Archaeopteryx – The Fossil that Proved Darwin was Right

1859: Charles Darwin published “On the Origin of Species.” Other scientists had proposed evolutionary theories before but Darwin was the first to work up a detailed case of how natural processes could transform one species into another.

Darwin claimed that even Classes could change – for example, the Class Reptilia could evolve into the Bird Class Aves.

“Where is the fossil proof??” exclaimed doubters. “Where is a transitional fossil that links one Class with another?”

The absence of missing links between Classes bothered Darwin.
………………………

Class to Class evolution would have to bridge immense gaps in anatomy and physiology:

  • Reptiles are a “Low Class.” They’re cold-blooded and can’t raise their body temperature much without basking in the sun. Birds are hot blooded and have so much metabolic heat that they can keep warm even in the snow.
  • Reptiles have scaly skin. Bird skin is clothed in feathers.
  • Reptiles have small, weak hearts and lungs. Birds have huge hearts and extremely efficient lungs.
  • Reptiles have small brains. Bird brains are gigantic, compared to their body mass.
  • Reptiles usually don’t spend much time in caring for their young. Birds lavish parental care on their babies.

Before 1861, it was hard to imagine how evolution could remake a reptile and make it into a bird.

……………..

Archaeopteryx changed all that. It was a bird because it had the complex flight feathers clearly preserved.  Feathers implied hot-bloodedness. And the brain appeared to be bigger than what a typical reptile had. Plus – the hind legs had long, narrow ankles, like a bird’s, not the flat-footed feet of a reptile. Archaeopteryx had three main hind toes pointing forward and a smaller toe pointed inward – the bird pattern, not the five-toed hind paw of a typical reptile.

The Archaeopteryx wing had three fingers arranged like a bird’s, not five as in most reptiles.

But Archaeopteryx  possessed extraordinarily primitive, reptilian features too. The tail had a long line of bony vertebrae. Modern birds have only a short, stubby vertebral column in the tail. Archaeopteryx had the three fingers of the hand separate instead of having the outer two fingers fused together.

Archaeopteryx had big, sharp claws on each of the three fingers instead of the blunt-tipped fingers of typical birds.

And Archaeopteryx had a mouthful of teeth instead of a modern bird’s beak.

More evidence of how birds evolved came in 1868. Professor Cope in New Jersey and Professor Huxley and Phillips in Oxford showed that meat-eating dinosaurs had been put together all wrong. Dinosaur legs weren’t flat-footed and five-toed. Carnivorous dinosaurs, in fact, had long, slim legs with ankles held high off the ground, and the hind foot had three main toes pointing forward. So these dinosaurs had bird-style legs.

Dinosaurs bridged most of the gap between primitive reptiles and Archaeopteryx. Most progressive paleontologists accepted the theory that Archaeopteryx evolved from a dinosaur.

The case became iron-clad in the 1880’s to early 1900’s. Excavations in the American West uncovered small meat-eating dinosaurs, like Ornitholestes, that had very long arms that matching those of Archaeopteryx closely.  The missing links were no longer missing. A primitive reptile had evolved into a primitive dinosaur which evolved into an advanced meat-eating dinosaur. And that dinosaur had evolved into Archaeopteryx, which in turn evolved into modern birds.

This is your last chance to see Archaeopteryx at HMNS. The exhibit is closing after labor day weekend. Don’t miss your chance to see the only Archaeopteryx on display in the Western Hemisphere.

A priest and a scientist walk into a bar…

So a priest and a scientist walk into a bar…for centuries, science and religion have squared off. Are they mutually exclusive, or can they coexist? Can a higher being be incorporated into scientific principles, or can science be used to explain the core beliefs of faith? Today’s guest post from Amy, our director of adult education, discusses your chance to answer these questions, as HMNS brings a priest and scientist together for a friendly discussion. Learn more about the two men and the issues at hand, and don’t miss your chance to hear both Father Coyne and Dr. Ayala speak at HMNS this upcoming Tuesday, April 27 at 6:30 p.m.

Science and Religion are portrayed to be in
harmony in the Tiffany window Education (1890).

In a world changing every day by science, many grapple with the debate of Science vs. Religion. Some think the two are not compatible, while others think the contrary. What kinds of questions belong to the discipline of science and what questions do not?  How can a scientist justify faith while insisting on scientific, empirical rigor in other matters?  Is such justification necessary? Questions like these will be addressed in a spirited discussion by Drs. Coyne and Ayala at HMNS.

Father Coyne first came to HMNS in 2003 to speak with Dr. Steven Weinberg in a program entitled The Presence of God in the Universe. Coyne returned in 2009 as part of the Darwin2009 Houston Lecture Series celebrating the 200th birthday of Charles Darwin and the 150th anniversary of the publication of On The Origin of the Species.

San Diego, CA
Creative Commons License photo credit: Girl flyer

Dr. George V. Coyne, S.J. served as Director of the Vatican Observatory for 28 years. Father Coyne founded and hosted the Divine Action series of conferences to bring together scientists and theologians from around the world. He retired as Director in August 2006 but still serves on the research staff and is President of the Vatican Observatory Foundation, a development arm of the Observatory.

The Vatican Observatory, one of the oldest astronomical observatories in the world (tracing its origins to Pope Gregory’s reform of the calendar in 1582) has been headquartered in the papal summer home of Castel Gandolfo since 1935, but it opened a branch in Tucson in the mid 1980s to take advantage of the area’s world-renowned astronomical facilities. In 1993, it inaugurated the Vatican Advanced Technology Telescope on Mt. Graham, Arizona.

Dr. Francisco Ayala was also part of the popular lecture series hosted at the Houston Museum of Natural Science.  You can read Dr. Ayala’ previous blog post here. Dr. Ayala is an evolutionary geneticist and molecular biologist who has vigorously opposed the entanglement of science and religion while also calling for mutual respect between the two. He is a University Professor of Biological Sciences, professor of philosophy, and professor of logic and the philosophy of science at the University of California at Irvine. He specializes in evolutionary genetics and uses DNA to track the path and flow of evolution. This March Ayala was awarded the 2010 Templeton Prize which honors a living person who has made an exceptional contribution to affirming life’s spiritual dimension, whether through insight, discovery, or practical works.

The mission of the museum is to “enhance in individuals the knowledge and delight in natural science and related subjects.” This lecture is a unique opportunity for our museum members, students and members of the community to hear two world-renown scientists address questions about Science and Religion to enhance their “delight in science” regardless of their religious beliefs.

The HMNS Distinguished Lecture entitled Science and Religion presented by Drs. Coyne and Ayala on April 27 is sponsored by KUHF 88.7 FM and the Center for Faith and Culture at the University of St. Thomas and is open to the public.  For ticket information click here.

Insects and Orchids: An Evolutionary Journey

I absolutely love orchids! I mean who doesn’t, really? They are my very favorite flower in the whole world. I can literally stare at them for hours and not get tired of them. I love to photograph them; I even had them in my wedding! I love their colors, their shapes, there is really no flower quite like the orchid.

Well, if you love these flowers as I do, I’ve thought of another reason for you to love insects! We would not have the amazing shapes, the striking colors, or the unique fragrances from orchids if it weren’t from our amazing little friends!

Orchids are an ancient flower - appearing some 80 million years ago, during the time of the dinosaurs - much older than scientists first believed. They flourished, as many organisms did, after the big extinction and began to figure out how to best survive in this new world. They can grow on every continent except for Antarctica and in almost every type of habitat. They can grow as epiphytes, attached to trees or shrubs, lithophytes, attached to rocks, or they can be terrestrial like most other flowers. They also figured out, because plants are very smart you know, that cross pollination, as opposed to self pollination, is the best way to survive. What is the best way to cross pollinate? With insects of course. So began an intricate process of co-evolution between these amazing flowers and their insect counter-parts.

Co-evolution can be defined simply as the change of a biological object over time that is triggered by the change of a related object. So, as the insects changed, so did the orchids which were dependent upon them. This has led to an incredible amount of diversity in the 25-30,000 species of orchids that exist today. Charles Darwin studied orchids and their relationship with insects; he developed this theory of co-evolution based on his findings. He introduced the theory of plant and insect interactions in his book, On the Origin of Species. Later, he published Fertilisation of Orchids, which explained in detail the complex relationships between these flowers and the insects that pollinate them and how this led to their co-evolution.

A Cocytius antaeus, the new world equivilant of the
Xanthopan morgani.

Today, this can be seen more than ever with some extremely unique orchids and their very interesting, and sometimes weird, ways of attracting insects. One of the most compelling pieces of evidence of this co-evolution is Angraecum sesquipedale or, Darwin’s Orchid in Madagascar. Darwin noticed that this orchid had an extremely long spur, so long that only an insect with a very long proboscis could reach the nectar inside. He actually predicted that there was an undiscovered moth out there with a foot-long proboscis that could pollinate this orchid. Well, he was right, and now we have Xanthopan morgani or the Morgan’s sphinx moth. This incredible moth was not discovered until 1903, but proved Darwin’s theory and was originally named Xanthopan morgani praedicta in honor of his prediction. The moth has an unbelievably long proboscis which can reach down into the flower to retrieve the precious nectar. In doing so, the moth rubs its head against the pollen producing organ of the plant and transfers the pollen to the next flower it drinks from.

(un)natural encounter
Creative Commons License photo credit: avmaier

Many other orchids use specific fragrances to lure insects. Some use sweet fragrances to attract certain bees and wasps, and others, putrid smells to attract flies. These happy insects are rewarded for their pollination with yummy nectar. Others use striking colors that flying insects can’t resist. Still others, about 1/3 of all orchids, produce no nectar. These have come up with some pretty tricky methods of attracting insects. These are some of the most specialized orchids of all. Some mimic the smell of food. Flying insects approach the flower and crawl all over it looking for the nectar. It is not until they are covered in pollen that they give up and move on to the next one, transferring the pollen in their search for food.

Even more deceiving are the orchids that use sex pheremones to attract unsuspecting pollinators. These orchids are amazing. They actually mimic the female bee or wasp visually, often using the same colors and tufts of hair. They give off a chemical that smells identical to the pheremone that the female insect would give off. The poor males climb on the flower, actually try to mate with it (sometimes leaving behind sperm) and move on to the next, spreading the pollen. What a smart flower! Watch this video to see a great example of this type of orchid.

Stemless Lady-slipper
Creative Commons License photo credit: *Micky

One last amazing orchid/insect relationship. The lady’s slipper orchid is a very unique looking flower. With a pouch-like structure, it resembles a pitcher plant, which is a known insect-eating plant. The pitcher plant uses its pouch to lure in insects which fall in and are digested inside. The slipper orchid, however, has a much more benevolent agenda. The pouch does lure insects, they do fall down inside, but they do not meet their doom there. The pouch is too small for the insect to stretch its wings so they cannot fly out. The only way out is to climb a ladder of hairs on the back. The insect must squeeze past where the pollen is kept to get away. They either leave with the pollen, or leave another plant’s pollen there, tricky tricky!

So, you see, if you’ve never thought of plants as intelligent, you may want to think again. Exquisite, exotic, luxurious, stunning, elegant, whatever term you use to decribe orchids, you can now add intelligent and highly evolved. I hope this gives you a whole new respect for these famous flowers, and the bugs that make them what they are!

If you like orchids and want to learn more about them, don’t miss the Houston Orchid Society’s upcoming Show and Sale, which will be held at the museum this year. It’s free! Saturday and Sunday only, April 17 & 18. For more info, visit our web site.

The gift that keeps on giving: Darwin and the Origin of Species

In conjunction with Darwin2009 Houston, a year-long celebration of Darwin’s 200th birthday and 150th anniversary of the publication of “On the Origin of Species,” HMNS will host a series of events exploring the contributions of this famous scientist.

Today’s guest blogger is Francisco J. Ayala, who shares some his findings here prior to his Feb. 24 lecture at the Museum, on “Darwin’s Gift to Science and Religion,” a part of HMNS’ Distinguished Lecture series.

The Origin of Species #1
Creative Commons License photo credit: gds

Darwin occupies an exalted place in the history of Western thought, deservedly receiving credit for the theory of evolution. In The Origin of Species, he laid out the evidence demonstrating the evolution of organisms.  However, Darwin accomplished something much more important than demonstrating evolution. Indeed, accumulating evidence for common descent with diversification may very well have been a subsidiary objective of Darwin’s masterpiece.  Darwin’s Origin of Species is, first and foremost, a sustained argument to solve the problem of how to account scientifically for the design of organisms. Darwin seeks to explain the design of organisms, their complexity, diversity, and marvelous contrivances as the result of natural processes. Darwin brings about the evidence for evolution because evolution is a necessary consequence of his theory of design.

The advances of physical science brought about by the Copernican Revolution had driven mankind’s conception of the universe to a split-personality state of affairs, which persisted well into the mid-nineteenth century.  Scientific explanations, derived from natural laws, dominated the world of nonliving matter, on the Earth as well as in the heavens.  Supernatural explanations, which depended on the unfathomable deeds of the Creator, were accepted as explanations of the origin and configuration of living creatures. Authors, such as William Paley in his Natural Theology of 1802, had developed the “argument from design,” the notion that the complex design of organisms could not have come about by chance, or by the mechanical laws of physics, chemistry, and astronomy, but was rather accomplished by an Omnipotent Deity, just as the complexity of a watch, designed to tell time, was accomplished by an intelligent watchmaker.

It was Darwin’s genius to resolve this conceptual schizophrenia.  Darwin completed the Copernican Revolution by drawing out for biology the notion of nature as a lawful system of matter in motion that human reason can explain without recourse to supernatural agencies. Darwin’s greatest accomplishment was to show that the complex organization and functionality of living beings can be explained as the result of a natural process—natural selection—without any need to resort to a Creator or other external agent.  The origin and adaptations of organisms in their profusion and wondrous variations were thus brought into the realm of science.

crab on the rocks
Creative Commons License photo credit: angela7dreams

Evolution can be seen as a two-step process. First, hereditary variation arises by mutation; second, selection occurs by which useful variations increase in frequency and those that are less useful or injurious are eliminated over the generations. “Useful” and “injurious” are terms used by Darwin in his definition of natural selection. The significant point is that individuals having useful variations “would have the best chance of surviving and procreating their kind.” As a consequence, useful variations increase in frequency over the generations, at the expense of those that are less useful or injurious.

Natural selection is much more than a “purifying” process, for it is able to generate novelty by increasing the probability of otherwise extremely improbable genetic combinations.  Natural selection in combination with mutation becomes, in this respect, a creative process.  Moreover, it is a process that has been occurring for many millions of years, in many different evolutionary lineages and a multitude of species, each consisting of a large number of individuals. Evolution by mutation and natural selection has produced the enormous diversity of the living world with its wondrous adaptations.

Francisco J. Ayala is a noted biologist and philosopher at the University of California at Irvine’s Department of Ecology and Evolutionary Biology. Don’t miss his lecture on Feb. 24 - or any of the other Darwin2009 events planned at HMNS this year.