Zeresenay Alemseged: Finding the origins of humanity

What Can Selam Teach Us About Human Evolution?

Introduction to Human Ancestry

• The speaker introduces the topic of human evolution, emphasizing that 90% of our evolutionary history occurred in Africa.

• As a paleoanthropologist, the speaker's role is to define humanity's place in nature and explore what makes us human.

The Significance of Selam

• Selam, a 3.3 million-year-old skeleton of a three-year-old girl from the species Australopithecus afarensis, is introduced as a key figure in understanding human ancestry.

• Discovered by the research team in Dikika, Ethiopia, Selam’s name means "peace" in many Ethiopian languages, symbolizing hope for peace globally.

Contextualizing Human Development

• The speaker discusses the timeline of early technologies and cultural artifacts: stone tools (2.6 million years ago), flutes (35,000 years ago), and beads (75,000 years ago).

• DNA analysis reveals that humans and chimpanzees diverged around seven million years ago with over 98% genetic similarity.

Challenges in Paleoanthropology

• While DNA provides insights into beginnings and endings, it does not explain intermediate developments; fossil evidence is crucial for understanding evolution.

• Finding fossils involves systematic scientific approaches often requiring travel to remote locations under challenging conditions.

Fieldwork Experiences

• The speaker recounts difficulties faced while reaching Dikika—500 kilometers from Addis Ababa—with significant time spent on just the last stretch due to rough terrain.

• Describes paleontological sites as akin to extinct game parks where large mammals once thrived but are now absent.

Discovering Selam

• Anecdotes illustrate the rarity of finding human ancestor remains compared to other animal bones during fieldwork.

• After years of searching and frustration, Selam was finally discovered encased in sandstone—a significant find representing an extraordinary piece of our history.

Emotional Impact of Discovery

• The speaker reflects on feelings of happiness mixed with responsibility upon discovering such an important fossil after millions of years.

Exploring Our Ancestry: Insights from the National Museum of Ethiopia

The Discovery of a Unique Fossil

• The speaker recounts their experience at the National Museum of Ethiopia, highlighting concerns for their child while discussing significant fossil findings.

• A comparison between the skull of the discovered fossil and that of a chimpanzee reveals distinct features such as a vertical forehead, indicating its belonging to the human family tree.

• The fossil is identified as belonging to the species Australopithecus afarensis, known as Lucy. Questions arise regarding its sex and age at death.

Determining Sex and Age

• Sexual dimorphism in primates indicates males are generally larger with bigger teeth than females; however, only baby teeth are available for analysis in this case.

• CT scanning technology allows researchers to visualize both baby and adult teeth, leading to the conclusion that the individual was female with small canine teeth.

• Estimates suggest she died around 3.3 million years ago when she was approximately three years old.

Insights into Early Human Development

• The skeleton provides insights into early human behavior; notably, it shows that infants had still-growing brains at age three, unlike chimpanzees whose brains are nearly fully developed by then.

• This extended period of childhood dependence on parents suggests complex social structures were already emerging over three million years ago.

Evolutionary Significance

• Analysis of the hyoid bone indicates it resembled that of a chimpanzee, suggesting vocalizations were more primitive compared to modern humans.

• The presence of both ape-like and human-like features illustrates gradual evolutionary changes rather than abrupt transitions.

Reevaluating Our Understanding of Ancestors

• Prior knowledge about ancestors primarily derived from adult fossils led to biased understandings; this new discovery helps fill gaps regarding infant development in early hominins.

• The absence of juvenile fossils previously skewed perceptions; this finding corrects that bias by providing crucial information about our ancestral lineage.

Reflections on Humanity's Legacy

Are We Up to the Challenge?

Addressing Africa's Challenges

• The speaker poses a critical question about humanity's ability to rise above challenges, particularly focusing on the chronic issues faced by Africa.

• Two potential paths are outlined: one leading to continued dependency and suffering, and another promoting confidence and independence for African nations.

• The speaker advocates for a positive perception of Africa, emphasizing the need for Africans to focus on self-image rather than external perceptions.

• A "positive African attitude" is introduced as essential for fostering a sense of pride and awareness of both problems and values within the continent.