But maybe you can explain archaea, and eukaryotes, Alice.

也许你应该解释一下古生菌和真核生。

They are the closest relatives to eukaryotes, according to recent DNA analyses.

根据最近的DNA分析，它们是与真核生最接近的亲属。

Prokaryotes didn't gradually morph into eukaryotes through a bunch of gradual evolutionary steps.

原核生不是通过一系列渐进的进化步骤逐渐变成真核生的。

Such modern intermediates might have been the end product for primeval eukaryotes.

这些现代中间可能是原始真核生的终产品。

Roughly one billion years later, prokaryotes evolved into more complicated eukaryotes.

大约 10 亿年后，原核生进化成更复的真核生。

We have isolated around 30 or 40 strains already of unicellular eukaryotes.

Malavin：我们已经分离出大约 30 或 40 株单细胞真核生。

Another  billion years passed before eukaryotes developed into multicellular organisms, which eventually  exploded into diverse kingdoms of complex life.

又过了 10 亿年，真核生才发展成为多细胞生，最终发展成复生命的不同王国。

For that reason, palaeontologists have used the compounds as a biomarker for the presence of eukaryotes in ancient rocks.

因此，古生学家使用这些化合作为古岩石中真核生存在的生标。

He said that while fungi are one of the more diverse groups of eukaryotes today, their ancient fossil record is " very scarce" .

他说，虽然真菌是当今最多样化的真核生之一，但关于它们的古老化石记录" 非常稀少" 。

The molecules are 1.6 billion years old and hint that eukaryotes were abundant and widespread much longer ago than earlier biochemical evidence had suggested.

这些分子有16亿年的历史，暗示着早在之前的生化学证据所显示的时间之前，真核生就已经广泛存在和繁殖了。

This absence has led to speculation that before 800 million years ago, eukaryotes were not abundant enough to leave a detectable sterol trace.

这种缺乏导致了一种猜测，即在8亿年前之前，真核生并不足以留下可检测到的类固醇痕迹。

Most modern eukaryotes rely on fat-like compounds called sterols, such as cholesterol, to build cell membranes and carry out other cellular functions.

大多数现代真核生依靠类似脂肪的固醇类化合（如胆固醇）来构建细胞膜并执行其他细胞功能。

This year, microbiologists took a major step toward understanding the origin of eukaryotes, the group that includes plants, animals, and other organisms with cell nuclei.

今年，微生学家在理解真核生的起源方面迈出了一大步，真核生是包括植、动和其他有细胞核的生的。

And that included humans as well as plants and many other complicated eukaryotes.

这包括人类以及植和许多其他复的真核生。

Eukaryote is the scientific term for organisms with a much larger and more complex type of cell– and this group includes all animals, plants, and fungi.

真核生是指具有更大更复细胞的生，真核生包括所有的动、植和真菌。

One possibility is that eukaryotes that make more-modern sterols gained a selective advantage between one billion and 800 million years ago, eventually displacing their protosterol-making counterparts.

可能的一种可能性是，在10亿到8亿年前，制造现代固醇的真核生获得了选择性优势，最终取代了它们制造原始固醇的同类。

In eukaryotes, if the introduced genes are derived from another organism, the resulting transgenic plants or animals can be propagated by normal breeding.

转基因羊已经被生产了出来，可以通过它们的奶生产有价值的蛋白。目的基因需要羊的启动子（酪蛋白或乳清蛋白）以确保在乳腺中表达。从奶中纯化蛋白要比从培养的细胞中纯化蛋白要容易的多。

Because sterols are found throughout the eukaryotic family tree, they are thought to have been present in the last common ancestor of all modern eukaryotes.

由于类固醇在真核生系谱中随处可见，因此人们认为它们存在于所有现代真核生的最后一个共同祖先中。

Problem is, it’s hard to know when that first eukaryote popped up on Earth, since it’s so tough to find and identify the oldest fossils.

问题是，很难知道第一个真核生是什么时候出现在地球上的， 因为要找到和鉴定最古老的化石非常困难。

If these multicellular eukaryotes were already around 1.6 billion years ago, it’s possible that other complex organisms, like animals, may have started appearing millions of years earlier than we thought.

如果这些多细胞真核生已经存在于大约 16 亿年前，那么其他复的生（ 例如动） 可能比我们想象的早出现了数百万年。