Refuting Creationism - Why Gaps In The Fossil Record Are To Be Expected, Naturally

Cretaceous fossil shrimp from Jbel Oum Tkout, Morocco
registered at the Museum d’histoire naturelle de Marrakech.

© Sinéad Lynch - UNIL

Why did some ancient animals fossilize while others vanished?

One of creationism’s favourite fallacies is the claim that gaps in the fossil record disprove evolution, based on a misrepresentation of something Charles Darwin wrote. According to this argument, Darwin supposedly insisted there should be a complete and continuous series of transitional fossils and admitted that any gaps would be fatal to his theory.

As with many creationist arguments, this is a distortion of both Darwin’s actual words and how science works. It reflects a peculiar misunderstanding of science as a belief system centred on the writings of historical figures — Darwin, in this case, cast as the ‘prophet’ of ‘evolutionism’. The implication is that by discrediting Darwin personally, or selectively quoting his early uncertainties, one can somehow bring down an entire field of modern science built on nearly two centuries of accumulating evidence.

The tactic ignores the fact that Darwin's style was to introduce the reader to a seemingly unaswerable problem, or potential difficulty for his theory, before explaining how his theory of evolution by natural selection provided an answer.

But why would any reasonable person expect the fossil record to preserve every generation of every species, in every habitat, across hundreds of millions of years—and for those remains to be conveniently accessible to palaeontologists today? The idea that scientists expect such completeness betrays a deep scientific illiteracy. Fossilisation is an exceptionally rare process requiring very specific conditions. There are many reasons why an organism is unlikely to fossilise, and relatively few that make fossilisation even possible.

Refuting Creationism - How The Common Barn Swallow Shows Evolution In Progress

Hirundo rustica rustica (left) and Hirundo rustica tytleri (right) have different sexually selected traits. For example, one has a red chest and the other has a pale chest.

A pair of Hirundo rustica erythrogaster.

Credit: Matt Wilkins.

A front-row seat to evolution: What common barn swallows can teach us about how new species form | CU Boulder Today | University of Colorado Boulder

This paper in Science passed me by last December but it's too good to ignore because it is an example of something that creationists insist has never been seen because it doesn't happen - evolution in progress. And, to annoy creationists even more, it's an example of something Charles Darwin proposed as a mechanism for speciation - mate selection - as the isolating mechanism.

Barn swallows are one of the species that has formed a commensal relationship with humans that does not, like many other commensal species, involve it in consuming our crops either in the fields or in storage, from when we began building permanent or semi-permanent buildings. They are now dependent on our barns and out-houses as nesting places.

Creationism in Crisis - Darwinian Evolution in Giraffes Confirmed

Three giraffes in Masai Mara National Park.

Credit: Byrdyak/Wikimedia Commons.
All Rights Reserved.

Female Giraffe, Giraffa camelopardalis, browsing

Credit: Bernard DUPONT via Wikimedia (CC SA-2.0)

Food, not sex, drove the evolution of giraffes’ long neck, new study finds | Penn State University

In a nice illustration of how science works, there had been conflicting explanations for how the Giraffe evolved its long neck, but before creationists get over-excited neither of them were alternatives to evolution; the debate was about the precise drivers of evolution. That the giraffe's neck evolved from a shorter neck of a common ancestor with the related okapi was never in dispute.

One school of thought was the standard Darwinian view that it was the result of an arms race between giraffes and their preferred food plants; the other was slightly more complex, involving female sex selection and the way male giraffes use their necks against rival males with longer neck being a distinct advantage and the winner winning the favours of the females. Since the length of the neck is not strictly sex-linked, meaning it is mostly coded for by genes located on autosomes, rather than on the Y sex chromosome, both males and females benefit from this sex-selection, or so the second school of thought ran.

Now, a team of scientists led by Penn State biologists believe they have resolved this dispute buy, in the time-honoured scientific way, by examining the evidence and letting it speak for itself. What they found was that females actually have proportionately longer necks than males, so sex selection is unlikely to be the driver. However, what they observed was that females are better able to reach leaves in the crowns of trees and so get the more nutritious food, with obvious benefits for their offspring

The team have published their work, another incidental refutation of creationism that comes from revealing scientific facts, open access, in the journal Mammalian Biology. It is also explained in a Penn State University News release:

Creationism in Crisis - Now Scientists and Philosophers have Discovered How Evolution Obeys a Fundamental Law of Nature

Scientists and philosophers team up to study concept of evolution beyond biological context | Carnegie Science

A paper written by a consortium of scientists and philosophers led by Carnegie’s Michael Wong and Robert Hazen, has outlined a law that some of us have been arguing is a fundamental law of evolution for many years. Their "law of increasing functional information" states:

The functional information of a system will increase (i.e., the system will evolve) if many different configurations of the system undergo selection for one or more functions.

Basically, in any selective environment, systems will tend towards structures that improve function by accumulating small (micro) differences which eventually result in large (macro) changes. In other words, replication in a selective environment will inevitably result in evolution towards greater fitness in that environment. Where that improved fitness comes from new or improved function then there will be an increase in complexity.

The exception to that law is in parasites where the whole system (the parasite-host complex) can become increasingly complex (by the host taking on many of the functions of the parasite) but the parasite itself can lose complexity.

The force driving that increase in complexity is, of course, natural selection, where selectors in the environment ensure those arrangements better suited to produce the next generation do so in preference to those less suited.

This fundamental law is of course, not restricted to biological systems but will operate in any situation where there is replication and selection, echoing something I wrote many years ago (Darwin's Powerful Science).

The consortium expresses this fundamental law as: