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coash · 12-03-2004, 02:40 PM

Claim CC200:
There are no transitional fossils. Evolution predicts a continuum between each fossil organism and its ancestors. Instead, we see systematic gaps in the fossil record.
Source:
Morris, Henry M., 1974. Scientific Creationism, Green Forest, AR: Master Books, pp. 78-90.
Watchtower Bible and Tract Society, 1985. Life--How Did It Get Here? Brooklyn, NY, pp. 57-59.
Response:

1. There are many transitional fossils. The only way that the claim of their absence may be remotely justified, aside from ignoring the evidence completely, is to redefine "transitional" as referring to a fossil which is a direct ancestor of one organism and a direct descendant of another. However, direct lineages are not required; they couldn't be verified even if found. What a transitional fossil is, in keeping with what the theory of evolution predicts, is a fossil which shows a mosaic of features from an older and a more recent organism.

2. Transitional fossils may coexist with gaps. We do not expect to find finely detailed sequences of fossils lasting for millions of years. Nevertheless, we do find several fine gradations of fossils between species and genera, and we find many other sequences between higher taxa that are still very well filled out.

Fossil transitions between species and genera:

1. Human ancestry. There are many fossils of human ancestors, and the differences between species are so gradual that it is not always clear where to draw the lines between them.

2. A gradual transitional fossil sequence connects the foraminifera Globigerinoides trilobus and Orbulina universa [Pearson et al. 1997]. O. universa, the later fossil, features a spherical test surrounding a "Globigerinoides-like" shell, showing that a feature is added, not lost. The evidence is seen in all major tropical ocean basins. Several intermediate morphospecies connect the two species, as may be seen in the figure included in Lindsay [1997].

3. The fossil record shows transitions between species of Phacops (a trilobite; Phacops rana is the Pennsylvania state fossil.). [Eldredge 1972; 1974; Strapple 1978]

4. Planktonic forminifera [Malmgren et al. 1984]. This is an example of "punctuated gradualism." A 10-million-year foraminifera fossil record shows long periods of stasis and other periods of relatively rapid but still gradual morphologic change.

5. Fossils of the diatom Rhizosolenia are very common (they are mined as diatomaceous earth), and they show a continuous record of almost 2 million years which includes a record of a speciation event. [Miller 1999, 44-45]

6. Lake Turkana mollusc species [Lewin 1981].

7. Cenozoic marine ostracodes [Cronin 1985].

8. The Eocene primate genus Cantius [Gingerich 1976, 1980, 1983].

9. Scallops of the genus Chesapecten show gradual change in one "ear" of their hinge over about 13 million years. The ribs also change. [Ward and Blackwelder 1975; Pojeta and Springer 2001]

10. The horns of titanotheres (extinct Cenozoic mammals) appear in progressively larger sizes, from nothing to prominence. Other head and neck features also evolved. These features are adaptations for head-on ramming analogous to sheep behavior. [Stanley 1974]

11. Gryphaea (coiled oysters) become larger and broader but thinner and flatter during the Early Jurassic [Hallam 1968].

Fossil transitionals between families, orders, and classes:

1. Human ancestry. Australopithecus, though its leg and pelvis bones show it walked upright, had a bony ridge on the forearm, probably vestigial, indicative of knuckle walking. [Richmond and Strait 2000]

2. Dinosaur-bird transitions.

3. Haasiophis terrasanctus is a primitive marine snake with well-developed hind limbs. Although other limbless snakes might be more ancestral, this fossil shows a relationship of snakes with limbed ancestors [Tchernov et al. 2000]. Pachyrhachis is another snake with legs related to Haasiophis [Caldwell and Lee 1997].

4. The jaws of mososaurs are also intermediate between snakes and lizards. Like the snake's stretchable jaws, they have highly flexible lower jaws, but, unlike snakes, they don't have highly flexible upper jaws. Some other skull features of mososaurs are intermediate between snakes and primitive lizards. [Lee et al. 1999; Tchernov et al. 2000; Caldwell and Lee 1997]

5. Transitions between mesonychids and whales.

6. Transitions between fish and tetrapods.

7. Transitions from condylarths (a kind of land mammal) to fully aquatic modern manatees. In particular, Pezosiren portelli is clearly a sirenian, but its hind limbs and pelvis are unreduced [Domning 2001a, 2001b].

Fossil transitionals between kingdoms and phyla:

1. The Cambrian fossils Halkiera and Wiwaxia have features which connect them with each other and with the modern phyla of Mollusca, Brachiopoda, and Annelida. In particular, one species of halkieriid has brachiopod-like shells on the dorsal side at each end. This is seen also in an immature stage of the living brachiopod species Neocrania. It has setae identical in structure to polychaetes, a group of annelids. Wiwaxia and Halkiera have the same basic arrangement of hollow sclerites, an arrangement which is similar to the chaetae arrangement of polychaetes. The undersurface of Wiwaxia has a soft sole like a mollusc's foot, and its jaw looks like a mollusc's mouth. Aplacophorans, which are a group of primitive molluscs, have a soft body covered with spicules similar to the sclerites of Wiwaxia. [Conway Morris 1998, 185-195]

2. Cambrian and Precambrain fossils Anomalocaris and Opabinia are transitional between arthropods and lobopods.

3. An ancestral echinoderm has been found, intermediate between modern echinoderms and other deuterostomes [Shu et al. 2004].

12-03-2004, 02:40 PM	#23 (permalink)
coash Banned	Claim CC200: There are no transitional fossils. Evolution predicts a continuum between each fossil organism and its ancestors. Instead, we see systematic gaps in the fossil record. Source: Morris, Henry M., 1974. Scientific Creationism, Green Forest, AR: Master Books, pp. 78-90. Watchtower Bible and Tract Society, 1985. Life--How Did It Get Here? Brooklyn, NY, pp. 57-59. Response: 1. There are many transitional fossils. The only way that the claim of their absence may be remotely justified, aside from ignoring the evidence completely, is to redefine "transitional" as referring to a fossil which is a direct ancestor of one organism and a direct descendant of another. However, direct lineages are not required; they couldn't be verified even if found. What a transitional fossil is, in keeping with what the theory of evolution predicts, is a fossil which shows a mosaic of features from an older and a more recent organism. 2. Transitional fossils may coexist with gaps. We do not expect to find finely detailed sequences of fossils lasting for millions of years. Nevertheless, we do find several fine gradations of fossils between species and genera, and we find many other sequences between higher taxa that are still very well filled out. Fossil transitions between species and genera: 1. Human ancestry. There are many fossils of human ancestors, and the differences between species are so gradual that it is not always clear where to draw the lines between them. 2. A gradual transitional fossil sequence connects the foraminifera Globigerinoides trilobus and Orbulina universa [Pearson et al. 1997]. O. universa, the later fossil, features a spherical test surrounding a "Globigerinoides-like" shell, showing that a feature is added, not lost. The evidence is seen in all major tropical ocean basins. Several intermediate morphospecies connect the two species, as may be seen in the figure included in Lindsay [1997]. 3. The fossil record shows transitions between species of Phacops (a trilobite; Phacops rana is the Pennsylvania state fossil.). [Eldredge 1972; 1974; Strapple 1978] 4. Planktonic forminifera [Malmgren et al. 1984]. This is an example of "punctuated gradualism." A 10-million-year foraminifera fossil record shows long periods of stasis and other periods of relatively rapid but still gradual morphologic change. 5. Fossils of the diatom Rhizosolenia are very common (they are mined as diatomaceous earth), and they show a continuous record of almost 2 million years which includes a record of a speciation event. [Miller 1999, 44-45] 6. Lake Turkana mollusc species [Lewin 1981]. 7. Cenozoic marine ostracodes [Cronin 1985]. 8. The Eocene primate genus Cantius [Gingerich 1976, 1980, 1983]. 9. Scallops of the genus Chesapecten show gradual change in one "ear" of their hinge over about 13 million years. The ribs also change. [Ward and Blackwelder 1975; Pojeta and Springer 2001] 10. The horns of titanotheres (extinct Cenozoic mammals) appear in progressively larger sizes, from nothing to prominence. Other head and neck features also evolved. These features are adaptations for head-on ramming analogous to sheep behavior. [Stanley 1974] 11. Gryphaea (coiled oysters) become larger and broader but thinner and flatter during the Early Jurassic [Hallam 1968]. Fossil transitionals between families, orders, and classes: 1. Human ancestry. Australopithecus, though its leg and pelvis bones show it walked upright, had a bony ridge on the forearm, probably vestigial, indicative of knuckle walking. [Richmond and Strait 2000] 2. Dinosaur-bird transitions. 3. Haasiophis terrasanctus is a primitive marine snake with well-developed hind limbs. Although other limbless snakes might be more ancestral, this fossil shows a relationship of snakes with limbed ancestors [Tchernov et al. 2000]. Pachyrhachis is another snake with legs related to Haasiophis [Caldwell and Lee 1997]. 4. The jaws of mososaurs are also intermediate between snakes and lizards. Like the snake's stretchable jaws, they have highly flexible lower jaws, but, unlike snakes, they don't have highly flexible upper jaws. Some other skull features of mososaurs are intermediate between snakes and primitive lizards. [Lee et al. 1999; Tchernov et al. 2000; Caldwell and Lee 1997] 5. Transitions between mesonychids and whales. 6. Transitions between fish and tetrapods. 7. Transitions from condylarths (a kind of land mammal) to fully aquatic modern manatees. In particular, Pezosiren portelli is clearly a sirenian, but its hind limbs and pelvis are unreduced [Domning 2001a, 2001b]. Fossil transitionals between kingdoms and phyla: 1. The Cambrian fossils Halkiera and Wiwaxia have features which connect them with each other and with the modern phyla of Mollusca, Brachiopoda, and Annelida. In particular, one species of halkieriid has brachiopod-like shells on the dorsal side at each end. This is seen also in an immature stage of the living brachiopod species Neocrania. It has setae identical in structure to polychaetes, a group of annelids. Wiwaxia and Halkiera have the same basic arrangement of hollow sclerites, an arrangement which is similar to the chaetae arrangement of polychaetes. The undersurface of Wiwaxia has a soft sole like a mollusc's foot, and its jaw looks like a mollusc's mouth. Aplacophorans, which are a group of primitive molluscs, have a soft body covered with spicules similar to the sclerites of Wiwaxia. [Conway Morris 1998, 185-195] 2. Cambrian and Precambrain fossils Anomalocaris and Opabinia are transitional between arthropods and lobopods. 3. An ancestral echinoderm has been found, intermediate between modern echinoderms and other deuterostomes [Shu et al. 2004].