Thắc mắc kinh điển đêm khuya: Vì sao "cậu nhỏ" luôn... đen ...?
vì melanin (hắc tố) nhé... ;)
đọc bài 'bí ẩn khủng long làm tình như nào' ở bbc, các nhà khoa học vẫn ko thể làm được điều đơn giản là phân biệt con nào là con cái, con nào là con đực, chưa nói gì đến việc làm tình như nào (ko thể biết được)...
But research into exactly how dinosaurs mated – or in fact, anything at all about how they hooked up (quan hệ) – has drawn a total blank. To this day, scientists can't even accurately distinguish (phân biệt chính xác) males from females, let alone tell you how they courted (tán tỉnh) or what kind of genitals (bộ phận sinh dục) they had. Without this fundamental knowledge (kiến thức cơ bản), much of their biology and behaviour remains a total mystery (điều bí ẩn). Only one thing is certain: they would have been doing it.
..."So you can see, if you look underneath here [he gestures towards the psittacosaurus' cloaca, under its tail] – there's lots of pigment (sắc tố; chất màu, chất nhuộm)," says Vinther. He explains that this is melanin (hắc tố), and it might be partly responsible for the extraordinary level of preservation in this specimen.
Though we tend to think of melanin as the dark compound that gives our skin (da) its colour, it has a kaleidoscopic (kính vạn hoa, có nhiều màu sắc biến ảo) range of uses in the natural world, from its application as a pigment in squid ink to its function as a protective layer at the backs of our eyes. It's also a potent antimicrobial – in amphibians and reptiles, it's commonly found in high concentrations in the liver, where it prevents the growth of potentially harmful microbes. But crucially, it's also found in many other situations where this would be useful.
"For example, the insects… they use melanin as a sort of immune system to protect against infection. So if you poke a hole in a moth, for example, with a needle [this is not recommended], then the area around where you poke the hole will secrete melanin," says Vinther.
For this reason, many animals, including humans, have higher concentrations of melanin – and therefore, darker skin – around the genitals. And this is just as true for dinosaurs as it is for humans. Looking at the distant relative in front of me, who – as one of my colleagues pointed out – is frozen in a pose as though they're trying to tiptoe past me, it feels odd to recognise such an intimate similarity.