The amoeba, being perhaps the simplest form of life and perhaps the basis of all subsequent ones, will certainly survive. Amoebae have the ability to go into dormant mode by wrapping themselves in a protective layer, and to remain in this state indefinitely.
They are resistant to radiation, and being a single-celled organism, they do not have the problem of mutations in reproduction. Amoebae reproduce on their own very quickly, they can be found all over the world in huge numbers, and they are very small, so the probability of their survival is very high.
The cockroach is perhaps the most famous of all animals that have a great potential for survival. Cockroaches are able to withstand moderate amounts of radiation, and were able to survive 300 meters from where the Hiroshima bomb exploded.
Of course, modern weapons are much more powerful, and cockroaches are unlikely to have survived the current nuclear blast. "Legendbusters" in their tests demonstrated that 10 percent of cockroaches survived the 10,000 rad radiation level. The Hiroshima bomb emitted 10,000 rads, so cockroaches might have survived being far away from the epicenter of the radiation.
In contrast, people exposed to 10,000 rads of radiation would instantly suffer a coma, and very soon it would lead to death. The cockroaches' ability to survive is due to their slow growth rate. Their cells reproduce every 48 hours, which reduces the risk of mutations.
Anyone who has seen scorpions living in captivity knows that they can withstand ultraviolet radiation. They also have a chance of surviving a nuclear explosion as well.
Scorpions live on every continent except Antarctica, and they can be frozen and brought back to life, which would help them in the event of a nuclear winter.
They can often be found in burrows and crevices, giving them some kind of physical protection from radiation and fallout. Scorpions are very resilient and have remained virtually unchanged throughout evolution due to their ideal shape.
4. braconid wasps
Braconids are a large family of parasitic wasps (wasps that lay eggs inside other animals). They are very resistant to radiation and have a good chance of surviving nuclear fallout.
Scientists have found that these wasps can withstand up to 180,000 rads of radiation, making them some of the most resilient animals in the world.
The only problem is whether they can find a prey to lay their eggs, but they may succeed. Also, braconids can be trained to smell harmful and explosive substances, just like dogs.
Lingulata belong to the class of brachiopods, or animals with flappy shells. The name of these animals is translated from Latin as "tongue" because of the shape of their shells.
There have been five mass extinctions in Earth's history, when most life was wiped out. Lingulata have survived all the mass extinctions, perhaps due to their ability to burrow deep into the ground during difficult periods and reappear later.
Despite their survival skills, scientists still can't say how they do it, but they probably also have a good chance of surviving a nuclear war.
6. Fruit flies
Fruit flies, or Drosophila, can survive high doses of radiation up to 64,000 rads.
Many insects are able to survive radiation because of slow cell division and very rapid reproduction, as in the case of fruit flies. The ability to reproduce means that they can change very quickly with any changes.
The small size of fruit flies also plays in their favor, as fewer cells are exposed to radiation and a smaller surface area absorbs it.
Surprisingly enough, it is quite possible that humans could survive a nuclear war. For one thing, the number of nuclear weapons in the world is decreasing. Although existing bombs could wipe everything off the face of the Earth, this is unlikely, since people are scattered all over the world.
Right now, bombs are 1,000 times more powerful than the one dropped on Hiroshima, but that doesn't mean that 1,000 times as many people will die.
Given the scattering of people around the planet and the availability of atomic shelters, there is a chance that enough people could survive to maintain a viable population. Fortunately, we are endowed with the intelligence to find a way out of many situations that is worth using in the first place to avoid dropping nuclear bombs.