EVO BIO Prelims Flashcards
A change among species over a long time span with some species dying out and new species emerging
Macroevolution
results in smaller, but still noticeable, changes that do not result in the divergence of a new species
Microevolution
evolutionary changes occur within a population.
microevolution
Evidences of macroevolution (5)
- Paleontology
- Morphology and Comparative Anatomy
- Comparative Embryology
- Comparative Biochemistry
- Geographical Distribution
provides the strongest evidence of evolution.
study of fossils
is the study of ancient life, from dinosaurs to prehistoric plants, mammals, fish, insects, fungi, and even microbes.
paleontology
Any trace or remains of an organism that has been preserved by natural processes.
fossils
Fossil records
- Coral Fossil
- Homo erectus Skull
- Megalodon Fossil
- Dinosaur Fossil
Earliest ancestor of horse with five toes and has the same size of the present day dog. What period?
Eohippus / Hyracotherium. Eocene period
The earliest ancestor of horse was replaced by ? In what period
Oligocene period, Mesohippus and miohippus
In what period did the horse has a size of pony and had three toes in the fore and three in hind leg
Miocene period, merychippus
In the Pliocene the merychippus was replaced by?
Pliohippus
In the Pleistocene, merychippus was replaced by?
Equus
Equus is?
Median toe touched the ground and bore a prominent hoof. Similar to modern day horse
is the study of external form and structure of various organs
Morphology
the study of internal structure is called
anatomy
Under morphology
Homologous Structures
Analogous Structures
Vestigial Organs
Homologous structures
Limb Structures of Vertebrates
homologous structure
similar physical features in organisms that share a common ancestor, but the features serve completely different functions
are similar in appearance and perform the same function but are developed on a totally different plan
analogous structure
Example of analogous structure
Wings of bird, bat, fly for flight
analogous structure is an example of what type of evolution
convergent evolution
Example of homologous structure
The forelimb of a frog, wings of birds, wings of bat and seal, flippers of whale and the arm of man are constructed on the same general plan, but perform different functions.
is the remnant of the caecum that is a large functional structure present at the junction of the small and the large intestine.
veriform appendix
It helps in the digestion of cellulose.
appendix
What does the structure of vermiform appendix indicates?
perhaps the ancestors of man ate only vegetable matter where the caecum played an important role
Over evolution what happened to the appendix.
underwent reduction in size and became vestigial.
organs, tissues or cells in a body which are no more functional the way they were in their ancestral form of the trait.
Vestigial organs
In snakes what are its vestigial organs
tiny hind leg bones and pelvic girdle buried in muscles toward their tail ends
is the study of development of embryo.
embryology
Vertebrate embryos begin their development as a single celled
zygote
The zygote divides to form a solid ball of cells called
morula
morula transforms into a hollow ball
blastula
The blastula transforms into
two or three-layered gastrula
organizes to form germ layers.
gastrula
what does Embryological development reveals
unity of plan
During development, all vertebrates have
notochord and paired pharyngeal pouches/slits.
In fish and amphibian larvae, the pouches become
gills
In humans, the first pair of pouches becomes ____ the second pair becomes___, while third and fourth pairs becomes ___
1) cavity of the middle ear and auditory tube
2) tonsils
3) & 4) thymus and parathyroid gland.
formulated the ‘recapitulation theory’ or the ‘biogenetic law’.
Haeckel
The law states as follows – ‘Ontogeny recapitulates phylogeny’
recapitulation theory
is the development of the organism starting from the ovum
ontogeny
is the evolutionary history of the individual.
phylogeny
According to this law, during the embryonic development of an organism, it recalls its entire evolutionary history.
recapitulation theory
Almost all living organisms use the same basic biochemical molecules, e.g., DNA, ATP, enzymes
comparative biochemistry
studies that have shown that many organisms use similar chemicals and genes
biochemistry and genetics
Similarities in amino acid sequences, DNA codes, etc. can be explained by
descent from a common ancestor
The study of the geographical distribution of plants and animals is known as
biogeography
Is geographical distribution continuous or discontinous
discontinous distribution
This means that animals showing discontinuous distribution
are descendants of the extinct population
Organisms that radiate to other geographical areas, where new environmental conditions exist, undergo
adaptive changes
Such an evolutionary process where new species are formed and adapts to new habitats and ways of life
adaptive radiation
two models with VARYING RATES OF SPECIATION
gradual speciation model
punctuated equilibrium model
species diverge gradually over time in small steps.
gradual speciation model
a new species changes quickly from the parent species and then remains largely unchanged for long periods of time afterward.
punctuated equilibrium model
Which of the model has faster tempo
punctuated equilibrium model
Section of a chromosome that encodes the information to build a protein
gene
location of gene is called
locus
Varieties of the information at a particular locus
allele
every organism has how many alleles
two
Zygosity
Homozygous: Two copies of the same allele at one locus
Heterozygous: Two different alleles at one locus
Alleles that dominates, is expressed
Dominant allele
Will be expressed, while a recessive allele is suppressed
recessive alleles
The collection of available alleles in a population
gene pool
Refers to how frequently a particular allele appears in a population.
allele frequency
Genetic information contained at a locus
genotype
Appearance of an organism based on from the underlying genotype
phenotype
A change in the frequency of gene variants, alleles, in a population, typically occurring over a relatively short time period
microevolution
examples of microevolution
mutation
genetic drift
gene flow
natural selection
creates new genetic variation in a gene pool
mutations
true or false? mutations alone have much effect on allele frequencies
false
true or false? mutations provide the genetic variation needed for other forces of evolution to act.
true
It occurs when individuals move into or out of a population
gene flow
involves the movement of genes into or out of a population, due to either the movement of individual organisms or their gametes
gene flow
Strong agent of evolution
gene flow
is a random change in allele frequencies that occurs in a small population
genetic drift
When a small number of parents produce just a few offspring, allele frequencies in the offspring may differ, just by chance
genetic drift
occurs when a population suddenly gets much smaller. This might happen because of a natural disaster such as a forest fire or disease epidemic.
bottleneck effect
true or false: in bottleneck effect, allele frequencies of the survivors may be different from those of the original population
true
occurs when a few individuals start or found a new population
founder effect
occurs when the environment exerts a pressure on a population so that only some phenotypes survive and reproduce successfully.
natural selection
Those phenotypes that survive a strong selection event, such as a drought, are a better fit for an environment that suffers drought.
darwinian fitness
