We are independent & ad-supported. We may earn a commission for purchases made through our links.

Advertiser Disclosure

Our website is an independent, advertising-supported platform. We provide our content free of charge to our readers, and to keep it that way, we rely on revenue generated through advertisements and affiliate partnerships. This means that when you click on certain links on our site and make a purchase, we may earn a commission. Learn more.

How We Make Money

We sustain our operations through affiliate commissions and advertising. If you click on an affiliate link and make a purchase, we may receive a commission from the merchant at no additional cost to you. We also display advertisements on our website, which help generate revenue to support our work and keep our content free for readers. Our editorial team operates independently from our advertising and affiliate partnerships to ensure that our content remains unbiased and focused on providing you with the best information and recommendations based on thorough research and honest evaluations. To remain transparent, we’ve provided a list of our current affiliate partners here.

What is a Last Common Ancestor?

Michael Anissimov
Updated Feb 04, 2024
Our promise to you
AllTheScience is dedicated to creating trustworthy, high-quality content that always prioritizes transparency, integrity, and inclusivity above all else. Our ensure that our content creation and review process includes rigorous fact-checking, evidence-based, and continual updates to ensure accuracy and reliability.

Our Promise to you

Founded in 2002, our company has been a trusted resource for readers seeking informative and engaging content. Our dedication to quality remains unwavering—and will never change. We follow a strict editorial policy, ensuring that our content is authored by highly qualified professionals and edited by subject matter experts. This guarantees that everything we publish is objective, accurate, and trustworthy.

Over the years, we've refined our approach to cover a wide range of topics, providing readers with reliable and practical advice to enhance their knowledge and skills. That's why millions of readers turn to us each year. Join us in celebrating the joy of learning, guided by standards you can trust.

Editorial Standards

At AllTheScience, we are committed to creating content that you can trust. Our editorial process is designed to ensure that every piece of content we publish is accurate, reliable, and informative.

Our team of experienced writers and editors follows a strict set of guidelines to ensure the highest quality content. We conduct thorough research, fact-check all information, and rely on credible sources to back up our claims. Our content is reviewed by subject matter experts to ensure accuracy and clarity.

We believe in transparency and maintain editorial independence from our advertisers. Our team does not receive direct compensation from advertisers, allowing us to create unbiased content that prioritizes your interests.

The last common ancestor refers to the most recent possible shared ancestor between two individuals, species, or groups of life. For instance, the last common ancestor of all animals is thought to have existed about 610 million years ago, though it may be much older. We can infer some of its features by looking at commonalities held by all living animals. For instance, the fundamentals of cellular metabolism are held in common among all animals.

There are two ways to figure out the last common ancestor of two subjects, and they're both imperfect. The first is to dig up fossils and make guesses about their place in the evolutionary tree, based on morphology and other clues. This can fail because interpretations can be incorrect, and the vast majority of all species never left any fossils. The second is to look at the genomes of living animals and see how much information they have in common. The less shared genetic information, the more distantly related to two are, and the differences between genomes can be used to estimate the approximate time of divergence. This approach can also fail, because species evolve at different rates that we can't always predict.

The last common ancestor of all life — sometimes called last universal common ancestor, or LUCA — lived between 3.6 and 4.2 billion years ago, an extremely long time ago, even by the standards of paleontologists. The common ancestor of animals lived at least 610 million years ago, as mentioned earlier. That of all vertebrates was probably a jawless fish that lived 530 million years ago, in the Early Cambrian. The last common ancestor of all terrestrial vertebrates was a lobe-finned fish that started crawling on land 375 million years ago. These fish are the direct ancestors of all human beings.

The last common ancestor of all living mammals existed at least 125 million years ago. The last common ancestor of all primates existed between 55 and 85 million years ago, while the last one of hominids ("great apes": humans, chimpanzees, orangutans, and gorillas) lived about 18 million years ago. Orangutans, gorillas, and chimps split from other primates 14, 8, and about 7 million years ago, respectively. Until recently it was thought that the ancestors of humans split from chimps 3-5 million years ago, but new fossils discoveries have suggested that this divergence took place earlier than initially thought.

The last common ancestor of all living humans lived only about 3,000 years ago, making us all very closely related. There is some confusion with the identification of "Mitochondrial Eve," believed to be the matrilineal most recent common ancestor (MRCA) of all living humans, who lived about 170,000 years ago. The matrilineal MRCA can only be traced through female DNA, however, and cannot be directly linked as a common ancestor of all humans.

AllTheScience is dedicated to providing accurate and trustworthy information. We carefully select reputable sources and employ a rigorous fact-checking process to maintain the highest standards. To learn more about our commitment to accuracy, read our editorial process.
Michael Anissimov
By Michael Anissimov

Michael is a longtime AllTheScience contributor who specializes in topics relating to paleontology, physics, biology, astronomy, chemistry, and futurism. In addition to being an avid blogger, Michael is particularly passionate about stem cell research, regenerative medicine, and life extension therapies. He has also worked for the Methuselah Foundation, the Singularity Institute for Artificial Intelligence, and the Lifeboat Foundation.

Discussion Comments

Michael Anissimov

Michael Anissimov

Michael is a longtime AllTheScience contributor who specializes in topics relating to paleontology, physics, biology...

Read more
AllTheScience, in your inbox

Our latest articles, guides, and more, delivered daily.

AllTheScience, in your inbox

Our latest articles, guides, and more, delivered daily.