1. It is any unusual physical deformity.
   It refers to a distasteful stereotype.
2. It's a trait of a distant ancestor that has reappeared.

An atavism is a trait of a distant ancestor that reappears in the modern day.

1. only humans
   humans and animals
2. only animals

It happens with humans and other animals.

1. a whale with legs
   a person with excessive body hair
2. an animal with an inherited physical defect

A good example is a whale with legs.

1. a good example
   depends on the amount of hair
2. not at all

Since ape faces are hairless, this is not an atavism, unless we are descendants of werewolves.

1. webbed fingers
   human tail
2. missing fingers

The human tail is the one you have heard about the most.

1. inherited DNA
   deformed gene
2. random fluke of nature

One theory says that genes, such as those governing growth of a tail, are not lost in evolution but are inactive. During the development of the embryo something unknown "turns on" that gene.

1. It's a surviving body part that doesn't serve its original purpose.
   It's an extinct part of the vestigial species.
2. It's any physical anomaly.

They are body parts that survive although they don't serve their original purpose, like an ostrich's wings, since it can't fly.

1. Legs used to help them swim but later became a nuisance and were lost.
   They used them to fight with until they perfected other means.
2. They once walked on dry land.

Scientists believe that millions of years ago the ancestors of the whale walked on land. At some stage they took to the sea, probably in search of food, and since they no longer needed their legs in the water, eventually lost them.

1. Evolution is dynamic and open to changes of all kinds.
   Things lost in evolution cannot reappear.
2. Evolution can easily be tampered with.

It states that evolution is irreversible: Once things are lost they cannot reappear.

1. The human tail is a genetic fluke.
   It has a direct correlation.
2. Humans are vertebrates and vertebrates can grow tails.

This would make the human tail a genetic fluke, but all vertebrates can grow a tail and humans are vertebrates. This fact seems to negate his theory.

1. nobody knows
   global warming
2. dietary changes

Scientists still don't know, despite all their research.

1. It can be used for any anomaly or behavioral throwback
   This would be inaccurate.
2. This is an ideal area for use of the term.

Atavism is used, inaccurately, to describe man's aggression as an atavism relating to his ancient past as a barbaric hunter.

1. Tend to refute evolution theory.
   They give credence to the theory of evolution.
2. We don't know.

The truth is we simply don't know.

1. designer children
   DNA studies
2. understanding evolution

They often think about controversial subjects like cloning or designer children.

1. These are clear examples.
   It's only speculation.
2. They are simply genetic flukes.

At present we can only speculate until more is known.