Physically, Homo sapiens may seem unremarkable in the animal kingdom. Yet, this species has ingeniously adapted to thrive across diverse habitats, from dense jungles to frigid arctic landscapes.

Alice Roberts, a remarkable figure in the realm of science, developed a keen passion for medicine, becoming both a surgeon and anatomist. Deeply intrigued by the evolutionary narratives of our primate relatives, she currently holds the position of Professor of Public Engagement in Science at the University of Birmingham, UK. Her expertise spans anthropology, archaeology, and paleopathology.

With an impressive portfolio in television, she has starred in shows such as Digging for Britain and Pompeii’s Lost Documents, and authored multiple books. Among them, Humans: Evolution of the Species, explores the journey of human evolution through captivating illustrations and worldwide contributions, including insights shared by Michael Marshall about her latest work.

Michael Marshall: What key insights does this latest installment of our evolutionary journey shed?

Alice Roberts: My time at the University of Bristol significantly shaped my perspective on humanity. While teaching anatomy to students, I constructed a dissection room within my veterinary school, where I had an eye-opening experience examining a lamb’s heart.

This moment allowed me to understand the heart’s evolution from fetus to adult form, prompting me to view humans as merely another mammal—a realization that transformed my perspective entirely.

How should we consider the implications of our bodies being results of evolutionary processes, and how does this history manifest in our skeletons and organs?

Inside our cells, biochemical processes trace back to the earliest single-celled organisms that once thrived in ancient oceans. Our limbs connect us to the first amphibians that ventured onto land approximately 360 million years ago. By studying changes in our arm bones, we can unravel the story of our evolutionary lineage. This exploration can apply to various parts of the human body.

Can you provide examples of these similarities and distinctions?

I’ve often noted that if a medical student were presented with a female chimpanzee’s humerus, they might struggle to discern the difference. The size and shape of the bones closely resemble those of humans, retaining their functional capabilities. Upon closer examination, the similarities are intriguing, particularly in the structure of hands; human thumbs stand out as longer and thicker than those of chimpanzees.

It’s fascinating to hear paleoanthropologists confidently compare ape and human hands to classify Homo habilis. How do you view this?

Indeed, if chimpanzee hands closely resemble human hands, then examining other hominins becomes complex. Categorizing fossils can be challenging, especially when the record is incomplete. As someone passionate about data, I find the lack of clarity concerning categorization quite disconcerting.

Humans appear to possess a uniquely developed brain. How significant is this distinction?

The most distinguishing features of humans can be summarized succinctly: bipedalism, small teeth, and a large brain. While the correlation between larger brains and bipedalism is still under investigation, various theories abound. Some argue that the evolution of a larger brain coincided with bipedalism, while others suggest that enhanced cognitive functions arose as a result of the freedom provided by walking upright—allowing for tool use and expanded social networks.

Our body size is comparable to that of other great apes, yet the differentiation lies in the structure of our brains. Human brains not only exhibit greater size but also an intricate folding pattern that accommodates vast amounts of cortex. This distinction influences our interactions with the natural world around us.

The number of human species that existed alongside us has grown remarkably. How has this evolved our understanding of human evolution?

Initially, Neanderthals were the only known other group. Now, we recognize that they coexisted but were not our direct ancestors, as approximately 20 distinct hominin species have been identified, with new discoveries emerging each year.

My groundbreaking series from 2008, Incredible Human Journey, highlights this evolving narrative. During a visit to Indonesia, I encountered the fossil of Homo floresiensis—a shocking revelation that reshaped my comprehension of human ancestry.

“The Hobbit” – Original Homo floresiensis

Observing the skeletons of Homo floresiensis side by side was deeply impactful; their small skulls and brains still yielded evidence of stone tool use. This discovery contradicted the long-held belief that larger brains lead to tool-making capabilities, compelling me to reevaluate what it truly means to be human.

While Neanderthals and Denisovans vanished, our species endured. What accounts for our survival?

Unpacking this question requires probing tens of thousands of years of evolutionary history. Evidence suggests that modern humans possessed intricate social networks, allowing for enhanced resource distribution during hardships. This interconnectedness likely played a pivotal role in our survival.

In the grand tapestry of evolution, will we see significant changes in the coming centuries?

Evolutionary changes are often catalyzed by drastic events, typically involving significant population declines, after which genetic diversity is crucial. In the near future, any observable changes in humans will likely pertain to immune responses rather than drastic physical transformations. We aren’t on the verge of growing additional limbs.

A compelling and concerning aspect of our evolution lies in our capacity to manipulate our DNA. The ethical implications of this capability remain a significant question mark for our future.

Do your professional insights influence your fiction writing?

I’ve authored two children’s books set during the Ice Age, imagining the first encounters between modern humans and Neanderthals to invigorate history through storytelling. My debut adult novel, Queen of Goddesses, set for release in September, explores the saga of Cleopatra and Mark Antony, reflecting on the unpredictable nature of human history much like the complexities of evolution itself.

What is humanity’s relationship with nature? How should it evolve?

With billions of us on this planet, human culture indeed appears exceptional. Yet, if we adopt an evolutionary lens, we discern a lack of rigid separations between us and the rest of the natural world. Understanding our origins emphasizes that we are inherently connected to all species.

As we observe the impacts of our lifestyles on biodiversity, we must recognize our moral responsibility to mitigate our negative effects. Regardless of perceived separations from nature, we are deeply intertwined with it; our survival hangs in the balance of its preservation.

This is an edited version of a New Scientist video interview to be published on youtube.com/NewScientist on June 10th. Michael Marshall is a writer based in Devon, England.