I hereby dedicate this thread to John 61X Breezy, the courageous man who asked for a mere week and some days to prepare, who any day now will appear and overthrow 150 years of biological science by nixing macroevolution! This is something to tell your grandchildren about! You were there!
In its broadest sense macroevolution is common descent with modification. Think of a family tree that (with a bit of luck) gets ever more branchy as the years go by. Everyone born into this family tree has descended from the same early ancestor. They share a common lineage or common descent.
For macroevolution, that "family tree" takes in all known life on earth and traces back to a primitive prokaryote (a cell without a nucleus). And, the evolutionary (phylogenetic) tree continually developed new branches (beginning as little twigs) as life continued to adapt to an ever-changing environment. Thus, the name "common descent with modification," also called the "fact of evolution."
I claim that macroevolution is a fact (like the sun rising in the morning) that follows from a mountain of solid evidence. Theories are the useful, polished explanations of those facts, so we have theories of evolution (natural selection, sexual selection, founder's effect, genetic drift, etc.) as well as the fact of evolution. It's not a case of one theory fitting all, though Darwin's natural selection is the main engine. Biologists do have disagreements over the theories of evolution, Stephen Jay Gould's "punctuated equilibrium" being a classic example, but they all accept the fact of evolution. (You won't find an ongoing debate in any reputable scientific journal over the fact of evolution. Nor will you find any legitimate, university textbook on biology or geology suggesting that the fact of evolution is still being debated in the scientific community.)
How do we test a scientific claim? If an hypothesis makes significant predictions that go beyond any evidence that it was designed to accommodate (the former being real predictions; the latter being ad hoc agreement) then we have our test. Therefore, in order to test macroevolution we need to look at its best predictions. Mr. Breezy must challenge those predictions! (Any other approach is totally irrelevant.) Fortunately, Dr. Douglas Theobald (Associate Professor of Biochemistry at Brandeis University, Massachusetts) has done us a great service by outlining the major predictions of macroevolution. Thus, I present his last update (2012) of that outline, copyrighted by Douglas L. Theobald and used with permission.
The full essay may be found on the Talk.Origins Archive website and has an excellent introduction to the nature of science and of phylogenetic (evolutionary) trees. (Phylogenetic trees are, in my opinion, the number one proof of macroevolution, so anyone attacking macroevolution should know tree basics.) The following outline also serves as a table of contents for Dr. Theobald's essay. Even if science is not your bowl of soup, you might enjoy romping around on this fun and educational website. Tired of pretentious, creationist drivel? The whole Talk.Origins Archive is one, big playground!
* * *
Part I. A unique, historical phylogenetic tree
1. Unity of life
2. Nested hierarchies
3. Convergence of independent phylogenies
Statistics of incongruent phylogenies
4. Transitional forms
- Legged whales
- Legged seacows
5. Chronology of common ancestors
Part 2. Past history
1. Anatomical vestiges
- Whales and dolphins with hindlimbs
- Human tails
3. Molecular vestiges
4. Ontogeny and developmental biology
- Mammalian ear bones, reptilian jaws
- Pharyngeal pouches, branchial arches
- Snake embryos with legs
- Embryonic human tail
- Marsupial eggshell and caruncle
5. Present biogeography
6. Past biogeography
- Apes and humans
Part 3. Evolutionary opportunism
1. Anatomical parahomology
2. Molecular parahomology
3. Anatomical convergence
4. Molecular convergence
5. Anatomical suboptimal function
6. Molecular suboptimal function
Part 4. Molecular evidence
1. Protein functional redundancy
2. DNA functional redundancy
4. Redundant pseudogenes
5. Endogenous retroviruses
Part 5. Change
4. The strange past
5. Stages of speciation
6. Speciation events
7. Morphological rates
8. Genetic rates
Theobald, Douglas L. "29+ Evidences for Macroevolution: The Scientific Case for Common Descent." The Talk.Origins Archive. Vers. 2.89. 2012. Web. 12 Mar. 2012
(Copyrighted by Douglas L. Theobald and used with permission.)
So, that's the outline of what macroevolution predicts. Are these major predictions fulfilled? Are there any credible alternative hypotheses that make these predictions? (Keep in mind that this debate is about hard evidence, not about theological speculation!) Those two questions are the only relevant questions in this debate.
* * *
Let's start off with something simple--the fossil record (under Part I-5 in the outline). Here are four major predictions in a nutshell:
1) Since the overall order of geologic strata has been worked out, and later dated by radiometric methods, we can make a very strong and testable prediction. The oldest strata in which fossils are found will contain fossils of very primitive life.
FACT: In Precambrian strata older than about 2 1/2 billion years all fossils are of primitive prokaryotes (cells without a nucleus). Not a single dinosaur bone or plant leaf to be found in the original rock! Not even fossil pollen which has a sturdy shell that preserves rather well! How is it possible that a large chunk of the geologic record is missing even the debris of more advanced life? Where was all that life hiding?
2) Macroevolution predicts that fossils found in the most recent strata will strongly resemble life on earth today, and that as we look at older and older strata we will find less and less similarity to life on earth today.
FACT: Darwin observed this relationship as did the great French biologist, Jean Lamark, who mentioned it around 1800. Dr. David Montgomery (and many others) have observed this relationship when climbing out of the Grand Canyon. Obviously, macroevolution has nailed this prediction! Now, can you think of any credible alternative hypothesis?
3) Macroevolution makes the strong prediction that members of certain, extensive plant families will not be found together in the fossil record, against all reasonable expectations, for the simple reason that those families evolved at different times. Later on, when both families co-exist, they might share the same fossil strata.
FACT: Modern flowering plants (angiosperms) and their distinct pollen are totally missing in the great coal forests/swamps of the Carboniferous Period! The idea that not one out of 300,000 species of modern flowering plants will show up in the great coal forests is not very credible given that they totally dominate plant life today and prosper in virtually every ecosystem where plants may be found. We find them everywhere today except in the depths of the ocean and the heart of Antarctica. Even sea grass, found in the surf zone, belongs to that group! And, don't forget their distinctive pollen and small, winged seeds which can be blown for hundreds of miles if the wind is right!
FACT: Ferns did not always live in shady places. In their Jurassic heyday some species occupied the open prairies--except that there is no evidence of grass then! Thus, we have another remarkable fulfillment of the above prediction. If not for macroevolution, we would expect to find ferns and grass living side by side given that they occupied the same, open habitat.
FACT: Coccolithophorids, a marine plankton, are found in oceans throughout the world. Diatoms, also a marine plankton, are so numerous that they contribute about 20% of the new oxygen released each year by photosynthesis. But the fossils for these two groups are not found together in the early Jurassic! If not for macroevolution, we would certainly expect to find these marine plankton well mixed in the fossil record. Hence, prediction #3 is fulfilled by yet another observed fact.
4) Here's another strong prediction. If we start with the oldest strata containing fossils and work our way up, we will find a logical progression consistent with macroevolution. Mammals, for instance, shouldn't precede amphibians and reptiles in which developments necessary for mammals first appear. Reptiles, which don't have to live near bodies of water, should not precede amphibians which depend on bodies of water. A full adaptation to land logically comes after dependence on bodies of water. In that vein, sea life should precede land life. Above all, new types of plants and animals should be continually appearing for the first time throughout the fossil record. Do we observe these strong predictions? Are there any good alternative hypotheses?
FACT: You won't find fossils of whales, dolphins, dinosaurs, or most modern fish in the Devonian (the age of fishes), nor fossils of elephants, horses, tigers, bears, or us in dinosaur strata despite wild, creationist claims. Nor do fossils of land life precede those of sea life. Humble Devonian forests bear little resemblance to later Carboniferous forests, which bear little resemblance to later Cretaceous forests. They have to come in that order to match the logical development of various innovations needed at each stage. Macroevolution gets it right!
Raise you hand if you are still awake! (Pass the Monster drinks and coffee! Doughnuts too! I'll take a couple of those glazed ones, thank you. Running archaic slide projector.)
For those of you who want some details of the fossil sequence, here's an outline of the first known appearances of life forms in the geologic record. (It's rather incomplete and unrepresentative but it does focus on familiar organisms.) In some cases those life forms may have appeared somewhat earlier since the oldest fossil we see may not actually be the very first, but the general pattern is not much changed. "Prehistoric Life: The Definitive History of Life on Earth," published by DK in 2012, served as a guide for much of this list. Almost every page is loaded with photos and stunning paintings so that you can make sense out of strange names. Some 20 scientists contributed to its various chapters, not counting an additional 7 or 8 special consultants! So, it's pretty accurate and highly readable--and fun.
3.5 billion years ago: We find only primitive prokaryotes (single-celled life lacking a nucleus).
2.4 billion years ago: We find cyanobacteria in which photosynthesis occurred. Oxygen, a waste product, was being pumped out into the atmosphere. Before then there was no oxygen in the air to speak of.
1.85 billion years ago: We observe the early eukaryotes, those being more complicated cells that organize their DNA into a nucleus.
1.5 billion years ago: About 350 million years later we find structurally complex eukaryotes. Lots of internal structures and organelles are present in these cells.
1.4 billion years ago: About 100 million years later we find a great increase in stromatolites (mound-forming mats of cyanobacteria that grew in successive layers). A few distant survivors can be found to this very day on the west coast of Australia.
0.72-0.64 billion years ago: Around 700 million years ago we find the first fossils of soft-bodied, multi-cellular animals (the metazoans).
550 million years ago: We find the first evidence of comb jellies, sponges, and other ctenophores.
A host of bizarre sea creatures with hard parts arise, including the famed trilobites. Sea snails also appear and it is thought that the first primitive fish made the scene based on some peculiar fossils.
Starfish show up in the fossil record. Trilobites diversity. (Every time you see the word "diversify" that means a group of closely related, new species (or higher taxa) appeared that were hitherto unknown in the fossil record. This is hard to explain without macroevolution! We also see the diversification of early corals which now include true, multi-cellular organisms. Previously, reefs consisted of algae (those that used calcium as a cement) and certain other single-celled life forms. The fossil of a sea creature turned up in what is now North America; it showed evidence of a backbone.
An assortment of jawless fish are observed in the fossil record along with the first jawed fish. Jaws have arrived but not true fish teeth! The first ray-finned fish show up. Scorpions and related arachnids invade the land but insect fossils are not yet found. Plants also invade the land, at least near the water's edge. The earliest plants are small since the specialized tissue for efficient water transport was lacking. Nor did they have true leaves.
DEVONIAN PERIOD: "The Age of Fish."
The first true fish teeth show up in the fossil record. The first bony, fresh-water fish fossils turn up. The first true sharks appear. Late in the Devonian we find fossils of nautilus-like animals with coiled shells. On land, horsetails and lichens appear along with the first amphibians. We also find fossils of the first real forests which are unlike anything today! "Seed" ferns are in their glory! Fossil evidence of insects munching away on plant leaves are now found.
CARBONIFEROUS PERIOD: "The Age of Coal and Amphibians."
We observe the rise of the great coal forests in lowland, swampy areas near the equator of that time. The coal seams of Pennsylvania and West Virginia, and of parts of Europe, then near the equator, were laid down. It is an age of ferns and seed ferns. The fossils of early conifers show up in forests dominated by lycopsids, cordaites, and seed plants. The oxygen level is extremely high, much higher than modern times. Huge insects show up in the fossil record! Some dragonflies had a 2-foot wingspan! (The high level of oxygen supports the evolution of giant insects.) Winged insects diversify even more. We also find the first plant-eating tetrapods. Reptiles are making headway in this age of amphibians.
Fossils of the first coniferous trees are found. Conifers and seed plants diversity. The first beetles show up in the fossil record. Some of the terrestrial amphibians increase in diversity. Mammal-like reptiles appear. The greatest of all known extinctions closes out the Permian, earth's ecosystem being in ruins.
Mammal-like reptiles increase their body size. The first dinosaurs, small forerunners of T-Rex and other late theropods, appear. They are not a promising group! Cycads and conifers saw an increase of diversity. The first bony (teleost) fish appear along with turtles. On land flies make their appearance. We also find fossils of the first mammals and they are small critters. They seem to have appeared at about the same time as the dinosaurs but went nowhere until a meteorite wiped out the dinosaurs.
The great, plant-eating sauropod dinosaurs diversify. Brachiosaurus, weighing in at 50 tons, walks the earth! The first fossils of salamanders and newts appear. Fossils are found of the first true birds and lizards. Theropods (Tyrannosaurus, Allosaurus, and velociraptor being theropod examples) diversify. Ginkgoes are in their heyday, reaching their maximum diversity. Jurassic conifers look more like modern conifers than those of the Triassic. Dominant ferns lived in similar open habitats as do grasses today! Mammals, still small critters underfoot of the dinosaurs, diversify into a range of body types. In the oceans the bony (teleost) fish undergo a huge radiation during the Jurassic and Cretaceus periods. Ammonites (looking a bit like nautiluses) are in their heyday. New corals (scleractinian corals) arise and now replace those of the Triassic.
Fossils are found of a new type of dinosaur, the ceratopsians, of which Triceratops is a classic example. This was also the time when T-Rex roamed. (Dinosaurs continued to diversify.) We find the first snakes, the first flowering plants (~125 million years ago) and their large diversification some 40 million years later. We find fossils of the first palm trees and other monocots such as orchids and lilies. The first termites and ants show up. Insects and reptiles diversify. Major changes in the conifers bring in many of the modern groups we see today. In the ocean and inland seas the fossils of great sea monsters are found, such as the plesiosaurs and mosasaurs. The largest flying animal of all time, a pterosaur named Quetzalcoatlus with something like a 50-foot wingspan, took to the air! The Cretaceous came to an abrupt end when a large meteorite struck the shallow seas in what is today the northern shoreline of the Yucatan peninsula.
PALEOCENE EPOC: (We now move to smaller time intervals called "epocs.")
Fossils show a quick, initial diversification of ants. Grass first shows up. Mammals undergo a rapid diversification. The first primates arrive.
Modern bird groups diversity. Whales, rodents, horses, elephants, bats, and camels make their first appearance. Fossils are now found of modern moths and butterflies. We see the beginnings of the great grassland ecosystems. Many of the modern animals appear.
The first eucalyptus fossils are found in Australia. Cats and deer arrive. Seashores get their first barnacles. Fossils of the first monkeys are found.
The Australian mega fauna diversifies. Fossils show much diversification in mammals, snakes, and especially rodents. Cattle, sheep, goats, and bison are part of that new lot. The great grasslands have fully arrived. Insects, especially termites and ants, diversity further. The first apes show up, followed by the first hominins (human-like).
Hippo fossils are found. Carnivores become larger and faster, and more diversity is found in grazing animals. Fossils of the first Homo show up, that being the genus (one level higher than species) that we belong to. Conifers living at high altitudes diversify.
Homo erectus, Homo antecessor, Homo heidelbergensis, Homo neanderthalensis, and Homo Sapiens arrive in that order.
------------- CONCLUSION -------------
Not only is the fossil record in a logical developmental order as predicted by macroevolution, but we see numerous examples of species and higher taxa appearing for the first time all the way up the fossil record. Invariably, when an important new group of animals or plants shows up diversification soon follows. That relationship is rather difficult to explain without macroevolution!
The four major predictions I looked at with respect to the fossil record are right on the money! Nothing wrong with macroevolution here! If there are any credible, alternative explanations then Mr. Breezy will have to inform us because I can't think of any. The fossil record is just the start of a mountain of evidence for macroevolution! But already we see macroevolution passing strong tests.
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