Evidence of Evolution
-long - fast - grasslands
All modern members of the horse family are large, _______-legged, __________- running animals adapted to living in open _______________.
different traits evolve at different rate and different times
Archaeopteryx fossil exhibit some traits that are characteristic of birds and other traits that are indistinguishable from those of carnivorous dinosaurs. This indicate that
specimen preserved in amber siberian permafrost, dry caves preserved as rocks
Fossil include
55
Horses are members of an animal family that produced many extinct species and originated approximately __________ million years ago.
relative dating was used in the past; today we use absolute dating
How has rock and fossil dating changed since Darwin's times
- They illustrate how major transition in life occurred - They help to fill in the gap in the fossil record between two separate groups
true about transitional fossils
sediment mineralize hardens
Rock fossils are created when three events occur: dead organisms are buried in ___________________the hard tissues ____________; the material that surrounds the remains __________________ to form rock
all major groups of vertebrates
Today, fossils have been found that link
-A four legged aquatic mammal that links marine mammals to their terrestrial ancestors - A fossil snake with legs that links modern snakes to the lizards from which they descended - Tiktaalik, a species that is transitional between fish and amphibians
What are some fossil findings in recent years that have bridged major gaps in our understanding of vertebrate evolution
Direct
What type of evidence for evolution is provided by fossils?
- broad feet - short legs - small body size
Which of the following are features of Hyracotherium, the earliest known members of the horse family, as revealed by the fossil record?
-increased - decreased - molars
As early horses evolved to give rise to modern species of the horse family, in most lineages, the size ________________, the number of toes _____________, and the _____________ became more complex with more ridges to accomodate differences in their food.
feathers
Despite the presence of many dinosaurian traits, Archaeopteryx fossil posses ______________, which are a definitive trait of birds.
Equidae
One of the best studied examples of evolutionary change is that one of the ____________ family. This family includes zebras and donkeys, among other animals.
major ground
One of the most successful studies in showing evolution by natural selection is the one done by Peter and Rosemary Grant on the Galapagos islands; these scientists studied a bird that was referred to by the _____________ finch
- beaks -food
The correspondence between the size of ____________ in different finch species on Galapagos and their ___________ source suggested to Darwin that natural selection acted on those birds.
wet
The medium ground finch of the Galapagos islands feeds on small seeds, produced in abundance during ___________ years
rarely
The process of fossilization occurs only
wooded areas
The short legs and broad feet of early horses made them well adapted to their habitat which was
- many fossil occur in rocks that are inaccessible - organisms decay or are scavenged before forming fossils - fossils can be destroyed before they are collected
are reasons why the fossil record is incomplete