Rock On #11

In Pennsylvania today (or at most other places on the world's land surface):

The land surface is accumulating sediment in a few small places, building up records of geologic history, but most places are eroding. Feedback: Today in Pennsylvania (and across most of the land surface of the planet), sediments are accumulating in a few human-made lakes, a few natural wetlands or natural lakes, along some streams and in some caves, but almost everywhere else is eroding. This is the typical state of affairs, so you need to correlate events across large regions to get a good geologic record.

Which of the following was probably important in contributing to extinction of most species at the same time the dinosaurs became extinct?

"Impact winter" caused when tiny pieces of dust or other materials, which were put in the air by the impact, blocked incoming sunshine for months or years, after larger pieces had fallen back to Earth. Feedback: The "impact winter" likely did occur; we know that the materials thrown up by a big volcano cool the planet a degree or two for a year or two, and the meteorite would have thrown up a lot more stuff. The meteorite impact was not nearly large enough to move the planet notably or to stop the rotation. Silicosis is a lung disease caused by breathing too much silica-laden dust; other dust materials are typically more damaging, but too much of any dust can be bad. Dissolution in water does not cause lung disease. (Just for your information, some dictionaries list the long version of one form of the disease, pneumonoultramicroscopicsilicovolcanoconiosis, as the longest word in the English language.)

The great extinction at the end of the Paleozoic Era that changed the living types on Earth and made way for the origin of dinosaurs during the Mesozoic Era occurred about:

225,000,000 years ago Feedback: Humans were trotting around 22,500 years ago. 225,000 years is barely enough time for evolution to have changed large animals a little bit, and although 2,250,000 years is enough time for noticeable change of large animals—increase in maximum size of members of the horse family, for example—the huge changes since the dinosaurs consumed a good bit more than 22,500,000 years (dinosaur extinction was about 65,000,000 years ago). The end of the Paleozoic Era and start of the Mesozoic Era came before that, and 225,000,000 years is about right. 22,500,000,000 years is more than the age of the Earth, and so doesn't work very well.

The picture above shows:

An upside-down dinosaur track. Feedback: This is a dinosaur track, from Dinosaur Ridge, and the dinosaur stomped down into the mud, so the track is upside-down; the instructional team used the power of modern computers to invert the picture.

The Petrified Forest of Arizona includes a great diversity of fossils. In the picture above, paleontologist Randall Irmis excavates a plate from a specimen of Buettneria.Based on the discussions of evolution in the class materials, it is likely that:

Buettneria is related to, but recognizably different from, species still alive today Feedback: Evolutionary theory indicates that living things change from generation to generation, but that all living things are related. Consistent with this, Buettneria is recognizably similar to, yet different from, amphibians still alive today.

Which of the following is not a part of the modern theory of evolution?

Evolution proceeds in the direction desired by members of a generation. Feedback: No matter how hard you and your friends wish that your children will be born with the ability to fly unassisted, the kids will have to use airlines like the rest of us. All the rest of these contribute to evolution.

Considering long-term averages, and assuming that we don't deploy space-based defenses against incoming meteorites, a reasonable estimate of the chance of an average U.S. citizen being killed by the effects of a meteorite or comet impact is that this risk is about the same as the chance of being killed by:

Crash of a commercial airplane. Feedback: Nobody that we know eats Pepsi cans, and while there are still meteorites in the solar system that can hit and kill, there are no dinosaurs left except on "The Flintstones". A reputable study found that a meteorite impact might not occur for millions of years (or might occur next year...) but then might kill billions of people; plane crashes usually kill a few to a few hundred each year. Add up the deaths over a sufficiently long time, and plane crashes and meteorite impacts likely are similarly dangerous. But car crashes, smoking, and being fat and lazy are way more dangerous to us.

Religion and science always disagree.

False Feedback: Pope John Paul II said that the Catholic Church has no problem with evolution, and Baptist Jimmy Carter also supported evolution, so it is clear that religion and science can agree.

Which of the following is part of the evidence that the odd layer marking the extinction of the dinosaurs was caused by a large meteorite impact?

High concentrations of iridium found in the layer. Feedback: We have seen several times that iron and silica are very common, that potassium-40 is also common in many rocks (although it changes to argon-40 with increasing age), and that argon-40 appears from potassium-40 over time and so can be quite common in many older rocks. However, iridium is rare on the surface of the Earth, common in meteorites, and common in the layer.

Extinction of existing species:

Occurred at a low level throughout geologic history, punctuated by mass extinctions when many types were killed over very short times. Feedback: Extinction has happened slowly throughout geologic history, but with a few dramatic, catastrophic mass extinctions. We may be causing the latest of those mass extinctions.

The pictures labeled I and II show fossils from a sediment core collected from the floor of the Atlantic ocean, east of South Carolina. The sediment has not been disturbed by landslides or mountain building or other processes. The pictures were taken by Brian Huber, of the Smithsonian Institution, using a scanning electron microscope. The two samples in the sediment core were separated by the unique layer marking the extinction that killed the dinosaurs.Which is correct?

II is younger than the unique layer, and thus sat above the unique layer in the sediment on the sea floor. Feedback: Before the impact, biodiversity was high, as shown in I, which includes fossils from below the unique layer and thus deposited before the meteorite hit. After the impact, most of the living types were killed, giving rise to the limited diversity seen in II from above the unique layer after the impact.

What is accurate about the scientific theory of evolution today?

It is being applied successfully in the real world in many ways, including helping fight new disease organisms, and even guiding the thinking of computer scientists. Feedback: As antibiotic resistance appears in disease organisms, evolutionary biologists are helping doctors find better strategies to keep us healthy. The processes behind evolution—try new things, keep the ones that work, repeat—has been used intentionally for guidance in many human endeavors, including "evolutionary computing" in computer science. Ecologists trying to rescue ecosystems are informed by understanding of the evolutionary processes that made, and are changing, those ecosystems. Even regulations for sport fishing are guided by our understanding of evolution. In the same way as other successful ideas in science, evolution is useful in many practical ways in the real world.

Which of the following is not a scientifically accepted statement about the occurrence of transitional forms in the fossil record?

No one has ever discovered a single fossil of any transitional form.

In childhood stories (such as Little Red Riding Hood), we humans worry about predatory mammals such as wolves or tigers rather than worrying about predatory dinosaurs such as allosaurs or tyrannosaurs. This is because:

Small mammals coexisting with the dinosaurs were not able to outcompete the dinosaurs for big-animal jobs, but after the dinosaurs were killed, some large mammals evolved from small mammals to fill the large-animal jobs, including the big-predator job.

You develop a new idea, which is in conflict with a widely accepted scientific idea. For your new idea to gain widespread acceptance, you probably will need to show that:

Your new idea does a better job than the previously accepted idea in predicting the outcomes of an interlocking web of important experiments or observations. Feedback: At last observation, Pepsi commercials were not highly scientific, even if science is involved in figuring out what sells. It is a romantic notion that you could overturn great knowledge with a single observation; however, observing nature is not easy, and nature occasionally fools us (you can, rarely, flip an honest coin twenty times and get twenty heads), so if a single observation disagrees with a lot of other information, that single observation will be checked in various ways to see if the new result "stands up" before the older body of knowledge is discarded. Before an idea gains wide currency, that idea is tried in various ways, in many labs, in many places in nature, while models are run and theory is developed. The interlocking of all of these provides the confidence that scientists can use in doing things successfully. Although received wisdom from sacred books can be used for inspiration, scientific ideas must be tested against nature. Social scientists have quite rightly learned that scientists are affected by their prejudices, their funding sources, their mating habits, and other things, and that the path of science is not nearly the straight-ahead road to understanding presented in some textbooks. Unfortunately, some of those social scientists have then gone off the deep end and claimed that science is no more useful than any other human story—claiming that astrology and astronomy are equally valid, for example, or palm-reading and modern medicine. These same social scientists seem to know where to find a real doctor when they get in trouble, however. Science is appealed to nature, and builds on the learning of people from around the world. Airplanes that fly, computers that calculate, small devices that make big explosions, etc. are not socially conditioned ideas but instead are demonstrations of the success of science coupled to engineering