What Is Phylogeny?

Definition: Phylogeny is the study of the evolutionary history of a species or group of organisms (such as birds). It creates lines of descent showing the relationships of organisms based on common or similar characteristics. It is an attempt to trace the evolutionary history of all living organisms.

Phylogenetic studies result in diagrams, called phylogenetic trees, showing the evolutionary relationships between organisms. The one shown above is one of the simpler diagrams called a spindle diagram. It is also known as a bubble diagram or a romerogram. Time is shown on the vertical axis. The width of each column indicates the diversity of individuals through time.

Another term to be familiar with is "cladistics." Cladistics is a method of categorizing organisms into groups (clads) based on shared characteristics among their most recent ancestors. Cladistic classification is a tool used in phylogenetical studies.

Of course, since both cladistics and phylogeny have as their foundation the assumption that evolution is true, logically that means they cannot be used to prove evolution is true. However, the diagrams they produce are commonly used as proof of evolution.

The best known phylogeny of birds was created by Dr. John Ahlquist and Dr. Charles Sibly. Published in 1991, the "Phylogeny and Classification of Birds" became an influential phylogeny for birds, and is now known as the Sibley–Ahlquist taxonomy.

Dr. Jon Ahlquist (Ph.D from Yale) was a molecular biologist who specialized in molecular phylogenetics, and he was also a leading ornithologist (bird expert). In 1988 he was a co-recipient of the Daniel Giraud Elliot Medal from the U.S. National Academy of Science for his work in bird DNA in 1988. He held professorships at Ohio University, the University of Louisville (Kentucky), and several South Carolina universities. He taught a variety of subjects that include: ornithology, comparative vertebrate anatomy, avian biology, molecular evolution, and systematic zoology. He was the leader in the field of bird evolution. He passed away in 2020 at the age of 75.

Dr. Ahlquist was a Christian who believed in evolution. However, in 1991 his continued study in both science and the Bible resulted in his changing his understanding of our origins from evolution to Biblical creation. He had noticed a problem in the field where he was the recognized expert... bird phylogenetics. He states:

“The techniques used by phylogeneticists to make their ‘trees’ are laden with evolutionary assumptions. They simply assume that evolution is a fact and then stuff their data into their algorithms, which therefore will always produce an evolutionary result. Regardless, we all have the same data, the difference is how we interpret it.”

This is common. When someone actually digs into the methods and processes on which "proofs" of evolution are based, what they'll find are not scientific facts, but a foundation of assumptions that are, in turn, all based on the assumption evolution is true. A foundation of sand.