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Biology library
Course: Biology library > Unit 26
Lesson 1: Evidence of evolution- Biodiversity and natural selection
- Evidence for evolution
- Fossils: Rocking the Earth
- Molecular evidence for evolutionary relationships examples
- Carbon 14 dating 1
- DNA spells evolution
- Variation in a species
- Reproductive isolation
- Evidence for evolution
- Surviving an extinction level event
- Cellular evidence of common ancestry
- A brief history of mass extinctions
- Evidence of evolution
- Common ancestry and continuing evolution
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Fossils: Rocking the Earth
Use fossils, like clues buried inside of rocks, to unlock the history of life on our planet. Play the Evolution Lab: http://www.pbs.org/nova/labs/lab/evolution/ .
Want to join the conversation?
- hey is it possible to make fossils artificially the way they make artificial diamonds...like under laboratory conditions(10 votes)
- It is possible to use a mold and a cast to create "fake" fossils. They look just like the real ones, but aren't.(6 votes)
- but the fossil cant show real picture(3 votes)
- The fossils can't show a real picture, but scientists can use computer programs to form a new picture using the fossil. The picture may not be completely correct, but the programs are so intelligent that the pictures are very close to how the actual organisms would look if they were still alive today.(9 votes)
- Why did he say that there are intermediates in-between species? Because it is just not true. For instance bats and rats are supposedly supposed to have evolved from one another, but there are no fossils supporting that. If there were that would be really weird, how would a rat with wings survive? Natural Selection just debunks that.(4 votes)
- No modern species evolved from any other modern species. Both modern species evolved from a common ancestor.
As I said on your other post on the "Human evolution overview" video the statement that there is no supporting fossil evidence is false.
Natural selection doesn't debunk anything about rats being genetically related to bats.(3 votes)
- Do fossils lose parts when underground(4 votes)
- They will slowly decay or disappear underground. If you want to know how long, it depends on many factors including the soil's acidity.(2 votes)
- are fossils infused with rocks like a femur bong stuck in the mud that turned to stone(3 votes)
- Fossils are hard mineral parts(like bones and teeth) were formed as follows:as the bone slowly decayed, water infused with the mineral seeped into the bone and replaced the chemicals in the bone and replaced it with rock like minerals.(3 votes)
- do fossils lose parts when underground(2 votes)
- Yes. Frequently parts of the skeleton are lost and never found or not found until long after the first part was found. A full or nearly full skeleton would not only get you in the news, but put you down in history (or at least your fossil)!(3 votes)
- How do you know the femur of a triceratops is the same as a grizzly bear and eagle?(2 votes)
- It has specific characteristics that are unique to the creature and/or related species; for example, ceratopsians (the taxonomic family containing Triceratops and co.) might have muscle attachment points on the bone that are found only on themselves, and so would be easy to recognize by a trained eye. However, there are times when bones are just too eroded or little in number to know anything besides what general family they belonged to, such as two-footed or four-footed dinosaurs. These bones are classified as indeterminate.(2 votes)
- Do you know what preserved trace fossils might include?(2 votes)
- why cant i do a assignment after this video? Why CANT I(2 votes)
Video transcript
How do we know that two species are related
if their common ancestor is no longer alive? How do we know what happened on Earth before
humans showed up? Sometimes the answers to questions like these
are right beneath our feet. Look in the right place, and you’ll find
fossils—traces of organisms that were once alive and that, with time, were preserved,
usually in rocks. And here’s the remarkable thing: When we get fossils out of the ground, they
have features that are shared with features found in living organisms. So tucked away inside rocks that are thousands
or millions of years old, we find fossils of bones and shells and leaves that resemble
those in organisms alive today. They give us a record of how life on Earth
has changed over time. It’s not complete, however, because not
all organisms get preserved, and not all fossils get found. So the more of these fossils we have, that
we can place on the tree, the more it tells us of when different features of organisms
evolved. Pull a fossil of a dinosaur femur, or thighbone,
out of a rock layer that’s, say, 68 million years old, and you know that dinosaur must
have lived about 68 million years ago. And you can compare it to the femurs of animals
both extinct and alive today. Which will give you an idea of how those organisms
are related… and how the femur in particular has been adapted to suit new organisms in
new environments, over and over again. The fossil record provides strong evidence
for evolution. It shows us that evolutionary change tends
to be gradual. It gives us physical proof of extinction,
and of single species splitting into two. And it contains creatures that are transitional
forms between one group of species and another. This is where you’re being sent now. To a place where living things become rocks,
and those rocks become clues that tether the ancient Earth to the modern one. Prepare to dig.