The Incubation Period

Ancestral line: “Eve” > L1/L0 > L2 > L3 > N

Your next signpost ancestor is the woman whose descendants formed haplogroup N. Haplogroup N comprises one of two grou
ps that were created by the descendants of L3.

The first of these groups, M, was the result of the first great wave of migration of modern humans to leave Africa. These people likely left the continent across the Horn of Africa near Ethiopia, and their descendants followed a coastal route eastward, eventually making it all the way to Australia and Polynesia.

The second great wave, also of L3 individuals, moved north rather than east and left the African continent across the Sinai Peninsula, in present-day Egypt. Also faced with the harsh desert conditions of the Sahara, these people likely followed the Nile basin, which would have proved a reliable water and food supply in spite of the surrounding desert and its frequent sandstorms.

Descendants of these migrants eventually formed haplogroup N. Early members of this group lived in the eastern Mediterranean region and western Asia, where they likely coexisted for a time with other hominids such as Neandertals. Excavations in Israel’s Kebara Cave (Mount Carmel) have unearthed Neandertal skeletons as recent as 60,000 years old, indicating that there was both geographic and temporal overlap of these two hominids.

The ancient members of haplogroup N spawned many sublineages, which went on to populate much of the rest of the globe. They are found throughout Asia, Europe, India, and the Americas.

Haplogroup R: Spreading Out

Ancestral line: “Eve” > L1/L0 > L2 > L3 > N > R

After several thousand years in the Near East, individuals belonging to a new group called haplogroup R began to move out and explore the surrounding areas. Some moved south, migrating back into northern Africa. Others went west across Anatolia (present-day Turkey) and north across the Caucasus Mountains of Georgia and southern Russia. Still others headed east into the Middle East, and on to Central Asia. All of these individuals had one thing in common: they shared a female ancestor from the N clan, a recent descendant of the migration out of Africa.

The story of haplogroup R is complicated, however, because these individuals can be found almost everywhere, and because their origin is quite ancient. In fact, the ancestor of haplogroup R lived relatively soon after humans moved out of Africa during the second wave, and her descendants undertook many of the same migrations as her own group, N.

Because the two groups lived side by side for thousands of years, it is likely that the migrations radiating out from the Near East comprised individuals from both of these groups. They simply moved together, bringing their N and R lineages to the same places around the same times. The tapestry of genetic lines became quickly entangled, and geneticists are currently working to unravel the different stories of haplogroups N and R, since they are found in many of the same far-reaching places.

Haplogroup K: Your Branch on the Tree

Ancestral line: “Eve” > L1/L0 > L2 > L3 > N > R > K

We finally arrive at your own clan, a group of individuals who descend from a woman in the R branch of the tree. Because of the great genetic diversity found in haplogroup K, it is likely that she lived around 50,000 years ago.

Interestingly, her descendants gave rise to several different subgroups, some of which exhibit very specific geographic homelands. The very old age of these subgroups has led to a wide distribution; today they harbor specific European, northern African, and Indian components, and are found in Arabia, the northern Caucasus Mountains, and throughout the Near East.

While some members of your haplogroup headed north into Scandinavia, or south into North Africa, most members of your haplogroup K stem from a group of individuals who moved northward out of the Near East. These women crossed the rugged Caucasus Mountains in southern Russia, and moved on to the steppes of the Black Sea.

Interestingly, your haplogroup is also very significant because its members constitute three of the four major Ashkenazi Jewish founder lineages.

The term “Ashkenazi” refers to Jews of mainly central and eastern European ancestry. Most historical records indicate that the founding of Ashkenazi Jewry took place in the Rhine Basin where it subsequently underwent vast population expansions. In more recent times, the Ashkenazi population was estimated at approximately 25,000 individuals around 1300 A.D., whereas that number had increased to about 8,500,000 individuals by the turn of the twentieth century.

Around half of all Ashkenazi Jews trace their mitochondrial lineage back to one of four women, and your haplogroup K represents a lineage that gave rise to three of them. While this lineage is found at a smaller frequency in non-Ashkenazi Jews, the three K lineages that helped found the Ashkenazi population are seldom found in other populations. While virtually absent in Europeans, they appear at frequencies of three percent or higher in groups from the Levant, Arabia, and Egypt. This indicates a strong genetic role in the Ashkenazi founder event, which likely occurred in the Near East.

Today, K has given rise to three of the four most common haplogroups in Ashkenazi Jews and is currently shared by over 3,000,000 people.

Your mtDNA results identify you as a member of haplogroup K. This haplogroup is the final destination of a genetic journey that began some 150,000 years ago with an ancient mtDNA haplogroup called L3.

Haplogroup L3 occurs only in Africa, but on that continent its derivatives are found nearly everywhere. L3’s subclades are most prevalent in East Africa.

This ancient lineage reflects an early divergence from humanity’s common genetic coalescence point.

“Mitochondrial Eve,” the common ancestor of all living humans, was born in Africa some 150,000 years ago. All existing MtDNA diversity began with Eve and it remains greatest, and subsequently oldest, in Africa.

Y chromosome polymorphisms on the male line of descent also point to an African origin for all humans, but our male common ancestor, “Adam,” lived only about 60,000 years ago.

MtDNA and the Y chromosome are independent parts of our genetic makeup and each tells a different tale of successive genetic mutations over the eons. That is why their approximate coalescence points are different. Yet while the dates vary, both paths point emphatically to a surprisingly recent African origin for all humans.

The oldest known fossil remains of anatomically modern humans were found in Ethiopia’s Omo River Valley. The skeletons, known as Omo I and Omo II, have been dated to about 195,000 years ago.

Although haplogroup L3 does not appear outside of Africa it is an important part of the human migrations from that continent to the rest of the world.

A single person of the L3 lineage gave rise to the M and N haplogroups some 80,000 years ago.

All Eurasian mtDNA lineages are subsequently descended from these two groups.

The African Ice Age was characterized by drought rather than by cold. But about 50,000 years ago a period of warmer temperatures and moist climate made even parts of the arid Sahara habitable. The climatic shift likely spurred hunter-gatherer migrations into a steppe-like Sahara?and beyond.

This “Saharan Gateway” led humans out of Africa to the Middle East. The route they took is uncertain. They may have traveled north down the Nile to the Mediterranean coast and the Sinai. Alternatively, they may have crossed what was then a land bridge connecting the Bab al Mandab to Arabia, after which they either skirted the then-lush, verdant eastern coast of the Red Sea or headed east along the Gulf of Aden towards the Arabian Sea.

When the climate again turned arid, expanding Saharan sands slammed the Saharan Gateway shut. The desert was at its driest between 20,000 and 40,000 years ago, and during this period Middle East migrants became isolated from Africa.

From their new Middle East location, however, they would go on to populate much of the world.

N is a macro-haplogroup descended from the African lineage L3. This line of descent, with haplogroup M, traces the first human migrations out of Africa. The ancient members of haplogroup N spawned sublineages found across Eurasia and, eventually, the Americas.

Early members of this group lived in the eastern Mediterranean and Near East region, where they likely coexisted for a time with pre-modern hominids such as Neandertals. Excavations in Israel’s Kebara cave (Mount Carmel) have unearthed Neandertal skeletons at least as recent as 60,000 years old.

Growing cognitive abilities likely gave these Upper Paleolithic humans tremendous social advantages, evidenced by the appearance of modern thought and behavior. This “great leap forward” may have enabled our ancestors to outcompete and eventually replace evolutionary dead-end lineages such as Neandertals.

The macro-haplogroup N is composed of many subclades, which are often geographically distinct.

Learning more about these subclades will add further clarity to the big picture of human genetic diversity, and is a primary goal of the Genographic Project.

Haplogroup R is descended from N and has since dispersed across much of the globe. The lineage, in its many subgroups, appears on all continents except Australia and Antarctica.

Subgroups preHV, U, T, and J are found in Europe and the Near East. The R5 and R6 lineages arose on the Indian subcontinent.

Haplogroup K appeared some 16,000 years ago (on the R line of descent) when Europe’s glaciers finally began a retreat from their ice age maximum. Humans of the era were living in the ice-free refuges of southern Europe?where K is still found in its highest concentrations.

As populations followed the retreating ice northward, the lineage’s descendents spread throughout most of Europe. Tests have revealed that Oetzi, the 5,200-year-old remains of a Copper Age man frozen in an Alpine glacier, belongs to haplogroup K.

Your Y chromosome results identify you as a member of haplogroup I, a lineage defined by a genetic marker called M170. This haplogroup is the final destination of a genetic journey that began some 60,000 years ago with an ancient Y chromosome marker called M168. The very widely dispersed M168 marker can be traced to a single individual - “Eurasian Adam.” This African man, who lived some 31,000 to 79,000 years ago, is the common ancestor of every non-African person living today. His descendants migrated out of Africa and became the only lineage to survive away from humanity’s home continent.

Population growth during the Upper Paleolithic era may have spurred the M168 lineage to seek new hunting grounds for the plains animals crucial to their survival. A period of moist and favorable climate had expanded the ranges of such animals at this time, so these nomadic peoples may have simply followed their food source.

Improved tools and rudimentary art appeared during this same epoch, suggesting significant mental and behavioral changes. These shifts may have been spurred by a genetic mutation that gave “Eurasian Adam’s” descendants a cognitive advantage over other contemporary, but now extinct, human lineages.

Some 90 to 95 percent of all non-Africans are descendants of the second great human migration out of Africa, which is defined by the marker M89.

M89 first appeared 45,000 years ago in Northern Africa or the Middle East. It arose on the original lineage (M168) of “Eurasian Adam,” and defines a large inland migration of hunters who followed expanding grasslands and plentiful game to the Middle East.

Many people of this lineage remained in the Middle East, but others continued their movement and followed the grasslands through Iran to the vast steppes of Central Asia. Herds of buffalo, antelope, woolly mammoths, and other game probably enticed them to explore new grasslands.

With much of Earth’s water frozen in massive ice sheets, the era’s vast steppes stretched from eastern France to Korea. The grassland hunters of the M89 lineage traveled both east and west along this steppe “superhighway” and eventually peopled much of the continent.

A group of M89 descendants moved north from the Middle East to Anatolia and the Balkans, trading familiar grasslands for forests and high country. Though their numbers were likely small, genetic traces of their journey are still found today.

Haplogroup I, is widespread throughout southeastern and central Europe and most common in the Balkans. Members of this haplogroup carry a 20,000-year-old marker dubbed M170.

This Y chromosome marker first appeared in the Middle East. Its subsequent spread into southeastern Europe may have accompanied the expansion of the prosperous Gravettian culture. These Upper Paleolithic people used effective communal hunting techniques and developed art notable for voluptuous female carvings often dubbed “Venus” figures.

The later spread of this lineage could be also tied to the mid-first millennium B.C. Celtic culture. The tantalizing possibility could explain the wider dispersal of this unique genetic marker.