A human’s sex is genetically determined. One of our 23 pairs of chromosomes carries genes that determine the embryo’s sex; ...

From Egg-Layers to Warm-Blooded Wonders The earliest synapsids laid eggs, much like today’s reptiles and birds. Over countless generations, some synapsids started developing characteristics that ...

From reproductive rights to climate change to Big Tech, The Independent is on the ground when the story is developing. Whether it's investigating the financials of Elon Musk's pro-Trump PAC or ...

Fossilized footprints of a primitive reptile found on a slab of rock from Australia could rewrite the story of how animals ...

What we discovered is that property of extended embryo retention goes all the way back to the start of the reptiles. So it was not the hard-shelled egg. It was extended embryo retention that they ...

The earliest reptiles, birds and mammals may have borne live young, researchers from Nanjing University and University of Bristol have revealed. Until now, the hard-shelled egg was thought to be the ...

Even so, mammals can’t reproduce through parthenogenesis, he says. Unlike reptiles, fish and birds, their embryo formation requires genomic imprinting, meaning specific genes from both the ...

So, the temperature of most reptile embryo’s environments can determine the gender. For example, eggs incubated at higher temperatures will produce one gender, while reptile eggs incubated at ...

The earliest reptiles, birds and mammals may have given birth to live young rather than laying eggs, new research suggests. Until now, the hard-shelled egg was thought to be the key to the success ...