I would think they are around B. 11 years old
Answer: I could be wrong but id say
Genetics is the study of genes. Genes are functional units of DNA that make up the human genome. They provide the information that directs a body's basic cellular activities. Research on the human genome has shown that, on average, the DNA sequences of any two people are 99.9 percent the same. However, that 0.1 percent variation is profoundly important. t accounts for three million differences in the nearly three billion base pairs of DNA sequence. These differences contribute to visible variations, like height and hair color, and invisible traits, such as increased risk for or protection from certain diseases such as heart attack, stroke, diabetes, and addiction. Genetics and lifestyle factors—such as diet, physical activity, and stress—affect high blood pressure risk. NIDA research has led to discoveries about how a person's surroundings affect drug use in particular. For example, a community that provides healthy after-school activities has been shown to reduce vulnerability to drug addiction, and data show that access to exercise can discourage drug-seeking behavior, an effect that is more pronounced in males than in females.
I belive the answer to the first one is no I would have to assume a habitual zone is one area on a planet. for example, an air conditioned building vs. the Savvanah dessert. However I am not sure maybe other answers will help more on this one. Sorry.... Earth-like planet would of course need water, plant life, animals, oxygen, fossil fuels etc. A challenge we would face on a travel to another liveable planet: do we have engough transportation? engough fuel to make it? How long can we live on this planet? Who or what else is present here? etc. Yes I do think they should discover a planet with earth like qualities befor investing in tools to get us to them. So money is not wasted. (make sure to put this into your own words )
Lol. Here I am.. Saying whatever the heck I want. :)