12. January 2024 · Comments Off on DINOSAURS · Categories: Blog

Scientists believe that a six-mile wide asteroid landed in what’s now Central America 66 million years ago, causing fires and leading to what they call a “nuclear winter.” This means that the dust and debris kicked up by the impact, and smoke and ash from the fires, filled the air and created a barrier to sunlight for a very long time, so that plants and animals that depended on sunlight could not grow. This in turn was believed to be the cause of the disappearance of dinosaurs that lived at that time all over the earth. They died off eventually from starvation, or dehydration, or other unknown causes (e.g., battles for the last vegetation).

Some recent studies have shown that:

The impact of the asteroid created the Chicxulub crater, which is buried under Mexico’s Yucatan Peninsula. The crater measures around 112 miles in diameter. The asteroid impact that wiped out most of the dinosaurs 66 million years ago sparked two years of darkness caused by the soot from raging wildfires that filled the sky and blocked the sun. This phenomenon further contributed to the wave of extinctions that followed.

Dinosaurs died off about 33,000 years after the asteroid hit the Earth, much sooner than scientists had believed, and the asteroid may not have been the sole cause of extinc-tion, according to a recent study. The asteroid impact that wiped out most of the dinosaurs 66 million years ago sparked two years of darkness caused by the soot from raging wildfires that filled the sky and blocked the sun. This phenomenon further contributed to the wave of extinctions that followed. The dust from the impact might have stayed in the atmosphere for up to 15 years, the team’s models suggest. During this time, global temperatures would have dropped by as much as 15 °C.

An in-depth analysis of the fossil record shows that placental mammals (the group that includes humans, dogs and bats), co-existed with dinosaurs for a short time before the dinosaurs went extinct. Since dinosaurs died off about 33,000 years after the asteroid hit Earth, this means that those mammals co-existed with dinosaurs for sometime around 33,000 years.

All modern humans share a common ancestor who lived around 200,000 years ago in Africa. Comparisons between known skin pigmentation genes in chimpanzees and modern Africans show that dark skin evolved along with the loss of body hair about 1.2 million years ago, and that this common ancestor had dark skin.

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