The most likely explanation, something called parthenogenesis.

最能的解释是一种称为孤雌生殖的东西。

It's a product of parthenogenesis which means it was born from an unfertilized egg.

这种繁殖叫孤雌生殖这就是说它由没有过的卵孵化而来。

Parthenogenesis, meanwhile, requires only one parent.

而孤雌生殖只需要一位父母。

Scientists think parthenogenesis could be evolutionarily beneficial in some contexts because, well, sex can be a drag.

科学家们认为，孤雌生殖有时候在进化上更有利，因为以成为一种负担。

In parthenogenesis, an embryo develops from an unfertilized egg cell that doubles its own chromosome count.

在孤雌生殖中，胚胎由的卵细胞在染色体数目翻倍后发育而来。

In fact, some animals only ever undergo parthenogenesis, while others can reproduce both sexually and parthenogenetically.

实际上，有些动物只进行孤雌生殖，而另外一些则既以进行有性繁殖，也能进行孤雌生殖。

Scientists also confirmed that parthenogenesis was taking place in some wild snake populations.

科学家们也发现，孤雌生殖还会在某些野生蛇类种群中发生。

Parthenogenesis is best confirmed with DNA analysis, and dinosaur DNA doesn't exist in fossils.

孤雌生殖的最好证实方式是使用 DNA 分析，而恐龙 DNA 并不存在于化石中。

Bdelloid rotifers, meanwhile, have been reproducing parthenogenetically for 60 million years.

与此同时，蛭形轮虫已经孤雌生殖了近 6000 万年。

In the summer, when food is abundant, pea aphids can rely on parthenogenesis, allowing their population to explode under favorable conditions.

在夏季食物充足的时候，豌豆蚜以孤雌生殖，让种群数量在有利环境中迅速膨胀。

But some aphids, katydids, lizards, geckos, and snakes only ever reproduce via parthenogenesis.

而有些蚜虫、蝈蝈、蜥蜴、壁虎、蛇等只进行孤雌生殖。

Scientists already knew that birds are capable of parthenogenesis, and now they've learned that crocs are also on board.

科学家早已知道鸟类具有孤雌生殖的能力，现在他们又发现鳄鱼也具有这种能力。

In a parthenogenetic population, on the other hand, individuals can only reproduce using their own genetic material.

另一方面，在孤雌生殖的群体中，个体只能利用自身的遗传物质进行繁殖。

Mayflies can default to parthenogenesis, which is quite handy because some females live for less than 5 minutes.

蜉蝣以默认进行孤雌生殖，这非常方便， 因为有些雌性寿命不到 5 分钟。

Parthenogenesis is characterized by a lack of genetic diversity, which can lead to harmful mutations and diseases.

孤雌生殖的特点是缺乏遗传多样性，这能导致有害的突变和疾病。

Even when there are males around, females may still use parthenogenesis.

即使周围有雄性，雌性仍能采用孤雌生殖。

Still, parthenogenesis plays an important role when population numbers need to grow fast in a short time.

尽管如此，当种群数量需要在短时间内快速增长时，孤雌生殖仍然起着重要作用。

But this wasn’t a case of cloning or parthenogenesis -- sometimes called " virgin birth" -- neither of which requires sperm.

但这不是克隆或孤雌生殖——有时称为“处女生育”——两者都不需要子。

Parthenogenesis is a type of asexual reproduction where an embryo develops without previous fertilization.

孤雌生殖是一种无性生殖，其中胚胎无需先前即发育。

But some species that have sex cells can undergo a type of asexual reproduction called parthenogenesis — meaning " virgin origin" in Greek.

不过，一些具有性细胞的物种以进行一种无性繁殖，即“孤雌生殖”，在希腊语中是“处女起源”的意思。