BLG 144 Midterm 1 EXAM QUESTIONS AND VERIFIED ANSWERS
2025(GRADED A+) DETAILED ANSWERS!!
based on idea that species are unchanging types and that variations
typological thinking
within species are unimportant/misleading
Aristotle believed that there's a ladder of nature that orders
great chain of being
based on increased size and complexity (humans are at the
top)
proposed a theory of evolution that species are not static but change through
time
Lamark's theory of "change -always producing larger and more complex or "BETTER" species
through time" and "inheritance -individual's phenotype changes as challenges in the environment
of acquired characters" get passed on to the offspring (ex. giraffe have begin to have
long necks for eating higher trees and now offspring has long
necks)
Darwin's theory of natural -species are not static, they change through time
selection
-Darwin proposed that species in the past are ancestors of species existing
today
descent with modification
1. species change through time
2. species are related by common ancestry.
around 3.4-3.6 billion years ago, life
how old is the earth
was formed earth per se is about
4.6 billion years old
trait in a fossil that is intermediate between older and
transitional feature
younger species ex. aquatic animals with fins
transition to terresterial animals with limbs
fossil any trace of an organism that lived in the past
all fossils found and recorded
fossil record
-indicates that over 99% of all species that have ever lived are now extinct
sequence of named intervals called eons, periods, eras, that
geological time scale
represent major events in earth's history
tetrapods 4-fotted
reduced or incompletely developed structure with no function
or structures in closely related species
vestigial traits
ex. tailbone in humans
, -evidence that species have changed through time
study of likeness
homology -examining striking similarities among certain organisms that
both inherited the trait from a common ancestor
occurs in DNA sequences
genetic homology
ex. gene sequences in two different organisms are almost completely
identical
recognized in embryos (development)
Developmental homology -similarity in structures within embryo that either continue to
develop until birth or grow to become another functional trait
similarity in adult morphology or form
structural homology ex. limbs of vertebrates;same structure, different function
(grasping for humans, digging for moles, etc)
how do the three levels of genetic homology causes the developmental homologies
homology interact observed in embryos, which lead to structural homologies
recognized in adults
1. individual organisms that make up a population vary in traits they
possess
darwin's 4 postulates 2. some of the trait differences are heritable;passed on to their offspring
genetically
3. many more offspring are produced than can possibly survive
4. individuals that survive best and produce more offspring is not
random; those with certain heritable traits are more likely to
survive and reproduce
fitness ability for an organism to produce surviving offspring
2025(GRADED A+) DETAILED ANSWERS!!
based on idea that species are unchanging types and that variations
typological thinking
within species are unimportant/misleading
Aristotle believed that there's a ladder of nature that orders
great chain of being
based on increased size and complexity (humans are at the
top)
proposed a theory of evolution that species are not static but change through
time
Lamark's theory of "change -always producing larger and more complex or "BETTER" species
through time" and "inheritance -individual's phenotype changes as challenges in the environment
of acquired characters" get passed on to the offspring (ex. giraffe have begin to have
long necks for eating higher trees and now offspring has long
necks)
Darwin's theory of natural -species are not static, they change through time
selection
-Darwin proposed that species in the past are ancestors of species existing
today
descent with modification
1. species change through time
2. species are related by common ancestry.
around 3.4-3.6 billion years ago, life
how old is the earth
was formed earth per se is about
4.6 billion years old
trait in a fossil that is intermediate between older and
transitional feature
younger species ex. aquatic animals with fins
transition to terresterial animals with limbs
fossil any trace of an organism that lived in the past
all fossils found and recorded
fossil record
-indicates that over 99% of all species that have ever lived are now extinct
sequence of named intervals called eons, periods, eras, that
geological time scale
represent major events in earth's history
tetrapods 4-fotted
reduced or incompletely developed structure with no function
or structures in closely related species
vestigial traits
ex. tailbone in humans
, -evidence that species have changed through time
study of likeness
homology -examining striking similarities among certain organisms that
both inherited the trait from a common ancestor
occurs in DNA sequences
genetic homology
ex. gene sequences in two different organisms are almost completely
identical
recognized in embryos (development)
Developmental homology -similarity in structures within embryo that either continue to
develop until birth or grow to become another functional trait
similarity in adult morphology or form
structural homology ex. limbs of vertebrates;same structure, different function
(grasping for humans, digging for moles, etc)
how do the three levels of genetic homology causes the developmental homologies
homology interact observed in embryos, which lead to structural homologies
recognized in adults
1. individual organisms that make up a population vary in traits they
possess
darwin's 4 postulates 2. some of the trait differences are heritable;passed on to their offspring
genetically
3. many more offspring are produced than can possibly survive
4. individuals that survive best and produce more offspring is not
random; those with certain heritable traits are more likely to
survive and reproduce
fitness ability for an organism to produce surviving offspring
