Where Do House Cats Come From?

Question

Life Science Studies: Heredity, Genetics, and Variation in Traits

Scientists have learned something new about house cats. They learned that all house cats came from five kinds of wild cats. These wild cats lived in the Middle East many thousands of years ago.

How did scientists learn this? They looked at 1,000 wild cats and house cats from many countries. They studied the cats' DNA. Why did they study DNA? DNA tells us many important things. It can tell us where animals come from.

What did scientists find? The DNA of some wild cats matched that of some house cats. Then, the scientists were able to track the cats' ancestry.

Scientists believe cats were domesticated just a few thousand years ago. How? They began to hunt on farms. They hunted mice. Then, the cats and the farmers became friends.

The study of cats is serious work for scientists. Cat DNA can help scientists better understand genetic diseases. Scientists can use what they learn to help people. They can also use what they learn to protect wild cats.

Information for this story came from AP.

Dig Deeper
Scientists studied DNA. It helped them learn that house cats came from Middle Eastern wild cats. How could it help them know that? DNA is the information molecule. It stores information that the cell needs. This allows the cell to put together amino acids. They must go in the correct sequence, or order. Then, the amino acids can make certain proteins. Proteins are large molecules. They are made up of chains of smaller molecules. These molecules are called amino acids. There are 20 different amino acids. These come together in different ways. They make up the thousands of different proteins found in the human body.

How is each DNA molecule shaped? Like a double-stranded spiral. It looks like a twisted ladder. What is that ladder made of? Nucleotide subunits. These make up the two strands of the DNA molecule. (Nucleotides are subunits of nucleic acids.) One part of the nucleotide is the side rail of the DNA "ladder." The other part is the nucleotide base. It makes up the rung. Really, two bases come together to make the rung. Each nucleotide base is joined to another base from the opposite strand.

There are four different nucleotides in DNA. They are known by their bases. The bases are adenine (A), thymine (T), cytosine (C), and guanine (G). The nucleotides are different sizes and shapes. They fit together like puzzle pieces. Adenine always pairs with thymine (A-T). Cytosine always pairs with guanine (C-G). These bases are often just called by the letter they start with. They are called A, T, C, and G. How can you remember how they pair? Think "All Tigers Can Growl."

Diagram showing DNA molecule, eukaryotic cell with inset of DNA base pairs.

Image credit: Soleil Nordic/Shutterstock (DNA); Christoph Burgstedt/Shutterstock (cell)

A DNA molecule is a shaped like a double-stranded spiral, or double-helix, and is found in the nucleus of eukaryotic cells.

The sequence of the bases is very important. The bases in a DNA strand are in a special order. This makes the code for making proteins. Think of a cookbook. It lists all the foods needed to make something. A set of bases is like this. It lists the amino acids needed for a certain protein. The cookbook uses just 4 bases. They are A, T, C, and G. These bases can code for 20 amino acids. Suppose 2 bases coded for 1 amino acid. There would be only 16 ways to put the amino acids together. But 3 bases code for each amino acid. This makes 64 ways to put the amino acids together.

The genetic code is called a triplet code. Why is it called this? Three bases code for each amino acid. They must be in a certain sequence. Each gene is made up of a sequence of bases. These are found at a certain place on the DNA.

Question 4


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What is the main idea of this news story?

Scientists say cats were domesticated a few thousand years ago.
Scientists are learning important things from cat DNA.
Wild cats now live in many different countries.
House cats come from five kinds of wild cats.

Answer 1

The main idea of this news story is that scientists are learning important things from cat DNA. This encompasses the discovery that house cats originated from five kinds of wild cats in the Middle East and highlights the significance of DNA in understanding the ancestry and genetics of both house cats and their wild counterparts.