Extinction is a natural part of life on Earth. But occasionally, extinction rates have surged far beyond usual levels, driving mass extinction events that have reshaped the trajectory of life.

The genome sequences of 51 giraffes from all over Africa contribute to the latest attempt in an ongoing pursuit to pin down a species number.

The offspring of crosses between related species can sometimes fill a new environmental niche, and such hybridizations may even lead to speciation.

In the 20th century, animals such as mules and ligers that had parents of different species were considered biological flukes, but genetic sequencing is beginning to unravel the critical role of hybridization in evolution.

Researchers analyzed more than 800 species.

From regulating each other’s gene expression to encoding different parts of the same proteins, the two genome types in every eukaryotic cell are far from independent.

Interactions between mitochondrial and nuclear genomes have further-reaching effects on physiological function, adaptation, and speciation than previously appreciated.

When different archaeal species mate, their CRISPR systems interact in ways that may influence their evolution.

A fish created by spontaneous androgenesis is the first known vertebrate to arise naturally by this asexual reproductive phenomenon. 

Speciation and development of new traits may not always go hand-in-hand.

Standard taxonomy lumps together bird species that should be separate, a new study suggests, raising the total number of estimated species from 9,000 to 18,000.

Rick Harrison, an evolutionary biologist known for his research on speciation, has passed away at age 70.

Scientists mutate a mating pheromone and its corresponding receptor in yeast to promote speciation.

New hadrosaur uncovered in Utah hints at surprising speciation.  

Bacterial populations’ differing strategies for responding to their environment can set genetic routes to speciation.

Species in a tightly knit genus of Old World primates have evolved tell-tale facial characteristics to prevent hybridization, a study shows.

The International Institute for Species Exploration announces its picks of novel species discovered in the past year, including a carnivorous mammal, a tiny shrimp, and a fungus.

A look at 2013’s noteworthy new species

The Howard Hughes Medical Institute this week released three short films to teach students about evolution and speciation.