Bringing Extinct Species Back to Life | Dr. Beth Shapiro

The definition of a species is a human concept, not a biological reality. Different concepts exist, such as the biological species concept (ability to interbreed and produce fertile offspring) and the genetic species concept (threshold of sequence similarity). The concept used often depends on the specific purpose or conversation.

Yes, Neanderthals and Homo sapiens interbred after modern humans moved out of Africa. Genetic studies show that most people today have between 2% and 5% Neanderthal DNA. This indicates that while they were distinct groups, they could produce fertile offspring, challenging strict biological species definitions.

Dinosaurs cannot be brought back because their DNA has not survived. The oldest DNA recoverable is from mammoths (around 1-2 million years old), while dinosaurs went extinct over 66 million years ago. DNA degrades over time due to UV light, freezing/thawing cycles, and microbial decay, leaving no usable genetic material.

De-extinction aims to restore ecological roles that were lost with extinct species. For example, mammoths in the Arctic could help restore grassland ecosystems by scraping snow, distributing seeds, and impacting plant diversity, making the environment more robust and resilient against climate change.

Birds present unique challenges because they cannot be cloned using the same somatic cell nuclear transfer process as mammals (like Dolly the sheep), due to difficulty accessing egg cells at the right stage. This necessitates developing different synthetic biology technologies specifically for avian species.

The woolly mammoth genome is approximately 99% similar to that of an Asian elephant. This close genetic relationship allows scientists to identify key genetic differences that made mammoths distinct and use this information to engineer those traits into an Asian elephant genome.

Direwolves are being recreated by identifying specific genetic changes that made them distinct from greywolves (e.g., size, robusticity, coat color) from fossil DNA. These identified traits are then engineered into a greywolf genome. Safety is paramount, and traits are selected or modified using edits known to be safe in living dogs, avoiding issues like albinism.

Gene drives are a powerful synthetic biology tool that could be used to manage populations, such as reducing mosquitoes that carry disease or suppressing invasive species like cheatgrass. They can be engineered to last for a fixed number of generations, offering a way to restore ecosystem balance, though careful consideration of safety measures is crucial.

It is argued that humans have always intervened in ecosystems, whether through hunting, domestication, or conservation. The current approach involves being stewards of ecosystems, using scientific tools to make them more robust and resilient. Doing nothing is also a decision that leads to less biodiversity, which is considered an unacceptable outcome.

Genetic diversity is being restored in black-footed ferret populations through cloning. Tissue samples from historically diverse populations, stored in facilities like the San Diego Frozen Zoo, are used to create new individuals, introducing genetic variety lost during population bottlenecks caused by disease and decline.

Yes, scientists are working on using synthetic biology and genetic engineering to make black-footed ferrets resistant to plague, which is a major threat to their wild populations. This involves identifying genetic underpinnings of susceptibility and editing their genome to confer resistance, allowing them to survive in their habitat.

Colossal Biosciences engages through advisory panels composed of local people, scientists, and conservationists for each project. They also use social media, podcasts, documentaries, and traditional scientific publications to communicate their work, aiming to generate excitement and discussion about the future of biodiversity and genetic technologies.