The science behind extinction

Stanford epidemiologist Stephen Luby sees three potential outcomes for humanity by 2100: extinction, the collapse of civilization with limited survival, or a thriving society.

Teaching students about the existential threat of a pandemic as they are living through one can help make the danger feel less hypothetical and much more real.

Complex disease transmission patterns could explain why it took tens of thousands of years after first contact for our ancestors to replace Neanderthals throughout Europe and Asia.

Scientists have debated until now what made Earth's oceans so inhospitable to life that some 96 percent of marine species died off at the end of the Permian period. New research shows the "Great Dying" was caused by global warming that left ocean animals unable to breathe.

In some ways, the planet's worst mass extinction — 250 million years ago, at the end of the Permian Period — may parallel climate change today, according to research co-authored by Stanford scientists Jonathan Payne and Erik Sperling.

“Among the slew of Very Bad Things implicated in the worst calamity the Earth has ever known, it was the global-warming-driven ocean anoxia that stands out as the primary agent of Armageddon. And in this reaper of the Paleozoic," study authors including Jonathan Payne and Erik Sperling, "see a future menace.”

When significant oxygen entered the atmosphere, ancient life multiplied. But after a few hundred million years, Earth’s oxygen plummeted, resulting in a die-off likely greater than the extinction of the dinosaurs.

The most catastrophic wipe-out on Earth didn’t happen to the dinosaurs. A study co-led by Malcom Hodgskiss, a PhD student in Geological Sciences at Stanford, found extreme changes in the atmosphere killed almost 100 percent of life on Earth about 2 billion years ago.

Upending an evolutionary theory proposed in the 1950s, scientists have found that the groups most resistant to extinction also contain the greatest ecological diversity – their members perform a larger number of different functions in ecosystems.

Scientists have long associated larger brain size with a cognitive ability to adapt to difficult scenarios, but new research suggests that mammals with relatively larger brains might be at a higher risk of extinction.

Paleoecologists Anthony Barnosky and Elizabeth Hadly warn in their book, “Tipping Point for Planet Earth: How Close Are We to the Edge?,” that “changes on Earth are aggregating in a way and at a speed that indicate a planetary tipping point is just ahead. The primary driver is overpopulation and attendant overconsumption of resources.”

Research co-authored by Luke Frishkoff, Gretchen Daily and Elizabeth Hadly shows the effects of deforestation and climate change are amplified in a way that pushes particularly vulnerable rainforest species towards extinction, while dry-climate species persist.

What will the world look like as iconic wild animals such as rhinos and tigers go extinct? Among other impacts: diminished biological diversity, fewer ecotourism job opportunities and the loss of benefits science is only beginning to discover, according to a call to action issued by a team of international scientists, including Stanford biologist Rodolfo Dirzo.

In today’s oceans, larger-bodied marine animals are more likely to become extinct than smaller creatures, according to a Stanford-led report. It’s a pattern that is unprecedented in the history of life on Earth, and one that is likely driven by human fishing.

An international study co-authored by Cassandra Brooks, PhD '17, has debunked the popular view that Antarctica and the Southern Ocean are in a much better environmental shape than the rest of the world.

Fossil study finds early human activity — not climate shifts — led to the systematic decline of large animals around the globe that predated human migration out of Africa. The findings add to concerns about continued biodiversity loss and the impact on ecosystems.

Stanford researchers show how warmer winters and booming demand for one of the world’s most expensive medicinal species may hurt ecosystems and communities in the Himalayas.

North America's birds are disappearing from the skies at a rate that's shocking even to ornithologists. Yet Stanford ecologist Paul Ehrlich sees some hope in this new jolt of bad news: "It might stir needed action in light of the public interest in our feathered friends."

The devastation of the vast majority of the world’s marine life is much closer than we think. According to Stanford paleobiologist Jonathan Payne, a scenario where all the ocean’s fish, mammals, and other creatures – even tiny animals like krill – are all gone is far from science fiction.

Analysis of thousands of vertebrate species reveals that extinction rates are likely much faster than previously thought. The researchers call for immediate global action, such as a ban on the wildlife trade, to slow the sixth mass extinction.

As humans diminish biodiversity, they’re increasing the risk of disease pandemics such as COVID-19. While some species are going extinct, those that tend to survive and thrive are more likely to host potentially dangerous pathogens that can make the jump to humans.