Chapter 12: Evidence Of Evolution Flashcards
Define Paleontology.
The study of fossil remains or other clues to past life.
Where can we find clues to evolution?
Clues to evolution lie in the earth, body structures, and molecules
Do you think evolution is testable?
Yes I think that evolution is testable. For example we use carbon dating to test how old an object dates back.
Define fossil.
Is any evidence of an organization from more than 10,000 years ago.
Why is the fossil record often incomplete?
First, the vast majority of organisms never leave a fossil trace.
Second, erosion or the movements of Earths continental plates have destroyed many fossil that did form.
Third, scientist are unlikely to ever discover the many fossils that must be buried deep in the Earth or submerged under water.
Compare two methods used to determine the age of a fossil.
Relative dating places a fossil into a sequence of events without assigning it a specific age.
Absolute dating is used to assign an age to a fossil by testing either the fossil itself or the sediments above and below the fossil.
Define Half-life.
It is the time it takes for half of the atoms in a sample of a radioactive substance to decay.
Define isotope.
It is a different forms of an element.
Define plate tectonics?
Earths surface consists of several rigid layers.
Discuss how plate tectonics has influenced our understanding of evolution.
The distribution of continents on earth has changed with time, due to shifting tectonic plates.
Define biogeography.
The study of the distribution of species across the planet.
Define adaptive radiation.
I’m which a population inhabiting a patchy or heterogeneous environment gives rise to multiple specialized forms in a relatively short time.
What do homologous structure reflect?
A Common ancestry
What do analogous structures reflect?
The structure evolve independently?
Describe an example of a homologous structure in vertebrates?
A human, a bat, a lion, a bird, a seal. Although their forelimbs have different functions, all of these vertebrates have skeletons that are similarly organized and composed of the same type of tissue.
Explain the relationship between analogous structures and convergent evolution.
Analogous structures are often the product of convergent evolution, which produces similar adaptations in organisms that do not share the same evolutionary lineage.
Describe an example of a analogous structure in flying organisms.
The wings of birds and butterflies both function in flight, but they are analogous structures because they are not made of the same materials, nor are they organized in the same way. They are not limited from a recent common ancestor.
Define vestigial structure .
A vestigial structure has no apparent function in one species, yet it is homologous to a functional organ in another.
List several example of vestigial structure?
Some snakes have tiny femurs that are vestigial but detectable only in the skeleton. Some whales likewise have a vestigial pelvis and hind limbs.
How can embryonic development help us understand an organisms evolutionary history
Comparing embryos at different stages, it should be possible to deduce some of the steps that have led to differences among species.
How should Ernst Haeckel be remembered as a scientist?
Ernst Haeckel made the connection between distance species.
Define evo-devo.
The discovery of genes that contributed to development has spawned the field of evolutionary development biology.
Define homeotic.
Is a general term describing any gene that, when mutated, leads to organisms with structures in abnormal or unusual places.
Explain the advantage of using molecules to determine evolutionary histories.
Molecular clocks help assign dates to evolutionary events.
Which two groups of macromolecules are used to trace phylogenetic?
Nucleic acids and proteins
What is the most likely explanation for similarities and differences in the amino acid sequences of proteins in different organisms.
It is highly unlikely that two unrelated species would evolve precisely the same DNA and protein sequences by chance. It is more likely that the similarities were inherited from a common ancestor and that differences arose by mutation.
Define molecular clock?
To estimate the time when the organism diverged from a common ancestor.
How are scientist studying the migration patterns of early humans?
Through the molecular clock.
How do the changes in beak size of the finches on the Galápagos Islands help us better understand how evolution works?
It helped understand that through natural selection it gives is the traits to adapt to changes in the environment. So as long as the environment is changing their will be evolution but if it is stable there can not be evolution.
