The Kid Should See This

What is Life? Dr. Samuel Ramsey explains with Crash Course Biology

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What are the seven characteristics that define life? Is fire alive? Are viruses alive? Will we find life beyond our own planet? Is biology in you?

“Biology is the study of lifeβ€”a four-letter word that connects you to 4 billion years worth of family tree. The word ‘life’ can be tricky to define, but a shared set of characteristics helps biologists identify living things.

“In this episode of Crash Course Biology, you’ll learn how all of life is connected, and why studying biology can help us better understand ourselves and our relationship to all living things.”

Dr Sammy Ramsey
Entomologist Dr. Samuel Ramsey introduces the world of biology in this new HHMI BioInteractive-produced Crash Course series, a refresh of their earlier version. He explains:

“No matter what size or shape life takes, every living thing is connected to every other living thing. Every bug, bat, and bacterium shares a common ancestor, a single-celled organism that lived about 4 billion years ago.”

all kinds of life

“But it’s not just evolution that connects us. The very molecules that make up our bodies were born in the heart of a fiery star long before Earth was formed, and that same stardust will move on after we’re gone to make up new ones…”


“This interconnectedness can be mind-blowing and perspective changing, but it’s not just something to marvel at in the abstract. It’s also a practical puzzle piece that helps us understand ourselves and our future. By knowing that we’re connected to mice on the family tree, ethically studying them can help us find cures for human diseases.

“And because life is connected by big biological processes, we can understand how our actions affect the water, the land, the climate, and in turn, us. By showing us life’s interconnectedness, biology can help us, and is helping us, find solutions to some of our biggest challenges.”

Dr. Sammy Ramsey
Watch these related videos next:
β€’Β Why are cicadas so loud? Entomologist Dr. Samuel Ramsey explains
β€’ What is an Animal? Rae Wynn-Grant explains with Crash Course Zoology
β€’ What is Botany? Alexis Nikole Nelson explains with Crash Course Botany
β€’ Why is it so hard to cure the common cold?
β€’Β Why is biodiversity so important?
β€’Β Are we thinking about alien life all wrong?

Bonus: We Are Dead Stars. Dr. Michelle Thaller explains.

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