Bio 101 Final

What were the pieces of evidence that led to the identification of Chicxulub as the asteroid impact site?

Alan Hildebrand discovered certain "gravity anomalies." He found that tektites form under high temperature, which could be a cause of the asteroid itself crashing into earth. He found that these tektites were also found mainly in Haiti and later labeled out that the asteroid should have been near that area. That's when later someone had contacted them that the asteroid was near the Yucatan peninsula.

What was the "glimpse" that Bates had "of how nature manufactures her species?"

Bates observed that certain species of caterpillars physically resembled another species of caterpillars that were "unsavory" to predators, a process termed "mimetic analogy"

Why was Darwin so delighted by Bates' discovery of mimicry?

Because Darwin's evidence supporting natural selection was based on observations of domestic animals, Bates provided Darwin with independent evidence of natural selection in nature.

The extinction of the dinosaurs, ammonites, and other creatures at the end of the Cretaceous was well known for many decades prior to the Alvarezes' discovery. Why did Walter Alvarez, a geologist, and Luis Alvarez, a nuclear physicist, crack a mystery that paleontologists and biologists had not?

Both of them found traces of iridium in places and he was purposing how exactly the extinction came about when Chris Mckee, an astronomer colleague, told him that an asteroid could have hit the earth. Alvarez started to think about this and decided that this asteroid had to be massive and had to have a great impact on the land.

What is the significance of the structure of the coelacanth pectoral and pelvic fins?

Coelacanth has special pectoral and pelvic fins which are different from ray-finned fish.Bones in lobe-finned fish are closely related to bones in human and tetrapod which allow better rotation of limbs. For this reason, coelacanth can move in alternating fashion: right front fin with the left rear fin, the left front with the right rear. In other words, this species can move like a four-leg animal.

What might be the local and global effects of future smaller or similar-sized asteroid impacts?

Depending on its size and speed, it could cause another extinction

Why did Darwin delay publishing his species theory?

Didn't want to risk professional reputation and recognition due to a radical theory went against creationism still needed more evidence to bolster his theory Did not want to concern his wife, Emma, about their "eternal life together" due to his heresies

What zoological evidence led Darwin to think that species evolved?

Species from Galapagos Islands and South America, fossils of armadillo-like creatures, capybara relatives, and sloth species, thirteen species of finches, all very similar to those on other islands. Islands had changed birds and "produced new species"

"Living fossil is a term that has been informally used to describe crocodiles, horseshoe crabs, ginkgo trees, and some other plants and animals. Are living members of these groups exceptionally long-lived species? How does the term "loving fossil" apply to the coelacanth?

The term "living fossil" applying to a species does not signify that the species can livelong. It is used to describe a living species descended from an ancestor that lived in the past and has not changed much. Coelacanth is one example for this term because it had transformed little comparing to its precursor found in 380 million years ago.

What were Thomas Malthus's ideas, and how did Darwin react to them?

Thomas: Essay on the Principle of Population, including checks on population growth to prevent overpopulation Darwin: Knew stronger, better adapted ones would survive, thus new species would be formed (species theory)

What geological phenomena and formations did Darwin witness? How did these shape his thinking about the age of the earth or how life changed?

Witnessed a band of shells and corals that laid about 30 feet above sea level, making him wonder if the sea level had fallen or if the island had risen mussel beds rose several feet above the water after an earthquake and fossilized trees thousands of feet high, which caused him to believe that the land had been uplifted

What experiences of his youth helped to prepare Darwin for the voyage on the Beagle?

loved chemistry expeditions to collect insects and bird hunt realized he did not want to be a doctor like the rest of his family Edmonstone's tales of the Tropics and beetle collecting Henslow's seven volume reading which gave Darwin a thirst for traveling Sedgwick's suggested readings and training