The sequence hypothesis was first proposed by Francis Crick in 1958. He later went on to win the Nobel prize shortly after, for his discoveries concerning the molecular structure of nucleic acids and its significance for information transfer in living material.

To understand the Sequence Hypothesis let us take a step back and look at the basic building blocks of life – specifically proteins and nucleic acids. I’ll try to keep this as simple as possible so even somebody without a background in the sciences can follow.
Proteins
Proteins are responsible for many functions in living organisms, including metabolism, DNA replication, responding to stimuli etc .. Amino acids are the building blocks of proteins, a protein is simply a giant molecule (macromolecule) consisting of one or more long chains of amino acids. Don’t be fooled by the familiarity of the term, its one of the most complex and difficult structures we have ever come across.
Nucleic Acids
Nucleic Acids which include DNA and RNA, and are absolutely essential for all forms of life. The are responsible for encoding, transmitting and expressing genetic information. These again are giant molecules (macromolecules) made of simpler nucleotides. They are considered by many to be the single most important factor for life as we know it today to exist.
The Sequence Hypothesis
In its simplest form it means that the amino acid sequence of a protein is determined by a particular sequence of nucleotides (the cistron) in the DNA of the organism producing the protein.
What this means in layman terms is that proteins can only be synthesized with the information contained in the DNA of the organism making the protein.
The chicken or an egg ?
Which Came First ? DNA or Proteins? It takes proteins to construct DNA. It takes DNA to make proteins. Even a simple study can show you both proteins and DNA are just too complex and specific to happen by chance. Life without these building blocks ( proteins, amino acids, carbohydrates etc .. ) is simply not possible.
For life to exist not only do you need these “building blocks” but you need them arranged in a very very specific way in a 3D structure. This arrangement or sequence is the genetic information they carry, even a small change here can completely break or distort the life form.
This clearly shows they both had to be created at the same time, for a consistent system architecture. This also points to a first cause who was outside the system to have designed it. This designer must have vastly superior intelligence and design skills to have done so with the kind of detail and intricacies we observe. We may be able to study processes, cobble together hypothesis, define laws around how things work etc. What the sciences will never be able to do is explain away the creator, in any rational or logical way.
Further Reading
Darwin’s Doubt
Creation vs. Evolution
Muncaster, R. O. (2000). Creation vs. evolution. Harvest House. [WorldCat, LibraryThing, Google Books, BookFinder]