First Human Embryos Edited in U.S.

[lavinia]

In a nutshell(i have to rush to classes) what i am implying is that genes often cross over during cell division, we call this mutation and it often happens in an organism to produce variation naturally, if we venture into introducing new genes (which is what we will eventually do) new mutations might occur which could potentially disrupt the path of nature, if and when this happens we could cause our own downfall rather than fix the issue, that is one of the main issues with impeding genetic engineering.I will post more later.

Biologists that I know do not believe in a "path of Nature". Can you explain what you mean by this?

 

[jim mcnamara]

No. thejosh made several errors. There is no 'path of nature'. And single mutations alone will not wipe out a species - they are not a time bomb.
What I think he means is: If a mutation that is fatal homozygously (means just one allele of the the pair is required to have the effect) is common in a population, all people with it will die. But. How did it get into enough people long enough to be "common" in the first place.
Without killing them first?

What kills species is usually major environmental change, which usually occurs over periods longer than one lifetime. Sometimes a catastrophic event can cause a so-called population bottleneck (Founder Effect) . A few hundred individuals survive a major population die out. Modern cheetahs are an example of this.
See:

As a species, cheetahs have famously low levels of genetic variation. This can probably be attributed to a population bottleneck they experienced around 10,000 years ago, barely avoiding extinction at the end of the last ice age. However, the situation has worsened in modern times.

evolution.berkeley.edu/evolibrary/news/070701_cheetah