Friday, September 4, 2015

In Search Of Deep Time, Henry Gee, c. 1999

An easy-to-read book on early cladistics. Maybe something for the beach for light reading but lots of cocktail trivia. Fun to read in light of where we are in 2015.

Full title: In Search of Deep Time: Beyond the Fossil Record to a New History of Life.

This small book could have been subtitled with "cladistics."

The "new history of life" appears to be a book about emergency of cladistics.

Chapters:
1. Nothing Beside Remains
2. Hunting Unicorns
3. There Are More Things
4. Darwin and His Precursors
5. The Gang of Four
6. The Being and Becoming of Birds
7. Are We Not Men?
The chapter titles could have been greatly improved.

Chapter 1: Nothing Beside Remains

Introduction of cladistics. Starts with his time in Kenya looking for hominioid fossils. A nice overview of the Leakeys.

Chapter 2: Hunting Unicorns

The fishes. Today there are more fishes than amphibians, reptiles, mammals, and birds put together.

Among the panoply of fishes, which are the ancestors of the tetrapods?

Tetrapods sprang from the greater subgroup of bony fished called the Sarcopterygii -- the so-called "lobe-finned" fished. Only four (from the original thousands) remain. Three of the four are the so-called lungfishes, one each from Africa, Australia, and South America. The fourth is the coelacanth. Thought to be dead, one was recovered off South Africa in 1938, after a gap of 70 million years. A second coelacanth turned up in the Comoro Islands in the Indian Ocean in 1952. Since then, more than 200 have been caught in that area, though many others have been spotted off Madagascar.

A coelacanth discovery in 1998 off Sulawesi in Indonesia was "the zoological surprise of the year."

Discussion of the extinct "osteolepiform" fishes as the missing link in this chapter.

Acanthostega -- a tetrapod missing link. Discussion of the hyomandibula, the equivalent of the tiny stapes ('stirrup') bone in our middle ear -- in fishes, the hyomandibula forms a substantial structural element that holds the back of the skull together. 

Modern tetrapods, the hyoid anchors muscles that work the tongue. The hyoid is a vestige of an elaborate basketlike structure that supports the internal gills of fishes. The tetrapod Acanthostega was an obligate aquatic animal.

Discussion of pteraspids, a jawless fish of the Devonian period.

Chapter 3: There Are More Things

Back to Darwin. Evolution.

Triceratops.

Discussion of sex: the origin of sex remains an important problem for evolutionary biologists. Sex explains how variation is maintained; it does not tell us why. Important concept: discussed also by Nick Lane in recent book (2015) the Vital Question.

Chapter 4: Darwin and His Precursors

Those before Darwin.

Chapter 5: The Gang of Four

Don Rosen, Peter Forey, Colin Patterson, Brian Gardiner; 1981; article in Bulletin of the American Museum of Natural History: argues that lungfishes (discussed earlier) were closest living relatives of the tetrapods.

Argued that cladistics was the way to do this -- not the classical way used for decades. Not welcomed by paleontologists.

Chapter 6: The Being and Becoming of Birds

Important link: Dromaeosaurs. Mentioned in passing in Dingus and Rowe The Mistaken Extinction, but an important link.

Chapter 7: Are We Not Men?

The cladistics of humans.

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