Evidence of Evolution Flashcards
A(n) ____ is any evidence of past life that is more than 10,000 years old.
fossil
Major geological and biological events of the past are used by scientists to describe the
geologic timescale
Common ancestry can be indicated by which of the following?
- homologous structures
- nucleotide and amino acid sequence similarities
Select all of the following that are true about molecular clocks.
- They can be used to estimate when humans and chimps diverged from a common ancestor.
- They use the mutation rate of genes to determine the time of divergence from a common ancestor.
Biogeography is the study of
the distribution of species across Earth.
____ dating involves assigning a specific age to a fossil by testing either the fossil or the sediments above and below it.
Absolute
Structures are called homologous if
the similarities between them reflect common ancestry.
Select all of the following that are true about vestigial structures.
- persist in related organisms even when no longer used
- include pelvic and hindlimb bones in whales
Organisms that do not share the same evolutionary lineage but have similar adaptations result from ____ evolution.
convergent
Anatomical structures that have similar functions but that evolved independently are called ____ structures.
analogous
Match each era with a major event that took place on Earth during that era.
Paleozoic Era – vascular plants appear
Mesozoic Era – dinosaurs appear
Cenozoic Era – humans appear
____ dating places fossils into a sequence of events without assigning a specific age.
Relative
Carbon-14 dating, a type of radiometric dating, uses ____ as a type of clock to measure the age of fossils.
isotopes
The surface of the Earth consists of several rigid layers called ____, which move in response to forces acting deep within the planet.
tectonic plates
Select all of the following that are homologous structures.
- middle ear bones of mammals and jaw-support bones in primitive fishes
- limbs of terrestrial vertebrates
What can you conclude about the evolution of chimpanzees and humans from the skull comparisons in the figure?
Although skulls in adults look different, comparisons at the fetal stage reveal homology.
Using the chart, select all of the statements that are accurate about the evolutionary relationships presented.
- Rabbits are more closely related to humans than cows are.
- Pigeons are more closely related to humans than bullfrogs are.
- Humans and chimps have the same amino acid sequence for the cytochrome c gene.
The study of fossil remains and other clues to past life on Earth is referred to as
Paleontology.
Rank the eras of the geologic timescale from the oldest (at the top) to the most recent (at the bottom).
- Paleozoic
- Mesozoic
- Cenozoic
The exact match in amino acid sequences of proteins found in closely related species is an example of how comparisons of ____ can indicate evolutionary relationships.
proteins
Select all the roles of plate tectonics in the distribution of organisms on Earth.
- mountain ranges emerge
- land that was underwater can be exposed
- oceans can separate continents that were once together
Select all of the following that explain why the fossil record is incomplete.
- Many fossils may never be discovered because they are buried deeply or submerged under water.
- Many organisms decomposed before they were buried in sediments.
- Erosion and movements of the Earth’s surface have destroyed many fossils that did form.
Select all of the following that are examples of convergent evolution.
- shape of shark fins and shape of dolphin flippers
- spines and modified stems of unrelated desert plants
- loss of pigmentation in cave animals
What has made the comparison of a few bases, one gene, or families of genes possible?
DNA sequencing
The deep-water trench that has separated the islands of Borneo and Sulawesi in the Malay Archipelago (Indonesia), preventing migration of organisms, is called ____ line.
Wallace’s
Select all the characteristics of homologous structures.
- common evolutionary origin
- include genes and chromosomes
- may have different functions
A homeotic gene is one that might affect
the location of limbs in an animal
Scientists use two methods to estimate the age of fossils. Select the two correct methods from the choices below.
- absolute dating
- relative dating
What survival advantage allowed placental mammals to displace marsupial mammals on many continents?
Placental mammals are born more fully developed than marsupials are.
The age of the Earth is approximately ____ years.
4.6 billion
Carbon-14 is a radioactive isotope with a half-life of 5,730 years. A squirrel bone found in southwestern Colorado contains 1/4 of the carbon-14 of a living squirrel. Approximately how old is the squirrel bone?
11,460 years
Select all of the following that are examples of vestigial structures.
- mitochondria in some protists
- human embryo tails
- hindlimb bones in snakes
Select all the forms of evidence scientists use to support the theory of evolution.
- biogeographical studies
- fossils
- molecular data
- embryological comparisons
Continental drift is the term used to describe the fact that the ____ of Earth are in motion.
continents
Prior to the formation of a land bridge about 3 MYA that allowed placental mammals to invade, marsupials were diverse and abundant on what other continent besides Australia?
South America
The wings of a bird and the wings of a butterfly are considered ____ structures.
analogous
Select all of the following that are true about marsupials.
- They include koalas and sugar gliders.
- They were at one time more widespread than placental mammals.
Two researchers found a fossil that was in rock known to be at least 1 million years old. What isotope can they use to determine the age of the fossil?
potassium-40
Select all of the following ways that cells can gain new functions, as revealed by analysis of DNA sequences.
- the transfer of genes from one organism to another
- duplication of genes
In humans, the tails found on human embryos and the muscles used for turning ears to receive sounds are examples of
vestigial structures
Select all of the following that are true about continental drift in Earth’s history.
- The continents were once united into one supercontinent.
- Plate tectonics can cause molten rock to emerge at Earth’s surface.
Select all the ways that homology is used in studies of evolutionary relationships.
- gene sequences can be compared
- physical features of modern organisms can be compared
- fossil structures can be compared to structures in surviving species
The discovery of genes that contribute to embryonic development began a new field of biology called
evolutionary developmental biology
If a DNA sequence differs by four mutations in two species and mutations occur about once every 10 million years, then how long ago did the two species diverge?
40 million years ago
In terrestrial vertebrates, the patterns of limb development in embryonic development are controlled by
homologous homeotic genes
A radioactive substance has a half-life of 5,000 years. If the original sample contained 20 grams of the radioactive isotope, how much remains after 5,000 years have elapsed?
10 grams
Previously the most widespread land mammal on Earth, marsupials are now abundant and diverse only on what continent due to its isolation?
Australia
Wallace’s line, as shown on the map, represents
a deep-water trench that prevented migration of species
Fossils, such as Tiktaalik, can provide information regarding
the evolution of organisms
Radiometric dating uses an unstable isotope’s ____, which is the time it takes for half of the atoms of the radioactive isotope to devay.
half-life
