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1973 The red queen hypothesis
CHAPTER THIRTY SIX
1973 The red queen hypothesis The concept Motivated by observations of extinction rates in the fossil record, Leigh Van Valen (1973) came up with a high-level theory of evolution he called the Red Queen hypothesis. This theory was designed to explain evolution of interacting species in a common environment. In this theory Van Valen argues that the beneficial evolutionary changes in one species will have negative consequences for other species. Accordingly, those negatively impacted species will respond with their own evolutionary changes which, to some extent, will negate the previous beneficial changes. This will lead to a stochastically constant flux in the evolutionary process that at some levels, like the extinction rates of taxa, will suggest constancy over sufficiently long periods of time.
The explanation Van Valen starts his theoretical development with a deep survey of extinction rates inferred from the fossil record. If similar taxonomic groups are analyzed together, then one can use the duration of each member of the group in the fossil record to create a sort of survival plot e e.g. how many members of the group survived 10 million years, 20 million years, and so on. On a log scale many of the plots show a linear decline in survival. This suggests a constant rate of extinction. Nothing in real life is simple, so in fact there are a number of groups where a linear decline is not seen. Van Valen devotes a section of his paper subtitled “Apparent Exceptions” to explain away these inconvenient observations. However, in the end Van Valen makes a more sober assessment of the data by saying that nevertheless “There is a strong first-order effect of linearity, and it is this, rather than its perturbations by special and diverse circumstances, that deserves primary attention” (Van Valen, 1973). While this seems like a reasonable way to proceed, one wonders if even a successful explanation of first-order effects deserves the attribution of a law.
Conceptual Breakthroughs in Evolutionary Ecology ISBN: 978-0-12-816013-8 https://doi.org/10.1016/B978-0-12-816013-8.00036-3
© 2020 Elsevier Inc. All rights reserved.
85
j
86
Conceptual Breakthroughs in Evolutionary Ecology
The theory assumes that species like predators or parasites that evolve an increased ability to secure their food will be met with an equal response by their prey to resist those advances. In the end the net change in fitness over time is expected to be 0. Van Valen notes that the law as he developed it cannot be derived from lower level principles, e.g. population genetic models. However, he leaves open the possibility that perhaps he has not been cleaver enough to ferret out these explanations. Given the prediction that fitness will show no net change over time has led Van Valen to a catchy description of his theory which borrows from the Red Queen’s quote in Lewis Carroll’s book “Through the looking glass”, “Now here you see, it takes all the running you can do, to keep in the same place”. The process of evolutionary response by interacting species given by Van Valen is not dissimilar to Ehrlich and Raven’s descriptions in their work (Ehrlich and Raven, 1964) on coevolution which is not cited by Van Valen. While the detailed equations of the Red Queen hypothesis have not been widely applied, the broad concept of evolution as a zerosum game have appeared often in evolutionary discussions.
Impact: 5 The inability of Van Valen to connect the Red Queen hypothesis to basic population genetic theory has probably limited the impact of this theory. However, these ideas set up the notion that coevolving species like parasites and their hosts may have a perpetual arms race. These ideas have been important therefore in setting up a simple expectation for these types of coevolutionary settings.
References Ehrlich, P.R., Raven, P.H., 1964. Butterflies and plants: a study in coevolution. Evolution 18, 586e608. Van Valen, L., 1973. A new evolutionary law. Evo. Evol. Theory 1, 1e30.
1973 The red queen hypothesis The concept Motivated by observations of extinction rates in the fossil record, Leigh Van Valen (1973) came up with a high-level theory of evolution he called the Red Queen hypothesis. This theory was designed to explain evolution of interacting species in a common environment. In this theory Van Valen argues that the beneficial evolutionary changes in one species will have negative consequences for other species. Accordingly, those negatively impacted species will respond with their own evolutionary changes which, to some extent, will negate the previous beneficial changes. This will lead to a stochastically constant flux in the evolutionary process that at some levels, like the extinction rates of taxa, will suggest constancy over sufficiently long periods of time.
The explanation Van Valen starts his theoretical development with a deep survey of extinction rates inferred from the fossil record. If similar taxonomic groups are analyzed together, then one can use the duration of each member of the group in the fossil record to create a sort of survival plot e e.g. how many members of the group survived 10 million years, 20 million years, and so on. On a log scale many of the plots show a linear decline in survival. This suggests a constant rate of extinction. Nothing in real life is simple, so in fact there are a number of groups where a linear decline is not seen. Van Valen devotes a section of his paper subtitled “Apparent Exceptions” to explain away these inconvenient observations. However, in the end Van Valen makes a more sober assessment of the data by saying that nevertheless “There is a strong first-order effect of linearity, and it is this, rather than its perturbations by special and diverse circumstances, that deserves primary attention” (Van Valen, 1973). While this seems like a reasonable way to proceed, one wonders if even a successful explanation of first-order effects deserves the attribution of a law.
Conceptual Breakthroughs in Evolutionary Ecology ISBN: 978-0-12-816013-8 https://doi.org/10.1016/B978-0-12-816013-8.00036-3
© 2020 Elsevier Inc. All rights reserved.
85
j
86
Conceptual Breakthroughs in Evolutionary Ecology
The theory assumes that species like predators or parasites that evolve an increased ability to secure their food will be met with an equal response by their prey to resist those advances. In the end the net change in fitness over time is expected to be 0. Van Valen notes that the law as he developed it cannot be derived from lower level principles, e.g. population genetic models. However, he leaves open the possibility that perhaps he has not been cleaver enough to ferret out these explanations. Given the prediction that fitness will show no net change over time has led Van Valen to a catchy description of his theory which borrows from the Red Queen’s quote in Lewis Carroll’s book “Through the looking glass”, “Now here you see, it takes all the running you can do, to keep in the same place”. The process of evolutionary response by interacting species given by Van Valen is not dissimilar to Ehrlich and Raven’s descriptions in their work (Ehrlich and Raven, 1964) on coevolution which is not cited by Van Valen. While the detailed equations of the Red Queen hypothesis have not been widely applied, the broad concept of evolution as a zerosum game have appeared often in evolutionary discussions.
Impact: 5 The inability of Van Valen to connect the Red Queen hypothesis to basic population genetic theory has probably limited the impact of this theory. However, these ideas set up the notion that coevolving species like parasites and their hosts may have a perpetual arms race. These ideas have been important therefore in setting up a simple expectation for these types of coevolutionary settings.
References Ehrlich, P.R., Raven, P.H., 1964. Butterflies and plants: a study in coevolution. Evolution 18, 586e608. Van Valen, L., 1973. A new evolutionary law. Evo. Evol. Theory 1, 1e30.