Sea Star Species Defy Darwin

To explore the evolutionary mechanism between sister sea star species, a research team headed by Jonathan Puritz of Institute of Marine Biology at the University of Hawaii investigated the genetic and phylogeographic differences between the species living off the Australian coast in the Coral Sea.

The findings, published last week in the Proceedings of the Royal Society, undermine the fundamental tenet of Darwinian evolution−natural selection.

The two sea star sister species, Cryptasterina pentagona and Cryptasterina hystera have recently been recognized as distinct species.  These echinoderms are identical in appearance but live in different regions and differ in their mode of reproduction—one lays eggs, the other delivers via live birth.

“It’s as dramatic a difference in life history as in any group of organisms,” said Rick Grasberg, professor of evolution and ecology at UC Davis and coauthor, according to ScienceDaily.

It is because of their biological similarities, except for reproduction, the investigators theorized these two species could “represent the minimal level of modification for the evolution” of speciation—a micronized model of evolution to explore.

In The Origin of Species, Charles Darwin argued that “by the theory of natural selection all living species have been connected with the parent-species of each genus”. Darwin proposed that new species are descendants from a common ancestor “by means of natural selection” -

On the theory of natural selection, we can clearly understand why she should not; for natural selection acts only by taking advantage of slight successive variations; she can never take a great and sudden leap, but must advance by the short and sure, though slow steps.

Natural selection can only act, according to Darwin, through “slight successive variations”−a slow, not a rapid process.  

The researchers looked at the diversity in DNA sequences from sea stars of both species and estimated the length of time since the species might have diverged. Contrary to Darwin’s natural selection theory, the researchers concluded that speciation must have happened instantaneously about 6,000 years ago,

Here, we use new population genetic and phylogeographic analyses to investigate an extraordinary example of both geographically localized and geologically instantaneous evolution

Puritz suggests that speciation of C. pentagona and C. hystera may have occurred through disruptive selection, not natural selection –

Our results suggest that disruptive selection for different life-history phenotypes between sea stars in different habitats may be a short pathway to rapid evolutionary divergence and speciation.

This new scientific evidence from the sea stars further underscores why scientists have been criticizing the fundamental of Darwin’s theory of evolution for more than 150 years. According to Swedish biologist Soren Lovtrup,

Today it is still commonly claimed that Darwin’s natural selection is the evolutionary mechanism par excellence. However, this assertion is not based on any factual evidence.

Massimo Paittelli-Palmarini of the University of Arizona sums up the current state of natural selection:

The point is, however, that organisms can be modified and refined by natural selection, but that is not the way new species and new classes and new phyla originated.

Evidence from these Australian sea stars serves as yet another example why evolution, once a theory in crisis, is in crisis without even a cohesive theory.

The scientific evidence is more compatible with the origin of life account as recorded in Genesis than any theory of evolution.

 

8 Responses to “Sea Star Species Defy Darwin”

  • VoR:

    First off, disruptive selection IS natural selection. It just refers to selection that is different between two different environments.

    Second, you couldn’t be more wrong. This paper only provides further proof of evolution. Evolution is strictly defined as modification through descent, or changes that are inherited from your ancestors.

    There are several different mechanisms, or processes, of evolution. These are mutation (the random alteration of the genome), migration (the sharing of genes between populations via reproduction), natural selection (the favoring of particular traits by an environment), or a process called drift (which is basically a random process).

    The authors of this paper do not prove any particular mechanism for the evolutionary change they are documenting (while they do speculate on a few); however, the irrefutably prove that this new species is descended from another species. They even provide an incredibly accurate measure of when it happened. In other words, the proved that this new species is a product of modification through descent.

    So, yes, it is most certainly evolution.

  • Thanks for the feedback. The authors always use the term “disruptive selection” – and never use the term “natural selection”. If fact, if you read the paper, with the emphasis on “life history”, the authors are essentially Lamarckian, not Darwinian.

    On the mutation issue, the authors concluded that the data does not conform to a stepwise mutation model: “The microsatellite data did not conform to a stepwise mutation model”.

    Agree with you “the authors of this paper do not prove any particular mechanism for the evolutionary change”. In fact, “Testing this hypothesis will require several types of new evidence”. A cohesive consensus on any theory of evolution remains a mirage – after 150 years, and running.

  • M. A. LaJoie:

    Selection, whether disruptive, stabilizing, or directional, whether it is “natural” or “intentional” still operates on existing variation. Darwin may or may not have considered the possibility of disruptive selection, (see http://en.wikipedia.org/wiki/Disruptive_selection ) but all that would be in question is how common it is. It certainly poses no “crisis”.

  • Agree with you – selection can only act on existing variations. The real issue is not the type of selection, however. The issue is the lack of evidence for the central tenet of Darwin’s theory – evolution through “slight, successive” changes – “natura non facit saltum”.

  • M. A. LaJoie:

    During an extinction even, a marginal species, can suddenly fill an emptied niche. The marginal species might have been around for a long time, in a geographically or environmentally isolated environment, only to suddenly appear in the fossil record.

    The evolution did occur by slight successive changes, but the sudden appearance masks the gradual nature of the change.

    But in any case, gradualism is certainly not a “central tenet”.

    Darwin was wrong about blended inheritance, a far more important flaw in his original theory. Genetics, however cleared up that difficulty.

  • Greetings!

    Thanks for your comment. In The Origin of Species, however, Darwin makes his case that natural selection can only precede gradually-completely ruling out any sudden changes. In the words of Darwin

    “If numerous species, belonging to the same genera or families, have really started into life at once [suddenly], the fact would be fatal to the theory of evolution through natural selection.”

    “On the theory of natural selection we can clearly understand the full meaning of that old canon in natural history, “’Natura non facit saltum.’” Natura non facit saltum means nature makes no sudden changes.

    “Natural selection acts solely by accumulating slight, successive, favourable variations; it can produce no great or sudden modifications.”

    For Darwin, the rejection of gradualism actually advances the argument for creation:

    “Under a scientific point of view, and as leading to further investigation, but little advantage is gained by believing that new forms are suddenly developed in an inexplicable manner from old and widely different forms, over the old belief in the creation of species from the dust of the Earth.”

    “Natural selection banish the belief of the continued creation of new organic beings, or of any great and sudden modification in their structure.”

    Since undermining the Genesis origin of life account was the central purpose of Darwin’s work, Darwin was forced to reject any sudden changes.

    What evidence do you have otherwise?

  • Regina Mccarthy:

    Does it really matter? Evolution is fascinating and factual, that said, it does not mean that is not God directed….whether slow and steady or punctuated equilibrium; God can have a hand in it all. By the way, even Genesis has two versions regarding the creation of life….why can’t Darwin?

  • Greetings!

    Thanks for your comment. Theistic evolution in which God controls evolution is a very popular alternative theory to Darwinism, neo-Darwinism, the Modern Evolutionary Synthesis theory, and the range of extended synthesis theories of evolution presented in Pigliucci’s and Muller’s book entitled “Evolution – The Extended Synthesis” published by MIT. The fact is consensus on a comprehensive theory of evolution does not exist – that is a fact.

    You could say that Genesis appears to have three versions Genesis 1:1, Genesis 1:2-31 and Genesis chapter 2. However, the Hebrew tradition of writing is similar to the 21st century style of scientific writing: Genesis 1:1 is the Abstract, Genesis 1:2-31 in the Introduction, and Genesis chapter 2 is the Discussion. This are same events presented in three different formats – with each succeeding section giving a more expanded description.

    The reason that God could never have had a hand in evolution is because at the end of the sixth day He said that everything was “very good” – it was a perfectly created world. By contrast, evolution entails eons a deadly destructive “survival of the fittest” process – a process that can never be considered “very good”. If God is a liar, then, that would be a different story. A “god” of evolution could never be the “God of Abraham, Isaac and Jacob”.

    It is important to note that death and destruction originated in Genesis chapter 3 after the “fall” – that is characterized by extinction, not evolution. Theistic evolution is fundamentally incompatible with a loving God.

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