The surface of Mars bears imprints of structures that resemble fluvial steam networks on Earth. Scientists therefore assume that there must have been once enough water on the red planet to feed water streams that incised their path into the soil. For years, however, scientists have been debating the source from which this water must have originated: was it rainwater that caused streams and rivers to swell? Or did water ice in the soil melt due to volcanic activity, and seep out to form rivers? Each of these scenarios leads to a completely different conclusion about the climatic history of the red planet, according to Science Daily.

Female seals don't change their spots, according to a new study by University of Alberta biologists. In fact, individual differences in boldness remain consistent over time, according to Science Daily.

The study is among the first to examine boldness in wild marine mammals in the burgeoning field of animal personality. Animal personality influences many ecological processes, like how individuals interact with other species or respond to changing environmental conditions.

Researchers studied female seals on Sable Island, home to the world's largest grey seal colony. Over a nine-year period from 2008 to 2016, biologist Christi Bubac measured boldness responses in the female seals when defending their offspring.

Domesticating rabbits has changed the structure of their brains so that they process fear completely differently to wild ones, scientists have shown, according to Daily Mail.

Pet bunnies are less afraid of contact with humans, thanks to 'profound' differences in their brains, revealed by advanced imaging scans.

Alterations were found in regions involved in their response to fear, the amygdala and medial prefrontal cortex.

Scientists at Uppsalla University in Sweden raised domestic and wild rabbits in similar conditions and used high-resolution MRI scanners to study how domestication affected their brains.

They're some of the strangest birds in the world, known for their bright plumage and their penchant for fruit.

The turacos, or banana-eaters, are today found only in Africa, living in forests and savannah, according to BBC.

A beautifully preserved fossil bird from 52 million years ago is shaking up the family tree of the exotic birds.

The fossil's weird features suggests it is the earliest known living relative not just of the turacos, but of cuckoos and bustards (large long-legged birds).

Scientists have discovered the fossil of an unusual large-bodied sponge-like sea-creature from half a billion years ago, according to Science Daily.

The creature belongs to an obscure and mysterious group of animals known as the chancelloriids, and scientists are unclear about where they fit in the tree of life.

They represent a lineage of spiny tube-shaped animals that arose during the Cambrian evolutionary "explosion" but went extinct soon afterwards. In some ways they resemble sponges, a group of simple filter-feeding animals, but many scientists have dismissed the similarities as superficial.

The new discovery by a team of scientists from the University of Leicester, the University of Oxford and Yunnan University, China, adds new evidence that could help solve the mystery.

The new species, named Allonnia nuda, was discovered in the Chengjiang deposits of Yunnan Province, China. It was surprisingly large in life (perhaps up to 50 cm or more) but had only a few very tiny spines.