TIL the gene that builds the mammalian placenta came from a virus. A retrovirus infected our ancestors over 100 million years ago, integrated into their DNA, and the gene encoding its cell-fusion protein got repurposed to bond mother and fetus.

TIL that the first Apple computer in schools was hand-delivered by Steve Wozniak, is still with the computer education center he gave it to, and barely worked at all.

TIL that around 8-10% of domestic rams are homosexual and refuse to mate with female sheep, readily mating with other rams only. While homosexual behavior occurs in many species, rams are the only mammal species other than humans where certain individuals mate exclusively with the same sex

TIL that Alexander the Great may have been buried alive. Historical records show he didn't decompose for six days after being declared dead. Modern scientists believe he suffered from Guillain-Barré Syndrome, a neurological disorder that paralyzed him.

TIL that the Great Salt Lake was originally Lake Bonneville which was so large it extended into modern day Idaho and Nevada.

TIL that babies under 6 months cannot have water. Their small stomachs easily fill up, reducing their intake of calorie-dense breast milk or formula. Additionally, their developing kidneys struggle to filter extra water, which can trigger water intoxication and dangerously low sodium levels.

TIL that this fish species, Amazon Molly, survived 100,000 years without males. Scientists thought it should be long dead but it's thriving.