comparative genomics + anatomy Flashcards
what are the 4 types of comparative genomics?
DNA
mitochondrial
proteins
retrovirus
define comparative DNA studies
= comparing of DNA of different species to determine similarities and differences
how can comparative DNA studies be used for evidence of evolution?
all living things use the same DNA code - so have evolved from a common ancestor
species more closer related have more similarities in their DNA
can identify genes preserved among species and organisms with unique characteristics
how is mitochondrial DNA inherited?
after sperm has penetrated egg, mitochondria in sperm are rapidly destroyed, so mitochondrial DNA comes only from the egg
how can mitochondrial DNA be used to provide evidence for evolution?
- allows tracking of a direct genetic line
- use similarity between mtDNA of individuals to provide estimate of closeness of relationship through maternal ancestors
what is mitochondrial DNA?
DNA found in the mitochondria of the cells, rather than in the nucelus
what is a retrovirus?
a virus that reproduces by inserting its genes into a cell’s DNA
what is an endogenous retrovirus?
a retrovirus that has become part of an organism’s genome and exists in every cell of the body
what is flanking DNA?
healthy DNA on either side of the retrovirus
how are retroviruses passed on?
a gamete gets a retrovirus
offspring will have a copy of the ERV in the same place, the same chromosome in every one of their cells
all subsequent generations will have a copy of the ERV in the same location
how do endogenous retroviruses provide evidence for evolution?
same virus in same location over many generations shows evidence for evolution
what is junk DNA?
non-coding sequences of DNA with no function or purpose
how can junk DNA be used as evidence for evolution?
similar to the comparison of other parts of DNA
more closely related species have more junk sequences in common - species have evolved from a common ancestor
how can comparative protein studies be used for evidence for evolution?
amino acids are the same for all living things - evidence all organisms came from a common ancestor
closer related organisms have more similar amino acid sequences in their proteins
species with more distant ancestor will have more differences in amino acid sequence
what are ubiquitous proteins?
proteins found in all organisms that are independent of the organism’s function or environment
they carry out the same function no matter where found
how can ubiquitous proteins provide evidence for evolution?
can be compared for similarities and thus relatedness
what are the 3 types of comparative anatomy?
- comparative embryology
- homologous structures
- vestigial structures
what is embryology?
comparing very early stages of development in organisms
how does comparative embryology provide evidence for evolution?
many vertebrae embryos are similar and have features not present in adults
similarities indicate common ancestors
common developmental pathway depends on the closeness of the relationship
providing evidence of common ancestors and evolution
what are homologous structures?
structures similar in structure used in different ways
how do homologous structures provide evidence for evolution?
similar structure, different function
shows they developed from a common ancestor and adapted to suit their environment
more similar structure and function = more closely related
what are vestigial structures?
structures that may have once been important but lost or changed their function
remains of organs that were once functional
reduced in size to conserve energy
how do vestigial structures provide evidence for evolution?
still have these structures even though we don’t use them
provide evidence of change over time
all have them - evolved from a common ancestor
what are the 5 types of evidence of evolution?
fossils
comparative anatomy
- vestigial organs
- homologous structures
- comparative embryology
comparative genomics
- comparative protein studies
- comparative DNA studies
- mitochondrial DNA
