EVOLUTION Write down only the words in red

Transcription

1 EVOLUTION Write down only the words in red

2 Develop an understanding of the world we live in. Run experiments, make observations, collect samples, measure and count stuff. Repeat endlessly. THE FUN WILL NEVER STOP!! We develop a theory that best explains all the information we have collected. Explanations can use only natural forces and processes. The goal is to understand the world/universe to make accurate predictions about the natural world.

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4 What is the evidence for evolution? Fossil Record History of life as documented by fossils, the remains or imprints of the organisms from earlier geological periods preserved in sedimentary rock. EXAMPLE - WHALES Comparative Anatomy Natural Selection and Adaptations

5 EXAMPLE: THE FOSSIL RECORD OF WHALES n article/0_0_0/evograms_03

6 EVIDENCE THAT AMBULOCETUS IS RELATED TO WHALES FROM GEOLOGISTS they analyzed the earth around the fossil and determined it was from an estuary (saltwater + freshwater) FROM CHEMISTS They determined the type of oxygen in the bones and showed the animal lived in an estuary FROM BIOLOGISTS- They determined that their skulls closely resemble the modern whale and are unlike any other mammal. THE EVOLUTION OF WHALES

7 WHY AREN T THERE MORE FOSSILS? Fossilization doesn t happen that often. The right conditions are common only in a very few habitats, such as river deltas, peat bogs, and tar pits. Many types of animals are fragile and do not preserve well. Many species have small ranges. Their chance of fossilization will be proportionally small. Even if fossils are made, other processes destroy fossils. Erosion, heat or pressure when fossils are buried deep underground. Discovering a fossil (if one exists) is also rare. Fossils are typically found when ground erodes, but before the fossils themselves erode. The millions of fossils that scientists have collected is called the FOSSIL RECORD

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9 AGE OF THE EARTH WHAT HAS BEEN GOING ON? THE oldest materials found are 4.3 billionyear-old zircon crystals. WHAT S HAPPENED IN THE LAST 600 MILLION YEARS?

10 AGE OF THE EARTH WHAT HAS BEEN GOING ON? WHAT S HAPPENED IN THE LAST 250 MILLION YEARS?

11 AGE OF THE EARTH WHAT HAS BEEN GOING ON? MAMMALS evolved 200 million years ago HOMO SAPIENS evolved 2 million years ago

12 What is the evidence for evolution? Fossil Record Comparative Anatomy Natural Selection and Adaptations History of life as documented by fossils, the remains or imprints of the organisms from earlier geological periods preserved in sedimentary rock. EXAMPLE - WHALES Many living things (organisms) have similar arrangements of physical traits, leading scientists to believe they are related to each other, much in the same way that members of a human family have similar physical traits.

13 SIMILARITIES BETWEEN SPECIES HOMOLOGY traits inherited by two different organisms from a common ancestor ANALOGY similarity due to convergent evolution, not common ancestry

14 SIMILARITIES BETWEEN SPECIES Whales, lizards, humans, and birds all have the same basic limb layout. But how did such different animals wind up with the same sort of limb? The answer is that they inherited it from a common ancestor, just as cousins might inherit the same trait from their grandfather. University of California Museum of Paleontology's Understanding Evolution (

15 SIMILARITIES BETWEEN SPECIES evolibrary/article/0_0_0/ similarity_hs_02

16 SIMILARITIES BETWEEN SPECIES Similarities between these tetrapod (4-limbed vertebrates) limbs: They are all built from many individual bones. They are all spin-offs of the same basic bone layout: one long bone attached to two other long bones.

17 SIMILARITIES BETWEEN SPECIES 1 HUMAN WHALE 3 2 LIZARD BIRD 4 Guess what animals these limbs belong to.

18 What is the evidence for evolution? Fossil Record Comparative Anatomy Natural Selection and Adaptations History of life as documented by fossils, the remains or imprints of the organisms from earlier geological periods preserved in sedimentary rock. EXAMPLE - WHALES Many living things (organisms) have similar arrangements of physical traits, leading scientists to believe they are related to each other, much in the same way that members of a human family have similar physical traits. How species change to succeed in their environment. Evidence of evolution in action, e.g., antibiotic resistance.

19 Evidence of Natural Selection Darwin collected a closely related group of 14 finch species in the Galápagos Islands u All were similar except for beak characteristics u Darwin hypothesized that different beak shapes were related to food gathering u Darwin wrote one might really fancy that one species has been taken and modified for different ends. 19

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21 All of these different types of evidence led scientists to the theory of evolution

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23 EVOLUTION A theory that the differences between modern plants and animals are because of changes that happened by a natural process over a very long time If we look today at the galaxies, stars, the planet Earth, and the life on planet Earth, we see that the natural world today is different than in the past: galaxies, stars, planets, and life forms have evolved. Evolution is a unifying concept for science. There is abundant and consistent evidence from astronomy, physics, biochemistry, geochronology, geology,

24 Isn t Evolution Just a Theory? When we use the word theory in everyday life, we usually mean an idea or a guess, but the word has a much different meaning in science. Have your students watch this short video to learn the vocabulary essential for understanding the nature of science and evolution. Discussion questions: How does the scientific meaning of a term like theory differ from the way it is used in everyday life? Can the facts of science change over