if dna if fossils live for 7500 yrs how can scientists say that the earth is millions of yrs old?

We do not date the Earth by how long ago animals living on it. That is kind of like saying "I am 26 years old so how can they say the Earth is 27 years old?"

The age of the Earth has nothing to do with DNA. Earth was formed 4.57 billion years ago, which can be confirmed by radioactive dating with potassium-40, uraium-238, or rubidium-87. DNA is not used to calculate the age of Earth. Also, there is NO DNA in fossils except in some amber fossils (fossils in which an organism itself is trapped in sticky tree sap) The oldest fossil is about 544 million years old, but life itself first formed 3.7 billion years ago. I have no idea where you got the number 7500..

That date of the earth has nothing to do with DNA.

Scientists use radiometric dating. We know the time it takes from certain radioactive elements to decay. It's called a half life, which means in a certain amount of time half of the material in the sample will have decayed. For some elements like uranium the half life is million of years.

These materials don't just disappear, they change into another material called an end product. Every type of radio active material has it's own end product. When you study a rock sample you can determine it's age based on the amount of radioactive material present versus the amount of the end product.

Radio carbon dating is used in studying samples of organic materials. I think the 7500 year number you are getting has to do with that. carbon 14 is a radioactive form of carbon and has a relatively short half life of about 5700 years.

Generally speaking, scientists have developed four different methods of determining the age of the earth. By using these methods, or a combination of them, the age of geological formations created by past events and even the fossilized bones of prehistoric animals can be determined.

The three primary methods are:

Radiation Measurement

Stratigraphic Superposition

The Fossil Record

Fossils are not dated by DNA, but through methods including radioactive dating (usually not Carbon-14; it doesn't have a long enough half-life to date anything past about 12,000 years old) and the geologic layer of rock/soil it was found in.

I think you are very confused about how scientist date the age of the earth. Fossils and DNA have nothing to do with it. Try this web site, it will make things much more clear for you. www.talkorigins.org/faqs/faq-age-of-earth.html

I really fail to see the logic in this.

So what? Just because DNA can survive for thousands of years doesn't mean that the earth isn't 4.6 billion years old.

DNA is only in LIVING things. When dating the Earth, you're typically dating very old rocks and minerals and whatnot. Rocks and other forms of non-living matter don't have DNA.

You should read the info in this link:

http://en.wikipedia.org/wiki/Age_of_the_Earth

scientist say the earth is billions of years old because they need billions of years to cover up the lies they are going to tell u about how we all evolved from a rock.

because the earth isn't millions of years old

stupid evolutionists