Chapter 7. The Evolution of Living Things. Diatryma and the Rooster. Diatryma weighed about 400 pounds (182 kg.) Flightless Cenozoic Era (57-35) million years ago Over 6 feet tall Enormous Beak Sharp Claws Distant relative of the chicken. Frog Crazy. Adaptation.
The Evolution of Living Things
Adaptation – a characteristic that helps an organism survive and reproduce in its environment
Adaptations Include Structures and Behaviors for:
1) finding food
3) moving from place to place
Species – a group of organisms that can mate with one another to produce fertile offspring
Human existence is less than a hairs width at the end of the diagram
Absence of short lived stars from star clusters 14-18 Ga1
Length it takes light to get to the earth from the most distant objects in the universe (10 Ga)2
Hubble expansion of the universe 7 - 20 Ga1
Evidence for an old solar system
Age of meteorites 4.4-4.6 Ga (isochron method)1
Age of moon 4.5 Ga (radiometric)1
Earth-meteorite system 4.54 Ga (lead isotope age)1
Evidence for an old earth:
Earths oldest rocks 3.8-3.9 Ga (radiometric)1
Evolution – the process by which populations accumulate inherited changes over time.
* Because of evolution scientists think that all living things and once living things, from daisies to crocodiles to humans share a common ancestor.
The fossil is a rock - Often the remains of preserved organisms are not of the organism itself but instead of minerals deposited where, especially, hard parts of the organism previously existed.
covered in sediment
A once living organism
The organism dies
The soft parts decay
The hard parts make a
mold (hollow impression)
which is replaced by minerals
There are six ways that organisms can turn into fossils, including:
1) unaltered preservation (like insects or plant parts trapped in amber, a hardened form of tree sap)
2) permineralization=petrification (in which rock-like minerals seep in slowly and replace the original organic tissues, forming a rock-like fossil - can preserve hard and soft parts - most bone and wood fossils are permineralized)
3) replacement (An organism's hard parts dissolve and are replaced by other minerals.
6) authigenic preservation
Most animals did not fossilize; they simply decayed and were lost from the fossil record. Paleontologists estimate that only a small percentage of the dinosaur genera that ever lived have been or will be found as fossils.
– the relative positions
of layers of sediment
determine the age of the
fossils found within them.
Non-radioisotope methods of direct dating: