Evolution predicts a continuum of organisms, not discrete kinds

From EvoWiki

Contents 1 Claim 2 Source 3 Response 4 Fallacies contained in this claim 5 References 6 Further Reading 7 See Also 8 Acknowledgments

Claim

Since evolution says organisms came from a common ancestor, and since they lived in a continuity of environments, we should see a continuum of organisms. There should be a continuous series of animals between cats and dogs so that one could not tell where cats left off and dogs began.

Source

• Morris, Henry M., 1974. Scientific Creationism, Master Books, Arkansas, pp. 70-71.

Response

1. Mutation acting alone would predict a continuum of organisms. However, natural selection, the other acknowledged component of biological evolution causes organisms to end up with narrower ranges of adaptations. In sexually reproducing species, distinct populations emerge that become sexually incompatible with other populations because local interbreeding tends to preserve genetic compatibility, while the failure to exchange genes with other populations tends to allow them to drift in different genetic directions, increasing the likihood of genetic incompatibility. Thus, populations will tend to break into distinct species over time.
2. Evolution predicts that organisms will fill an ecological niche in their environment. Certain possible adaptations are attractors in evolutionary change because they are locally optimal methods of competing for some resource. Organisms that fail to adopt the most approximately optimal methods of competing will be eliminated, and since a continuum of organisms entails many organisms with less than optimal strategies, this possibility is ruled out by natural selection.
3. Evolution predicts a common ancestor to cats and dogs, a series of animals between that ancestor and modern cats, and a different series of animals between that same common ancestor and modern dogs. The scientific evidence supports these predictions.
4. Evolution does indeed predict a continuum (of sorts) of organisms. But not a dogs-to-cats continuum. Rather, a past-to-future continuum, where you can find intermediaries between any two given organisms that have a direct lineage. Evolution specifically predicts a lack of continuum of present organisms (dog-to-cat) due to those unfit intermediate-cousins not having survived to reproduce and give rise to them. This is not a true continuum because there can be no intermediary between parent and offspring. Ultimately, evolution is discrete. Not a continuum.
5. There is no scientifically rigorous definition for the term "kind", and it is only used by creationists, who in turn refuse to define it.
6. Contradicts "Evolution doesn't make predictions".
7. add more responses

Fallacies contained in this claim

• Straw Man (misunderstanding of evolution)

References

1. Darwin, C., 1872. The Origin of Species, 1st Edition. Senate, London. [1]

Further Reading

1. Darwin, C., 1872. The Origin of Species, 1st Edition. Senate, London. [2]

See Also

• Why is Creationism not a Scientific Theory?

Acknowledgments