Feline Phylogeny

Introduction

This piece is a bit more whimsical than the rest of the series. It depicts the phylogenetic tree of the Felidae (cat) family using a linear dendrogram. A tree of life, for the feline tree of life. I used slightly outdated data, put together by interns at RawGraphs, which leads to some discrepancies from the generally accepted modern phylogeny. Phylogeny is ever evolving, so the differences didn't really bother me.

Data & Design

38 species in 13 genera from 3 subfamilies. The mass of a representative adult male from each species is encoded by the area of the circle at the termini of the dendrogram. I assigned a colour to each species, and also to each genus/subfamily.

Gradient Innovation

The branches of the dendrogram have a linear gradient fill progressing from the colour of the previous node to the colour of the subsequent node. I assume it's been implemented elsewhere before, since it is a rather simple idea, but it was my one main novel visual contribution here. Particularly helpful for such phylogenetic trees, since it helps convey the gradual progression of evolutionary changes over time. Divergence from common ancestry. Perhaps I should have applied some colour theory.

The first cats are believed to have emerged 25 million years ago, during the Oligocene. The entire Machairodontinae subfamily (to which the saber-toothed tiger belonged) is unfortunately extinct. Only species in the Panthera genus are called 'big cats'. Tiger, lion, jaguar, leopard, and snow leopard. The last one is the only one of the five that cannot roar.

There is some David v Goliath action going on amongst all the cats—one of the smallest ones, the black-footed cat, is considered to be the most successful predator of the lot. Its killing instinct dwarfs the lion and the tiger, two massive apex predator cousins with great PR teams and rather disappointing results.

Speaking of tigers, I highly recommend taking a safari through Ranthambore National Park if you're ever around that corner of the world. Perhaps finding yourself? It's a large wildlife sanctuary, and the tigers just roam around the jungle. Here is a picture from my trip back in October 2016:

I varied the stroke width of the dendrogram moving from left to right, to convey the relative breadth of the classification at each level.

"All the branches of a tree at every stage of its height when put together are equal in thickness to the trunk [below them]." — Leonardo da Vinci, Treatise on Painting, 1482-1499

The painter/draughtsman/engineer/scientist/theorist/sculptor/architect sketched out a 'Rule of Trees' centuries ago, and used it for naturalism in his art. This is the principle I implemented to some degree in the dendrogram, which had uniform stroke widths originally.

There is a little legend below the dendrogram that conveys the technical names for the information presented above. Like the column labels in a spreadsheet, appended at the bottom instead. Not entirely happy with the spacing and so on.

I played with fonts a bit to better distinguish the different kinds of labels. Some madness in the methods, some methods to the madness.

Coat Patterns

The background, reminiscent of tiger stripes, is meant to represent a ball of yarn, and a curled up cat. If you have a sharp eye you might realise it's the calligram sun motif I use in all the pieces. There is a set of six circles filling out the negative space that feature the coat patterns for six species. The soft fur and the diverse coat patterns are one of the key distinguishing characteristics of the cat family as a whole.

Genetics & Variation

You can learn interesting things about genetics (specifically Chromosome X inactivation) by looking at the pattern of colours on a calico (tri-colour) cat. Unpigmented areas are white, pigmented areas with the black X inactivated are orange, while pigmented areas with the orange X inactivated are black.

Siamese cats with point colouration exhibit acromelanism. They have partial albinism due to a mutated enzyme that helps produce melanin. The mutated tyrosinase is inactive at regular body temperatures, but it works at cooler temperatures. This leads to the white body and the dark face/paws/ears. Physical temperature gradients brought to life by the chemistry of life!

Pictured above is Soviet linguist Yuri Knorozov and his Siamese cat Asya. Yuri is famous for deciphering the Mayan script in 1952. Or making a seminally significant advance, at least. He listed Asya as a co-author on his papers, used this picture as an author photo, and fought a lifelong battle with editors who had the temerity to remove her name and crop out her image. A man's undying commitment to his feline familiar inspires. Muses come in many forms after all.

I rendered the fur patterns included in the visualisation in black-and-white. I also added a rippled glass texture to better bring out their role in camouflage. The colour of the circle's circumference can help identify which species the pattern comes from, since it is the same gradient stroke as the final branch for a particular species.

A few are rather obvious. From left to right, for the three in Figure 8: a tiger, a domestic cat, and a cheetah. The three in Figure 9: a jaguar, a clouded leopard, and a leopard.

The domestic cat pattern pictured above is from none other than my [formerly] own kitten Zafran! He's doing quite well with his new family in New York.