Our ancestors lost nearly 99% of their population, 900,000 years ago

Sep 6, 2023

900,000 years ago, human ancestors faced extinction with a population crash, impacting genetic diversity and driving the evolution of modern humans. Antarctica's research stations have left high levels of pollution, but the extent of the impact is unknown. Melting sea-ice around Antarctica is causing emperor penguins to abandon breeding colonies, resulting in the deaths of many chicks. AI is being trained to describe smells, with potential applications in perfumes and food products.

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Introduction

00:00 • 2min

The Impact of Population Loss on Human Evolution and the Role of Climate Change

01:57 • 3min

Waste Management and Contamination in Antarctica's Research Stations

05:22 • 3min

Loss of Penguin Chicks and AI Training to Describe Smells

08:44 • 2min

AI's Role in Identifying and Describing Smells

10:23 • 3min

In this episode:

00:30 Early humans pushed to brink of extinction

Around 900,000 years ago the ancestors of modern humans were pushed to the brink of extinction, according to new research. Genetic studies suggest that the breeding population of our ancestors in Africa dropped to just 1,280 and didn’t expand again for another 117,000 years. This population crash would likely have had an impact on human genetic diversity, and may have driven the evolution of important features of modern humans, such as brain size.

Nature News: Human ancestors nearly went extinct 900,000 years ago

3:49 The pollution legacy of Antarctica’s research stations

Poor historical waste practices have left high levels of pollution around Antartica’s research facilities. By surveying the seafloor near Australia’s Casey research station, researchers have revealed high concentrations of hydrocarbons and heavy metals.This pollution is likely to be widespread, but its impact on the continent is unknown.

Nature News: Antarctic research stations have polluted a pristine wilderness

07:43 Melting sea-ice causes catastrophic penguin breeding failure

Persistently low levels of sea-ice around Antarctica have caused emperor penguins to abandon their breeding colonies early, resulting in the death of large numbers of chicks. Although the affected populations only represent a small number of the total emperor penguins on the continent, it’s unclear how they’ll fare if trends in sea-ice melt continue.

Science: Emperor penguins abandon breeding grounds as ice melts around them

09:23 The AI trained to describe smells

Researchers have developed an artificial-intelligence that can describe how compounds smell by analysing their molecular structures. The system’s description of scents are often similar to those of trained human sniffers, and may have applications in the food and perfume industries. Currently the AI works on individual molecules, and is unable to identify the smells associated with complex combinations of molecules, something humans noses do with ease.

Nature: AI predicts chemicals’ smells from their structures

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