Evolution What the Fossils Say and Why it Matters

Spineless Wonders of Evolution 195 tube feet lengthens and straightens out (fig. 8.9). However, later research showed that Rowe’ ...

196 Evolution? The Fossils Say YES! tightly curved and thinner, more dish-like shells that are much wider than long (fig. 8.10), ...

Spineless Wonders of Evolution 197 years old) rocks along the Gulf Coast of Texas, Louisiana, Mississippi, and Alabama (fig. 8.1 ...

198 Evolution? The Fossils Say YES! shows both stasis and gradual evolution, but the conclusion is clear: these trilobites were ...

Spineless Wonders of Evolution 199 and in fossil manipulation, and the establishment of a progressively refined timescale contri ...

200 Evolution? The Fossils Say YES! if they are supposedly unchanged through millions of years, they would have no transitional ...

Spineless Wonders of Evolution 201 to their ancestry (Newell 1959; Fisher 1982, 1984) or related to both the horseshoe crabs and ...

202 Evolution? The Fossils Say YES! which is reduced to two smooth button-shaped shields for the head and thorax and almost no t ...

Spineless Wonders of Evolution 203 the lip of the shell are segmented gills, kidneys, hearts, gonads, and paired retractor muscl ...

204 Evolution? The Fossils Say YES! Once arthropods evolved, they diverged into a wide variety of body forms, from elongate mult ...

Spineless Wonders of Evolution 205 a caterpillar to an adult moth or butterfly, or from a maggot to an adult fly. Thus we can ex ...

206 Evolution? The Fossils Say YES! For Further Reading Benton, M. J., and P. N. Pearson. 2001. Speciation in the fossil record. ...

Spineless Wonders of Evolution 207 Raff, Rudolf A. 1998. The Shape of Life: Genes, Development, and the Evolution of Animal Form ...

CambrianOrdovicianSilurianDevonianMiss.Penn.Permian Triassic Jurassic Hagfishes Lampreys Heterostracans Osteostracans Anaspids P ...

9 Fish Tales Show Some Backbone! We can trace without a break, always following out the same law, the evolution of man from the ...

210 Evolution? The Fossils Say YES! (the coelom) of the Deuterostomata forms from an outpocketing of the inner layer of cells, o ...

Fish Tales 211 With these basic parts of the chordate body plan outlined, we can now look at the steps that produced a vertebrat ...

FIGURE 9.3. The hemichordates include the pterobranchs and the acorn worm (shown here). This creature looks superficially wormli ...

Fish Tales 213 FIGURE 9.4. A diagrammatic family tree showing how chordates evolved from more primitive forms, as postulated by ...

FIGURE 9.5. (A) The tunicates, or “sea squirts,” have adult body forms (right diagram) that look nothing like chordates. However ...