Unit 6 Lesson 9: Effects of Change Flashcards
The most successful organisms are those that are best adapted to their environments. Organisms adapt to their environments through a process of natural selection and evolution which includes the following steps:
- An individual is born with a particular trait that makes it easier to survive and reproduce.
- The individual reproduces, and its offspring inherit the advantageous trait.
- The trait increases the fitness of the offspring to survive. They, too, reproduce and pass along the trait.
- Over a very long series of generations, the species evolves so that all members of the species have the advantageous trait (or the trait is so significant that a new, better-adapted species develops).
But what happens to a species that is well-adapted to its environment if the environment changes?
In many cases, the species will die off, or go extinct. In other cases, the species will adapt and evolve in the new environment, changing dramatically over time. The outcome depends on many factors, but perhaps the most significant is time. If environmental change occurs very rapidly it may be impossible for the species to adapt rapidly enough to survive.
What happened during the Cretaceous Period? What was the K-Pg extention
the Cretaceous Period, during the time of the dinosaurs. This catastrophic event is called the K-Pg extinction, or Cretaceous-Paleogene Extinction. Evidence suggests that the K-Pg extinction was the result of a meteor strike. The K-Pg extinction occurred about 65.5 million years ago, and its impact was so immense that it wiped out nearly all large animals and many smaller invertebrates. Such a large-scale die-off in a relatively short geological time is called a mass extinction.
Using a mathematical model called an impact calculator, the researchers were able to figure out what would have happened to living things near the impact site.
- Anything within 625 miles, which covers an area larger than Texas and Mexico combined, would have been instantly killed by a fireball.
- Earthquakes would have set off a giant tsunami (tidal wave) 1,000 feet tall, which would have flooded the land.
- 600 mile per hour winds, which is faster than most commercial airplanes, would have blown outward from the impact site.
- Just hours after the impact, the sky would be darkened by the dust created, and bits of burning dust, ash, and rubble would start falling out of the sky.
- The soot and ash in the atmosphere, along with the smog created by fires, would have darkened the sky for months, killing vegetation and cooling the climate.
After the K-Pg event, three quarters of plants and animals became extinct. In addition to the non-avian dinosaurs, these included pterosaurs, many species of birds and lizards, marine animals such as plesiosaurs and mosasaurs, and many species of plankton. what did this event lead to
The event also led to a rapid growth of new species including new types of birds, fish, and lizards. In particular, the number and diversity of mammals expanded rapidly.
Which of mammals’ ablity may have been an advatage
Researchers believe that mammals’ ability to maintain their body temperature even in colder conditions may have been an advantage. Mammals were also able to adapt to a very different environment with flowering plants, fruits, berries, and new kinds of forest habitats.
How did dinos going extinct benfit mamaals
When dinosaurs went extinct, a lot of competitors and predators of mammals disappeared, meaning that a great deal of the pressure limiting what mammals could do ecologically was removed. They clearly took advantage of that opportunity.
Within 200,000 years after the K-Pg extinction event, researchers discovered that mammals went from being nocturnal (nighttime) creatures to being active during the
day
How did researchers gather evidence about the likely impact of the K-Pg meteor strike on Earth’s surface and atmosphere?
They collected and analyzed rock cores from the Chicxulub Crater.
Mammals’ rapid evolution after the extinction of the dinosaurs included the development of many new species from just a few ancestors.
Is this statement true or false?
true; This type of rapid evolution is called adaptive radiation.
