How can evolution be proven

Creationists, though, dismiss these fossil studies. They argue that Archaeopteryx is not a missing link between reptiles and birds—it is just an extinct bird with reptilian features. They want evolutionists to produce a weird, chimeric monster that cannot be classified as belonging to any known group. Even if a creationist does accept a fossil as transitional between two species, he or she may then insist on seeing other fossils intermediate between it and the first two.

These frustrating requests can proceed ad infinitum and place an unreasonable burden on the always incomplete fossil record. Nevertheless, evolutionists can cite further supportive evidence from molecular biology.

All organisms share most of the same genes, but as evolution predicts, the structures of these genes and their products diverge among species, in keeping with their evolutionary relationships. These molecular data also show how various organisms are transitional within evolution.

Living things have fantastically intricate features—at the anatomical, cellular and molecular levels—that could not function if they were any less complex or sophisticated.

The only prudent conclusion is that they are the products of intelligent design, not evolution. In theologian William Paley wrote that if one finds a pocket watch in a field, the most reasonable conclusion is that someone dropped it, not that natural forces created it there. By analogy, Paley argued, the complex structures of living things must be the handiwork of direct, divine invention. Darwin wrote On the Origin of Species as an answer to Paley: he explained how natural forces of selection, acting on inherited features, could gradually shape the evolution of ornate organic structures.

Generations of creationists have tried to counter Darwin by citing the example of the eye as a structure that could not have evolved. The eye's ability to provide vision depends on the perfect arrangement of its parts, these critics say.

Natural selection could thus never favor the transitional forms needed during the eye's evolution—what good is half an eye? Biology has vindicated Darwin: researchers have identified primitive eyes and light-sensing organs throughout the animal kingdom and have even tracked the evolutionary history of eyes through comparative genetics.

It now appears that in various families of organisms, eyes have evolved independently. Today's intelligent-design advocates are more sophisticated than their predecessors, but their arguments and goals are not fundamentally different. They criticize evolution by trying to demonstrate that it could not account for life as we know it and then insist that the only tenable alternative is that life was designed by an unidentified intelligence. Recent discoveries prove that even at the microscopic level, life has a quality of complexity that could not have come about through evolution.

As a household example of irreducible complexity, Behe chooses the mousetrap—a machine that could not function if any of its pieces were missing and whose pieces have no value except as parts of the whole. What is true of the mousetrap, he says, is even truer of the bacterial flagellum, a whiplike cellular organelle used for propulsion that operates like an outboard motor. The proteins that make up a flagellum are uncannily arranged into motor components, a universal joint and other structures like those that a human engineer might specify.

The possibility that this intricate array could have arisen through evolutionary modification is virtually nil, Behe argues, and that bespeaks intelligent design.

He makes similar points about the blood's clotting mechanism and other molecular systems. Yet evolutionary biologists have answers to these objections. First, there exist flagellae with forms simpler than the one that Behe cites, so it is not necessary for all those components to be present for a flagellum to work. The sophisticated components of this flagellum all have precedents elsewhere in nature, as described by Kenneth R. Miller of Brown University and others.

In fact, the entire flagellum assembly is extremely similar to an organelle that Yersinia pestis , the bubonic plague bacterium, uses to inject toxins into cells. The key is that the flagellum's component structures, which Behe suggests have no value apart from their role in propulsion, can serve multiple functions that would have helped favor their evolution. The final evolution of the flagellum might then have involved only the novel recombination of sophisticated parts that initially evolved for other purposes.

Similarly, the blood-clotting system seems to involve the modification and elaboration of proteins that were originally used in digestion, according to studies by Russell F. Doolittle of the University of California, San Diego. So some of the complexity that Behe calls proof of intelligent design is not irreducible at all.

Essentially his argument is that living things are complex in a way that undirected, random processes could never produce. The only logical conclusion, Dembski asserts, in an echo of Paley years ago, is that some superhuman intelligence created and shaped life. Dembski's argument contains several holes.

It is wrong to insinuate that the field of explanations consists only of random processes or designing intelligences. Researchers into nonlinear systems and cellular automata at the Santa Fe Institute and elsewhere have demonstrated that simple, undirected processes can yield extraordinarily complex patterns.

Some of the complexity seen in organisms may therefore emerge through natural phenomena that we as yet barely understand. But that is far different from saying that the complexity could not have arisen naturally. Only methodological naturalism can determine how all life came to be. A central tenet of modern science is methodological naturalism—it seeks to explain the universe purely in terms of observed or testable natural mechanisms.

Thus, physics describes the atomic nucleus with specific concepts governing matter and energy, and it tests those descriptions experimentally. Physicists introduce new particles, such as quarks, to flesh out their theories only when data show that the previous descriptions cannot adequately explain observed phenomena.

The new particles do not have arbitrary properties, moreover—their definitions are tightly constrained, because the new particles must fit within the existing framework of physics.

In contrast, intelligent-design theorists invoke shadowy entities that conveniently have whatever unconstrained abilities are needed to solve the mystery at hand. Rather than expanding scientific inquiry, such answers shut it down.

How does one disprove the existence of omnipotent intelligences? Intelligent design offers few answers. For instance, when and how did a designing intelligence intervene in life's history? By creating the first DNA? The first cell? The first human? Was every species designed, or just a few early ones? Proponents of intelligent-design theory frequently decline to be pinned down on these points.

They do not even make real attempts to reconcile their disparate ideas about intelligent design. Instead they pursue argument by exclusion—that is, they belittle evolutionary explanations as far-fetched or incomplete and then imply that only design-based alternatives remain. Logically, this is misleading: even if one naturalistic explanation is flawed, it does not mean that all are.

Moreover, it does not make one intelligent-design theory more reasonable than another. Listeners are essentially left to fill in the blanks for themselves, and some will undoubtedly do so by substituting their religious beliefs for scientific ideas. The common ancestry explanation predicts these to be different mutations, because it would be highly unlikely for the same mutation to occur a second time.

When the genetic codes of guinea pigs and fruit bats are examined, we find different mutations than the one primates have, which is what common ancestry predicts. As genetic information has become more widely available in the last two decades, many more of these kinds of nested relationships among species have been found.

Common ancestry explains the genetic evidence beautifully, while alternative explanations seem less and less plausible. No matter what position a person takes on evolution, it is important to understand why almost all professional biologists affirm the evolution of all life on Earth. At BioLogos, we see God as crafting and governing the entire evolutionary process to bring about the abundance of species we see today.

Of course it is possible that God supernaturally created each of the species separately, but did so in the pattern that so strongly suggests common ancestry. So too we believe that body plans, fossils, biogeography, and the genetic code all testify truly to the way God created.

We may legitimately wonder why God chose to create species in this long and meandering fashion, instead of snapping his fingers and having things appear fully formed.

From Genesis to Revelation, God works with and through his creation, bringing his plans to fruition slowly and carefully. We are admonished many times in the Bible to trust in God and his ways, even if they do not fit our limited human ideas of what is optimal or most expedient.

What seems to us to meander—in body plans no less than salvation history—reflects the providence of God. Join us to receive the latest articles, podcasts, videos, and more, and help us show how science and faith work hand in hand.

Evolutionary creationists believe that God created humans in his image, and that God created humans using natural processes that scientists describe as evolution. How can these beliefs work together? In the last couple of decades, our understanding of genetics has grown dramatically, providing overwhelming evidence that humans share common ancestors with all life on earth.

Properly understood, evolution is a scientific theory about the development of life and is consistent with Christian theology. If God is good, how can we account for the enormous amount of suffering caused by predation, disease, and natural disasters? God is the creator and sustainer of all things, and evolution is the best scientific explanation for the relatedness of life on Earth.

Part Two in the Uniquely unique mini-series. When we look for what makes humans unique on this planet, looking at our biology is an obvious first step. Does human genetic variation today provide evidence that we can trace our ancestry exclusively from a single couple?

People on all sides of the creation debate are convinced the other sides are doing it all wrong. The reason Lamarck's theory of evolution is generally wrong is that acquired characteristics don't affect the DNA of sperm and eggs. A giraffe's gametes, for example, aren't affected by whether it stretches its neck; they simply reflect the genes the giraffe inherited from its parents. But as Quanta reported , some aspects of evolution are Lamarckian.

For example, a Swedish study published in in the European Journal of Human Genetics found that the grandchildren of men who starved as children during a famine passed on better cardiovascular health to their grandchildren.

Researchers hypothesize that although experiences such as food deprivation don't change the DNA sequences in the gametes, they may result in external modifications to DNA that turn genes "on" or "off. For instance, a chemical modification called methylation can affect which genes are turned on or off. Such epigenetic changes can be passed down to offspring. In this way, a person's experiences could affect the DNA he or she passes down, analogous to the way Lamarck thought a giraffe craning its neck would affect the neck length of its offspring.

Even though scientists could predict what early whales should look like, they lacked the fossil evidence to back up their claim. Creationists viewed this absence, not just with regard to whale evolution but more generally, as proof that evolution didn't occur, as pointed out in a Scientific American article. But since the early s, scientists have found evidence from paleontology, developmental biology and genetics to support the idea that whales evolved from land mammals.

These same lines of evidence support the theory of evolution as a whole. The critical piece of evidence was discovered in , when paleontologists found the fossilized remains of Ambulocetus natans , which means "swimming-walking whale," according to a review published in the journal Evolution: Education and Outreach. Its forelimbs had fingers and small hooves, but its hind feet were enormous relative to its size.

The animal was clearly adapted for swimming, but it was also capable of moving clumsily on land, much like a seal.

When it swam, the ancient creature moved like an otter, pushing back with its hind feet and undulating its spine and tail. Modern whales propel themselves through the water with powerful beats of their horizontal tail flukes, but A. In recent years, more and more of these transitional species, or "missing links," have been discovered, lending further support to Darwin's theory.

For example, in , a geologist discovered the fossil of an extinct aquatic mammal, called Indohyus , that was about the size of a cat and had hooves and a long tail. Scientists think the animal belonged to a group related to cetaceans such as Ambulocetus natans. This creature is considered a "missing link" between artiodactyls — a group of hoofed mammals even-toed ungulates that includes hippos, pigs, and cows — and whales, according to the National Science Foundation. Researchers knew that whales were related to artiodactyls, but until the discovery of this fossil, there were no known artiodactyls that shared physical characteristics with whales.

After all, hippos, thought to be cetaceans' closest living relatives, are very different from whales. Indohyus , on the other hand, was an artiodactyl, indicated by the structure of its hooves and ankles, and it also had some similarities to whales, in the structure of its ears, for example.

Likewise, 8 percent of the human genome, we now know, is viral DNA, which has come into our lineage by infection over the last million years or so. Some of that viral DNA is still functioning as genes that are important for human life and reproduction. CRISPR is an acronym for a gene-editing tool discovered in the last years that is very powerful and inexpensive. With it, scientists can now edit genomes, delete mutations or insert sections of new genes.

It promises a lot of wonderful medical possibilities and a lot of really troubling moral and societal choices. But how far does it go? Does it go to the point where wealthy people will be able to choose designer children, whose genomes have been edited to make them smarter or stronger?

These are, to put it mildly, really difficult ethical propositions. But it is something that has always existed in nature. Microbes were using CRISPR to protect themselves and to edit their own genomes before it was ever discovered and put to use in a laboratory by some really brainy humans. Simon Worrall curates Book Talk. Follow him on Twitter or at simonworrallauthor. All rights reserved. Your book opens with Charles Darwin making a little sketch in a notebook. Put us inside that moment and explain how the image of the tree of life has altered over the centuries.

The British research lab at Porton Down has been much in the news recently because of the Skripal affair. Take us inside this top-secret facility and talk about the strange case of NCTC 1. Share Tweet Email. Why it's so hard to treat pain in infants. This wild African cat has adapted to life in a big city.

Animals Wild Cities This wild African cat has adapted to life in a big city Caracals have learned to hunt around the urban edges of Cape Town, though the predator faces many threats, such as getting hit by cars.

India bets its energy future on solar—in ways both small and big. Environment Planet Possible India bets its energy future on solar—in ways both small and big Grassroots efforts are bringing solar panels to rural villages without electricity, while massive solar arrays are being built across the country.

Go Further. Animals Climate change is shrinking many Amazonian birds.