What Happened When Modern Humans Met Neanderthals?

In short, they interbred, according to Svante Pääbo, a Swedish biologist and pioneer of paleogenetics, the study of preserved genetic material from the remains of ancient organisms, including ancient human DNA. He has served as director of the Department of Evolutionary Genetics at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, since 1997.

He explains in this lecture that Neanderthals and Denisovans have a common ancestor in Africa. About half a million years ago, these species of humans came out of Africa and evolved into what we call Neanderthals in Western Eurasia and Denisovans in Eastern Eurasia. Much later modern humans appeared in Africa and then spread, initially to the Middle East, then to Eurasia where they encountered Neanderthals and Denisovans. Eventually, those earlier species became extinct, replaced by modern humans.

Pääbo’s lab famously retrieved and sequenced ancient Neanderthal DNA and produced a high-quality genome sequence that allowed for the reconstruction of the recent evolutionary history of our species. Once the genome was sequenced and studied it became apparent that ancient and modern humans interbred. In fact, most present-day humans have some Neanderthal DNA.

Svante Pääbo’s was selected by Scripps Institution of Oceanography at the UC San Diego as the recipient of the 2018 Nierenberg Prize for Science in the Public Interest. He gave this fascinating lecture on that occasion.

Watch A Neanderthal Perspective on Human Origins with Svante Pääbo – 2018 Nierenberg Prize for Science in the Public Interest

Evolution and Creationism as Science and Myth

Myths symbolize ideas, values, history and other issues that are important to a people. They may be true or false, mundane or fantastic; their significance is their meaning, not their narrative content.

Science is a way of knowing about the natural world. Its conclusions tentatively may be true or false, but its significance is its explanatory power: one has confidence in the process of science, even though some explanations change over time.

Myth and science thus seem very different, but each has been utilized by proponents of both sides of the Christian creationism and evolution controversy. Understanding this role is essential in comprehending (much less mediating) this persistent conflict.

Eugenie C. Scott served as the executive director of the National Center for Science Education, an organization that works to keep publicly (though not scientifically) controversial topics like evolution and climate change in the public schools. Her work has involved a mixture of science, communication, religion, education, law, and community activism.

Watch Evolution and Creationism as Science and Myth

Why Do People Reject Good Science?

Many people will consider factual information and it will change their understanding. But there are some for whom, “Providing more, accurate information doesn’t seem to change their opinions or make them alter their erroneous views,” says Eugenie Scott, Founding Executive Director of National Center for Science Education. For example, Americans have a much lower incidence of acceptance of evolution than people in any other developed country in the world. The same is true about the acceptance of anthropogenic climate change, despite the scientific evidence for both.

What explains this knowledge resistance?

We all view factual information through a filter of ideology, values, and group identification but these filters often make ideas very resistant to change because they prevent us from looking dispassionately at empirical evidence, facts and logic. Scott explores what drives knowledge resistance and what can break it down.

Eugenie C. Scott served as the executive director of the National Center for Science Education, an organization that works to keep publicly (though not scientifically) controversial topics like evolution and climate change in the public schools. Her work has involved a mixture of science, communication, religion, education, law, and community activism.

Watch Why Do People Reject Good Science?

Cancer from an Evolutionary Perspective

Humans have a relatively high risk of developing cancer in their lifetimes. But cancer is not unique to humans. Across the tree of life, we can trace cancer vulnerabilities back to the origins of multicellularity. Cancer is observed in almost all multicellular phyla, including lineages leading to plants, fungi, and animals.

However, species vary remarkably in their susceptibility to cancer. And some organisms are much better at killing problem cells. Amy Boddy discusses how this variation is characterized by life history trade-offs, especially longevity. Interestingly, different species have evolved different ways to fight cell mutations that cause cancer. This may lead to a better understanding of cancer susceptibility across human populations.

Amy Boddy is an Assistant Professor in the Integrated Anthropological Sciences Unit and a Research Associate in the Broom Center for Demography at UC Santa Barbara. Boddy completed her PhD in molecular biology and genetics at the Wayne State University – School of Medicine in 2013. Her work uses applications from evolution and ecology to understand human health and disease. She uses a combination of genomics, computational biology and evolutionary theory to understand life history trade-offs between survival and reproduction across different levels of biological organization. One component of her research program examines how environmental cues, such as high extrinsic mortality, may guide resource allocations to cancer defenses and reproduction. Current cancer research topics include comparative oncology, intragenomic conflict, cellular life history trade-offs, and early life adversity and cancer outcomes later in life. In addition to her cancer research, she studies maternal/fetal conflict theory and the consequences of fetal microchimeric cells in maternal health and disease.

Watch Cancer Across the Tree of Life: New Insights into an Ancient Disease

Imagination and Human Origins

Try to remember the first time in your life when you imagined something. It may have been imagining what was behind the door or under the bed, or a fantastic universe of wonders and exciting adventure. As children, our imaginations are furtive and encouraged as ways in which we develop our cognitive capabilities. As we grow older, we may not imagine in quite the same ways, but we continue to heavily use and depend on our imagination in our daily lives, imagining different situations that might occur in a few moments or in a few years. Thus, we actually spend a large amount of time in our own particular universe imagining many possible different ones.

Why do we do this and how did this capacity evolve in humans? Imagination probably helped our ancestors to be successful in making decisions and live in complex societies, and imagination is key to advancing technology. In this CARTA symposium, imagination is explored as a unique and enhanced human ability, and experts from all fields discuss its evolutionary origins, the fundamental genetic and neurological basis of human imagination, the impact of human imagination in science and art, and the consequences of imagination impairment.

Browse more programs in CARTA: Imagination and Human Origins