The Extinction of Pleistocene Mammals Essay

“A minority disputes this theory, arguing that other events-such as volcanic eruptions, sea-level changes or a series of impacts-were to blame for the spectacular loss of species that occurred at the transition between the Cretaceous and Tertiary periods…”

“Sex, Drugs, Disasters, and the Extinction of Dinosaurs” is written by Stephen Jay Gould, professor of geology and zoology at Harvard. This essay is one of more than a hundred articles on evolution, zoology, and paleontology published by Gould in national magazines and journals. It tells about scientific proposals for the extinction of dinosaurs – a confusing but an exciting problem that humanity tries to solve. By analyzing and describing each of the claims for the reptiles’ demise – sex, drugs, and disasters – Gould differentiates bad science from good science and explains what makes some theories silly speculations, while the other, a testable hypothesis.

Although Martin is correct in his observation that humans have a direct impact on extinction, he cannot refute the fact that meteors can cause extinction. His argument in regards to dinosaur extinction was flawed. Martin argues that every child in the first grade knows that dinosaurs vanished 65 million years ago. However, there is no evidence that there were humans on this Earth when dinosaurs existed so his whole argument becomes null. He cites factual inaccuracies in this

Megafaunal extinction is a reference to how large animals such as the woolly mammoth became extinct, especially in North America. This extinction had an effect on Paleolithic cultures at the time, because some were extremely affected by it. In fact, the Clovis culture around North America became extinct with the animals. This is important, as it showed that after the extinction, the people didn't die out, but instead they spread out, with groups hunting smaller animals or bison instead of mammoths. It helped evolve Native American cultures, as after the megafaunal phase, some of the cultures became farmers or developers of cities. (Social and

Dinosaurs ruled the earth for over 65 million years and thankfully for the human race, they became extinct. Ultimately, only a major catastrophe could completely wipe out an entire species, let alone an entity of dinosaurs and the debacle on the causes of dinosaur extinction have flooded the minds of paleontologists for centuries. Geologist and zoologist Stephen Jay Gould published “Sex, Drugs, Disasters, and the Extinction of Dinosaurs,” to compare scientific and speculative causes of dinosaur decimation. Personally, I found this passage very informational and enjoyed reading it. Gould provides three theories that capture the reader’s curiosity, allowing room for pondering in one’s mind.

The question of what caused the extinction of megafauna during the Late Pleistocene period is one that archaeologists have struggled to answer for decades, but why should it matter? Discovering with certainty the cause of megafaunal extinction would

8. The periods in which there were mass extinctions are Permian – volcanic eruptions which spewed lava and put CO2 into the air which warmed the climate an estimated 6 degrees Celsius. The resulting of oxygen deficiency. And Cretaceous – asteroid or comet

In Stephen Jay Gould’s “Sex, Drugs, Disasters, and the Extinction of Dinosaurs”, Gould investigates three possible theories hypothesizing the reason behind the extinction of dinosaurs. The first theory suggests that dinosaurs became extinct due to a rise in temperature, which caused sperm to die, leading to the sterilization of male dinosaurs. The second hypothesis offer that many dinosaurs consumed bitter plants that contained psychoactive agents which their lives could not detoxify out of their systems. The last speculation about the dinosaur’s extinction is that a large cloud of dust formed in the atmosphere after an asteroid hit Earth’s surface. This dust cloud blocked out the sunlight, causing temperatures to drop and made photosynthesis impossible. Gould uses these three theories to lead to his central claim that science isn’t just about making fascinating claims, but should have a well developed hypothesis.

Neanderthals and modern humans coexisted for well over 100,000 years.  Then suddenly Homo neandertalensis began to die out and surrender the earth to Homo sapiens.  Paleontologists and anthropologists have entertained several possibilities to the causes of this event: interbreeding among Neanderthals and humans, competition for natural resources, and Darwin’s theory of “survival of the fittest.”  What the real cause has been has plagued scientists for years. Now, due to an international research team from Germany, those possibilities have been even further deduced, making it easier to pinpoint the exact reason Homo neandertalensis became extinct.

The Paleocene-Eocene Thermal Maximum was a period of time around the Paleocene-Eocene boundary during which the Earth experienced a significant rise in temperature. As we discussed in class January 27-February 3, the PETM period conveniently coincides with primate evolution and dispersal worldwide. This period of thermal increase is important to primate evolution because this rise in temperature worldwide created an ideal, survivable environment for primates globally. This rise in temperature encouraged primates to expand their territories into areas not previously inhabitable, such as the Arctic Circle. Additionally, I believe that the PETM may have encouraged primates to evolve into broader adaptive radii in order to exploit more tropical food sources and landscapes. In general, it is acknowledged that the PETM allowed primates to become more pervasive worldwide.

Hypothesis supporting climate change as a factor in Neanderthal extinction has taken on two forms - Neanderthals inability to adapt to harsh environments and prey extinction. Traditionally, Neanderthal extinction has been contributed to sudden climate change in which the species was unable to adapt (Houldcroft & Underdown 2015). Despite the fact that Neanderthal fossil exhibit ecomorphological characteristics that suggest they were adapted to colder ‘ice age’ environments; there is considerable evidence that supports the hypothesis that climatic changes are responsible for their sudden disappearance (Rae et al 2011; Stewart 2005). Neanderthal species were unlike any

Dinosaur extinction: An analysis of events and theories that possibly led to the dinosaurs' demise.

There have been five well known extinctions on this earth. The one most well known is the mass extinction that ended the dinosaurs. Mass extinction is often described as the elimination of a large number of species in a short period of time. Despite what many think, the elimination of species is almost commonplace at this point. The Earth is currently in the middle of a sixth mass extinction, and it’s been caused by the human race.

The entirety of Earth’s ecosystem was affected by the K-Pg extinction, caused by volcanoes, oceanic shifts, and ultimately, an asteroid. Lucky for humans, mammals capitalized on the opportunity

They say as mammals continued to evolve, they drove the dinosaurs into extinction (“What Killed the Dinosaurs”). “Not only did mammals likely compete with dinosaurs for resources, many species survived the end-Cretaceous extinction and subsequently came to dominate Earth.” (“What Killed the Dinosaurs?”). This is primarily because the early mammals were a lot smaller than the mammals that exist today. “Some of the world's earliest mammals were the multituberculates, a group of small rodent like animals that first emerged on Earth about 165 million years ago.” (Welsh, Jennifer). Scientists predict that any mass extinction event that caused animals to go extinct affected larger animals than it did the smaller animals, such as mammals ("Dinosaurs Became Extinct 'due to Laying Eggs'"). Mammals remained small for almost 100 million years, while they out competed small and baby dinosaurs for food, shelter and resources until they were extinct. Once the dinosaurs were out of the way mammals were able to evolve and grow large in size like the mammals that exist today today (LiveScience). Fossil evidence sheds some light on this theory as well. Fossils of mammals believed to date back to about eighty five million years ago show that mammals began to change rapidly and grow. “This matches up with other mammal groups, including recently discovered species from the Late Cretaceous (between 100 million and 65 million years ago) showing highly specialized