Related topics: genome

The Paleozoic diet: Why animals eat what they eat

In what is likely the first study to look at how dietary preferences evolved across the animal kingdom, UA researchers looked at more than a million species, going back 800 million years. The team reports several unexpected ...

Human ancestors were 'grounded,' new analysis shows

African apes adapted to living on the ground, a finding that indicates human evolved from an ancestor not limited to tree or other elevated habitats. The analysis adds a new chapter to evolution, shedding additional light ...

Dolphin smarts

Imagine you are blindfolded and placed into a pool of water with a dolphin. The dolphin performs a movement, such as spinning in a circle, or swimming in a zig-zag pattern, and your task is to imitate this movement, without ...

Alligator study reveals insight into dinosaur hearing

To determine where a sound is coming from, animal brains analyze the minute difference in time it takes a sound to reach each ear—a cue known as interaural time difference. What happens to the cue once the signals get to ...

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Common descent

A group of organisms is said to have common descent if they have a common ancestor. In modern biology, it is generally accepted that all living organisms on Earth are descended from a common ancestor or ancestral gene pool.

A theory of universal common descent via an evolutionary process was proposed by Charles Darwin in his book On the Origin of Species (1859), and later in The Descent of Man (1871). This theory is now generally accepted by biologists, and the last universal common ancestor (LUCA or LUA), that is, the most recent common ancestor of all currently living organisms, is believed to have appeared about 3.9 billion years ago. The theory of a common ancestor between all organisms is one of the principles of evolution, although for single cell organisms and viruses, single phylogeny is disputed (see: origin of life).

In his book The Ancestor's Tale, Richard Dawkins uses the word concestor as a substitute for "common ancestor." This new word is very gradually entering scientific parlance.

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